Java tutorial
/* * Copyright (C) 2014 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.android.deskclock; import android.animation.ArgbEvaluator; import android.animation.ObjectAnimator; import android.animation.PropertyValuesHolder; import android.animation.ValueAnimator; import android.graphics.drawable.Drawable; import android.support.v4.graphics.drawable.DrawableCompat; import android.util.Property; import android.view.View; import android.view.animation.Interpolator; import android.widget.ImageView; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; public class AnimatorUtils { public static final long ANIM_DURATION_SHORT = 266L; // 8/30 frames long public static final Interpolator DECELERATE_ACCELERATE_INTERPOLATOR = new Interpolator() { @Override public float getInterpolation(float x) { return 0.5f + 4.0f * (x - 0.5f) * (x - 0.5f) * (x - 0.5f); } }; public static final Property<View, Integer> BACKGROUND_ALPHA = new Property<View, Integer>(Integer.class, "background.alpha") { @Override public Integer get(View view) { return view.getBackground().getAlpha(); } @Override public void set(View view, Integer value) { view.getBackground().setAlpha(value); } }; public static final Property<ImageView, Integer> DRAWABLE_ALPHA = new Property<ImageView, Integer>( Integer.class, "drawable.alpha") { @Override public Integer get(ImageView view) { return view.getDrawable().getAlpha(); } @Override public void set(ImageView view, Integer value) { view.getDrawable().setAlpha(value); } }; public static final Property<ImageView, Integer> DRAWABLE_TINT = new Property<ImageView, Integer>(Integer.class, "drawable.tint") { @Override public Integer get(ImageView view) { return null; } @Override public void set(ImageView view, Integer value) { // Ensure the drawable is wrapped using DrawableCompat. final Drawable drawable = view.getDrawable(); final Drawable wrappedDrawable = DrawableCompat.wrap(drawable); if (wrappedDrawable != drawable) { view.setImageDrawable(wrappedDrawable); } // Set the new tint value via DrawableCompat. DrawableCompat.setTint(wrappedDrawable, value); } }; public static final ArgbEvaluator ARGB_EVALUATOR = new ArgbEvaluator(); private static Method sAnimateValue; private static boolean sTryAnimateValue = true; public static void setAnimatedFraction(ValueAnimator animator, float fraction) { if (Utils.isLMR1OrLater()) { animator.setCurrentFraction(fraction); return; } if (sTryAnimateValue) { // try to set the animated fraction directly so that it isn't affected by the // internal animator scale or time (b/17938711) try { if (sAnimateValue == null) { sAnimateValue = ValueAnimator.class.getDeclaredMethod("animateValue", float.class); sAnimateValue.setAccessible(true); } sAnimateValue.invoke(animator, fraction); return; } catch (NoSuchMethodException | InvocationTargetException | IllegalAccessException e) { // something went wrong, don't try that again LogUtils.e("Unable to use animateValue directly", e); sTryAnimateValue = false; } } // if that doesn't work then just fall back to setting the current play time animator.setCurrentPlayTime(Math.round(fraction * animator.getDuration())); } public static void reverse(ValueAnimator... animators) { for (ValueAnimator animator : animators) { final float fraction = animator.getAnimatedFraction(); if (fraction > 0.0f) { animator.reverse(); setAnimatedFraction(animator, 1.0f - fraction); } } } public static void cancel(ValueAnimator... animators) { for (ValueAnimator animator : animators) { animator.cancel(); } } public static ValueAnimator getScaleAnimator(View view, float... values) { return ObjectAnimator.ofPropertyValuesHolder(view, PropertyValuesHolder.ofFloat(View.SCALE_X, values), PropertyValuesHolder.ofFloat(View.SCALE_Y, values)); } }