/*
* Copyright (C) 2007 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.widget;
import android.annotation.Widget;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.content.res.TypedArray;
import android.database.DataSetObserver;
import android.util.AttributeSet;
import android.view.KeyEvent;
import android.view.View;
import android.view.ViewGroup;
/**
* A view that displays one child at a time and lets the user pick among them.
* The items in the Spinner come from the {@link Adapter} associated with
* this view.
*
* @attr ref android.R.styleable#Spinner_prompt
*/
@Widget
public class Spinner extends AbsSpinner implements OnClickListener {
private CharSequence mPrompt;
public Spinner(Context context) {
this(context, null);
}
public Spinner(Context context, AttributeSet attrs) {
this(context, attrs, com.android.internal.R.attr.spinnerStyle);
}
public Spinner(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
TypedArray a = context.obtainStyledAttributes(attrs,
com.android.internal.R.styleable.Spinner, defStyle, 0);
mPrompt = a.getString(com.android.internal.R.styleable.Spinner_prompt);
a.recycle();
}
@Override
public int getBaseline() {
View child = null;
if (getChildCount() > 0) {
child = getChildAt(0);
} else if (mAdapter != null && mAdapter.getCount() > 0) {
child = makeAndAddView(0);
// TODO: We should probably put the child in the recycler
}
if (child != null) {
return child.getTop() + child.getBaseline();
} else {
return -1;
}
}
/**
* <p>A spinner does not support item click events. Calling this method
* will raise an exception.</p>
*
* @param l this listener will be ignored
*/
@Override
public void setOnItemClickListener(OnItemClickListener l) {
throw new RuntimeException("setOnItemClickListener cannot be used with a spinner.");
}
/**
* @see android.view.View#onLayout(boolean,int,int,int,int)
*
* Creates and positions all views
*
*/
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
super.onLayout(changed, l, t, r, b);
mInLayout = true;
layout(0, false);
mInLayout = false;
}
/**
* Creates and positions all views for this Spinner.
*
* @param delta Change in the selected position. +1 moves selection is moving to the right,
* so views are scrolling to the left. -1 means selection is moving to the left.
*/
@Override
void layout(int delta, boolean animate) {
int childrenLeft = mSpinnerPadding.left;
int childrenWidth = mRight - mLeft - mSpinnerPadding.left - mSpinnerPadding.right;
if (mDataChanged) {
handleDataChanged();
}
// Handle the empty set by removing all views
if (mItemCount == 0) {
resetList();
return;
}
if (mNextSelectedPosition >= 0) {
setSelectedPositionInt(mNextSelectedPosition);
}
recycleAllViews();
// Clear out old views
removeAllViewsInLayout();
// Make selected view and center it
mFirstPosition = mSelectedPosition;
View sel = makeAndAddView(mSelectedPosition);
int width = sel.getMeasuredWidth();
int selectedOffset = childrenLeft + (childrenWidth / 2) - (width / 2);
sel.offsetLeftAndRight(selectedOffset);
// Flush any cached views that did not get reused above
mRecycler.clear();
invalidate();
checkSelectionChanged();
mDataChanged = false;
mNeedSync = false;
setNextSelectedPositionInt(mSelectedPosition);
}
/**
* Obtain a view, either by pulling an existing view from the recycler or
* by getting a new one from the adapter. If we are animating, make sure
* there is enough information in the view's layout parameters to animate
* from the old to new positions.
*
* @param position Position in the spinner for the view to obtain
* @return A view that has been added to the spinner
*/
private View makeAndAddView(int position) {
View child;
if (!mDataChanged) {
child = mRecycler.get(position);
if (child != null) {
// Position the view
setUpChild(child);
return child;
}
}
// Nothing found in the recycler -- ask the adapter for a view
child = mAdapter.getView(position, null, this);
// Position the view
setUpChild(child);
return child;
}
/**
* Helper for makeAndAddView to set the position of a view
* and fill out its layout paramters.
*
* @param child The view to position
*/
private void setUpChild(View child) {
// Respect layout params that are already in the view. Otherwise
// make some up...
