FileDocCategorySizeDatePackage
ListView.javaAPI DocAndroid 1.5 API122372Wed May 06 22:41:56 BST 2009android.widget

ListView

public class ListView extends AbsListView
A view that shows items in a vertically scrolling list. The items come from the {@link ListAdapter} associated with this view.
attr
ref android.R.styleable#ListView_entries
attr
ref android.R.styleable#ListView_divider
attr
ref android.R.styleable#ListView_dividerHeight
attr
ref android.R.styleable#ListView_choiceMode
attr
ref android.R.styleable#ListView_headerDividersEnabled
attr
ref android.R.styleable#ListView_footerDividersEnabled

Fields Summary
static final int
NO_POSITION
Used to indicate a no preference for a position type.
public static final int
CHOICE_MODE_NONE
Normal list that does not indicate choices
public static final int
CHOICE_MODE_SINGLE
The list allows up to one choice
public static final int
CHOICE_MODE_MULTIPLE
The list allows multiple choices
private static final float
MAX_SCROLL_FACTOR
When arrow scrolling, ListView will never scroll more than this factor times the height of the list.
private static final int
MIN_SCROLL_PREVIEW_PIXELS
When arrow scrolling, need a certain amount of pixels to preview next items. This is usually the fading edge, but if that is small enough, we want to make sure we preview at least this many pixels.
private ArrayList
mHeaderViewInfos
private ArrayList
mFooterViewInfos
android.graphics.drawable.Drawable
mDivider
int
mDividerHeight
private boolean
mClipDivider
private boolean
mHeaderDividersEnabled
private boolean
mFooterDividersEnabled
private boolean
mAreAllItemsSelectable
private boolean
mItemsCanFocus
private int
mChoiceMode
private android.util.SparseBooleanArray
mCheckStates
private final android.graphics.Rect
mTempRect
private ArrowScrollFocusResult
mArrowScrollFocusResult
Constructors Summary
public ListView(android.content.Context context)


       
        this(context, null);
    
public ListView(android.content.Context context, android.util.AttributeSet attrs)

        this(context, attrs, com.android.internal.R.attr.listViewStyle);
    
public ListView(android.content.Context context, android.util.AttributeSet attrs, int defStyle)

        super(context, attrs, defStyle);

        TypedArray a = context.obtainStyledAttributes(attrs,
                com.android.internal.R.styleable.ListView, defStyle, 0);

        CharSequence[] entries = a.getTextArray(
                com.android.internal.R.styleable.ListView_entries);
        if (entries != null) {
            setAdapter(new ArrayAdapter<CharSequence>(context,
                    com.android.internal.R.layout.simple_list_item_1, entries));
        }

        final Drawable d = a.getDrawable(com.android.internal.R.styleable.ListView_divider);
        if (d != null) {
            // If a divider is specified use its intrinsic height for divider height
            setDivider(d);
        }

        // Use the height specified, zero being the default
        final int dividerHeight = a.getDimensionPixelSize(
                com.android.internal.R.styleable.ListView_dividerHeight, 0);
        if (dividerHeight != 0) {
            setDividerHeight(dividerHeight);
        }

        mHeaderDividersEnabled = a.getBoolean(R.styleable.ListView_headerDividersEnabled, true);
        mFooterDividersEnabled = a.getBoolean(R.styleable.ListView_footerDividersEnabled, true);

        a.recycle();
    
Methods Summary
public voidaddFooterView(android.view.View v, java.lang.Object data, boolean isSelectable)
Add a fixed view to appear at the bottom of the list. If addFooterView is called more than once, the views will appear in the order they were added. Views added using this call can take focus if they want.

NOTE: Call this before calling setAdapter. This is so ListView can wrap the supplied cursor with one that that will also account for header views.

param
v The view to add.
param
data Data to associate with this view
param
isSelectable true if the footer view can be selected

        FixedViewInfo info = new FixedViewInfo();
        info.view = v;
        info.data = data;
        info.isSelectable = isSelectable;
        mFooterViewInfos.add(info);

        // in the case of re-adding a footer view, or adding one later on,
        // we need to notify the observer
        if (mDataSetObserver != null) {
            mDataSetObserver.onChanged();
        }
    
public voidaddFooterView(android.view.View v)
Add a fixed view to appear at the bottom of the list. If addFooterView is called more than once, the views will appear in the order they were added. Views added using this call can take focus if they want.

NOTE: Call this before calling setAdapter. This is so ListView can wrap the supplied cursor with one that that will also account for header views.

param
v The view to add.

        addFooterView(v, null, true);
    
public voidaddHeaderView(android.view.View v, java.lang.Object data, boolean isSelectable)
Add a fixed view to appear at the top of the list. If addHeaderView is called more than once, the views will appear in the order they were added. Views added using this call can take focus if they want.

NOTE: Call this before calling setAdapter. This is so ListView can wrap the supplied cursor with one that that will also account for header views.

param
v The view to add.
param
data Data to associate with this view
param
isSelectable whether the item is selectable


        if (mAdapter != null) {
            throw new IllegalStateException(
                    "Cannot add header view to list -- setAdapter has already been called.");
        }

        FixedViewInfo info = new FixedViewInfo();
        info.view = v;
        info.data = data;
        info.isSelectable = isSelectable;
        mHeaderViewInfos.add(info);
    
public voidaddHeaderView(android.view.View v)
Add a fixed view to appear at the top of the list. If addHeaderView is called more than once, the views will appear in the order they were added. Views added using this call can take focus if they want.

NOTE: Call this before calling setAdapter. This is so ListView can wrap the supplied cursor with one that that will also account for header views.

param
v The view to add.

        addHeaderView(v, null, true);
    
private android.view.ViewaddViewAbove(android.view.View theView, int position)

        int abovePosition = position - 1;
        View view = obtainView(abovePosition);
        int edgeOfNewChild = theView.getTop() - mDividerHeight;
        setupChild(view, abovePosition, edgeOfNewChild, false, mListPadding.left, false, false);
        return view;
    
private android.view.ViewaddViewBelow(android.view.View theView, int position)

        int belowPosition = position + 1;
        View view = obtainView(belowPosition);
        int edgeOfNewChild = theView.getBottom() + mDividerHeight;
        setupChild(view, belowPosition, edgeOfNewChild, true, mListPadding.left, false, false);
        return view;
    
private voidadjustViewsUpOrDown()
Make sure views are touching the top or bottom edge, as appropriate for our gravity

        final int childCount = getChildCount();
        int delta;

        if (childCount > 0) {
            View child;

            if (!mStackFromBottom) {
                // Uh-oh -- we came up short. Slide all views up to make them
                // align with the top
                child = getChildAt(0);
                delta = child.getTop() - mListPadding.top;
                if (mFirstPosition != 0) {
                    // It's OK to have some space above the first item if it is
                    // part of the vertical spacing
                    delta -= mDividerHeight;
                }
                if (delta < 0) {
                    // We only are looking to see if we are too low, not too high
                    delta = 0;
                }
            } else {
                // we are too high, slide all views down to align with bottom
                child = getChildAt(childCount - 1);
                delta = child.getBottom() - (getHeight() - mListPadding.bottom);

                if (mFirstPosition + childCount < mItemCount) {
                    // It's OK to have some space below the last item if it is
                    // part of the vertical spacing
                    delta += mDividerHeight;
                }

                if (delta > 0) {
                    delta = 0;
                }
            }

            if (delta != 0) {
                offsetChildrenTopAndBottom(-delta);
            }
        }
    
private intamountToScroll(int direction, int nextSelectedPosition)
Determine how much we need to scroll in order to get the next selected view visible, with a fading edge showing below as applicable. The amount is capped at {@link #getMaxScrollAmount()} .

param
direction either {@link android.view.View#FOCUS_UP} or {@link android.view.View#FOCUS_DOWN}.
param
nextSelectedPosition The position of the next selection, or {@link #INVALID_POSITION} if there is no next selectable position
return
The amount to scroll. Note: this is always positive! Direction needs to be taken into account when actually scrolling.

        final int listBottom = getHeight() - mListPadding.bottom;
        final int listTop = mListPadding.top;

        final int numChildren = getChildCount();

        if (direction == View.FOCUS_DOWN) {
            int indexToMakeVisible = numChildren - 1;
            if (nextSelectedPosition != INVALID_POSITION) {
                indexToMakeVisible = nextSelectedPosition - mFirstPosition;
            }

            final int positionToMakeVisible = mFirstPosition + indexToMakeVisible;
            final View viewToMakeVisible = getChildAt(indexToMakeVisible);

            int goalBottom = listBottom;
            if (positionToMakeVisible < mItemCount - 1) {
                goalBottom -= getArrowScrollPreviewLength();
            }

            if (viewToMakeVisible.getBottom() <= goalBottom) {
                // item is fully visible.
                return 0;
            }

            if (nextSelectedPosition != INVALID_POSITION
                    && (goalBottom - viewToMakeVisible.getTop()) >= getMaxScrollAmount()) {
                // item already has enough of it visible, changing selection is good enough
                return 0;
            }

            int amountToScroll = (viewToMakeVisible.getBottom() - goalBottom);

            if ((mFirstPosition + numChildren) == mItemCount) {
                // last is last in list -> make sure we don't scroll past it
                final int max = getChildAt(numChildren - 1).getBottom() - listBottom;
                amountToScroll = Math.min(amountToScroll, max);
            }

            return Math.min(amountToScroll, getMaxScrollAmount());
        } else {
            int indexToMakeVisible = 0;
            if (nextSelectedPosition != INVALID_POSITION) {
                indexToMakeVisible = nextSelectedPosition - mFirstPosition;
            }
            final int positionToMakeVisible = mFirstPosition + indexToMakeVisible;
            final View viewToMakeVisible = getChildAt(indexToMakeVisible);
            int goalTop = listTop;
            if (positionToMakeVisible > 0) {
                goalTop += getArrowScrollPreviewLength();
            }
            if (viewToMakeVisible.getTop() >= goalTop) {
                // item is fully visible.
                return 0;
            }

            if (nextSelectedPosition != INVALID_POSITION &&
                    (viewToMakeVisible.getBottom() - goalTop) >= getMaxScrollAmount()) {
                // item already has enough of it visible, changing selection is good enough
                return 0;
            }

            int amountToScroll = (goalTop - viewToMakeVisible.getTop());
            if (mFirstPosition == 0) {
                // first is first in list -> make sure we don't scroll past it
                final int max = listTop - getChildAt(0).getTop();
                amountToScroll = Math.min(amountToScroll,  max);
            }
            return Math.min(amountToScroll, getMaxScrollAmount());
        }
    
private intamountToScrollToNewFocus(int direction, android.view.View newFocus, int positionOfNewFocus)
Determine how much we need to scroll in order to get newFocus in view.

param
direction either {@link android.view.View#FOCUS_UP} or {@link android.view.View#FOCUS_DOWN}.
param
newFocus The view that would take focus.
param
positionOfNewFocus The position of the list item containing newFocus
return
The amount to scroll. Note: this is always positive! Direction needs to be taken into account when actually scrolling.

        int amountToScroll = 0;
        newFocus.getDrawingRect(mTempRect);
        offsetDescendantRectToMyCoords(newFocus, mTempRect);
        if (direction == View.FOCUS_UP) {
            if (mTempRect.top < mListPadding.top) {
                amountToScroll = mListPadding.top - mTempRect.top;
                if (positionOfNewFocus > 0) {
                    amountToScroll += getArrowScrollPreviewLength();
                }
            }
        } else {
            final int listBottom = getHeight() - mListPadding.bottom;
            if (mTempRect.bottom > listBottom) {
                amountToScroll = mTempRect.bottom - listBottom;
                if (positionOfNewFocus < mItemCount - 1) {
                    amountToScroll += getArrowScrollPreviewLength();
                }
            }
        }
        return amountToScroll;
    
booleanarrowScroll(int direction)
Scrolls to the next or previous item if possible.

