Android实现点击缩略图放大效果

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.AnimatorSet;
import android.animation.ObjectAnimator;
import android.graphics.Point;
import android.graphics.Rect;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.view.animation.DecelerateInterpolator;
import android.widget.ImageView;
public class MainActivity extends AppCompatActivity {
// 持有这个动画的引用，让他可以在动画执行中途取消
private Animator mCurrentAnimator;
private int mShortAnimationDuration;
private View imageView1;
private View imageView2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
imageView1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
zoomImageFromThumb(imageView1,R.mipmap.ic_launcher);
}
});
imageView2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
zoomImageFromThumb(imageView2,R.mipmap.ic_launcher);
}
});
// 系统默认的短动画执行时间 200
mShortAnimationDuration = getResources().getInteger(
android.R.integer.config_shortAnimTime);
}
private void initView() {
imageView1 = (ImageView) findViewById(R.id.imageView1);
imageView2 = (ImageView) findViewById(R.id.imageView2);
}
private void zoomImageFromThumb(final View thumbView, int imageResId) {
// 如果有动画正在运行，取消这个动画
if (mCurrentAnimator != null) {
mCurrentAnimator.cancel();
}
// 加载显示大图的ImageView
final ImageView expandedImageView = (ImageView) findViewById(
R.id.expanded_image);
expandedImageView.setImageResource(imageResId);
// 计算初始小图的边界位置和最终大图的边界位置。
final Rect startBounds = new Rect();
final Rect finalBounds = new Rect();
final Point globalOffset = new Point();
// 小图的边界就是小ImageView的边界，大图的边界因为是铺满全屏的，所以就是整个布局的边界。
// 然后根据偏移量得到正确的坐标。
thumbView.getGlobalVisibleRect(startBounds);
findViewById(R.id.imageView1).getGlobalVisibleRect(finalBounds, globalOffset);
startBounds.offset(-globalOffset.x, -globalOffset.y);
finalBounds.offset(-globalOffset.x, -globalOffset.y);
// 计算初始的缩放比例。最终的缩放比例为1。并调整缩放方向，使看着协调。
float startScale=0;
if ((float) finalBounds.width() / finalBounds.height()
(float) startBounds.width() / startBounds.height()) {
// 横向缩放
float startWidth = startScale * finalBounds.width();
float deltaWidth = (startWidth - startBounds.width()) / 2;
startBounds.left -= deltaWidth;
startBounds.right += deltaWidth;
} else {
// 竖向缩放
float startHeight = startScale * finalBounds.height();
float deltaHeight = (startHeight - startBounds.height()) / 2;
startBounds.top -= deltaHeight;
startBounds.bottom += deltaHeight;
}
// 隐藏小图，并显示大图
thumbView.setAlpha(0f);
expandedImageView.setVisibility(View.VISIBLE);
// 将大图的缩放中心点移到左上角。默认是从中心缩放
expandedImageView.setPivotX(0f);
expandedImageView.setPivotY(0f);
//对大图进行缩放动画
AnimatorSet set = new AnimatorSet();
set.play(ObjectAnimator.ofFloat(expandedImageView, View.X, startBounds.left, finalBounds.left))
.with(ObjectAnimator.ofFloat(expandedImageView, View.Y, startBounds.top, finalBounds.top))
.with(ObjectAnimator.ofFloat(expandedImageView, View.SCALE_X, startScale, 1f))
.with(ObjectAnimator.ofFloat(expandedImageView, View.SCALE_Y, startScale, 1f));
set.setDuration(mShortAnimationDuration);
set.setInterpolator(new DecelerateInterpolator());
set.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
mCurrentAnimator = null;
}
@Override
public void onAnimationCancel(Animator animation) {
mCurrentAnimator = null;
}
});
set.start();
mCurrentAnimator = set;
// 点击大图时，反向缩放大图，然后隐藏大图，显示小图。
final float startScaleFinal = startScale;
expandedImageView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (mCurrentAnimator != null) {
mCurrentAnimator.cancel();
}
AnimatorSet set = new AnimatorSet();
set.play(ObjectAnimator
.ofFloat(expandedImageView, View.X, startBounds.left))
.with(ObjectAnimator
.ofFloat(expandedImageView,
View.Y,startBounds.top))
.with(ObjectAnimator
.ofFloat(expandedImageView,
View.SCALE_X, startScaleFinal))
.with(ObjectAnimator
.ofFloat(expandedImageView,
View.SCALE_Y, startScaleFinal));
set.setDuration(mShortAnimationDuration);
set.setInterpolator(new DecelerateInterpolator());
set.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
thumbView.setAlpha(1f);
expandedImageView.setVisibility(View.GONE);
mCurrentAnimator = null;
}
@Override
public void onAnimationCancel(Animator animation) {
thumbView.setAlpha(1f);
expandedImageView.setVisibility(View.GONE);
mCurrentAnimator = null;
}
});
set.start();
mCurrentAnimator = set;
}
});
}
}