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SlidingPaneLayout.javaAPI DocAndroid 5.1 API61259Thu Mar 12 22:22:56 GMT 2015android.support.v4.widget

SlidingPaneLayout

public class SlidingPaneLayout extends android.view.ViewGroup
SlidingPaneLayout provides a horizontal, multi-pane layout for use at the top level of a UI. A left (or first) pane is treated as a content list or browser, subordinate to a primary detail view for displaying content.

Child views may overlap if their combined width exceeds the available width in the SlidingPaneLayout. When this occurs the user may slide the topmost view out of the way by dragging it, or by navigating in the direction of the overlapped view using a keyboard. If the content of the dragged child view is itself horizontally scrollable, the user may grab it by the very edge.

Thanks to this sliding behavior, SlidingPaneLayout may be suitable for creating layouts that can smoothly adapt across many different screen sizes, expanding out fully on larger screens and collapsing on smaller screens.

SlidingPaneLayout is distinct from a navigation drawer as described in the design guide and should not be used in the same scenarios. SlidingPaneLayout should be thought of only as a way to allow a two-pane layout normally used on larger screens to adapt to smaller screens in a natural way. The interaction patterns expressed by SlidingPaneLayout imply a physicality and direct information hierarchy between panes that does not necessarily exist in a scenario where a navigation drawer should be used instead.

Appropriate uses of SlidingPaneLayout include pairings of panes such as a contact list and subordinate interactions with those contacts, or an email thread list with the content pane displaying the contents of the selected thread. Inappropriate uses of SlidingPaneLayout include switching between disparate functions of your app, such as jumping from a social stream view to a view of your personal profile - cases such as this should use the navigation drawer pattern instead. ({@link DrawerLayout DrawerLayout} implements this pattern.)

Like {@link android.widget.LinearLayout LinearLayout}, SlidingPaneLayout supports the use of the layout parameter layout_weight on child views to determine how to divide leftover space after measurement is complete. It is only relevant for width. When views do not overlap weight behaves as it does in a LinearLayout.

When views do overlap, weight on a slideable pane indicates that the pane should be sized to fill all available space in the closed state. Weight on a pane that becomes covered indicates that the pane should be sized to fill all available space except a small minimum strip that the user may use to grab the slideable view and pull it back over into a closed state.

Fields Summary
private static final String
TAG
private static final int
DEFAULT_OVERHANG_SIZE
Default size of the overhang for a pane in the open state. At least this much of a sliding pane will remain visible. This indicates that there is more content available and provides a "physical" edge to grab to pull it closed.
private static final int
DEFAULT_FADE_COLOR
If no fade color is given by default it will fade to 80% gray.
private int
mSliderFadeColor
The fade color used for the sliding panel. 0 = no fading.
private static final int
MIN_FLING_VELOCITY
Minimum velocity that will be detected as a fling
private int
mCoveredFadeColor
The fade color used for the panel covered by the slider. 0 = no fading.
private android.graphics.drawable.Drawable
mShadowDrawableLeft
Drawable used to draw the shadow between panes by default.
private android.graphics.drawable.Drawable
mShadowDrawableRight
Drawable used to draw the shadow between panes to support RTL (right to left language).
private final int
mOverhangSize
The size of the overhang in pixels. This is the minimum section of the sliding panel that will be visible in the open state to allow for a closing drag.
private boolean
mCanSlide
True if a panel can slide with the current measurements
private android.view.View
mSlideableView
The child view that can slide, if any.
private float
mSlideOffset
How far the panel is offset from its closed position. range [0, 1] where 0 = closed, 1 = open.
private float
mParallaxOffset
How far the non-sliding panel is parallaxed from its usual position when open. range [0, 1]
private int
mSlideRange
How far in pixels the slideable panel may move.
private boolean
mIsUnableToDrag
A panel view is locked into internal scrolling or another condition that is preventing a drag.
private int
mParallaxBy
Distance in pixels to parallax the fixed pane by when fully closed
private float
mInitialMotionX
private float
mInitialMotionY
private PanelSlideListener
mPanelSlideListener
private final ViewDragHelper
mDragHelper
private boolean
mPreservedOpenState
Stores whether or not the pane was open the last time it was slideable. If open/close operations are invoked this state is modified. Used by instance state save/restore.
private boolean
mFirstLayout
private final android.graphics.Rect
mTmpRect
private final ArrayList
mPostedRunnables
static final SlidingPanelLayoutImpl
IMPL
Constructors Summary
public SlidingPaneLayout(android.content.Context context)

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

        this(context, attrs, 0);
public SlidingPaneLayout(android.content.Context context, android.util.AttributeSet attrs, int defStyle)

        super(context, attrs, defStyle);

        final float density = context.getResources().getDisplayMetrics().density;
        mOverhangSize = (int) (DEFAULT_OVERHANG_SIZE * density + 0.5f);

        final ViewConfiguration viewConfig = ViewConfiguration.get(context);

        setWillNotDraw(false);