param
direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN}
return
whether selection was moved

        try {
            mInLayout = true;
            final boolean handled = arrowScrollImpl(direction);
            if (handled) {
                playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction));
            }
            return handled;
        } finally {
            mInLayout = false;
        }
    
private android.widget.ListView$ArrowScrollFocusResultarrowScrollFocused(int direction)
Do an arrow scroll based on focus searching. If a new view is given focus, return the selection delta and amount to scroll via an {@link ArrowScrollFocusResult}, otherwise, return null.

param
direction either {@link android.view.View#FOCUS_UP} or {@link android.view.View#FOCUS_DOWN}.
return
The result if focus has changed, or null.

        final View selectedView = getSelectedView();
        View newFocus;
        if (selectedView != null && selectedView.hasFocus()) {
            View oldFocus = selectedView.findFocus();
            newFocus = FocusFinder.getInstance().findNextFocus(this, oldFocus, direction);
        } else {
            if (direction == View.FOCUS_DOWN) {
                final boolean topFadingEdgeShowing = (mFirstPosition > 0);
                final int listTop = mListPadding.top +
                        (topFadingEdgeShowing ? getArrowScrollPreviewLength() : 0);
                final int ySearchPoint =
                        (selectedView != null && selectedView.getTop() > listTop) ?
                                selectedView.getTop() :
                                listTop;
                mTempRect.set(0, ySearchPoint, 0, ySearchPoint);
            } else {
                final boolean bottomFadingEdgeShowing =
                        (mFirstPosition + getChildCount() - 1) < mItemCount;
                final int listBottom = getHeight() - mListPadding.bottom -
                        (bottomFadingEdgeShowing ? getArrowScrollPreviewLength() : 0);
                final int ySearchPoint =
                        (selectedView != null && selectedView.getBottom() < listBottom) ?
                                selectedView.getBottom() :
                                listBottom;
                mTempRect.set(0, ySearchPoint, 0, ySearchPoint);
            }
            newFocus = FocusFinder.getInstance().findNextFocusFromRect(this, mTempRect, direction);
        }

        if (newFocus != null) {
            final int positionOfNewFocus = positionOfNewFocus(newFocus);

            // if the focus change is in a different new position, make sure
            // we aren't jumping over another selectable position
            if (mSelectedPosition != INVALID_POSITION && positionOfNewFocus != mSelectedPosition) {
                final int selectablePosition = lookForSelectablePositionOnScreen(direction);
                if (selectablePosition != INVALID_POSITION &&
                        ((direction == View.FOCUS_DOWN && selectablePosition < positionOfNewFocus) ||
                        (direction == View.FOCUS_UP && selectablePosition > positionOfNewFocus))) {
                    return null;
                }
            }

            int focusScroll = amountToScrollToNewFocus(direction, newFocus, positionOfNewFocus);

            final int maxScrollAmount = getMaxScrollAmount();
            if (focusScroll < maxScrollAmount) {
                // not moving too far, safe to give next view focus
                newFocus.requestFocus(direction);
                mArrowScrollFocusResult.populate(positionOfNewFocus, focusScroll);
                return mArrowScrollFocusResult;
            } else if (distanceToView(newFocus) < maxScrollAmount){
                // Case to consider:
                // too far to get entire next focusable on screen, but by going
                // max scroll amount, we are getting it at least partially in view,
                // so give it focus and scroll the max ammount.
                newFocus.requestFocus(direction);
                mArrowScrollFocusResult.populate(positionOfNewFocus, maxScrollAmount);
                return mArrowScrollFocusResult;
            }
        }
        return null;
    
private booleanarrowScrollImpl(int direction)
Handle an arrow scroll going up or down. Take into account whether items are selectable, whether there are focusable items etc.

param
direction Either {@link android.view.View#FOCUS_UP} or {@link android.view.View#FOCUS_DOWN}.
return
Whether any scrolling, selection or focus change occured.

        if (getChildCount() <= 0) {
            return false;
        }

        View selectedView = getSelectedView();

        int nextSelectedPosition = lookForSelectablePositionOnScreen(direction);
        int amountToScroll = amountToScroll(direction, nextSelectedPosition);

        // if we are moving focus, we may OVERRIDE the default behavior
        final ArrowScrollFocusResult focusResult = mItemsCanFocus ? arrowScrollFocused(direction) : null;
        if (focusResult != null) {
            nextSelectedPosition = focusResult.getSelectedPosition();
            amountToScroll = focusResult.getAmountToScroll();
        }

        boolean needToRedraw = focusResult != null;
        if (nextSelectedPosition != INVALID_POSITION) {
            handleNewSelectionChange(selectedView, direction, nextSelectedPosition, focusResult != null);
            setSelectedPositionInt(nextSelectedPosition);
            setNextSelectedPositionInt(nextSelectedPosition);
            selectedView = getSelectedView();
            if (mItemsCanFocus && focusResult == null) {
                // there was no new view found to take focus, make sure we
                // don't leave focus with the old selection
                final View focused = getFocusedChild();
                if (focused != null) {
                    focused.clearFocus();
                }
            }
            needToRedraw = true;
            checkSelectionChanged();
        }

        if (amountToScroll > 0) {
            scrollListItemsBy((direction == View.FOCUS_UP) ? amountToScroll : -amountToScroll);
            needToRedraw = true;
        }

        // if we didn't find a new focusable, make sure any existing focused
        // item that was panned off screen gives up focus.
        if (mItemsCanFocus && (focusResult == null)
                && selectedView != null && selectedView.hasFocus()) {
            final View focused = selectedView.findFocus();
            if (distanceToView(focused) > 0) {
                focused.clearFocus();
            }
        }

        // if  the current selection is panned off, we need to remove the selection
        if (nextSelectedPosition == INVALID_POSITION && selectedView != null
                && !isViewAncestorOf(selectedView, this)) {
            selectedView = null;
            hideSelector();

            // but we don't want to set the ressurect position (that would make subsequent
            // unhandled key events bring back the item we just scrolled off!)
            mResurrectToPosition = INVALID_POSITION;
        }

        if (needToRedraw) {
            if (selectedView != null) {
                positionSelector(selectedView);
                mSelectedTop = selectedView.getTop();
            }
            invalidate();
            invokeOnItemScrollListener();
            return true;
        }

        return false;
    
protected booleancanAnimate()

        return super.canAnimate() && mItemCount > 0;
    
public voidclearChoices()
Clear any choices previously set

        if (mCheckStates != null) {
            mCheckStates.clear();
        }
    
private booleancommonKey(int keyCode, int count, android.view.KeyEvent event)

        if (mAdapter == null) {
            return false;
        }

        if (mDataChanged) {
            layoutChildren();
        }

        boolean handled = false;
        int action = event.getAction();

        if (action != KeyEvent.ACTION_UP) {
            if (mSelectedPosition < 0) {
                switch (keyCode) {
                case KeyEvent.KEYCODE_DPAD_UP:
                case KeyEvent.KEYCODE_DPAD_DOWN:
                case KeyEvent.KEYCODE_DPAD_CENTER:
                case KeyEvent.KEYCODE_ENTER:
                case KeyEvent.KEYCODE_SPACE:
                    if (resurrectSelection()) {
                        return true;
                    }
                }
            }
            switch (keyCode) {
            case KeyEvent.KEYCODE_DPAD_UP:
                if (!event.isAltPressed()) {
                    while (count > 0) {
                        handled = arrowScroll(FOCUS_UP);
                        count--;
                    }
                } else {
                    handled = fullScroll(FOCUS_UP);
                }
                break;

            case KeyEvent.KEYCODE_DPAD_DOWN:
                if (!event.isAltPressed()) {
                    while (count > 0) {
                        handled = arrowScroll(FOCUS_DOWN);
                        count--;
                    }
                } else {
                    handled = fullScroll(FOCUS_DOWN);
                }
                break;

            case KeyEvent.KEYCODE_DPAD_LEFT:
                handled = handleHorizontalFocusWithinListItem(View.FOCUS_LEFT);
                break;
            case KeyEvent.KEYCODE_DPAD_RIGHT:
                handled = handleHorizontalFocusWithinListItem(View.FOCUS_RIGHT);
                break;

            case KeyEvent.KEYCODE_DPAD_CENTER:
            case KeyEvent.KEYCODE_ENTER:
                if (mItemCount > 0 && event.getRepeatCount() == 0) {
                    keyPressed();
                }
                handled = true;
                break;

            case KeyEvent.KEYCODE_SPACE:
                if (mPopup == null || !mPopup.isShowing()) {
                    if (!event.isShiftPressed()) {
                        pageScroll(FOCUS_DOWN);
                    } else {
                        pageScroll(FOCUS_UP);
                    }
                    handled = true;
                }
                break;
            }
        }

        if (!handled) {
            handled = sendToTextFilter(keyCode, count, event);
        }

        if (handled) {
            return true;
        } else {
            switch (action) {
                case KeyEvent.ACTION_DOWN:
                    return super.onKeyDown(keyCode, event);

                case KeyEvent.ACTION_UP:
                    return super.onKeyUp(keyCode, event);

                case KeyEvent.ACTION_MULTIPLE:
                    return super.onKeyMultiple(keyCode, count, event);

                default: // shouldn't happen
                    return false;
            }
        }
    
private voidcorrectTooHigh(int childCount)
Check if we have dragged the bottom of the list too high (we have pushed the top element off the top of the screen when we did not need to). Correct by sliding everything back down.

param
childCount Number of children

        // First see if the last item is visible. If it is not, it is OK for the
        // top of the list to be pushed up.
        int lastPosition = mFirstPosition + childCount - 1;
        if (lastPosition == mItemCount - 1 && childCount > 0) {

            // Get the last child ...
            final View lastChild = getChildAt(childCount - 1);

            // ... and its bottom edge
            final int lastBottom = lastChild.getBottom();

            // This is bottom of our drawable area
            final int end = (mBottom - mTop) - mListPadding.bottom;

            // This is how far the bottom edge of the last view is from the bottom of the
            // drawable area
            int bottomOffset = end - lastBottom;
            View firstChild = getChildAt(0);
            final int firstTop = firstChild.getTop();

            // Make sure we are 1) Too high, and 2) Either there are more rows above the
            // first row or the first row is scrolled off the top of the drawable area
            if (bottomOffset > 0 && (mFirstPosition > 0 || firstTop < mListPadding.top))  {
                if (mFirstPosition == 0) {
                    // Don't pull the top too far down
                    bottomOffset = Math.min(bottomOffset, mListPadding.top - firstTop);
                }
                // Move everything down
                offsetChildrenTopAndBottom(bottomOffset);
                if (mFirstPosition > 0) {
                    // Fill the gap that was opened above mFirstPosition with more rows, if
                    // possible
                    fillUp(mFirstPosition - 1, firstChild.getTop() - mDividerHeight);
                    // Close up the remaining gap
                    adjustViewsUpOrDown();
                }

            }
        }
    
private voidcorrectTooLow(int childCount)
Check if we have dragged the bottom of the list too low (we have pushed the bottom element off the bottom of the screen when we did not need to). Correct by sliding everything back up.

param
childCount Number of children

        // First see if the first item is visible. If it is not, it is OK for the
        // bottom of the list to be pushed down.
        if (mFirstPosition == 0 && childCount > 0) {

            // Get the first child ...
            final View firstChild = getChildAt(0);

            // ... and its top edge
            final int firstTop = firstChild.getTop();

            // This is top of our drawable area
            final int start = mListPadding.top;

            // This is bottom of our drawable area
            final int end = (mBottom - mTop) - mListPadding.bottom;

            // This is how far the top edge of the first view is from the top of the
            // drawable area
            int topOffset = firstTop - start;
            View lastChild = getChildAt(childCount - 1);
            final int lastBottom = lastChild.getBottom();
            int lastPosition = mFirstPosition + childCount - 1;

