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      1 /*
      2  * Copyright (C) 2015 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 package com.android.launcher3.allapps;
     17 
     18 import android.animation.ObjectAnimator;
     19 import android.content.Context;
     20 import android.content.res.Resources;
     21 import android.graphics.Canvas;
     22 import android.graphics.ColorFilter;
     23 import android.graphics.PixelFormat;
     24 import android.graphics.Rect;
     25 import android.graphics.drawable.Drawable;
     26 import android.view.Gravity;
     27 
     28 import com.android.launcher3.R;
     29 
     30 /**
     31  * This is a custom composite drawable that has a fixed virtual size and dynamically lays out its
     32  * children images relatively within its bounds.  This way, we can reduce the memory usage of a
     33  * single, large sparsely populated image.
     34  */
     35 public class AllAppsBackgroundDrawable extends Drawable {
     36 
     37     /**
     38      * A helper class to positon and orient a drawable to be drawn.
     39      */
     40     protected static class TransformedImageDrawable {
     41         private Drawable mImage;
     42         private float mXPercent;
     43         private float mYPercent;
     44         private int mGravity;
     45         private int mAlpha;
     46 
     47         /**
     48          * @param gravity If one of the Gravity center values, the x and y offset will take the width
     49          *                and height of the image into account to center the image to the offset.
     50          */
     51         public TransformedImageDrawable(Resources res, int resourceId, float xPct, float yPct,
     52                 int gravity) {
     53             mImage = res.getDrawable(resourceId);
     54             mXPercent = xPct;
     55             mYPercent = yPct;
     56             mGravity = gravity;
     57         }
     58 
     59         public void setAlpha(int alpha) {
     60             mImage.setAlpha(alpha);
     61             mAlpha = alpha;
     62         }
     63 
     64         public int getAlpha() {
     65             return mAlpha;
     66         }
     67 
     68         public void updateBounds(Rect bounds) {
     69             int width = mImage.getIntrinsicWidth();
     70             int height = mImage.getIntrinsicHeight();
     71             int left = bounds.left + (int) (mXPercent * bounds.width());
     72             int top = bounds.top + (int) (mYPercent * bounds.height());
     73             if ((mGravity & Gravity.CENTER_HORIZONTAL) == Gravity.CENTER_HORIZONTAL) {
     74                 left -= (width / 2);
     75             }
     76             if ((mGravity & Gravity.CENTER_VERTICAL) == Gravity.CENTER_VERTICAL) {
     77                 top -= (height / 2);
     78             }
     79             mImage.setBounds(left, top, left + width, top + height);
     80         }
     81 
     82         public void draw(Canvas canvas) {
     83             mImage.draw(canvas);
     84         }
     85 
     86         public Rect getBounds() {
     87             return mImage.getBounds();
     88         }
     89     }
     90 
     91     protected final TransformedImageDrawable mHand;
     92     protected final TransformedImageDrawable[] mIcons;
     93     private final int mWidth;
     94     private final int mHeight;
     95 
     96     private ObjectAnimator mBackgroundAnim;
     97 
     98     public AllAppsBackgroundDrawable(Context context) {
     99         Resources res = context.getResources();
    100         mHand = new TransformedImageDrawable(res, R.drawable.ic_all_apps_bg_hand,
    101                 0.575f, 0.f, Gravity.CENTER_HORIZONTAL);
    102         mIcons = new TransformedImageDrawable[4];
    103         mIcons[0] = new TransformedImageDrawable(res, R.drawable.ic_all_apps_bg_icon_1,
    104                 0.375f, 0, Gravity.CENTER_HORIZONTAL);
    105         mIcons[1] = new TransformedImageDrawable(res, R.drawable.ic_all_apps_bg_icon_2,
    106                 0.3125f, 0.2f, Gravity.CENTER_HORIZONTAL);
    107         mIcons[2] = new TransformedImageDrawable(res, R.drawable.ic_all_apps_bg_icon_3,
    108                 0.475f, 0.26f, Gravity.CENTER_HORIZONTAL);
    109         mIcons[3] = new TransformedImageDrawable(res, R.drawable.ic_all_apps_bg_icon_4,
    110                 0.7f, 0.125f, Gravity.CENTER_HORIZONTAL);
    111         mWidth = res.getDimensionPixelSize(R.dimen.all_apps_background_canvas_width);
    112         mHeight = res.getDimensionPixelSize(R.dimen.all_apps_background_canvas_height);
    113     }
    114 
    115     /**
    116      * Animates the background alpha.
    117      */
    118     public void animateBgAlpha(float finalAlpha, int duration) {
    119         int finalAlphaI = (int) (finalAlpha * 255f);
    120         if (getAlpha() != finalAlphaI) {
    121             mBackgroundAnim = cancelAnimator(mBackgroundAnim);
    122             mBackgroundAnim = ObjectAnimator.ofInt(this, "alpha", finalAlphaI);
    123             mBackgroundAnim.setDuration(duration);
    124             mBackgroundAnim.start();
    125         }
    126     }
    127 
    128     /**
    129      * Sets the background alpha immediately.
    130      */
    131     public void setBgAlpha(float finalAlpha) {
    132         int finalAlphaI = (int) (finalAlpha * 255f);
    133         if (getAlpha() != finalAlphaI) {
    134             mBackgroundAnim = cancelAnimator(mBackgroundAnim);
    135             setAlpha(finalAlphaI);
    136         }
    137     }
    138 
    139     @Override
    140     public int getIntrinsicWidth() {
    141         return mWidth;
    142     }
    143 
    144     @Override
    145     public int getIntrinsicHeight() {
    146         return mHeight;
    147     }
    148 
    149     @Override
    150     public void draw(Canvas canvas) {
    151         mHand.draw(canvas);
    152         for (int i = 0; i < mIcons.length; i++) {
    153             mIcons[i].draw(canvas);
    154         }
    155     }
    156 
    157     @Override
    158     protected void onBoundsChange(Rect bounds) {
    159         super.onBoundsChange(bounds);
    160         mHand.updateBounds(bounds);
    161         for (int i = 0; i < mIcons.length; i++) {
    162             mIcons[i].updateBounds(bounds);
    163         }
    164         invalidateSelf();
    165     }
    166 
    167     @Override
    168     public void setAlpha(int alpha) {
    169         mHand.setAlpha(alpha);
    170         for (int i = 0; i < mIcons.length; i++) {
    171             mIcons[i].setAlpha(alpha);
    172         }
    173         invalidateSelf();
    174     }
    175 
    176     @Override
    177     public int getAlpha() {
    178         return mHand.getAlpha();
    179     }
    180 
    181     @Override
    182     public void setColorFilter(ColorFilter colorFilter) {
    183         // Do nothing
    184     }
    185 
    186     @Override
    187     public int getOpacity() {
    188         return PixelFormat.TRANSLUCENT;
    189     }
    190 
    191     private ObjectAnimator cancelAnimator(ObjectAnimator animator) {
    192         if (animator != null) {
    193             animator.cancel();
    194         }
    195         return null;
    196     }
    197 }
    198