ViewGroup.LayoutParams lp = child.getLayoutParams();
if (lp == null) {
lp = generateDefaultLayoutParams();
}
addViewInLayout(child, 0, lp);
child.setSelected(hasFocus());
// Get measure specs
int childHeightSpec = ViewGroup.getChildMeasureSpec(mHeightMeasureSpec,
mSpinnerPadding.top + mSpinnerPadding.bottom, lp.height);
int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec,
mSpinnerPadding.left + mSpinnerPadding.right, lp.width);
// Measure child
child.measure(childWidthSpec, childHeightSpec);
int childLeft;
int childRight;
// Position vertically based on gravity setting
int childTop = mSpinnerPadding.top
+ ((mMeasuredHeight - mSpinnerPadding.bottom -
mSpinnerPadding.top - child.getMeasuredHeight()) / 2);
int childBottom = childTop + child.getMeasuredHeight();
int width = child.getMeasuredWidth();
childLeft = 0;
childRight = childLeft + width;
child.layout(childLeft, childTop, childRight, childBottom);
}
@Override
public boolean performClick() {
boolean handled = super.performClick();
if (!handled) {
handled = true;
Context context = getContext();
final DropDownAdapter adapter = new DropDownAdapter(getAdapter());
AlertDialog.Builder builder = new AlertDialog.Builder(context);
if (mPrompt != null) {
builder.setTitle(mPrompt);
}
builder.setSingleChoiceItems(adapter, getSelectedItemPosition(), this).show();
}
return handled;
}
public void onClick(DialogInterface dialog, int which) {
setSelection(which);
dialog.dismiss();
}
/**
* Sets the prompt to display when the dialog is shown.
* @param prompt the prompt to set
*/
public void setPrompt(CharSequence prompt) {
mPrompt = prompt;
}
/**
* Sets the prompt to display when the dialog is shown.
* @param promptId the resource ID of the prompt to display when the dialog is shown
*/
public void setPromptId(int promptId) {
mPrompt = getContext().getText(promptId);
}
/**
* @return The prompt to display when the dialog is shown
*/
public CharSequence getPrompt() {
return mPrompt;
}
/**
* <p>Wrapper class for an Adapter. Transforms the embedded Adapter instance
* into a ListAdapter.</p>
*/
private static class DropDownAdapter implements ListAdapter, SpinnerAdapter {
private SpinnerAdapter mAdapter;
/**
* <p>Creates a new ListAddapter wrapper for the specified adapter.</p>
*
* @param adapter the Adapter to transform into a ListAdapter
*/
public DropDownAdapter(SpinnerAdapter adapter) {
this.mAdapter = adapter;
}
public int getCount() {
return mAdapter == null ? 0 : mAdapter.getCount();
}
public Object getItem(int position) {
return mAdapter == null ? null : mAdapter.getItem(position);
}
public long getItemId(int position) {
return mAdapter == null ? -1 : mAdapter.getItemId(position);
}
public View getView(int position, View convertView, ViewGroup parent) {
return getDropDownView(position, convertView, parent);
}
public View getDropDownView(int position, View convertView, ViewGroup parent) {
return mAdapter == null ? null :
mAdapter.getDropDownView(position, convertView, parent);
}
public boolean hasStableIds() {
return mAdapter != null && mAdapter.hasStableIds();
}
public void registerDataSetObserver(DataSetObserver observer) {
if (mAdapter != null) {
mAdapter.registerDataSetObserver(observer);
}
}
public void unregisterDataSetObserver(DataSetObserver observer) {
if (mAdapter != null) {
mAdapter.unregisterDataSetObserver(observer);
}
}
/**
* <p>Always returns false.</p>
*
* @return false
*/
public boolean areAllItemsEnabled() {
return true;
}
/**
* <p>Always returns false.</p>
*
* @return false
*/
public boolean isEnabled(int position) {
return true;
}
public int getItemViewType(int position) {
return 0;
}
public int getViewTypeCount() {
return 1;
}
public boolean isEmpty() {
return getCount() == 0;
}
}
}
|