            // Make sure we are 1) Too low, and 2) Either there are more rows below the
            // last row or the last row is scrolled off the bottom of the drawable area
            if (topOffset > 0 && (lastPosition < mItemCount - 1 || lastBottom > end))  {
                if (lastPosition == mItemCount - 1 ) {
                    // Don't pull the bottom too far up
                    topOffset = Math.min(topOffset, lastBottom - end);
                }
                // Move everything up
                offsetChildrenTopAndBottom(-topOffset);
                if (lastPosition < mItemCount - 1) {
                    // Fill the gap that was opened below the last position with more rows, if
                    // possible
                    fillDown(lastPosition + 1, lastChild.getBottom() + mDividerHeight);
                    // Close up the remaining gap
                    adjustViewsUpOrDown();
                }
            }
        }
    
protected voiddispatchDraw(android.graphics.Canvas canvas)

        // Draw the dividers
        final int dividerHeight = mDividerHeight;

        if (dividerHeight > 0 && mDivider != null) {
            // Only modify the top and bottom in the loop, we set the left and right here
            final Rect bounds = mTempRect;
            bounds.left = mPaddingLeft;
            bounds.right = mRight - mLeft - mPaddingRight;

            final int count = getChildCount();
            final int headerCount = mHeaderViewInfos.size();
            final int footerLimit = mItemCount - mFooterViewInfos.size() - 1;
            final boolean headerDividers = mHeaderDividersEnabled;
            final boolean footerDividers = mFooterDividersEnabled;
            final int first = mFirstPosition;
            final boolean areAllItemsSelectable = mAreAllItemsSelectable;
            final ListAdapter adapter = mAdapter;

            if (!mStackFromBottom) {
                int bottom;
                int listBottom = mBottom - mTop - mListPadding.bottom;

                for (int i = 0; i < count; i++) {
                    if ((headerDividers || first + i >= headerCount) &&
                            (footerDividers || first + i < footerLimit)) {
                        View child = getChildAt(i);
                        bottom = child.getBottom();
                        // Don't draw dividers next to items that are not enabled
                        if (bottom < listBottom && (areAllItemsSelectable ||
                                (adapter.isEnabled(first + i) && (i == count - 1 ||
                                        adapter.isEnabled(first + i + 1))))) {
                            bounds.top = bottom;
                            bounds.bottom = bottom + dividerHeight;
                            drawDivider(canvas, bounds, i);
                        }
                    }
                }
            } else {
                int top;
                int listTop = mListPadding.top;

                for (int i = 0; i < count; i++) {
                    if ((headerDividers || first + i >= headerCount) &&
                            (footerDividers || first + i < footerLimit)) {
                        View child = getChildAt(i);
                        top = child.getTop();
                        // Don't draw dividers next to items that are not enabled
                        if (top > listTop && (areAllItemsSelectable ||
                                (adapter.isEnabled(first + i) && (i == count - 1 ||
                                        adapter.isEnabled(first + i + 1))))) {
                            bounds.top = top - dividerHeight;
                            bounds.bottom = top;
                            // Give the method the child ABOVE the divider, so we
                            // subtract one from our child
                            // position. Give -1 when there is no child above the
                            // divider.
                            drawDivider(canvas, bounds, i - 1);
                        }
                    }
                }
            }
        }

        // Draw the indicators (these should be drawn above the dividers) and children
        super.dispatchDraw(canvas);
    
public booleandispatchKeyEvent(android.view.KeyEvent event)

        // Dispatch in the normal way
        boolean handled = super.dispatchKeyEvent(event);
        if (!handled) {
            // If we didn't handle it...
            View focused = getFocusedChild();
            if (focused != null && event.getAction() == KeyEvent.ACTION_DOWN) {
                // ... and our focused child didn't handle it
                // ... give it to ourselves so we can scroll if necessary
                handled = onKeyDown(event.getKeyCode(), event);
            }
        }
        return handled;
    
private intdistanceToView(android.view.View descendant)
Determine the distance to the nearest edge of a view in a particular direciton.

param
descendant A descendant of this list.
return
The distance, or 0 if the nearest edge is already on screen.

        int distance = 0;
        descendant.getDrawingRect(mTempRect);
        offsetDescendantRectToMyCoords(descendant, mTempRect);
        final int listBottom = mBottom - mTop - mListPadding.bottom;
        if (mTempRect.bottom < mListPadding.top) {
            distance = mListPadding.top - mTempRect.bottom;
        } else if (mTempRect.top > listBottom) {
            distance = mTempRect.top - listBottom;
        }
        return distance;
    
voiddrawDivider(android.graphics.Canvas canvas, android.graphics.Rect bounds, int childIndex)
Draws a divider for the given child in the given bounds.

param
canvas The canvas to draw to.
param
bounds The bounds of the divider.
param
childIndex The index of child (of the View) above the divider. This will be -1 if there is no child above the divider to be drawn.

        // This widget draws the same divider for all children
        final Drawable divider = mDivider;
        final boolean clipDivider = mClipDivider;

        if (!clipDivider) {
            divider.setBounds(bounds);
        } else {
            canvas.save();
            canvas.clipRect(bounds);
        }

        divider.draw(canvas);

        if (clipDivider) {
            canvas.restore();
        }
    
private voidfillAboveAndBelow(android.view.View sel, int position)
Once the selected view as been placed, fill up the visible area above and below it.

param
sel The selected view
param
position The position corresponding to sel

        final int dividerHeight = mDividerHeight;
        if (!mStackFromBottom) {
            fillUp(position - 1, sel.getTop() - dividerHeight);
            adjustViewsUpOrDown();
            fillDown(position + 1, sel.getBottom() + dividerHeight);
        } else {
            fillDown(position + 1, sel.getBottom() + dividerHeight);
            adjustViewsUpOrDown();
            fillUp(position - 1, sel.getTop() - dividerHeight);
        }
    
private android.view.ViewfillDown(int pos, int nextTop)
Fills the list from pos down to the end of the list view.

param
pos The first position to put in the list
param
nextTop The location where the top of the item associated with pos should be drawn
return
The view that is currently selected, if it happens to be in the range that we draw.

        View selectedView = null;

        int end = (mBottom - mTop) - mListPadding.bottom;

        while (nextTop < end && pos < mItemCount) {
            // is this the selected item?
            boolean selected = pos == mSelectedPosition;
            View child = makeAndAddView(pos, nextTop, true, mListPadding.left, selected);

            nextTop = child.getBottom() + mDividerHeight;
            if (selected) {
                selectedView = child;
            }
            pos++;
        }

        return selectedView;
    
private android.view.ViewfillFromMiddle(int childrenTop, int childrenBottom)
Put mSelectedPosition in the middle of the screen and then build up and down from there. This method forces mSelectedPosition to the center.

param
childrenTop Top of the area in which children can be drawn, as measured in pixels
param
childrenBottom Bottom of the area in which children can be drawn, as measured in pixels
return
Currently selected view

        int height = childrenBottom - childrenTop;

        int position = reconcileSelectedPosition();

        View sel = makeAndAddView(position, childrenTop, true,
                mListPadding.left, true);
        mFirstPosition = position;

        int selHeight = sel.getMeasuredHeight();
        if (selHeight <= height) {
            sel.offsetTopAndBottom((height - selHeight) / 2);
        }

        fillAboveAndBelow(sel, position);

        if (!mStackFromBottom) {
            correctTooHigh(getChildCount());
        } else {
            correctTooLow(getChildCount());
        }

        return sel;
    
private android.view.ViewfillFromSelection(int selectedTop, int childrenTop, int childrenBottom)
Fills the grid based on positioning the new selection at a specific location. The selection may be moved so that it does not intersect the faded edges. The grid is then filled upwards and downwards from there.

param
selectedTop Where the selected item should be
param
childrenTop Where to start drawing children
param
childrenBottom Last pixel where children can be drawn
return
The view that currently has selection

        int fadingEdgeLength = getVerticalFadingEdgeLength();
        final int selectedPosition = mSelectedPosition;

        View sel;

        final int topSelectionPixel = getTopSelectionPixel(childrenTop, fadingEdgeLength,
                selectedPosition);
        final int bottomSelectionPixel = getBottomSelectionPixel(childrenBottom, fadingEdgeLength,
                selectedPosition);

        sel = makeAndAddView(selectedPosition, selectedTop, true, mListPadding.left, true);


        // Some of the newly selected item extends below the bottom of the list
        if (sel.getBottom() > bottomSelectionPixel) {
            // Find space available above the selection into which we can scroll
            // upwards
            final int spaceAbove = sel.getTop() - topSelectionPixel;

            // Find space required to bring the bottom of the selected item
            // fully into view
            final int spaceBelow = sel.getBottom() - bottomSelectionPixel;
            final int offset = Math.min(spaceAbove, spaceBelow);

            // Now offset the selected item to get it into view
            sel.offsetTopAndBottom(-offset);
        } else if (sel.getTop() < topSelectionPixel) {
            // Find space required to bring the top of the selected item fully
            // into view
            final int spaceAbove = topSelectionPixel - sel.getTop();

            // Find space available below the selection into which we can scroll
            // downwards
            final int spaceBelow = bottomSelectionPixel - sel.getBottom();
            final int offset = Math.min(spaceAbove, spaceBelow);

            // Offset the selected item to get it into view
            sel.offsetTopAndBottom(offset);
        }

        // Fill in views above and below
        fillAboveAndBelow(sel, selectedPosition);

        if (!mStackFromBottom) {
            correctTooHigh(getChildCount());
        } else {
            correctTooLow(getChildCount());
        }

        return sel;
    
private android.view.ViewfillFromTop(int nextTop)
Fills the list from top to bottom, starting with mFirstPosition

param
nextTop The location where the top of the first item should be drawn
return
The view that is currently selected

        mFirstPosition = Math.min(mFirstPosition, mSelectedPosition);
        mFirstPosition = Math.min(mFirstPosition, mItemCount - 1);
        if (mFirstPosition < 0) {
            mFirstPosition = 0;
        }
        return fillDown(mFirstPosition, nextTop);
    
voidfillGap(boolean down)
{@inheritDoc}

        final int count = getChildCount();
        if (down) {
            final int startOffset = count > 0 ? getChildAt(count - 1).getBottom() + mDividerHeight :
                    getListPaddingTop();
            fillDown(mFirstPosition + count, startOffset);
            correctTooHigh(getChildCount());
        } else {
            final int startOffset = count > 0 ? getChildAt(0).getTop() - mDividerHeight :
                    getHeight() - getListPaddingBottom();
            fillUp(mFirstPosition - 1, startOffset);
            correctTooLow(getChildCount());
        }
    
private android.view.ViewfillSpecific(int position, int top)
Put a specific item at a specific location on the screen and then build up and down from there.

param
position The reference view to use as the starting point
param
top Pixel offset from the top of this view to the top of the reference view.
return
The selected view, or null if the selected view is outside the visible area.

        boolean tempIsSelected = position == mSelectedPosition;
        View temp = makeAndAddView(position, top, true, mListPadding.left, tempIsSelected);
        // Possibly changed again in fillUp if we add rows above this one.
        mFirstPosition = position;

        View above;
        View below;

        final int dividerHeight = mDividerHeight;
        if (!mStackFromBottom) {
            above = fillUp(position - 1, temp.getTop() - dividerHeight);
            // This will correct for the top of the first view not touching the top of the list
            adjustViewsUpOrDown();
            below = fillDown(position + 1, temp.getBottom() + dividerHeight);
            int childCount = getChildCount();
            if (childCount > 0) {
                correctTooHigh(childCount);
            }
        } else {
            below = fillDown(position + 1, temp.getBottom() + dividerHeight);
            // This will correct for the bottom of the last view not touching the bottom of the list
            adjustViewsUpOrDown();
            above = fillUp(position - 1, temp.getTop() - dividerHeight);
            int childCount = getChildCount();
            if (childCount > 0) {
                 correctTooLow(childCount);
            }
        }

        if (tempIsSelected) {
            return temp;
        } else if (above != null) {
            return above;
        } else {
            return below;
        }
    
private android.view.ViewfillUp(int pos, int nextBottom)
Fills the list from pos up to the top of the list view.

