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/*
* Copyright (C) 2013 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.squashandstretch;
import android.animation.AnimatorSet;
import android.animation.ObjectAnimator;
import android.animation.PropertyValuesHolder;
import android.animation.ValueAnimator;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.AccelerateInterpolator;
import android.view.animation.DecelerateInterpolator;
/**
* This example shows how to add some life to a view during animation by deforming the shape.
* As the button "falls", it stretches along the line of travel. When it hits the bottom, it
* squashes, like a real object when hitting a surface. Then the button reverses these actions
* to bounce back up to the start.
*
* Watch the associated video for this demo on the DevBytes channel of developer.android.com
* or on the DevBytes playlist in the androiddevelopers channel on YouTube at
* https://www.youtube.com/playlist?list=PLWz5rJ2EKKc_XOgcRukSoKKjewFJZrKV0.
*/
public class SquashAndStretch extends Activity {
private static final AccelerateInterpolator sAccelerator = new AccelerateInterpolator();
private static final DecelerateInterpolator sDecelerator = new DecelerateInterpolator();
ViewGroup mContainer = null;
private static final long BASE_DURATION = 300;
private long sAnimatorScale = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mContainer = (ViewGroup) findViewById(R.id.container);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == R.id.menu_slow) {
sAnimatorScale = item.isChecked() ? 1 : 5;
item.setChecked(!item.isChecked());
}
return super.onOptionsItemSelected(item);
}
public void onButtonClick(View view) {
long animationDuration = (long) (BASE_DURATION * sAnimatorScale);
// Scale around bottom/middle to simplify squash against the window bottom
view.setPivotX(view.getWidth() / 2);
view.setPivotY(view.getHeight());
// Animate the button down, accelerating, while also stretching in Y and squashing in X
PropertyValuesHolder pvhTY = PropertyValuesHolder.ofFloat(View.TRANSLATION_Y,
mContainer.getHeight() - view.getHeight());
PropertyValuesHolder pvhSX = PropertyValuesHolder.ofFloat(View.SCALE_X, .7f);
PropertyValuesHolder pvhSY = PropertyValuesHolder.ofFloat(View.SCALE_Y, 1.2f);
ObjectAnimator downAnim = ObjectAnimator.ofPropertyValuesHolder(
view, pvhTY, pvhSX, pvhSY);
downAnim.setInterpolator(sAccelerator);
downAnim.setDuration((long) (animationDuration * 2));
// Stretch in X, squash in Y, then reverse
pvhSX = PropertyValuesHolder.ofFloat(View.SCALE_X, 2);
pvhSY = PropertyValuesHolder.ofFloat(View.SCALE_Y, .5f);
ObjectAnimator stretchAnim =
ObjectAnimator.ofPropertyValuesHolder(view, pvhSX, pvhSY);
stretchAnim.setRepeatCount(1);
stretchAnim.setRepeatMode(ValueAnimator.REVERSE);
stretchAnim.setInterpolator(sDecelerator);
stretchAnim.setDuration(animationDuration);
// Animate back to the start
pvhTY = PropertyValuesHolder.ofFloat(View.TRANSLATION_Y, 0);
pvhSX = PropertyValuesHolder.ofFloat(View.SCALE_X, 1);
pvhSY = PropertyValuesHolder.ofFloat(View.SCALE_Y, 1);
ObjectAnimator upAnim =
ObjectAnimator.ofPropertyValuesHolder(view, pvhTY, pvhSX, pvhSY);
upAnim.setDuration((long) (animationDuration * 2));
upAnim.setInterpolator(sDecelerator);
AnimatorSet set = new AnimatorSet();
set.playSequentially(downAnim, stretchAnim, upAnim);
set.start();
}
}
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