| /* |
| * Copyright 2012 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 com.example.android.animationsdemo; |
| |
| import android.content.Context; |
| import android.content.res.TypedArray; |
| import android.graphics.Canvas; |
| import android.graphics.Rect; |
| import android.graphics.drawable.Drawable; |
| import android.util.AttributeSet; |
| import android.widget.ImageButton; |
| |
| /** |
| * An image button that uses a blue highlight (@link android.R.attr.selectableItemBackground} to |
| * indicate pressed and focused states. |
| */ |
| public class TouchHighlightImageButton extends ImageButton { |
| /** |
| * The highlight drawable. This generally a {@link android.graphics.drawable.StateListDrawable} |
| * that's transparent in the default state, and contains a semi-transparent overlay |
| * for the focused and pressed states. |
| */ |
| private Drawable mForegroundDrawable; |
| |
| /** |
| * The cached bounds of the view. |
| */ |
| private Rect mCachedBounds = new Rect(); |
| |
| public TouchHighlightImageButton(Context context) { |
| super(context); |
| init(); |
| } |
| |
| public TouchHighlightImageButton(Context context, AttributeSet attrs) { |
| super(context, attrs); |
| init(); |
| } |
| |
| public TouchHighlightImageButton(Context context, AttributeSet attrs, int defStyle) { |
| super(context, attrs, defStyle); |
| init(); |
| } |
| |
| /** |
| * General view initialization used common to all constructors of the view. |
| */ |
| private void init() { |
| // Reset default ImageButton background and padding. |
| setBackgroundColor(0); |
| setPadding(0, 0, 0, 0); |
| |
| // Retrieve the drawable resource assigned to the android.R.attr.selectableItemBackground |
| // theme attribute from the current theme. |
| TypedArray a = getContext() |
| .obtainStyledAttributes(new int[]{android.R.attr.selectableItemBackground}); |
| mForegroundDrawable = a.getDrawable(0); |
| mForegroundDrawable.setCallback(this); |
| a.recycle(); |
| } |
| |
| @Override |
| protected void drawableStateChanged() { |
| super.drawableStateChanged(); |
| |
| // Update the state of the highlight drawable to match |
| // the state of the button. |
| if (mForegroundDrawable.isStateful()) { |
| mForegroundDrawable.setState(getDrawableState()); |
| } |
| |
| // Trigger a redraw. |
| invalidate(); |
| } |
| |
| @Override |
| protected void onDraw(Canvas canvas) { |
| // First draw the image. |
| super.onDraw(canvas); |
| |
| // Then draw the highlight on top of it. If the button is neither focused |
| // nor pressed, the drawable will be transparent, so just the image |
| // will be drawn. |
| mForegroundDrawable.setBounds(mCachedBounds); |
| mForegroundDrawable.draw(canvas); |
| } |
| |
| @Override |
| protected void onSizeChanged(int w, int h, int oldw, int oldh) { |
| super.onSizeChanged(w, h, oldw, oldh); |
| |
| // Cache the view bounds. |
| mCachedBounds.set(0, 0, w, h); |
| } |
| } |