param
pos The first position to put in the list
param
nextBottom The location where the bottom of the item associated with pos should be drawn
return
The view that is currently selected

        View selectedView = null;

        int end = mListPadding.top;

        while (nextBottom > end && pos >= 0) {
            // is this the selected item?
            boolean selected = pos == mSelectedPosition;
            View child = makeAndAddView(pos, nextBottom, false, mListPadding.left, selected);
            nextBottom = child.getTop() - mDividerHeight;
            if (selected) {
                selectedView = child;
            }
            pos--;
        }

        mFirstPosition = pos + 1;

        return selectedView;
    
intfindMotionRow(int y)

        int childCount = getChildCount();
        if (childCount > 0) {
            for (int i = 0; i < childCount; i++) {
                View v = getChildAt(i);
                if (y <= v.getBottom()) {
                    return mFirstPosition + i;
                }
            }
            return mFirstPosition + childCount - 1;
        }
        return INVALID_POSITION;
    
android.view.ViewfindViewInHeadersOrFooters(java.util.ArrayList where, int id)

        if (where != null) {
            int len = where.size();
            View v;

            for (int i = 0; i < len; i++) {
                v = where.get(i).view;

                if (!v.isRootNamespace()) {
                    v = v.findViewById(id);

                    if (v != null) {
                        return v;
                    }
                }
            }
        }
        return null;
    
android.view.ViewfindViewTagInHeadersOrFooters(java.util.ArrayList where, java.lang.Object tag)

        if (where != null) {
            int len = where.size();
            View v;

            for (int i = 0; i < len; i++) {
                v = where.get(i).view;

                if (!v.isRootNamespace()) {
                    v = v.findViewWithTag(tag);

                    if (v != null) {
                        return v;
                    }
                }
            }
        }
        return null;
    
protected android.view.ViewfindViewTraversal(int id)

        View v;
        v = super.findViewTraversal(id);
        if (v == null) {
            v = findViewInHeadersOrFooters(mHeaderViewInfos, id);
            if (v != null) {
                return v;
            }
            v = findViewInHeadersOrFooters(mFooterViewInfos, id);
            if (v != null) {
                return v;
            }
        }
        return v;
    
protected android.view.ViewfindViewWithTagTraversal(java.lang.Object tag)

        View v;
        v = super.findViewWithTagTraversal(tag);
        if (v == null) {
            v = findViewTagInHeadersOrFooters(mHeaderViewInfos, tag);
            if (v != null) {
                return v;
            }

            v = findViewTagInHeadersOrFooters(mFooterViewInfos, tag);
            if (v != null) {
                return v;
            }
        }
        return v;
    
booleanfullScroll(int direction)
Go to the last or first item if possible (not worrying about panning across or navigating within the internal focus of the currently selected item.)

param
direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN}
return
whether selection was moved

        boolean moved = false;
        if (direction == FOCUS_UP) {
            if (mSelectedPosition != 0) {
                int position = lookForSelectablePosition(0, true);
                if (position >= 0) {
                    mLayoutMode = LAYOUT_FORCE_TOP;
                    setSelectionInt(position);
                    invokeOnItemScrollListener();
                }
                moved = true;
            }
        } else if (direction == FOCUS_DOWN) {
            if (mSelectedPosition < mItemCount - 1) {
                int position = lookForSelectablePosition(mItemCount - 1, true);
                if (position >= 0) {
                    mLayoutMode = LAYOUT_FORCE_BOTTOM;
                    setSelectionInt(position);
                    invokeOnItemScrollListener();
                }
                moved = true;
            }
        }

        if (moved) {
            invalidate();
        }

        return moved;
    
public ListAdaptergetAdapter()
Returns the adapter currently in use in this ListView. The returned adapter might not be the same adapter passed to {@link #setAdapter(ListAdapter)} but might be a {@link WrapperListAdapter}.

return
The adapter currently used to display data in this ListView.
see
#setAdapter(ListAdapter)

        return mAdapter;
    
private intgetArrowScrollPreviewLength()

return
The amount to preview next items when arrow srolling.

        return Math.max(MIN_SCROLL_PREVIEW_PIXELS, getVerticalFadingEdgeLength());
    
private intgetBottomSelectionPixel(int childrenBottom, int fadingEdgeLength, int selectedPosition)
Calculate the bottom-most pixel we can draw the selection into

param
childrenBottom Bottom pixel were children can be drawn
param
fadingEdgeLength Length of the fading edge in pixels, if present
param
selectedPosition The position that will be selected
return
The bottom-most pixel we can draw the selection into

        int bottomSelectionPixel = childrenBottom;
        if (selectedPosition != mItemCount - 1) {
            bottomSelectionPixel -= fadingEdgeLength;
        }
        return bottomSelectionPixel;
    
public intgetCheckedItemPosition()
Returns the currently checked item. The result is only valid if the choice mode has not been set to {@link #CHOICE_MODE_SINGLE}.

return
The position of the currently checked item or {@link #INVALID_POSITION} if nothing is selected
see
#setChoiceMode(int)

        if (mChoiceMode == CHOICE_MODE_SINGLE && mCheckStates != null && mCheckStates.size() == 1) {
            return mCheckStates.keyAt(0);
        }

        return INVALID_POSITION;
    
public android.util.SparseBooleanArraygetCheckedItemPositions()
Returns the set of checked items in the list. The result is only valid if the choice mode has not been set to {@link #CHOICE_MODE_SINGLE}.

return
A SparseBooleanArray which will return true for each call to get(int position) where position is a position in the list.

        if (mChoiceMode != CHOICE_MODE_NONE) {
            return mCheckStates;
        }
        return null;
    
public intgetChoiceMode()

see
#setChoiceMode(int)
return
The current choice mode

        return mChoiceMode;
    
public android.graphics.drawable.DrawablegetDivider()
Returns the drawable that will be drawn between each item in the list.

return
the current drawable drawn between list elements

        return mDivider;
    
public intgetDividerHeight()

return
Returns the height of the divider that will be drawn between each item in the list.

        return mDividerHeight;
    
public intgetFooterViewsCount()

        return mFooterViewInfos.size();
    
public intgetHeaderViewsCount()

        return mHeaderViewInfos.size();
    
public booleangetItemsCanFocus()

return
Whether the views created by the ListAdapter can contain focusable items.

        return mItemsCanFocus;
    
public intgetMaxScrollAmount()

return
The maximum amount a list view will scroll in response to an arrow event.

        return (int) (MAX_SCROLL_FACTOR * (mBottom - mTop));
    
private intgetTopSelectionPixel(int childrenTop, int fadingEdgeLength, int selectedPosition)
Calculate the top-most pixel we can draw the selection into

param
childrenTop Top pixel were children can be drawn
param
fadingEdgeLength Length of the fading edge in pixels, if present
param
selectedPosition The position that will be selected
return
The top-most pixel we can draw the selection into

        // first pixel we can draw the selection into
        int topSelectionPixel = childrenTop;
        if (selectedPosition > 0) {
            topSelectionPixel += fadingEdgeLength;
        }
        return topSelectionPixel;
    
private booleanhandleHorizontalFocusWithinListItem(int direction)
To avoid horizontal focus searches changing the selected item, we manually focus search within the selected item (as applicable), and prevent focus from jumping to something within another item.

param
direction one of {View.FOCUS_LEFT, View.FOCUS_RIGHT}
return
Whether this consumes the key event.

        if (direction != View.FOCUS_LEFT && direction != View.FOCUS_RIGHT)  {
            throw new IllegalArgumentException("direction must be one of"
                    + " {View.FOCUS_LEFT, View.FOCUS_RIGHT}");
        }

        final int numChildren = getChildCount();
        if (mItemsCanFocus && numChildren > 0 && mSelectedPosition != INVALID_POSITION) {
            final View selectedView = getSelectedView();
            if (selectedView != null && selectedView.hasFocus() &&
                    selectedView instanceof ViewGroup) {

                final View currentFocus = selectedView.findFocus();
                final View nextFocus = FocusFinder.getInstance().findNextFocus(
                        (ViewGroup) selectedView, currentFocus, direction);
                if (nextFocus != null) {
                    // do the math to get interesting rect in next focus' coordinates
                    currentFocus.getFocusedRect(mTempRect);
                    offsetDescendantRectToMyCoords(currentFocus, mTempRect);
                    offsetRectIntoDescendantCoords(nextFocus, mTempRect);
                    if (nextFocus.requestFocus(direction, mTempRect)) {
                        return true;
                    }
                }
                // we are blocking the key from being handled (by returning true)
                // if the global result is going to be some other view within this
                // list.  this is to acheive the overall goal of having
                // horizontal d-pad navigation remain in the current item.
                final View globalNextFocus = FocusFinder.getInstance().findNextFocus(
                        (ViewGroup) getRootView(), currentFocus, direction);
                if (globalNextFocus != null) {
                    return isViewAncestorOf(globalNextFocus, this);
                }
            }
        }
        return false;
    
private voidhandleNewSelectionChange(android.view.View selectedView, int direction, int newSelectedPosition, boolean newFocusAssigned)
When selection changes, it is possible that the previously selected or the next selected item will change its size. If so, we need to offset some folks, and re-layout the items as appropriate.

param
selectedView The currently selected view (before changing selection). should be null if there was no previous selection.
param
direction Either {@link android.view.View#FOCUS_UP} or {@link android.view.View#FOCUS_DOWN}.
param
newSelectedPosition The position of the next selection.
param
newFocusAssigned whether new focus was assigned. This matters because when something has focus, we don't want to show selection (ugh).

        if (newSelectedPosition == INVALID_POSITION) {
            throw new IllegalArgumentException("newSelectedPosition needs to be valid");
        }

        // whether or not we are moving down or up, we want to preserve the
        // top of whatever view is on top:
        // - moving down: the view that had selection
        // - moving up: the view that is getting selection
        View topView;
        View bottomView;
        int topViewIndex, bottomViewIndex;
        boolean topSelected = false;
        final int selectedIndex = mSelectedPosition - mFirstPosition;
        final int nextSelectedIndex = newSelectedPosition - mFirstPosition;
        if (direction == View.FOCUS_UP) {
            topViewIndex = nextSelectedIndex;
            bottomViewIndex = selectedIndex;
            topView = getChildAt(topViewIndex);
            bottomView = selectedView;
            topSelected = true;
        } else {
            topViewIndex = selectedIndex;
            bottomViewIndex = nextSelectedIndex;
            topView = selectedView;
            bottomView = getChildAt(bottomViewIndex);
        }

        final int numChildren = getChildCount();

        // start with top view: is it changing size?
        if (topView != null) {
            topView.setSelected(!newFocusAssigned && topSelected);
            measureAndAdjustDown(topView, topViewIndex, numChildren);
        }

        // is the bottom view changing size?
        if (bottomView != null) {
            bottomView.setSelected(!newFocusAssigned && !topSelected);
            measureAndAdjustDown(bottomView, bottomViewIndex, numChildren);
        }
    
private booleanisDirectChildHeaderOrFooter(android.view.View child)

param
child a direct child of this list.
return
Whether child is a header or footer view.


        final ArrayList<FixedViewInfo> headers = mHeaderViewInfos;
        final int numHeaders = headers.size();
        for (int i = 0; i < numHeaders; i++) {
            if (child == headers.get(i).view) {
                return true;
            }
        }
        final ArrayList<FixedViewInfo> footers = mFooterViewInfos;
        final int numFooters = footers.size();
        for (int i = 0; i < numFooters; i++) {
            if (child == footers.get(i).view) {
                return true;
            }
        }
        return false;
    
public booleanisItemChecked(int position)
Returns the checked state of the specified position. The result is only valid if the choice mode has not been set to {@link #CHOICE_MODE_SINGLE} or {@link #CHOICE_MODE_MULTIPLE}.