        ViewCompat.setAccessibilityDelegate(this, new AccessibilityDelegate());
        ViewCompat.setImportantForAccessibility(this, ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_YES);

        mDragHelper = ViewDragHelper.create(this, 0.5f, new DragHelperCallback());
        mDragHelper.setMinVelocity(MIN_FLING_VELOCITY * density);
Methods Summary
protected booleancanScroll(android.view.View v, boolean checkV, int dx, int x, int y)
Tests scrollability within child views of v given a delta of dx.

param
v View to test for horizontal scrollability
param
checkV Whether the view v passed should itself be checked for scrollability (true), or just its children (false).
param
dx Delta scrolled in pixels
param
x X coordinate of the active touch point
param
y Y coordinate of the active touch point
return
true if child views of v can be scrolled by delta of dx.

        if (v instanceof ViewGroup) {
            final ViewGroup group = (ViewGroup) v;
            final int scrollX = v.getScrollX();
            final int scrollY = v.getScrollY();
            final int count = group.getChildCount();
            // Count backwards - let topmost views consume scroll distance first.
            for (int i = count - 1; i >= 0; i--) {
                // TODO: Add versioned support here for transformed views.
                // This will not work for transformed views in Honeycomb+
                final View child = group.getChildAt(i);
                if (x + scrollX >= child.getLeft() && x + scrollX < child.getRight() &&
                        y + scrollY >= child.getTop() && y + scrollY < child.getBottom() &&
                        canScroll(child, true, dx, x + scrollX - child.getLeft(),
                                y + scrollY - child.getTop())) {
                    return true;
                }
            }
        }

        return checkV && ViewCompat.canScrollHorizontally(v, (isLayoutRtlSupport() ? dx : -dx));
public booleancanSlide()

return
true if content in this layout can be slid open and closed
deprecated
Renamed to {@link #isSlideable()} - this method is going away soon!

        return mCanSlide;
protected booleancheckLayoutParams(ViewGroup.LayoutParams p)

        return p instanceof LayoutParams && super.checkLayoutParams(p);
private booleanclosePane(android.view.View pane, int initialVelocity)

        if (mFirstLayout || smoothSlideTo(0.f, initialVelocity)) {
            mPreservedOpenState = false;
            return true;
        }
        return false;
public booleanclosePane()
Close the sliding pane if it is currently slideable. If first layout has already completed this will animate.

return
true if the pane was slideable and is now closed/in the process of closing

        return closePane(mSlideableView, 0);
public voidcomputeScroll()

        if (mDragHelper.continueSettling(true)) {
            if (!mCanSlide) {
                mDragHelper.abort();
                return;
            }

            ViewCompat.postInvalidateOnAnimation(this);
        }
private voiddimChildView(android.view.View v, float mag, int fadeColor)

        final LayoutParams lp = (LayoutParams) v.getLayoutParams();

        if (mag > 0 && fadeColor != 0) {
            final int baseAlpha = (fadeColor & 0xff000000) >>> 24;
            int imag = (int) (baseAlpha * mag);
            int color = imag << 24 | (fadeColor & 0xffffff);
            if (lp.dimPaint == null) {
                lp.dimPaint = new Paint();
            }
            lp.dimPaint.setColorFilter(new PorterDuffColorFilter(color, PorterDuff.Mode.SRC_OVER));
            if (ViewCompat.getLayerType(v) != ViewCompat.LAYER_TYPE_HARDWARE) {
                ViewCompat.setLayerType(v, ViewCompat.LAYER_TYPE_HARDWARE, lp.dimPaint);
            }
            invalidateChildRegion(v);
        } else if (ViewCompat.getLayerType(v) != ViewCompat.LAYER_TYPE_NONE) {
            if (lp.dimPaint != null) {
                lp.dimPaint.setColorFilter(null);
            }
            final DisableLayerRunnable dlr = new DisableLayerRunnable(v);
            mPostedRunnables.add(dlr);
            ViewCompat.postOnAnimation(this, dlr);
        }
voiddispatchOnPanelClosed(android.view.View panel)

        if (mPanelSlideListener != null) {
            mPanelSlideListener.onPanelClosed(panel);
        }
        sendAccessibilityEvent(AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED);
voiddispatchOnPanelOpened(android.view.View panel)

        if (mPanelSlideListener != null) {
            mPanelSlideListener.onPanelOpened(panel);
        }
        sendAccessibilityEvent(AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED);
voiddispatchOnPanelSlide(android.view.View panel)

        if (mPanelSlideListener != null) {
            mPanelSlideListener.onPanelSlide(panel, mSlideOffset);
        }
public voiddraw(android.graphics.Canvas c)

        super.draw(c);
        final boolean isLayoutRtl = isLayoutRtlSupport();
        Drawable shadowDrawable;
        if (isLayoutRtl) {
            shadowDrawable = mShadowDrawableRight;
        } else {
            shadowDrawable = mShadowDrawableLeft;
        }

