design/base/android/support/design/widget/AnimationUtils.java

/*
 * Copyright (C) 2015 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 android.support.design.widget;

import android.support.v4.view.animation.FastOutLinearInInterpolator;
import android.support.v4.view.animation.FastOutSlowInInterpolator;
import android.support.v4.view.animation.LinearOutSlowInInterpolator;
import android.view.animation.Animation;
import android.view.animation.DecelerateInterpolator;
import android.view.animation.Interpolator;
import android.view.animation.LinearInterpolator;

class AnimationUtils {

    static final Interpolator LINEAR_INTERPOLATOR = new LinearInterpolator();
    static final Interpolator FAST_OUT_SLOW_IN_INTERPOLATOR = new FastOutSlowInInterpolator();
    static final Interpolator FAST_OUT_LINEAR_IN_INTERPOLATOR = new FastOutLinearInInterpolator();
    static final Interpolator LINEAR_OUT_SLOW_IN_INTERPOLATOR = new LinearOutSlowInInterpolator();
    static final Interpolator DECELERATE_INTERPOLATOR = new DecelerateInterpolator();

    /**
     * Linear interpolation between {@code startValue} and {@code endValue} by {@code fraction}.
     */
    static float lerp(float startValue, float endValue, float fraction) {
        return startValue + (fraction * (endValue - startValue));
    }

    static int lerp(int startValue, int endValue, float fraction) {
        return startValue + Math.round(fraction * (endValue - startValue));
    }

    static class AnimationListenerAdapter implements Animation.AnimationListener {
        @Override
        public void onAnimationStart(Animation animation) {
        }

        @Override
        public void onAnimationEnd(Animation animation) {
        }

        @Override
        public void onAnimationRepeat(Animation animation) {
        }
    }

}