param
position The item whose checked state to return
return
The item's checked state
see
#setChoiceMode(int)

        if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null) {
            return mCheckStates.get(position);
        }

        return false;
    
private booleanisViewAncestorOf(android.view.View child, android.view.View parent)
Return true if child is an ancestor of parent, (or equal to the parent).

        if (child == parent) {
            return true;
        }

        final ViewParent theParent = child.getParent();
        return (theParent instanceof ViewGroup) && isViewAncestorOf((View) theParent, parent);
    
protected voidlayoutChildren()

        final boolean blockLayoutRequests = mBlockLayoutRequests;
        if (!blockLayoutRequests) {
            mBlockLayoutRequests = true;
        } else {
            return;
        }

        try {
            super.layoutChildren();

            invalidate();

            if (mAdapter == null) {
                resetList();
                invokeOnItemScrollListener();
                return;
            }

            int childrenTop = mListPadding.top;
            int childrenBottom = mBottom - mTop - mListPadding.bottom;

            int childCount = getChildCount();
            int index;
            int delta = 0;

            View sel;
            View oldSel = null;
            View oldFirst = null;
            View newSel = null;

            View focusLayoutRestoreView = null;

            // Remember stuff we will need down below
            switch (mLayoutMode) {
            case LAYOUT_SET_SELECTION:
                index = mNextSelectedPosition - mFirstPosition;
                if (index >= 0 && index < childCount) {
                    newSel = getChildAt(index);
                }
                break;
            case LAYOUT_FORCE_TOP:
            case LAYOUT_FORCE_BOTTOM:
            case LAYOUT_SPECIFIC:
            case LAYOUT_SYNC:
                break;
            case LAYOUT_MOVE_SELECTION:
            default:
                // Remember the previously selected view
                index = mSelectedPosition - mFirstPosition;
                if (index >= 0 && index < childCount) {
                    oldSel = getChildAt(index);
                }

                // Remember the previous first child
                oldFirst = getChildAt(0);

                if (mNextSelectedPosition >= 0) {
                    delta = mNextSelectedPosition - mSelectedPosition;
                }

                // Caution: newSel might be null
                newSel = getChildAt(index + delta);
            }


            boolean dataChanged = mDataChanged;
            if (dataChanged) {
                handleDataChanged();
            }

            // Handle the empty set by removing all views that are visible
            // and calling it a day
            if (mItemCount == 0) {
                resetList();
                invokeOnItemScrollListener();
                return;
            }

            setSelectedPositionInt(mNextSelectedPosition);

            // Pull all children into the RecycleBin.
            // These views will be reused if possible
            final int firstPosition = mFirstPosition;
            final RecycleBin recycleBin = mRecycler;

            // reset the focus restoration
            View focusLayoutRestoreDirectChild = null;


            // Don't put header or footer views into the Recycler. Those are
            // already cached in mHeaderViews;
            if (dataChanged) {
                for (int i = 0; i < childCount; i++) {
                    recycleBin.addScrapView(getChildAt(i));
                    if (ViewDebug.TRACE_RECYCLER) {
                        ViewDebug.trace(getChildAt(i),
                                ViewDebug.RecyclerTraceType.MOVE_TO_SCRAP_HEAP, index, i);
                    }
                }
            } else {
                recycleBin.fillActiveViews(childCount, firstPosition);
            }

            // take focus back to us temporarily to avoid the eventual
            // call to clear focus when removing the focused child below
            // from messing things up when ViewRoot assigns focus back
            // to someone else
            final View focusedChild = getFocusedChild();
            if (focusedChild != null) {
                // TODO: in some cases focusedChild.getParent() == null

                // we can remember the focused view to restore after relayout if the
                // data hasn't changed, or if the focused position is a header or footer
                if (!dataChanged || isDirectChildHeaderOrFooter(focusedChild)) {
                    focusLayoutRestoreDirectChild = focusedChild;
                    // remember the specific view that had focus
                    focusLayoutRestoreView = findFocus();
                    if (focusLayoutRestoreView != null) {
                        // tell it we are going to mess with it
                        focusLayoutRestoreView.onStartTemporaryDetach();
                    }
                }
                requestFocus();
            }

            // Clear out old views
            //removeAllViewsInLayout();
            detachAllViewsFromParent();

            switch (mLayoutMode) {
            case LAYOUT_SET_SELECTION:
                if (newSel != null) {
                    sel = fillFromSelection(newSel.getTop(), childrenTop, childrenBottom);
                } else {
                    sel = fillFromMiddle(childrenTop, childrenBottom);
                }
                break;
            case LAYOUT_SYNC:
                sel = fillSpecific(mSyncPosition, mSpecificTop);
                break;
            case LAYOUT_FORCE_BOTTOM:
                sel = fillUp(mItemCount - 1, childrenBottom);
                adjustViewsUpOrDown();
                break;
            case LAYOUT_FORCE_TOP:
                mFirstPosition = 0;
                sel = fillFromTop(childrenTop);
                adjustViewsUpOrDown();
                break;
            case LAYOUT_SPECIFIC:
                sel = fillSpecific(reconcileSelectedPosition(), mSpecificTop);
                break;
            case LAYOUT_MOVE_SELECTION:
                sel = moveSelection(oldSel, newSel, delta, childrenTop, childrenBottom);
                break;
            default:
                if (childCount == 0) {
                    if (!mStackFromBottom) {
                        final int position = lookForSelectablePosition(0, true);
                        setSelectedPositionInt(position);
                        sel = fillFromTop(childrenTop);
                    } else {
                        final int position = lookForSelectablePosition(mItemCount - 1, false);
                        setSelectedPositionInt(position);
                        sel = fillUp(mItemCount - 1, childrenBottom);
                    }
                } else {
                    if (mSelectedPosition >= 0 && mSelectedPosition < mItemCount) {
                        sel = fillSpecific(mSelectedPosition,
                                oldSel == null ? childrenTop : oldSel.getTop());
                    } else if (mFirstPosition < mItemCount) {
                        sel = fillSpecific(mFirstPosition,
                                oldFirst == null ? childrenTop : oldFirst.getTop());
                    } else {
                        sel = fillSpecific(0, childrenTop);
                    }
                }
                break;
            }

            // Flush any cached views that did not get reused above
            recycleBin.scrapActiveViews();

            if (sel != null) {
               // the current selected item should get focus if items
               // are focusable
               if (mItemsCanFocus && hasFocus() && !sel.hasFocus()) {
                   final boolean focusWasTaken = (sel == focusLayoutRestoreDirectChild &&
                           focusLayoutRestoreView.requestFocus()) || sel.requestFocus();
                   if (!focusWasTaken) {
                       // selected item didn't take focus, fine, but still want
                       // to make sure something else outside of the selected view
                       // has focus
                       final View focused = getFocusedChild();
                       if (focused != null) {
                           focused.clearFocus();
                       }
                       positionSelector(sel);
                   } else {
                       sel.setSelected(false);
                       mSelectorRect.setEmpty();
                   }
               } else {
                   positionSelector(sel);
               }
               mSelectedTop = sel.getTop();
            } else {
               mSelectedTop = 0;
               mSelectorRect.setEmpty();

               // even if there is not selected position, we may need to restore
               // focus (i.e. something focusable in touch mode)
               if (hasFocus() && focusLayoutRestoreView != null) {
                   focusLayoutRestoreView.requestFocus();
               }
            }

            // tell focus view we are done mucking with it, if it is still in
            // our view hierarchy.
            if (focusLayoutRestoreView != null
                    && focusLayoutRestoreView.getWindowToken() != null) {
                focusLayoutRestoreView.onFinishTemporaryDetach();
            }
            
            mLayoutMode = LAYOUT_NORMAL;
            mDataChanged = false;
            mNeedSync = false;
            setNextSelectedPositionInt(mSelectedPosition);

            updateScrollIndicators();

            if (mItemCount > 0) {
                checkSelectionChanged();
            }

            invokeOnItemScrollListener();
        } finally {
            if (!blockLayoutRequests) {
                mBlockLayoutRequests = false;
            }
        }
    
intlookForSelectablePosition(int position, boolean lookDown)
Find a position that can be selected (i.e., is not a separator).

param
position The starting position to look at.
param
lookDown Whether to look down for other positions.
return
The next selectable position starting at position and then searching either up or down. Returns {@link #INVALID_POSITION} if nothing can be found.

        final ListAdapter adapter = mAdapter;
        if (adapter == null || isInTouchMode()) {
            return INVALID_POSITION;
        }

        final int count = adapter.getCount();
        if (!mAreAllItemsSelectable) {
            if (lookDown) {
                position = Math.max(0, position);
                while (position < count && !adapter.isEnabled(position)) {
                    position++;
                }
            } else {
                position = Math.min(position, count - 1);
                while (position >= 0 && !adapter.isEnabled(position)) {
                    position--;
                }
            }

            if (position < 0 || position >= count) {
                return INVALID_POSITION;
            }
            return position;
        } else {
            if (position < 0 || position >= count) {
                return INVALID_POSITION;
            }
            return position;
        }
    
private intlookForSelectablePositionOnScreen(int direction)

param
direction either {@link android.view.View#FOCUS_UP} or {@link android.view.View#FOCUS_DOWN}.
return
The position of the next selectable position of the views that are currently visible, taking into account the fact that there might be no selection. Returns {@link #INVALID_POSITION} if there is no selectable view on screen in the given direction.

        final int firstPosition = mFirstPosition;
        if (direction == View.FOCUS_DOWN) {
            int startPos = (mSelectedPosition != INVALID_POSITION) ?
                    mSelectedPosition + 1 :
                    firstPosition;
            if (startPos >= mAdapter.getCount()) {
                return INVALID_POSITION;
            }
            if (startPos < firstPosition) {
                startPos = firstPosition;
            }
            
            final int lastVisiblePos = getLastVisiblePosition();
            final ListAdapter adapter = getAdapter();
            for (int pos = startPos; pos <= lastVisiblePos; pos++) {
                if (adapter.isEnabled(pos)
                        && getChildAt(pos - firstPosition).getVisibility() == View.VISIBLE) {
                    return pos;
                }
            }
        } else {
            int last = firstPosition + getChildCount() - 1;
            int startPos = (mSelectedPosition != INVALID_POSITION) ?
                    mSelectedPosition - 1 :
                    firstPosition + getChildCount() - 1;
            if (startPos < 0) {
                return INVALID_POSITION;
            }
            if (startPos > last) {
                startPos = last;
            }

            final ListAdapter adapter = getAdapter();
            for (int pos = startPos; pos >= firstPosition; pos--) {
                if (adapter.isEnabled(pos)
                        && getChildAt(pos - firstPosition).getVisibility() == View.VISIBLE) {
                    return pos;
                }
            }
        }
        return INVALID_POSITION;
    
private android.view.ViewmakeAndAddView(int position, int y, boolean flow, int childrenLeft, boolean selected)
Obtain the view and add it to our list of children. The view can be made fresh, converted from an unused view, or used as is if it was in the recycle bin.

param
position Logical position in the list
param
y Top or bottom edge of the view to add
param
flow If flow is true, align top edge to y. If false, align bottom edge to y.
param
childrenLeft Left edge where children should be positioned
param
selected Is this position selected?
return
View that was added

        View child;


        if (!mDataChanged) {
            // Try to use an exsiting view for this position
            child = mRecycler.getActiveView(position);
            if (child != null) {
                if (ViewDebug.TRACE_RECYCLER) {
                    ViewDebug.trace(child, ViewDebug.RecyclerTraceType.RECYCLE_FROM_ACTIVE_HEAP,
                            position, getChildCount());
                }