        final View shadowView = getChildCount() > 1 ? getChildAt(1) : null;
        if (shadowView == null || shadowDrawable == null) {
            // No need to draw a shadow if we don't have one.
            return;
        }

        final int top = shadowView.getTop();
        final int bottom = shadowView.getBottom();

        final int shadowWidth = shadowDrawable.getIntrinsicWidth();
        final int left;
        final int right;
        if (isLayoutRtlSupport()) {
            left = shadowView.getRight();
            right = left + shadowWidth;
        } else {
            right = shadowView.getLeft();
            left = right - shadowWidth;
        }

        shadowDrawable.setBounds(left, top, right, bottom);
        shadowDrawable.draw(c);
protected booleandrawChild(android.graphics.Canvas canvas, android.view.View child, long drawingTime)

        final LayoutParams lp = (LayoutParams) child.getLayoutParams();
        boolean result;
        final int save = canvas.save(Canvas.CLIP_SAVE_FLAG);

        if (mCanSlide && !lp.slideable && mSlideableView != null) {
            // Clip against the slider; no sense drawing what will immediately be covered.
            canvas.getClipBounds(mTmpRect);
            if (isLayoutRtlSupport()) {
                mTmpRect.left = Math.max(mTmpRect.left, mSlideableView.getRight());
            } else {
                mTmpRect.right = Math.min(mTmpRect.right, mSlideableView.getLeft());
            }
            canvas.clipRect(mTmpRect);
        }

        if (Build.VERSION.SDK_INT >= 11) { // HC
            result = super.drawChild(canvas, child, drawingTime);
        } else {
            if (lp.dimWhenOffset && mSlideOffset > 0) {
                if (!child.isDrawingCacheEnabled()) {
                    child.setDrawingCacheEnabled(true);
                }
                final Bitmap cache = child.getDrawingCache();
                if (cache != null) {
                    canvas.drawBitmap(cache, child.getLeft(), child.getTop(), lp.dimPaint);
                    result = false;
                } else {
                    Log.e(TAG, "drawChild: child view " + child + " returned null drawing cache");
                    result = super.drawChild(canvas, child, drawingTime);
                }
            } else {
                if (child.isDrawingCacheEnabled()) {
                    child.setDrawingCacheEnabled(false);
                }
                result = super.drawChild(canvas, child, drawingTime);
            }
        }

        canvas.restoreToCount(save);

        return result;
protected ViewGroup.LayoutParamsgenerateDefaultLayoutParams()

        return new LayoutParams();
protected ViewGroup.LayoutParamsgenerateLayoutParams(ViewGroup.LayoutParams p)

        return p instanceof MarginLayoutParams
                ? new LayoutParams((MarginLayoutParams) p)
                : new LayoutParams(p);
public ViewGroup.LayoutParamsgenerateLayoutParams(android.util.AttributeSet attrs)

        return new LayoutParams(getContext(), attrs);
public intgetCoveredFadeColor()

return
The ARGB-packed color value used to fade the fixed pane

        return mCoveredFadeColor;
public intgetParallaxDistance()

return
The distance the lower pane will parallax by when the upper pane is fully closed.
see
#setParallaxDistance(int)

        return mParallaxBy;
public intgetSliderFadeColor()

return
The ARGB-packed color value used to fade the sliding pane

        return mSliderFadeColor;
private voidinvalidateChildRegion(android.view.View v)

        IMPL.invalidateChildRegion(this, v);
booleanisDimmed(android.view.View child)

        if (child == null) {
            return false;
        }
        final LayoutParams lp = (LayoutParams) child.getLayoutParams();
        return mCanSlide && lp.dimWhenOffset && mSlideOffset > 0;
private booleanisLayoutRtlSupport()

        return ViewCompat.getLayoutDirection(this) == ViewCompat.LAYOUT_DIRECTION_RTL;
public booleanisOpen()
Check if the layout is completely open. It can be open either because the slider itself is open revealing the left pane, or if all content fits without sliding.

return
true if sliding panels are completely open

        return !mCanSlide || mSlideOffset == 1;
public booleanisSlideable()
Check if the content in this layout cannot fully fit side by side and therefore the content pane can be slid back and forth.

return
true if content in this layout can be slid open and closed

        return mCanSlide;
protected voidonAttachedToWindow()

        super.onAttachedToWindow();
        mFirstLayout = true;
protected voidonDetachedFromWindow()

        super.onDetachedFromWindow();
        mFirstLayout = true;

        for (int i = 0, count = mPostedRunnables.size(); i < count; i++) {
            final DisableLayerRunnable dlr = mPostedRunnables.get(i);
            dlr.run();
        }
        mPostedRunnables.clear();
public booleanonInterceptTouchEvent(android.view.MotionEvent ev)

        final int action = MotionEventCompat.getActionMasked(ev);

