src/com/android/launcher3/anim/PropertySetter.java

/*
 * Copyright (C) 2016 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.launcher3.anim;

import android.animation.Animator;
import android.animation.ObjectAnimator;
import android.animation.TimeInterpolator;
import android.util.Property;
import android.view.View;

/**
 * Utility class for setting a property with or without animation
 */
public class PropertySetter {

    public static final PropertySetter NO_ANIM_PROPERTY_SETTER = new PropertySetter();

    public void setViewAlpha(View view, float alpha, TimeInterpolator interpolator) {
        if (view != null) {
            view.setAlpha(alpha);
            AlphaUpdateListener.updateVisibility(view);
        }
    }

    public <T> void setFloat(T target, Property<T, Float> property, float value,
            TimeInterpolator interpolator) {
        property.set(target, value);
    }

    public <T> void setInt(T target, Property<T, Integer> property, int value,
            TimeInterpolator interpolator) {
        property.set(target, value);
    }

    public static class AnimatedPropertySetter extends PropertySetter {

        private final long mDuration;
        private final AnimatorSetBuilder mStateAnimator;

        public AnimatedPropertySetter(long duration, AnimatorSetBuilder builder) {
            mDuration = duration;
            mStateAnimator = builder;
        }

        @Override
        public void setViewAlpha(View view, float alpha, TimeInterpolator interpolator) {
            if (view == null || view.getAlpha() == alpha) {
                return;
            }
            ObjectAnimator anim = ObjectAnimator.ofFloat(view, View.ALPHA, alpha);
            anim.addListener(new AlphaUpdateListener(view));
            anim.setDuration(mDuration).setInterpolator(interpolator);
            mStateAnimator.play(anim);
        }

        @Override
        public <T> void setFloat(T target, Property<T, Float> property, float value,
                TimeInterpolator interpolator) {
            if (property.get(target) == value) {
                return;
            }
            Animator anim = ObjectAnimator.ofFloat(target, property, value);
            anim.setDuration(mDuration).setInterpolator(interpolator);
            mStateAnimator.play(anim);
        }

        @Override
        public <T> void setInt(T target, Property<T, Integer> property, int value,
                TimeInterpolator interpolator) {
            if (property.get(target) == value) {
                return;
            }
            Animator anim = ObjectAnimator.ofInt(target, property, value);
            anim.setDuration(mDuration).setInterpolator(interpolator);
            mStateAnimator.play(anim);
        }
    }
}