                // Found it -- we're using an existing child
                // This just needs to be positioned
                setupChild(child, position, y, flow, childrenLeft, selected, true);

                return child;
            }
        }

        // Make a new view for this position, or convert an unused view if possible
        child = obtainView(position);

        // This needs to be positioned and measured
        setupChild(child, position, y, flow, childrenLeft, selected, false);

        return child;
    
private voidmeasureAndAdjustDown(android.view.View child, int childIndex, int numChildren)
Re-measure a child, and if its height changes, lay it out preserving its top, and adjust the children below it appropriately.

param
child The child
param
childIndex The view group index of the child.
param
numChildren The number of children in the view group.

        int oldHeight = child.getHeight();
        measureItem(child);
        if (child.getMeasuredHeight() != oldHeight) {
            // lay out the view, preserving its top
            relayoutMeasuredItem(child);

            // adjust views below appropriately
            final int heightDelta = child.getMeasuredHeight() - oldHeight;
            for (int i = childIndex + 1; i < numChildren; i++) {
                getChildAt(i).offsetTopAndBottom(heightDelta);
            }
        }
    
final intmeasureHeightOfChildren(int widthMeasureSpec, int startPosition, int endPosition, int maxHeight, int disallowPartialChildPosition)
Measures the height of the given range of children (inclusive) and returns the height with this ListView's padding and divider heights included. If maxHeight is provided, the measuring will stop when the current height reaches maxHeight.

param
widthMeasureSpec The width measure spec to be given to a child's {@link View#measure(int, int)}.
param
startPosition The position of the first child to be shown.
param
endPosition The (inclusive) position of the last child to be shown. Specify {@link #NO_POSITION} if the last child should be the last available child from the adapter.
param
maxHeight The maximum height that will be returned (if all the children don't fit in this value, this value will be returned).
param
disallowPartialChildPosition In general, whether the returned height should only contain entire children. This is more powerful--it is the first inclusive position at which partial children will not be allowed. Example: it looks nice to have at least 3 completely visible children, and in portrait this will most likely fit; but in landscape there could be times when even 2 children can not be completely shown, so a value of 2 (remember, inclusive) would be good (assuming startPosition is 0).
return
The height of this ListView with the given children.


        final ListAdapter adapter = mAdapter;
        if (adapter == null) {
            return mListPadding.top + mListPadding.bottom;
        }

        // Include the padding of the list
        int returnedHeight = mListPadding.top + mListPadding.bottom;
        final int dividerHeight = ((mDividerHeight > 0) && mDivider != null) ? mDividerHeight : 0;
        // The previous height value that was less than maxHeight and contained
        // no partial children
        int prevHeightWithoutPartialChild = 0;
        int i;
        View child;

        // mItemCount - 1 since endPosition parameter is inclusive
        endPosition = (endPosition == NO_POSITION) ? adapter.getCount() - 1 : endPosition;
        final AbsListView.RecycleBin recycleBin = mRecycler;
        final boolean recyle = recycleOnMeasure();

        for (i = startPosition; i <= endPosition; ++i) {
            child = obtainView(i);

            measureScrapChild(child, i, widthMeasureSpec);

            if (i > 0) {
                // Count the divider for all but one child
                returnedHeight += dividerHeight;
            }

            // Recycle the view before we possibly return from the method
            if (recyle) {
                recycleBin.addScrapView(child);
            }

            returnedHeight += child.getMeasuredHeight();

            if (returnedHeight >= maxHeight) {
                // We went over, figure out which height to return.  If returnedHeight > maxHeight,
                // then the i'th position did not fit completely.
                return (disallowPartialChildPosition >= 0) // Disallowing is enabled (> -1)
                            && (i > disallowPartialChildPosition) // We've past the min pos
                            && (prevHeightWithoutPartialChild > 0) // We have a prev height
                            && (returnedHeight != maxHeight) // i'th child did not fit completely
                        ? prevHeightWithoutPartialChild
                        : maxHeight;
            }

            if ((disallowPartialChildPosition >= 0) && (i >= disallowPartialChildPosition)) {
                prevHeightWithoutPartialChild = returnedHeight;
            }
        }

        // At this point, we went through the range of children, and they each
        // completely fit, so return the returnedHeight
        return returnedHeight;
    
private voidmeasureItem(android.view.View child)
Measure a particular list child. TODO: unify with setUpChild.

param
child The child.

        ViewGroup.LayoutParams p = child.getLayoutParams();
        if (p == null) {
            p = new ViewGroup.LayoutParams(
                    ViewGroup.LayoutParams.FILL_PARENT,
                    ViewGroup.LayoutParams.WRAP_CONTENT);
        }

        int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec,
                mListPadding.left + mListPadding.right, p.width);
        int lpHeight = p.height;
        int childHeightSpec;
        if (lpHeight > 0) {
            childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY);
        } else {
            childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
        }
        child.measure(childWidthSpec, childHeightSpec);
    
private voidmeasureScrapChild(android.view.View child, int position, int widthMeasureSpec)

        LayoutParams p = (LayoutParams) child.getLayoutParams();
        if (p == null) {
            p = new LayoutParams(ViewGroup.LayoutParams.FILL_PARENT,
                    ViewGroup.LayoutParams.WRAP_CONTENT, 0);
            child.setLayoutParams(p);
        }
        p.viewType = mAdapter.getItemViewType(position);

        int childWidthSpec = ViewGroup.getChildMeasureSpec(widthMeasureSpec,
                mListPadding.left + mListPadding.right, p.width);
        int lpHeight = p.height;
        int childHeightSpec;
        if (lpHeight > 0) {
            childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY);
        } else {
            childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
        }
        child.measure(childWidthSpec, childHeightSpec);
    
private android.view.ViewmoveSelection(android.view.View oldSel, android.view.View newSel, int delta, int childrenTop, int childrenBottom)
Fills the list based on positioning the new selection relative to the old selection. The new selection will be placed at, above, or below the location of the new selection depending on how the selection is moving. The selection will then be pinned to the visible part of the screen, excluding the edges that are faded. The list is then filled upwards and downwards from there.

param
oldSel The old selected view. Useful for trying to put the new selection in the same place
param
newSel The view that is to become selected. Useful for trying to put the new selection in the same place
param
delta Which way we are moving
param
childrenTop Where to start drawing children
param
childrenBottom Last pixel where children can be drawn
return
The view that currently has selection

        int fadingEdgeLength = getVerticalFadingEdgeLength();
        final int selectedPosition = mSelectedPosition;

        View sel;

        final int topSelectionPixel = getTopSelectionPixel(childrenTop, fadingEdgeLength,
                selectedPosition);
        final int bottomSelectionPixel = getBottomSelectionPixel(childrenTop, fadingEdgeLength,
                selectedPosition);

        if (delta > 0) {
            /*
             * Case 1: Scrolling down.
             */

            /*
             *     Before           After
             *    |       |        |       |
             *    +-------+        +-------+
             *    |   A   |        |   A   |
             *    |   1   |   =>   +-------+
             *    +-------+        |   B   |
             *    |   B   |        |   2   |
             *    +-------+        +-------+
             *    |       |        |       |
             *
             *    Try to keep the top of the previously selected item where it was.
             *    oldSel = A
             *    sel = B
             */

            // Put oldSel (A) where it belongs
            oldSel = makeAndAddView(selectedPosition - 1, oldSel.getTop(), true,
                    mListPadding.left, false);

            final int dividerHeight = mDividerHeight;

            // Now put the new selection (B) below that
            sel = makeAndAddView(selectedPosition, oldSel.getBottom() + dividerHeight, true,
                    mListPadding.left, true);

            // Some of the newly selected item extends below the bottom of the list
            if (sel.getBottom() > bottomSelectionPixel) {

                // Find space available above the selection into which we can scroll upwards
                int spaceAbove = sel.getTop() - topSelectionPixel;

                // Find space required to bring the bottom of the selected item fully into view
                int spaceBelow = sel.getBottom() - bottomSelectionPixel;

                // Don't scroll more than half the height of the list
                int halfVerticalSpace = (childrenBottom - childrenTop) / 2;
                int offset = Math.min(spaceAbove, spaceBelow);
                offset = Math.min(offset, halfVerticalSpace);

                // We placed oldSel, so offset that item
                oldSel.offsetTopAndBottom(-offset);
                // Now offset the selected item to get it into view
                sel.offsetTopAndBottom(-offset);
            }

            // Fill in views above and below
            if (!mStackFromBottom) {
                fillUp(mSelectedPosition - 2, sel.getTop() - dividerHeight);
                adjustViewsUpOrDown();
                fillDown(mSelectedPosition + 1, sel.getBottom() + dividerHeight);
            } else {
                fillDown(mSelectedPosition + 1, sel.getBottom() + dividerHeight);
                adjustViewsUpOrDown();
                fillUp(mSelectedPosition - 2, sel.getTop() - dividerHeight);
            }
        } else if (delta < 0) {
            /*
             * Case 2: Scrolling up.
             */

            /*
             *     Before           After
             *    |       |        |       |
             *    +-------+        +-------+
             *    |   A   |        |   A   |
             *    +-------+   =>   |   1   |
             *    |   B   |        +-------+
             *    |   2   |        |   B   |
             *    +-------+        +-------+
             *    |       |        |       |
             *
             *    Try to keep the top of the item about to become selected where it was.
             *    newSel = A
             *    olSel = B
             */

            if (newSel != null) {
                // Try to position the top of newSel (A) where it was before it was selected
                sel = makeAndAddView(selectedPosition, newSel.getTop(), true, mListPadding.left,
                        true);
            } else {
                // If (A) was not on screen and so did not have a view, position
                // it above the oldSel (B)
                sel = makeAndAddView(selectedPosition, oldSel.getTop(), false, mListPadding.left,
                        true);
            }

            // Some of the newly selected item extends above the top of the list
            if (sel.getTop() < topSelectionPixel) {
                // Find space required to bring the top of the selected item fully into view
                int spaceAbove = topSelectionPixel - sel.getTop();

               // Find space available below the selection into which we can scroll downwards
                int spaceBelow = bottomSelectionPixel - sel.getBottom();

                // Don't scroll more than half the height of the list
                int halfVerticalSpace = (childrenBottom - childrenTop) / 2;
                int offset = Math.min(spaceAbove, spaceBelow);
                offset = Math.min(offset, halfVerticalSpace);

                // Offset the selected item to get it into view
                sel.offsetTopAndBottom(offset);
            }

            // Fill in views above and below
            fillAboveAndBelow(sel, selectedPosition);
        } else {

            int oldTop = oldSel.getTop();

            /*
             * Case 3: Staying still
             */
            sel = makeAndAddView(selectedPosition, oldTop, true, mListPadding.left, true);

            // We're staying still...
            if (oldTop < childrenTop) {
                // ... but the top of the old selection was off screen.
                // (This can happen if the data changes size out from under us)
                int newBottom = sel.getBottom();
                if (newBottom < childrenTop + 20) {
                    // Not enough visible -- bring it onscreen
                    sel.offsetTopAndBottom(childrenTop - sel.getTop());
                }
            }

            // Fill in views above and below
            fillAboveAndBelow(sel, selectedPosition);
        }

        return sel;
    
protected voidonFinishInflate()

        super.onFinishInflate();

        int count = getChildCount();
        if (count > 0) {
            for (int i = 0; i < count; ++i) {
                addHeaderView(getChildAt(i));
            }
            removeAllViews();
        }
    
protected voidonFocusChanged(boolean gainFocus, int direction, android.graphics.Rect previouslyFocusedRect)

        super.onFocusChanged(gainFocus, direction, previouslyFocusedRect);

        int closetChildIndex = -1;
        if (gainFocus && previouslyFocusedRect != null) {
            previouslyFocusedRect.offset(mScrollX, mScrollY);