        // Preserve the open state based on the last view that was touched.
        if (!mCanSlide && action == MotionEvent.ACTION_DOWN && getChildCount() > 1) {
            // After the first things will be slideable.
            final View secondChild = getChildAt(1);
            if (secondChild != null) {
                mPreservedOpenState = !mDragHelper.isViewUnder(secondChild,
                        (int) ev.getX(), (int) ev.getY());
            }
        }

        if (!mCanSlide || (mIsUnableToDrag && action != MotionEvent.ACTION_DOWN)) {
            mDragHelper.cancel();
            return super.onInterceptTouchEvent(ev);
        }

        if (action == MotionEvent.ACTION_CANCEL || action == MotionEvent.ACTION_UP) {
            mDragHelper.cancel();
            return false;
        }

        boolean interceptTap = false;

        switch (action) {
            case MotionEvent.ACTION_DOWN: {
                mIsUnableToDrag = false;
                final float x = ev.getX();
                final float y = ev.getY();
                mInitialMotionX = x;
                mInitialMotionY = y;

                if (mDragHelper.isViewUnder(mSlideableView, (int) x, (int) y) &&
                        isDimmed(mSlideableView)) {
                    interceptTap = true;
                }
                break;
            }

            case MotionEvent.ACTION_MOVE: {
                final float x = ev.getX();
                final float y = ev.getY();
                final float adx = Math.abs(x - mInitialMotionX);
                final float ady = Math.abs(y - mInitialMotionY);
                final int slop = mDragHelper.getTouchSlop();
                if (adx > slop && ady > adx) {
                    mDragHelper.cancel();
                    mIsUnableToDrag = true;
                    return false;
                }
            }
        }

        final boolean interceptForDrag = mDragHelper.shouldInterceptTouchEvent(ev);

        return interceptForDrag || interceptTap;
protected voidonLayout(boolean changed, int l, int t, int r, int b)

        final boolean isLayoutRtl = isLayoutRtlSupport();
        if (isLayoutRtl) {
            mDragHelper.setEdgeTrackingEnabled(ViewDragHelper.EDGE_RIGHT);
        } else {
            mDragHelper.setEdgeTrackingEnabled(ViewDragHelper.EDGE_LEFT);
        }
        final int width = r - l;
        final int paddingStart = isLayoutRtl ? getPaddingRight() : getPaddingLeft();
        final int paddingEnd = isLayoutRtl ? getPaddingLeft() : getPaddingRight();
        final int paddingTop = getPaddingTop();

        final int childCount = getChildCount();
        int xStart = paddingStart;
        int nextXStart = xStart;

        if (mFirstLayout) {
            mSlideOffset = mCanSlide && mPreservedOpenState ? 1.f : 0.f;
        }

        for (int i = 0; i < childCount; i++) {
            final View child = getChildAt(i);

            if (child.getVisibility() == GONE) {
                continue;
            }

            final LayoutParams lp = (LayoutParams) child.getLayoutParams();

            final int childWidth = child.getMeasuredWidth();
            int offset = 0;

            if (lp.slideable) {
                final int margin = lp.leftMargin + lp.rightMargin;
                final int range = Math.min(nextXStart,
                        width - paddingEnd - mOverhangSize) - xStart - margin;
                mSlideRange = range;
                final int lpMargin = isLayoutRtl ? lp.rightMargin : lp.leftMargin;
                lp.dimWhenOffset = xStart + lpMargin + range + childWidth / 2 >
                        width - paddingEnd;
                final int pos = (int) (range * mSlideOffset);
                xStart += pos + lpMargin;
                mSlideOffset = (float) pos / mSlideRange;
            } else if (mCanSlide && mParallaxBy != 0) {
                offset = (int) ((1 - mSlideOffset) * mParallaxBy);
                xStart = nextXStart;
            } else {
                xStart = nextXStart;
            }

            final int childRight;
            final int childLeft;
            if (isLayoutRtl) {
                childRight = width - xStart + offset;
                childLeft = childRight - childWidth;
            } else {
                childLeft = xStart - offset;
                childRight = childLeft + childWidth;
            }

            final int childTop = paddingTop;
            final int childBottom = childTop + child.getMeasuredHeight();
            child.layout(childLeft, paddingTop, childRight, childBottom);

            nextXStart += child.getWidth();
        }

        if (mFirstLayout) {
            if (mCanSlide) {
                if (mParallaxBy != 0) {
                    parallaxOtherViews(mSlideOffset);
                }
                if (((LayoutParams) mSlideableView.getLayoutParams()).dimWhenOffset) {
                    dimChildView(mSlideableView, mSlideOffset, mSliderFadeColor);
                }
            } else {
                // Reset the dim level of all children; it's irrelevant when nothing moves.
                for (int i = 0; i < childCount; i++) {
                    dimChildView(getChildAt(i), 0, mSliderFadeColor);
                }
            }
            updateObscuredViewsVisibility(mSlideableView);
        }

        mFirstLayout = false;
protected voidonMeasure(int widthMeasureSpec, int heightMeasureSpec)

