1 /*
2  * Copyright (C) 2010 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.apis.animation;
18 
19 // Need the following import to get access to the app resources, since this
20 // class is in a sub-package.
21 import android.animation.ObjectAnimator;
22 import android.animation.TypeEvaluator;
23 import android.animation.ValueAnimator;
24 import com.example.android.apis.R;
25 
26 import java.util.ArrayList;
27 
28 import android.app.Activity;
29 import android.content.Context;
30 import android.graphics.Canvas;
31 import android.graphics.Paint;
32 import android.graphics.RadialGradient;
33 import android.graphics.Shader;
34 import android.graphics.drawable.ShapeDrawable;
35 import android.graphics.drawable.shapes.OvalShape;
36 import android.os.Bundle;
37 import android.view.View;
38 import android.widget.Button;
39 import android.widget.LinearLayout;
40 
41 public class CustomEvaluator extends Activity {
42 
43     @Override
onCreate(Bundle savedInstanceState)44     public void onCreate(Bundle savedInstanceState) {
45         super.onCreate(savedInstanceState);
46         setContentView(R.layout.animator_custom_evaluator);
47         LinearLayout container = (LinearLayout) findViewById(R.id.container);
48         final MyAnimationView animView = new MyAnimationView(this);
49         container.addView(animView);
50 
51         Button starter = (Button) findViewById(R.id.startButton);
52         starter.setOnClickListener(new View.OnClickListener() {
53             public void onClick(View v) {
54                 animView.startAnimation();
55             }
56         });
57     }
58 
59     public class XYHolder {
60         private float mX;
61         private float mY;
62 
XYHolder(float x, float y)63         public XYHolder(float x, float y) {
64             mX = x;
65             mY = y;
66         }
67 
getX()68         public float getX() {
69             return mX;
70         }
71 
setX(float x)72         public void setX(float x) {
73             mX = x;
74         }
75 
getY()76         public float getY() {
77             return mY;
78         }
79 
setY(float y)80         public void setY(float y) {
81             mY = y;
82         }
83     }
84 
85     public class XYEvaluator implements TypeEvaluator {
evaluate(float fraction, Object startValue, Object endValue)86         public Object evaluate(float fraction, Object startValue, Object endValue) {
87             XYHolder startXY = (XYHolder) startValue;
88             XYHolder endXY = (XYHolder) endValue;
89             return new XYHolder(startXY.getX() + fraction * (endXY.getX() - startXY.getX()),
90                     startXY.getY() + fraction * (endXY.getY() - startXY.getY()));
91         }
92     }
93 
94     public class BallXYHolder {
95 
96         private ShapeHolder mBall;
97 
BallXYHolder(ShapeHolder ball)98         public BallXYHolder(ShapeHolder ball) {
99             mBall = ball;
100         }
101 
setXY(XYHolder xyHolder)102         public void setXY(XYHolder xyHolder) {
103             mBall.setX(xyHolder.getX());
104             mBall.setY(xyHolder.getY());
105         }
106 
getXY()107         public XYHolder getXY() {
108             return new XYHolder(mBall.getX(), mBall.getY());
109         }
110     }
111 
112     public class MyAnimationView extends View implements ValueAnimator.AnimatorUpdateListener {
113 
114         public final ArrayList<ShapeHolder> balls = new ArrayList<ShapeHolder>();
115         ValueAnimator bounceAnim = null;
116         ShapeHolder ball = null;
117         BallXYHolder ballHolder = null;
118 
MyAnimationView(Context context)119         public MyAnimationView(Context context) {
120             super(context);
121             ball = createBall(25, 25);
122             ballHolder = new BallXYHolder(ball);
123         }
124 
createAnimation()125         private void createAnimation() {
126             if (bounceAnim == null) {
127                 XYHolder startXY = new XYHolder(0f, 0f);
128                 XYHolder endXY = new XYHolder(300f, 500f);
129                 bounceAnim = ObjectAnimator.ofObject(ballHolder, "xY",
130                         new XYEvaluator(), endXY);
131                 bounceAnim.setDuration(1500);
132                 bounceAnim.addUpdateListener(this);
133             }
134         }
135 
startAnimation()136         public void startAnimation() {
137             createAnimation();
138             bounceAnim.start();
139         }
140 
createBall(float x, float y)141         private ShapeHolder createBall(float x, float y) {
142             OvalShape circle = new OvalShape();
143             circle.resize(50f, 50f);
144             ShapeDrawable drawable = new ShapeDrawable(circle);
145             ShapeHolder shapeHolder = new ShapeHolder(drawable);
146             shapeHolder.setX(x - 25f);
147             shapeHolder.setY(y - 25f);
148             int red = (int)(Math.random() * 255);
149             int green = (int)(Math.random() * 255);
150             int blue = (int)(Math.random() * 255);
151             int color = 0xff000000 | red << 16 | green << 8 | blue;
152             Paint paint = drawable.getPaint(); //new Paint(Paint.ANTI_ALIAS_FLAG);
153             int darkColor = 0xff000000 | red/4 << 16 | green/4 << 8 | blue/4;
154             RadialGradient gradient = new RadialGradient(37.5f, 12.5f,
155                     50f, color, darkColor, Shader.TileMode.CLAMP);
156             paint.setShader(gradient);
157             shapeHolder.setPaint(paint);
158             return shapeHolder;
159         }
160 
161         @Override
onDraw(Canvas canvas)162         protected void onDraw(Canvas canvas) {
163             canvas.save();
164             canvas.translate(ball.getX(), ball.getY());
165             ball.getShape().draw(canvas);
166             canvas.restore();
167         }
168 
onAnimationUpdate(ValueAnimator animation)169         public void onAnimationUpdate(ValueAnimator animation) {
170             invalidate();
171         }
172 
173     }
174 }