            // figure out which item should be selected based on previously
            // focused rect
            Rect otherRect = mTempRect;
            int minDistance = Integer.MAX_VALUE;
            final int childCount = getChildCount();
            final int firstPosition = mFirstPosition;
            final ListAdapter adapter = mAdapter;

            for (int i = 0; i < childCount; i++) {
                // only consider selectable views
                if (!adapter.isEnabled(firstPosition + i)) {
                    continue;
                }

                View other = getChildAt(i);
                other.getDrawingRect(otherRect);
                offsetDescendantRectToMyCoords(other, otherRect);
                int distance = getDistance(previouslyFocusedRect, otherRect, direction);

                if (distance < minDistance) {
                    minDistance = distance;
                    closetChildIndex = i;
                }
            }
        }

        if (closetChildIndex >= 0) {
            setSelection(closetChildIndex + mFirstPosition);
        } else {
            requestLayout();
        }
    
public booleanonKeyDown(int keyCode, android.view.KeyEvent event)

        return commonKey(keyCode, 1, event);
    
public booleanonKeyMultiple(int keyCode, int repeatCount, android.view.KeyEvent event)

        return commonKey(keyCode, repeatCount, event);
    
public booleanonKeyUp(int keyCode, android.view.KeyEvent event)

        return commonKey(keyCode, 1, event);
    
protected voidonMeasure(int widthMeasureSpec, int heightMeasureSpec)

        // Sets up mListPadding
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        int widthMode = MeasureSpec.getMode(widthMeasureSpec);
        int heightMode = MeasureSpec.getMode(heightMeasureSpec);
        int widthSize = MeasureSpec.getSize(widthMeasureSpec);
        int heightSize = MeasureSpec.getSize(heightMeasureSpec);

        int childWidth = 0;
        int childHeight = 0;

        mItemCount = mAdapter == null ? 0 : mAdapter.getCount();
        if (mItemCount > 0 && (widthMode == MeasureSpec.UNSPECIFIED ||
                heightMode == MeasureSpec.UNSPECIFIED)) {
            final View child = obtainView(0);

            measureScrapChild(child, 0, widthMeasureSpec);

            childWidth = child.getMeasuredWidth();
            childHeight = child.getMeasuredHeight();

            if (recycleOnMeasure()) {
                mRecycler.addScrapView(child);
            }
        }

        if (widthMode == MeasureSpec.UNSPECIFIED) {
            widthSize = mListPadding.left + mListPadding.right + childWidth +
                    getVerticalScrollbarWidth();
        }

        if (heightMode == MeasureSpec.UNSPECIFIED) {
            heightSize = mListPadding.top + mListPadding.bottom + childHeight +
                    getVerticalFadingEdgeLength() * 2;
        }

        if (heightMode == MeasureSpec.AT_MOST) {
            // TODO: after first layout we should maybe start at the first visible position, not 0
            heightSize = measureHeightOfChildren(widthMeasureSpec, 0, NO_POSITION, heightSize, -1);
        }

        setMeasuredDimension(widthSize, heightSize);
        mWidthMeasureSpec = widthMeasureSpec;        
    
public voidonRestoreInstanceState(android.os.Parcelable state)

        SavedState ss = (SavedState) state;

        super.onRestoreInstanceState(ss.getSuperState());

        if (ss.checkState != null) {
           mCheckStates = ss.checkState;
        }

    
public android.os.ParcelableonSaveInstanceState()

    

    
       
        Parcelable superState = super.onSaveInstanceState();
        return new SavedState(superState, mCheckStates);
    
public booleanonTouchEvent(android.view.MotionEvent ev)

        if (mItemsCanFocus && ev.getAction() == MotionEvent.ACTION_DOWN && ev.getEdgeFlags() != 0) {
            // Don't handle edge touches immediately -- they may actually belong to one of our
            // descendants.
            return false;
        }
        return super.onTouchEvent(ev);
    
booleanpageScroll(int direction)
Scrolls up or down by the number of items currently present on screen.

param
direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN}
return
whether selection was moved

        int nextPage = -1;
        boolean down = false;

        if (direction == FOCUS_UP) {
            nextPage = Math.max(0, mSelectedPosition - getChildCount() - 1);
        } else if (direction == FOCUS_DOWN) {
            nextPage = Math.min(mItemCount - 1, mSelectedPosition + getChildCount() - 1);
            down = true;
        }

        if (nextPage >= 0) {
            int position = lookForSelectablePosition(nextPage, down);
            if (position >= 0) {
                mLayoutMode = LAYOUT_SPECIFIC;
                mSpecificTop = mPaddingTop + getVerticalFadingEdgeLength();

                if (down && position > mItemCount - getChildCount()) {
                    mLayoutMode = LAYOUT_FORCE_BOTTOM;
                }

                if (!down && position < getChildCount()) {
                    mLayoutMode = LAYOUT_FORCE_TOP;
                }

                setSelectionInt(position);
                invokeOnItemScrollListener();
                invalidate();

                return true;
            }
        }

        return false;
    
public booleanperformItemClick(android.view.View view, int position, long id)

        boolean handled = false;

        if (mChoiceMode != CHOICE_MODE_NONE) {
            handled = true;

            if (mChoiceMode == CHOICE_MODE_MULTIPLE) {
                boolean oldValue = mCheckStates.get(position, false);
                mCheckStates.put(position, !oldValue);
            } else {
                boolean oldValue = mCheckStates.get(position, false);
                if (!oldValue) {
                    mCheckStates.clear();
                    mCheckStates.put(position, true);
                }
            }

            mDataChanged = true;
            rememberSyncState();
            requestLayout();
        }

        handled |= super.performItemClick(view, position, id);

        return handled;
    
private intpositionOfNewFocus(android.view.View newFocus)

param
newFocus The view that would have focus.
return
the position that contains newFocus

        final int numChildren = getChildCount();
        for (int i = 0; i < numChildren; i++) {
            final View child = getChildAt(i);
            if (isViewAncestorOf(newFocus, child)) {
                return mFirstPosition + i;
            }
        }
        throw new IllegalArgumentException("newFocus is not a child of any of the"
                + " children of the list!");
    
protected booleanrecycleOnMeasure()

return
True to recycle the views used to measure this ListView in UNSPECIFIED/AT_MOST modes, false otherwise.
hide

        return true;
    
private voidrelayoutMeasuredItem(android.view.View child)
Layout a child that has been measured, preserving its top position. TODO: unify with setUpChild.

param
child The child.

        final int w = child.getMeasuredWidth();
        final int h = child.getMeasuredHeight();
        final int childLeft = mListPadding.left;
        final int childRight = childLeft + w;
        final int childTop = child.getTop();
        final int childBottom = childTop + h;
        child.layout(childLeft, childTop, childRight, childBottom);
    
private voidremoveFixedViewInfo(android.view.View v, java.util.ArrayList where)

        int len = where.size();
        for (int i = 0; i < len; ++i) {
            FixedViewInfo info = where.get(i);
            if (info.view == v) {
                where.remove(i);
                break;
            }
        }
    
public booleanremoveFooterView(android.view.View v)
Removes a previously-added footer view.

param
v The view to remove
return
true if the view was removed, false if the view was not a footer view

        if (mFooterViewInfos.size() > 0) {
            boolean result = false;
            if (((HeaderViewListAdapter) mAdapter).removeFooter(v)) {
                mDataSetObserver.onChanged();
                result = true;
            }
            removeFixedViewInfo(v, mFooterViewInfos);
            return result;
        }
        return false;
    
public booleanremoveHeaderView(android.view.View v)
Removes a previously-added header view.

param
v The view to remove
return
true if the view was removed, false if the view was not a header view

        if (mHeaderViewInfos.size() > 0) {
            boolean result = false;
            if (((HeaderViewListAdapter) mAdapter).removeHeader(v)) {
                mDataSetObserver.onChanged();
                result = true;
            }
            removeFixedViewInfo(v, mHeaderViewInfos);
            return result;
        }
        return false;
    
public booleanrequestChildRectangleOnScreen(android.view.View child, android.graphics.Rect rect, boolean immediate)


        int rectTopWithinChild = rect.top;

        // offset so rect is in coordinates of the this view
        rect.offset(child.getLeft(), child.getTop());
        rect.offset(-child.getScrollX(), -child.getScrollY());

        final int height = getHeight();
        int listUnfadedTop = getScrollY();
        int listUnfadedBottom = listUnfadedTop + height;
        final int fadingEdge = getVerticalFadingEdgeLength();

        if (showingTopFadingEdge()) {
            // leave room for top fading edge as long as rect isn't at very top
            if ((mSelectedPosition > 0) || (rectTopWithinChild > fadingEdge)) {
                listUnfadedTop += fadingEdge;
            }
        }

        int childCount = getChildCount();
        int bottomOfBottomChild = getChildAt(childCount - 1).getBottom();

        if (showingBottomFadingEdge()) {
            // leave room for bottom fading edge as long as rect isn't at very bottom
            if ((mSelectedPosition < mItemCount - 1)
                    || (rect.bottom < (bottomOfBottomChild - fadingEdge))) {
                listUnfadedBottom -= fadingEdge;
            }
        }

        int scrollYDelta = 0;

        if (rect.bottom > listUnfadedBottom && rect.top > listUnfadedTop) {
            // need to MOVE DOWN to get it in view: move down just enough so
            // that the entire rectangle is in view (or at least the first
            // screen size chunk).

            if (rect.height() > height) {
                // just enough to get screen size chunk on
                scrollYDelta += (rect.top - listUnfadedTop);
            } else {
                // get entire rect at bottom of screen
                scrollYDelta += (rect.bottom - listUnfadedBottom);
            }

            // make sure we aren't scrolling beyond the end of our children
            int distanceToBottom = bottomOfBottomChild - listUnfadedBottom;
            scrollYDelta = Math.min(scrollYDelta, distanceToBottom);
        } else if (rect.top < listUnfadedTop && rect.bottom < listUnfadedBottom) {
            // need to MOVE UP to get it in view: move up just enough so that
            // entire rectangle is in view (or at least the first screen
            // size chunk of it).

            if (rect.height() > height) {
                // screen size chunk
                scrollYDelta -= (listUnfadedBottom - rect.bottom);
            } else {
                // entire rect at top
                scrollYDelta -= (listUnfadedTop - rect.top);
            }

            // make sure we aren't scrolling any further than the top our children
            int top = getChildAt(0).getTop();
            int deltaToTop = top - listUnfadedTop;
            scrollYDelta = Math.max(scrollYDelta, deltaToTop);
        }

        final boolean scroll = scrollYDelta != 0;
        if (scroll) {
            scrollListItemsBy(-scrollYDelta);
            positionSelector(child);
            mSelectedTop = child.getTop();
            invalidate();
        }
        return scroll;
    
voidresetList()
The list is empty. Clear everything out.

        super.resetList();
        mLayoutMode = LAYOUT_NORMAL;
    
private voidscrollListItemsBy(int amount)
Scroll the children by amount, adding a view at the end and removing views that fall off as necessary.

param
amount The amount (positive or negative) to scroll.

        offsetChildrenTopAndBottom(amount);

        final int listBottom = getHeight() - mListPadding.bottom;
        final int listTop = mListPadding.top;
        final AbsListView.RecycleBin recycleBin = mRecycler;

        if (amount < 0) {
            // shifted items up

            // may need to pan views into the bottom space
            int numChildren = getChildCount();
            View last = getChildAt(numChildren - 1);
            while (last.getBottom() < listBottom) {
                final int lastVisiblePosition = mFirstPosition + numChildren - 1;
                if (lastVisiblePosition < mItemCount - 1) {
                    last = addViewBelow(last, lastVisiblePosition);
                    numChildren++;
                } else {
                    break;
                }
            }