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

        if (widthMode != MeasureSpec.EXACTLY) {
            if (isInEditMode()) {
                // Don't crash the layout editor. Consume all of the space if specified
                // or pick a magic number from thin air otherwise.
                // TODO Better communication with tools of this bogus state.
                // It will crash on a real device.
                if (widthMode == MeasureSpec.AT_MOST) {
                    widthMode = MeasureSpec.EXACTLY;
                } else if (widthMode == MeasureSpec.UNSPECIFIED) {
                    widthMode = MeasureSpec.EXACTLY;
                    widthSize = 300;
                }
            } else {
                throw new IllegalStateException("Width must have an exact value or MATCH_PARENT");
            }
        } else if (heightMode == MeasureSpec.UNSPECIFIED) {
            if (isInEditMode()) {
                // Don't crash the layout editor. Pick a magic number from thin air instead.
                // TODO Better communication with tools of this bogus state.
                // It will crash on a real device.
                if (heightMode == MeasureSpec.UNSPECIFIED) {
                    heightMode = MeasureSpec.AT_MOST;
                    heightSize = 300;
                }
            } else {
                throw new IllegalStateException("Height must not be UNSPECIFIED");
            }
        }

        int layoutHeight = 0;
        int maxLayoutHeight = -1;
        switch (heightMode) {
            case MeasureSpec.EXACTLY:
                layoutHeight = maxLayoutHeight = heightSize - getPaddingTop() - getPaddingBottom();
                break;
            case MeasureSpec.AT_MOST:
                maxLayoutHeight = heightSize - getPaddingTop() - getPaddingBottom();
                break;
        }

        float weightSum = 0;
        boolean canSlide = false;
        final int widthAvailable = widthSize - getPaddingLeft() - getPaddingRight();
        int widthRemaining = widthAvailable;
        final int childCount = getChildCount();

        if (childCount > 2) {
            Log.e(TAG, "onMeasure: More than two child views are not supported.");
        }

        // We'll find the current one below.
        mSlideableView = null;

        // First pass. Measure based on child LayoutParams width/height.
        // Weight will incur a second pass.
        for (int i = 0; i < childCount; i++) {
            final View child = getChildAt(i);
            final LayoutParams lp = (LayoutParams) child.getLayoutParams();

            if (child.getVisibility() == GONE) {
                lp.dimWhenOffset = false;
                continue;
            }

            if (lp.weight > 0) {
                weightSum += lp.weight;

                // If we have no width, weight is the only contributor to the final size.
                // Measure this view on the weight pass only.
                if (lp.width == 0) continue;
            }

            int childWidthSpec;
            final int horizontalMargin = lp.leftMargin + lp.rightMargin;
            if (lp.width == LayoutParams.WRAP_CONTENT) {
                childWidthSpec = MeasureSpec.makeMeasureSpec(widthAvailable - horizontalMargin,
                        MeasureSpec.AT_MOST);
            } else if (lp.width == LayoutParams.FILL_PARENT) {
                childWidthSpec = MeasureSpec.makeMeasureSpec(widthAvailable - horizontalMargin,
                        MeasureSpec.EXACTLY);
            } else {
                childWidthSpec = MeasureSpec.makeMeasureSpec(lp.width, MeasureSpec.EXACTLY);
            }

            int childHeightSpec;
            if (lp.height == LayoutParams.WRAP_CONTENT) {
                childHeightSpec = MeasureSpec.makeMeasureSpec(maxLayoutHeight, MeasureSpec.AT_MOST);
            } else if (lp.height == LayoutParams.FILL_PARENT) {
                childHeightSpec = MeasureSpec.makeMeasureSpec(maxLayoutHeight, MeasureSpec.EXACTLY);
            } else {
                childHeightSpec = MeasureSpec.makeMeasureSpec(lp.height, MeasureSpec.EXACTLY);
            }

            child.measure(childWidthSpec, childHeightSpec);
            final int childWidth = child.getMeasuredWidth();
            final int childHeight = child.getMeasuredHeight();

            if (heightMode == MeasureSpec.AT_MOST && childHeight > layoutHeight) {
                layoutHeight = Math.min(childHeight, maxLayoutHeight);
            }

            widthRemaining -= childWidth;
            canSlide |= lp.slideable = widthRemaining < 0;
            if (lp.slideable) {
                mSlideableView = child;
            }
        }

