This application demonstrates the seeking capability of ValueAnimator.
/*
* Copyright (C) 2010 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.apis.animation;
import java.util.ArrayList;
import android.animation.Animator;
import android.animation.AnimatorSet;
import android.animation.ObjectAnimator;
import android.animation.ValueAnimator;
import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.RadialGradient;
import android.graphics.Shader;
import android.graphics.drawable.ShapeDrawable;
import android.graphics.drawable.shapes.OvalShape;
import android.graphics.drawable.shapes.Shape;
import android.os.Bundle;
import android.view.View;
import android.view.animation.BounceInterpolator;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.SeekBar;
/**
* This application demonstrates the seeking capability of ValueAnimator. The
* SeekBar in the UI allows you to set the position of the animation. Pressing
* the Run button will play from the current position of the animation.
*/
public class AnimationSeeking extends Activity {
private static final int DURATION = 1500;
private SeekBar mSeekBar;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.animation_seeking);
LinearLayout container = (LinearLayout) findViewById(R.id.container);
final MyAnimationView animView = new MyAnimationView(this);
container.addView(animView);
Button starter = (Button) findViewById(R.id.startButton);
starter.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
animView.startAnimation();
}
});
mSeekBar = (SeekBar) findViewById(R.id.seekBar);
mSeekBar.setMax(DURATION);
mSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
public void onStopTrackingTouch(SeekBar seekBar) {
}
public void onStartTrackingTouch(SeekBar seekBar) {
}
public void onProgressChanged(SeekBar seekBar, int progress,
boolean fromUser) {
// prevent seeking on app creation
if (animView.getHeight() != 0) {
animView.seek(progress);
}
}
});
}
public class MyAnimationView extends View implements
ValueAnimator.AnimatorUpdateListener, Animator.AnimatorListener {
private static final int RED = 0xffFF8080;
private static final int BLUE = 0xff8080FF;
private static final int CYAN = 0xff80ffff;
private static final int GREEN = 0xff80ff80;
private static final float BALL_SIZE = 100f;
public final ArrayList<ShapeHolder> balls = new ArrayList<ShapeHolder>();
AnimatorSet animation = null;
ValueAnimator bounceAnim = null;
ShapeHolder ball = null;
public MyAnimationView(Context context) {
super(context);
ball = addBall(200, 0);
}
private void createAnimation() {
if (bounceAnim == null) {
bounceAnim = ObjectAnimator.ofFloat(ball, "y", ball.getY(),
getHeight() - BALL_SIZE).setDuration(1500);
bounceAnim.setInterpolator(new BounceInterpolator());
bounceAnim.addUpdateListener(this);
}
}
public void startAnimation() {
createAnimation();
bounceAnim.start();
}
public void seek(long seekTime) {
createAnimation();
bounceAnim.setCurrentPlayTime(seekTime);
}
private ShapeHolder addBall(float x, float y) {
OvalShape circle = new OvalShape();
circle.resize(BALL_SIZE, BALL_SIZE);
ShapeDrawable drawable = new ShapeDrawable(circle);
ShapeHolder shapeHolder = new ShapeHolder(drawable);
shapeHolder.setX(x);
shapeHolder.setY(y);
int red = (int) (100 + Math.random() * 155);
int green = (int) (100 + Math.random() * 155);
int blue = (int) (100 + Math.random() * 155);
int color = 0xff000000 | red << 16 | green << 8 | blue;
Paint paint = drawable.getPaint();
int darkColor = 0xff000000 | red / 4 << 16 | green / 4 << 8 | blue
/ 4;
RadialGradient gradient = new RadialGradient(37.5f, 12.5f, 50f,
color, darkColor, Shader.TileMode.CLAMP);
paint.setShader(gradient);
shapeHolder.setPaint(paint);
balls.add(shapeHolder);
return shapeHolder;
}
@Override
protected void onDraw(Canvas canvas) {
canvas.translate(ball.getX(), ball.getY());
ball.getShape().draw(canvas);
}
public void onAnimationUpdate(ValueAnimator animation) {
invalidate();
long playtime = bounceAnim.getCurrentPlayTime();
// mSeekBar.setProgress((int)playtime);
}
public void onAnimationCancel(Animator animation) {
}
public void onAnimationEnd(Animator animation) {
balls.remove(((ObjectAnimator) animation).getTarget());
}
public void onAnimationRepeat(Animator animation) {
}
public void onAnimationStart(Animator animation) {
}
}
}
/**
* A data structure that holds a Shape and various properties that can be used
* to define how the shape is drawn.
*/
class ShapeHolder {
private float x = 0, y = 0;
private ShapeDrawable shape;
private int color;
private RadialGradient gradient;
private float alpha = 1f;
private Paint paint;
public void setPaint(Paint value) {
paint = value;
}
public Paint getPaint() {
return paint;
}
public void setX(float value) {
x = value;
}
public float getX() {
return x;
}
public void setY(float value) {
y = value;
}
public float getY() {
return y;
}
public void setShape(ShapeDrawable value) {
shape = value;
}
public ShapeDrawable getShape() {
return shape;
}
public int getColor() {
return color;
}
public void setColor(int value) {
shape.getPaint().setColor(value);
color = value;
}
public void setGradient(RadialGradient value) {
gradient = value;
}
public RadialGradient getGradient() {
return gradient;
}
public void setAlpha(float alpha) {
this.alpha = alpha;
shape.setAlpha((int) ((alpha * 255f) + .5f));
}
public float getWidth() {
return shape.getShape().getWidth();
}
public void setWidth(float width) {
Shape s = shape.getShape();
s.resize(width, s.getHeight());
}
public float getHeight() {
return shape.getShape().getHeight();
}
public void setHeight(float height) {
Shape s = shape.getShape();
s.resize(s.getWidth(), height);
}
public ShapeHolder(ShapeDrawable s) {
shape = s;
}
}
//layout/animation_seeking.xml
<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright (C) 2010 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.
-->
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/container"
>
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Run"
android:id="@+id/startButton"
/>
<SeekBar
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/seekBar"
/>
</LinearLayout>
</LinearLayout>
Related examples in the same category