            // may have brought in the last child of the list that is skinnier
            // than the fading edge, thereby leaving space at the end.  need
            // to shift back
            if (last.getBottom() < listBottom) {
                offsetChildrenTopAndBottom(listBottom - last.getBottom());
            }

            // top views may be panned off screen
            View first = getChildAt(0);
            while (first.getBottom() < listTop) {
                AbsListView.LayoutParams layoutParams = (LayoutParams) first.getLayoutParams();
                if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) {
                    removeViewInLayout(first);
                    recycleBin.addScrapView(first);
                } else {
                    detachViewFromParent(first);
                }
                first = getChildAt(0);
                mFirstPosition++;
            }
        } else {
            // shifted items down
            View first = getChildAt(0);

            // may need to pan views into top
            while ((first.getTop() > listTop) && (mFirstPosition > 0)) {
                first = addViewAbove(first, mFirstPosition);
                mFirstPosition--;
            }

            // may have brought the very first child of the list in too far and
            // need to shift it back
            if (first.getTop() > listTop) {
                offsetChildrenTopAndBottom(listTop - first.getTop());
            }

            int lastIndex = getChildCount() - 1;
            View last = getChildAt(lastIndex);

            // bottom view may be panned off screen
            while (last.getTop() > listBottom) {
                AbsListView.LayoutParams layoutParams = (LayoutParams) last.getLayoutParams();
                if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) {
                    removeViewInLayout(last);
                    recycleBin.addScrapView(last);
                } else {
                    detachViewFromParent(last);
                }
                last = getChildAt(--lastIndex);
            }
        }
    
public voidsetAdapter(ListAdapter adapter)
Sets the data behind this ListView. The adapter passed to this method may be wrapped by a {@link WrapperListAdapter}, depending on the ListView features currently in use. For instance, adding headers and/or footers will cause the adapter to be wrapped.

param
adapter The ListAdapter which is responsible for maintaining the data backing this list and for producing a view to represent an item in that data set.
see
#getAdapter()

        if (null != mAdapter) {
            mAdapter.unregisterDataSetObserver(mDataSetObserver);
        }

        resetList();
        mRecycler.clear();

        if (mHeaderViewInfos.size() > 0|| mFooterViewInfos.size() > 0) {
            mAdapter = new HeaderViewListAdapter(mHeaderViewInfos, mFooterViewInfos, adapter);
        } else {
            mAdapter = adapter;
        }

        mOldSelectedPosition = INVALID_POSITION;
        mOldSelectedRowId = INVALID_ROW_ID;
        if (mAdapter != null) {
            mAreAllItemsSelectable = mAdapter.areAllItemsEnabled();
            mOldItemCount = mItemCount;
            mItemCount = mAdapter.getCount();
            checkFocus();

            mDataSetObserver = new AdapterDataSetObserver();
            mAdapter.registerDataSetObserver(mDataSetObserver);

            mRecycler.setViewTypeCount(mAdapter.getViewTypeCount());

            int position;
            if (mStackFromBottom) {
                position = lookForSelectablePosition(mItemCount - 1, false);
            } else {
                position = lookForSelectablePosition(0, true);
            }
            setSelectedPositionInt(position);
            setNextSelectedPositionInt(position);

            if (mItemCount == 0) {
                // Nothing selected
                checkSelectionChanged();
            }

        } else {
            mAreAllItemsSelectable = true;
            checkFocus();
            // Nothing selected
            checkSelectionChanged();
        }

        if (mCheckStates != null) {
            mCheckStates.clear();
        }

        requestLayout();
    
public voidsetChoiceMode(int choiceMode)
Defines the choice behavior for the List. By default, Lists do not have any choice behavior ({@link #CHOICE_MODE_NONE}). By setting the choiceMode to {@link #CHOICE_MODE_SINGLE}, the List allows up to one item to be in a chosen state. By setting the choiceMode to {@link #CHOICE_MODE_MULTIPLE}, the list allows any number of items to be chosen.

param
choiceMode One of {@link #CHOICE_MODE_NONE}, {@link #CHOICE_MODE_SINGLE}, or {@link #CHOICE_MODE_MULTIPLE}

        mChoiceMode = choiceMode;
        if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates == null) {
            mCheckStates = new SparseBooleanArray();
        }
    
public voidsetDivider(android.graphics.drawable.Drawable divider)
Sets the drawable that will be drawn between each item in the list. If the drawable does not have an intrinsic height, you should also call {@link #setDividerHeight(int)}

param
divider The drawable to use.

        if (divider != null) {
            mDividerHeight = divider.getIntrinsicHeight();
            mClipDivider = divider instanceof ColorDrawable;
        } else {
            mDividerHeight = 0;
            mClipDivider = false;
        }
        mDivider = divider;
        requestLayoutIfNecessary();
    
public voidsetDividerHeight(int height)
Sets the height of the divider that will be drawn between each item in the list. Calling this will override the intrinsic height as set by {@link #setDivider(Drawable)}

param
height The new height of the divider in pixels.

        mDividerHeight = height;
        requestLayoutIfNecessary();
    
public voidsetFooterDividersEnabled(boolean footerDividersEnabled)
Enables or disables the drawing of the divider for footer views.

param
footerDividersEnabled True to draw the footers, false otherwise.
see
#setHeaderDividersEnabled(boolean)
see
#addFooterView(android.view.View)

        mFooterDividersEnabled = footerDividersEnabled;
        invalidate();
    
public voidsetHeaderDividersEnabled(boolean headerDividersEnabled)
Enables or disables the drawing of the divider for header views.

param
headerDividersEnabled True to draw the headers, false otherwise.
see
#setFooterDividersEnabled(boolean)
see
#addHeaderView(android.view.View)

        mHeaderDividersEnabled = headerDividersEnabled;
        invalidate();
    
public voidsetItemChecked(int position, boolean value)
Sets the checked state of the specified position. The is only valid if the choice mode has been set to {@link #CHOICE_MODE_SINGLE} or {@link #CHOICE_MODE_MULTIPLE}.

param
position The item whose checked state is to be checked
param
value The new checked sate for the item

        if (mChoiceMode == CHOICE_MODE_NONE) {
            return;
        }

        if (mChoiceMode == CHOICE_MODE_MULTIPLE) {
            mCheckStates.put(position, value);
        } else {
            boolean oldValue = mCheckStates.get(position, false);
            mCheckStates.clear();
            if (!oldValue) {
                mCheckStates.put(position, true);
            }
        }

        // Do not generate a data change while we are in the layout phase
        if (!mInLayout && !mBlockLayoutRequests) {
            mDataChanged = true;
            rememberSyncState();
            requestLayout();
        }
    
public voidsetItemsCanFocus(boolean itemsCanFocus)
Indicates that the views created by the ListAdapter can contain focusable items.

param
itemsCanFocus true if items can get focus, false otherwise

        mItemsCanFocus = itemsCanFocus;
        if (!itemsCanFocus) {
            setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS);
        }
    
public voidsetSelection(int position)
Sets the currently selected item. If in touch mode, the item will not be selected but it will still be positioned appropriately. If the specified selection position is less than 0, then the item at position 0 will be selected.

param
position Index (starting at 0) of the data item to be selected.

        setSelectionFromTop(position, 0);
    
public voidsetSelectionAfterHeaderView()
setSelectionAfterHeaderView set the selection to be the first list item after the header views.

        final int count = mHeaderViewInfos.size();
        if (count > 0) {
            mNextSelectedPosition = 0;
            return;
        }

        if (mAdapter != null) {
            setSelection(count);
        } else {
            mNextSelectedPosition = count;
            mLayoutMode = LAYOUT_SET_SELECTION;
        }

    
public voidsetSelectionFromTop(int position, int y)
Sets the selected item and positions the selection y pixels from the top edge of the ListView. (If in touch mode, the item will not be selected but it will still be positioned appropriately.)

param
position Index (starting at 0) of the data item to be selected.
param
y The distance from the top edge of the ListView (plus padding) that the item will be positioned.

        if (mAdapter == null) {
            return;
        }

        if (!isInTouchMode()) {
            position = lookForSelectablePosition(position, true);
            if (position >= 0) {
                setNextSelectedPositionInt(position);
            }
        } else {
            mResurrectToPosition = position;
        }

        if (position >= 0) {
            mLayoutMode = LAYOUT_SPECIFIC;
            mSpecificTop = mListPadding.top + y;

            if (mNeedSync) {
                mSyncPosition = position;
                mSyncRowId = mAdapter.getItemId(position);
            }

            requestLayout();
        }
    
voidsetSelectionInt(int position)
Makes the item at the supplied position selected.

param
position the position of the item to select

        setNextSelectedPositionInt(position);
        layoutChildren();
    
private voidsetupChild(android.view.View child, int position, int y, boolean flowDown, int childrenLeft, boolean selected, boolean recycled)
Add a view as a child and make sure it is measured (if necessary) and positioned properly.

param
child The view to add
param
position The position of this child
param
y The y position relative to which this view will be positioned
param
flowDown If true, align top edge to y. If false, align bottom edge to y.
param
childrenLeft Left edge where children should be positioned
param
selected Is this position selected?
param
recycled Has this view been pulled from the recycle bin? If so it does not need to be remeasured.

        final boolean isSelected = selected && shouldShowSelector();
        final boolean updateChildSelected = isSelected != child.isSelected();
        final boolean needToMeasure = !recycled || updateChildSelected || child.isLayoutRequested();

        // Respect layout params that are already in the view. Otherwise make some up...
        // noinspection unchecked
        AbsListView.LayoutParams p = (AbsListView.LayoutParams) child.getLayoutParams();
        if (p == null) {
            p = new AbsListView.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT,
                    ViewGroup.LayoutParams.WRAP_CONTENT, 0);
        }
        p.viewType = mAdapter.getItemViewType(position);

        if (recycled || (p.recycledHeaderFooter &&
                p.viewType == AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER)) {
            attachViewToParent(child, flowDown ? -1 : 0, p);
        } else {
            if (p.viewType == AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER) {
                p.recycledHeaderFooter = true;
            }
            addViewInLayout(child, flowDown ? -1 : 0, p, true);
        }

        if (updateChildSelected) {
            child.setSelected(isSelected);
        }

        if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null) {
            if (child instanceof Checkable) {
                ((Checkable) child).setChecked(mCheckStates.get(position));
            }
        }

        if (needToMeasure) {
            int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec,
                    mListPadding.left + mListPadding.right, p.width);
            int lpHeight = p.height;
            int childHeightSpec;
            if (lpHeight > 0) {
                childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY);
            } else {
                childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
            }
            child.measure(childWidthSpec, childHeightSpec);
        } else {
            cleanupLayoutState(child);
        }

        final int w = child.getMeasuredWidth();
        final int h = child.getMeasuredHeight();
        final int childTop = flowDown ? y : y - h;

        if (needToMeasure) {
            final int childRight = childrenLeft + w;
            final int childBottom = childTop + h;
            child.layout(childrenLeft, childTop, childRight, childBottom);
        } else {
            child.offsetLeftAndRight(childrenLeft - child.getLeft());
            child.offsetTopAndBottom(childTop - child.getTop());
        }

        if (mCachingStarted && !child.isDrawingCacheEnabled()) {
            child.setDrawingCacheEnabled(true);
        }
    
private booleanshowingBottomFadingEdge()

return
Whether the list needs to show the bottom fading edge

        final int childCount = getChildCount();
        final int bottomOfBottomChild = getChildAt(childCount - 1).getBottom();
        final int lastVisiblePosition = mFirstPosition + childCount - 1;

        final int listBottom = mScrollY + getHeight() - mListPadding.bottom;

        return (lastVisiblePosition < mItemCount - 1)
                         || (bottomOfBottomChild < listBottom);
    
private booleanshowingTopFadingEdge()

return
Whether the list needs to show the top fading edge

        final int listTop = mScrollY + mListPadding.top;
        return (mFirstPosition > 0) || (getChildAt(0).getTop() > listTop);