        // Resolve weight and make sure non-sliding panels are smaller than the full screen.
        if (canSlide || weightSum > 0) {
            final int fixedPanelWidthLimit = widthAvailable - mOverhangSize;

            for (int i = 0; i < childCount; i++) {
                final View child = getChildAt(i);

                if (child.getVisibility() == GONE) {
                    continue;
                }

                final LayoutParams lp = (LayoutParams) child.getLayoutParams();

                if (child.getVisibility() == GONE) {
                    continue;
                }

                final boolean skippedFirstPass = lp.width == 0 && lp.weight > 0;
                final int measuredWidth = skippedFirstPass ? 0 : child.getMeasuredWidth();
                if (canSlide && child != mSlideableView) {
                    if (lp.width < 0 && (measuredWidth > fixedPanelWidthLimit || lp.weight > 0)) {
                        // Fixed panels in a sliding configuration should
                        // be clamped to the fixed panel limit.
                        final int childHeightSpec;
                        if (skippedFirstPass) {
                            // Do initial height measurement if we skipped measuring this view
                            // the first time around.
                            if (lp.height == LayoutParams.WRAP_CONTENT) {
                                childHeightSpec = MeasureSpec.makeMeasureSpec(maxLayoutHeight,
                                        MeasureSpec.AT_MOST);
                            } else if (lp.height == LayoutParams.FILL_PARENT) {
                                childHeightSpec = MeasureSpec.makeMeasureSpec(maxLayoutHeight,
                                        MeasureSpec.EXACTLY);
                            } else {
                                childHeightSpec = MeasureSpec.makeMeasureSpec(lp.height,
                                        MeasureSpec.EXACTLY);
                            }
                        } else {
                            childHeightSpec = MeasureSpec.makeMeasureSpec(
                                    child.getMeasuredHeight(), MeasureSpec.EXACTLY);
                        }
                        final int childWidthSpec = MeasureSpec.makeMeasureSpec(
                                fixedPanelWidthLimit, MeasureSpec.EXACTLY);
                        child.measure(childWidthSpec, childHeightSpec);
                    }
                } else if (lp.weight > 0) {
                    int childHeightSpec;
                    if (lp.width == 0) {
                        // This was skipped the first time; figure out a real height spec.
                        if (lp.height == LayoutParams.WRAP_CONTENT) {
                            childHeightSpec = MeasureSpec.makeMeasureSpec(maxLayoutHeight,
                                    MeasureSpec.AT_MOST);
                        } else if (lp.height == LayoutParams.FILL_PARENT) {
                            childHeightSpec = MeasureSpec.makeMeasureSpec(maxLayoutHeight,
                                    MeasureSpec.EXACTLY);
                        } else {
                            childHeightSpec = MeasureSpec.makeMeasureSpec(lp.height,
                                    MeasureSpec.EXACTLY);
                        }
                    } else {
                        childHeightSpec = MeasureSpec.makeMeasureSpec(
                                child.getMeasuredHeight(), MeasureSpec.EXACTLY);
                    }

                    if (canSlide) {
                        // Consume available space
                        final int horizontalMargin = lp.leftMargin + lp.rightMargin;
                        final int newWidth = widthAvailable - horizontalMargin;
                        final int childWidthSpec = MeasureSpec.makeMeasureSpec(
                                newWidth, MeasureSpec.EXACTLY);
                        if (measuredWidth != newWidth) {
                            child.measure(childWidthSpec, childHeightSpec);
                        }
                    } else {
                        // Distribute the extra width proportionally similar to LinearLayout
                        final int widthToDistribute = Math.max(0, widthRemaining);
                        final int addedWidth = (int) (lp.weight * widthToDistribute / weightSum);
                        final int childWidthSpec = MeasureSpec.makeMeasureSpec(
                                measuredWidth + addedWidth, MeasureSpec.EXACTLY);
                        child.measure(childWidthSpec, childHeightSpec);
                    }
                }
            }
        }

        final int measuredWidth = widthSize;
        final int measuredHeight = layoutHeight + getPaddingTop() + getPaddingBottom();

        setMeasuredDimension(measuredWidth, measuredHeight);
        mCanSlide = canSlide;

        if (mDragHelper.getViewDragState() != ViewDragHelper.STATE_IDLE && !canSlide) {
            // Cancel scrolling in progress, it's no longer relevant.
            mDragHelper.abort();
        }
private voidonPanelDragged(int newLeft)

        if (mSlideableView == null) {
            // This can happen if we're aborting motion during layout because everything now fits.
            mSlideOffset = 0;
            return;
        }
        final boolean isLayoutRtl = isLayoutRtlSupport();
        final LayoutParams lp = (LayoutParams) mSlideableView.getLayoutParams();

        int childWidth = mSlideableView.getWidth();
        final int newStart = isLayoutRtl ? getWidth() - newLeft - childWidth : newLeft;

        final int paddingStart = isLayoutRtl ? getPaddingRight() : getPaddingLeft();
        final int lpMargin = isLayoutRtl ? lp.rightMargin : lp.leftMargin;
        final int startBound = paddingStart + lpMargin;

        mSlideOffset = (float) (newStart - startBound) / mSlideRange;

        if (mParallaxBy != 0) {
            parallaxOtherViews(mSlideOffset);
        }

        if (lp.dimWhenOffset) {
            dimChildView(mSlideableView, mSlideOffset, mSliderFadeColor);
        }
        dispatchOnPanelSlide(mSlideableView);
protected voidonRestoreInstanceState(android.os.Parcelable state)

