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      1 /*
      2  * Copyright (C) 2013 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 
     17 package com.example.android.bouncer;
     18 
     19 import android.animation.ValueAnimator;
     20 import android.animation.ValueAnimator.AnimatorUpdateListener;
     21 import android.app.Activity;
     22 import android.content.Context;
     23 import android.graphics.Bitmap;
     24 import android.graphics.BitmapFactory;
     25 import android.graphics.Canvas;
     26 import android.graphics.Paint;
     27 import android.os.Bundle;
     28 import android.util.AttributeSet;
     29 import android.view.View;
     30 import android.view.animation.AccelerateInterpolator;
     31 
     32 /**
     33  * See the comments in Bouncer for the overall functionality of this app. Changes for this
     34  * variation are down in the animation setup code.
     35  */
     36 public class Bouncer2 extends Activity {
     37 
     38     @Override
     39     public void onCreate(Bundle savedInstanceState) {
     40         super.onCreate(savedInstanceState);
     41         setContentView(R.layout.activity_bouncer2);
     42     }
     43 
     44     static class MyView extends View {
     45 
     46         Bitmap mBitmap;
     47         Paint paint = new Paint();
     48         int mShapeX, mShapeY;
     49         int mShapeW, mShapeH;
     50 
     51         public MyView(Context context, AttributeSet attrs, int defStyle) {
     52             super(context, attrs, defStyle);
     53             setupShape();
     54         }
     55 
     56         public MyView(Context context, AttributeSet attrs) {
     57             super(context, attrs);
     58             setupShape();
     59         }
     60 
     61         public MyView(Context context) {
     62             super(context);
     63             setupShape();
     64         }
     65 
     66         public void setShapeX(int shapeX) {
     67             int minX = mShapeX;
     68             int maxX = mShapeX + mShapeW;
     69             mShapeX = shapeX;
     70             minX = Math.min(mShapeX, minX);
     71             maxX = Math.max(mShapeX + mShapeW, maxX);
     72             invalidate(minX, mShapeY, maxX, mShapeY + mShapeH);
     73         }
     74 
     75         public void setShapeY(int shapeY) {
     76             int minY = mShapeY;
     77             int maxY = mShapeY + mShapeH;
     78             mShapeY = shapeY;
     79             minY = Math.min(mShapeY, minY);
     80             maxY = Math.max(mShapeY + mShapeH, maxY);
     81             invalidate(mShapeX, minY, mShapeX + mShapeW, maxY);
     82         }
     83 
     84         private void setupShape() {
     85             mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.electricsheep);
     86             mShapeW = mBitmap.getWidth();
     87             mShapeH = mBitmap.getHeight();
     88             setOnClickListener(new View.OnClickListener() {
     89                 @Override
     90                 public void onClick(View v) {
     91                     startAnimation();
     92                 }
     93             });
     94         }
     95 
     96         @Override
     97         protected void onSizeChanged(int w, int h, int oldw, int oldh) {
     98             mShapeX = (w - mBitmap.getWidth()) / 2;
     99             mShapeY = 0;
    100         }
    101 
    102         @Override
    103         protected void onDraw(Canvas canvas) {
    104             canvas.drawBitmap(mBitmap, mShapeX, mShapeY, paint);
    105         }
    106 
    107         void startAnimation() {
    108             ValueAnimator anim = getValueAnimator();
    109             anim.setRepeatCount(ValueAnimator.INFINITE);
    110             anim.setRepeatMode(ValueAnimator.REVERSE);
    111             // This variation finally has the shape bouncing, due to the use of an
    112             // AccelerateInterpolator, which speeds up as the animation proceed. Note that
    113             // when the animation reverses, the interpolator acts in reverse, decelerating
    114             // movement.
    115             anim.setInterpolator(new AccelerateInterpolator());
    116             anim.start();
    117         }
    118 
    119         ValueAnimator getValueAnimator() {
    120             ValueAnimator anim = ValueAnimator.ofFloat(0, 1);
    121             anim.addUpdateListener(new AnimatorUpdateListener() {
    122                 @Override
    123                 public void onAnimationUpdate(ValueAnimator animation) {
    124                     setShapeY((int) (animation.getAnimatedFraction() * (getHeight() - mShapeH)));
    125                 }
    126             });
    127             return anim;
    128         }
    129     }
    130 }
    131