        SavedState ss = (SavedState) state;
        super.onRestoreInstanceState(ss.getSuperState());

        if (ss.isOpen) {
            openPane();
        } else {
            closePane();
        }
        mPreservedOpenState = ss.isOpen;
protected android.os.ParcelableonSaveInstanceState()

        Parcelable superState = super.onSaveInstanceState();

        SavedState ss = new SavedState(superState);
        ss.isOpen = isSlideable() ? isOpen() : mPreservedOpenState;

        return ss;
protected voidonSizeChanged(int w, int h, int oldw, int oldh)

        super.onSizeChanged(w, h, oldw, oldh);
        // Recalculate sliding panes and their details
        if (w != oldw) {
            mFirstLayout = true;
        }
public booleanonTouchEvent(android.view.MotionEvent ev)

        if (!mCanSlide) {
            return super.onTouchEvent(ev);
        }

        mDragHelper.processTouchEvent(ev);

        final int action = ev.getAction();
        boolean wantTouchEvents = true;

        switch (action & MotionEventCompat.ACTION_MASK) {
            case MotionEvent.ACTION_DOWN: {
                final float x = ev.getX();
                final float y = ev.getY();
                mInitialMotionX = x;
                mInitialMotionY = y;
                break;
            }

            case MotionEvent.ACTION_UP: {
                if (isDimmed(mSlideableView)) {
                    final float x = ev.getX();
                    final float y = ev.getY();
                    final float dx = x - mInitialMotionX;
                    final float dy = y - mInitialMotionY;
                    final int slop = mDragHelper.getTouchSlop();
                    if (dx * dx + dy * dy < slop * slop &&
                            mDragHelper.isViewUnder(mSlideableView, (int) x, (int) y)) {
                        // Taps close a dimmed open pane.
                        closePane(mSlideableView, 0);
                        break;
                    }
                }
                break;
            }
        }

        return wantTouchEvents;
private booleanopenPane(android.view.View pane, int initialVelocity)

        if (mFirstLayout || smoothSlideTo(1.f, initialVelocity)) {
            mPreservedOpenState = true;
            return true;
        }
        return false;
public booleanopenPane()
Open the sliding pane if it is currently slideable. If first layout has already completed this will animate.

return
true if the pane was slideable and is now open/in the process of opening

        return openPane(mSlideableView, 0);
private voidparallaxOtherViews(float slideOffset)

        final boolean isLayoutRtl = isLayoutRtlSupport();
        final LayoutParams slideLp = (LayoutParams) mSlideableView.getLayoutParams();
        final boolean dimViews = slideLp.dimWhenOffset &&
                (isLayoutRtl ? slideLp.rightMargin : slideLp.leftMargin) <= 0;
        final int childCount = getChildCount();
        for (int i = 0; i < childCount; i++) {
            final View v = getChildAt(i);
            if (v == mSlideableView) continue;

            final int oldOffset = (int) ((1 - mParallaxOffset) * mParallaxBy);
            mParallaxOffset = slideOffset;
            final int newOffset = (int) ((1 - slideOffset) * mParallaxBy);
            final int dx = oldOffset - newOffset;

            v.offsetLeftAndRight(isLayoutRtl ? -dx : dx);

            if (dimViews) {
                dimChildView(v, isLayoutRtl ? mParallaxOffset - 1 :
                    1 - mParallaxOffset, mCoveredFadeColor);
            }
        }
public voidrequestChildFocus(android.view.View child, android.view.View focused)

        super.requestChildFocus(child, focused);
        if (!isInTouchMode() && !mCanSlide) {
            mPreservedOpenState = child == mSlideableView;
        }
voidsetAllChildrenVisible()

        for (int i = 0, childCount = getChildCount(); i < childCount; i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() == INVISIBLE) {
                child.setVisibility(VISIBLE);
            }
        }
public voidsetCoveredFadeColor(int color)
Set the color used to fade the pane covered by the sliding pane out when the pane will become fully covered in the closed state.

param
color An ARGB-packed color value

        mCoveredFadeColor = color;
public voidsetPanelSlideListener(android.support.v4.widget.SlidingPaneLayout$PanelSlideListener listener)

        mPanelSlideListener = listener;
public voidsetParallaxDistance(int parallaxBy)
Set a distance to parallax the lower pane by when the upper pane is in its fully closed state. The lower pane will scroll between this position and its fully open state.

param
parallaxBy Distance to parallax by in pixels

        mParallaxBy = parallaxBy;
        requestLayout();
public voidsetShadowDrawable(android.graphics.drawable.Drawable d)

deprecated
Renamed to {@link #setShadowDrawableLeft(Drawable d)} to support LTR (left to right language) and {@link #setShadowDrawableRight(Drawable d)} to support RTL (right to left language) during opening/closing.
param
d drawable to use as a shadow

        setShadowDrawableLeft(d);
public voidsetShadowDrawableLeft(android.graphics.drawable.Drawable d)
Set a drawable to use as a shadow cast by the right pane onto the left pane during opening/closing.

param
d drawable to use as a shadow

        mShadowDrawableLeft = d;
public voidsetShadowDrawableRight(android.graphics.drawable.Drawable d)
Set a drawable to use as a shadow cast by the left pane onto the right pane during opening/closing to support right to left language.

param
d drawable to use as a shadow

        mShadowDrawableRight = d;
public voidsetShadowResource(int resId)
Set a drawable to use as a shadow cast by the right pane onto the left pane during opening/closing.

param
resId Resource ID of a drawable to use

        setShadowDrawable(getResources().getDrawable(resId));
public voidsetShadowResourceLeft(int resId)
Set a drawable to use as a shadow cast by the right pane onto the left pane during opening/closing.

param
resId Resource ID of a drawable to use

        setShadowDrawableLeft(getResources().getDrawable(resId));
public voidsetShadowResourceRight(int resId)
Set a drawable to use as a shadow cast by the left pane onto the right pane during opening/closing to support right to left language.

param
resId Resource ID of a drawable to use

        setShadowDrawableRight(getResources().getDrawable(resId));
public voidsetSliderFadeColor(int color)
Set the color used to fade the sliding pane out when it is slid most of the way offscreen.

param
color An ARGB-packed color value

        mSliderFadeColor = color;
public voidsmoothSlideClosed()

deprecated
Renamed to {@link #closePane()} - this method is going away soon!

        closePane();
public voidsmoothSlideOpen()

deprecated
Renamed to {@link #openPane()} - this method is going away soon!

        openPane();
booleansmoothSlideTo(float slideOffset, int velocity)
Smoothly animate mDraggingPane to the target X position within its range.

param
slideOffset position to animate to
param
velocity initial velocity in case of fling, or 0.

        if (!mCanSlide) {
            // Nothing to do.
            return false;
        }

        final boolean isLayoutRtl = isLayoutRtlSupport();
        final LayoutParams lp = (LayoutParams) mSlideableView.getLayoutParams();

        int x;
        if (isLayoutRtl) {
            int startBound = getPaddingRight() + lp.rightMargin;
            int childWidth = mSlideableView.getWidth();
            x = (int) (getWidth() - (startBound + slideOffset * mSlideRange + childWidth));
        } else {
            int startBound = getPaddingLeft() + lp.leftMargin;
            x = (int) (startBound + slideOffset * mSlideRange);
        }

        if (mDragHelper.smoothSlideViewTo(mSlideableView, x, mSlideableView.getTop())) {
            setAllChildrenVisible();
            ViewCompat.postInvalidateOnAnimation(this);
            return true;
        }
        return false;
voidupdateObscuredViewsVisibility(android.view.View panel)

        final boolean isLayoutRtl = isLayoutRtlSupport();
        final int startBound = isLayoutRtl ? (getWidth() - getPaddingRight()) :
            getPaddingLeft();
        final int endBound = isLayoutRtl ? getPaddingLeft() :
            (getWidth() - getPaddingRight());
        final int topBound = getPaddingTop();
        final int bottomBound = getHeight() - getPaddingBottom();
        final int left;
        final int right;
        final int top;
        final int bottom;
        if (panel != null && viewIsOpaque(panel)) {
            left = panel.getLeft();
            right = panel.getRight();
            top = panel.getTop();
            bottom = panel.getBottom();
        } else {
            left = right = top = bottom = 0;
        }

        for (int i = 0, childCount = getChildCount(); i < childCount; i++) {
            final View child = getChildAt(i);

            if (child == panel) {
                // There are still more children above the panel but they won't be affected.
                break;
            }

            final int clampedChildLeft = Math.max((isLayoutRtl ? endBound :
                startBound), child.getLeft());
            final int clampedChildTop = Math.max(topBound, child.getTop());
            final int clampedChildRight = Math.min((isLayoutRtl ? startBound :
                endBound), child.getRight());
            final int clampedChildBottom = Math.min(bottomBound, child.getBottom());
            final int vis;
            if (clampedChildLeft >= left && clampedChildTop >= top &&
                    clampedChildRight <= right && clampedChildBottom <= bottom) {
                vis = INVISIBLE;
            } else {
                vis = VISIBLE;
            }
            child.setVisibility(vis);
        }
private static booleanviewIsOpaque(android.view.View v)

        if (ViewCompat.isOpaque(v)) return true;

        // View#isOpaque didn't take all valid opaque scrollbar modes into account
        // before API 18 (JB-MR2). On newer devices rely solely on isOpaque above and return false
        // here. On older devices, check the view's background drawable directly as a fallback.
        if (Build.VERSION.SDK_INT >= 18) return false;

        final Drawable bg = v.getBackground();
        if (bg != null) {
            return bg.getOpacity() == PixelFormat.OPAQUE;
        }
        return false;