v17/leanback/src/android/support/v17/leanback/widget/MediaNowPlayingView.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 android.support.v17.leanback.widget;

import android.animation.Animator;
import android.animation.AnimatorInflater;
import android.animation.ObjectAnimator;
import android.content.Context;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.support.v17.leanback.R;

/**
 * The view displaying 3 animated peak meters next to each other when a media item is playing.
 * @hide
 */
public class MediaNowPlayingView extends LinearLayout{

    private final ImageView mImage1;
    private final ImageView mImage2;
    private final ImageView mImage3;
    private final ObjectAnimator mObjectAnimator1;
    private final ObjectAnimator mObjectAnimator2;
    private final ObjectAnimator mObjectAnimator3;

    public MediaNowPlayingView(Context context, AttributeSet attrs) {
        super(context, attrs);

        LayoutInflater.from(context).inflate(R.layout.lb_playback_now_playing_bars, this, true);
        mImage1 = (ImageView) findViewById(R.id.bar1);
        mImage2 = (ImageView) findViewById(R.id.bar2);
        mImage3 = (ImageView) findViewById(R.id.bar3);

        mImage1.setPivotY(mImage1.getDrawable().getIntrinsicHeight());
        mImage2.setPivotY(mImage2.getDrawable().getIntrinsicHeight());
        mImage3.setPivotY(mImage3.getDrawable().getIntrinsicHeight());

        setDropScale(mImage1);
        setDropScale(mImage2);
        setDropScale(mImage3);

        mObjectAnimator1 = (ObjectAnimator) AnimatorInflater.loadAnimator(context,
                R.animator.lb_playback_now_bar1_animator);
        mObjectAnimator1.setTarget(mImage1);

        mObjectAnimator2 = (ObjectAnimator) AnimatorInflater.loadAnimator(context,
                R.animator.lb_playback_now_bar2_animator);
        mObjectAnimator2.setTarget(mImage2);

        mObjectAnimator3 = (ObjectAnimator) AnimatorInflater.loadAnimator(context,
                R.animator.lb_playback_now_bar3_animator);
        mObjectAnimator3.setTarget(mImage3);
    }

    static void setDropScale(View view) {
        view.setScaleY(1f / 12f);
    }

    @Override
    public void setVisibility(int visibility) {
        super.setVisibility(visibility);
        if (visibility == View.GONE) {
            stopAnimation();
        } else {
            startAnimation();
        }
    }

    @Override
    protected void onAttachedToWindow() {
        super.onAttachedToWindow();
        if (getVisibility() == View.VISIBLE)
            startAnimation();
    }

    @Override
    protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();
        stopAnimation();
    }

    private void startAnimation() {
        startAnimation(mObjectAnimator1);
        startAnimation(mObjectAnimator2);
        startAnimation(mObjectAnimator3);
        mImage1.setVisibility(View.VISIBLE);
        mImage2.setVisibility(View.VISIBLE);
        mImage3.setVisibility(View.VISIBLE);
    }

    private void stopAnimation() {
        stopAnimation(mObjectAnimator1, mImage1);
        stopAnimation(mObjectAnimator2, mImage2);
        stopAnimation(mObjectAnimator3, mImage3);
        mImage1.setVisibility(View.GONE);
        mImage2.setVisibility(View.GONE);
        mImage3.setVisibility(View.GONE);
    }

    private void startAnimation(Animator animator) {
        if (!animator.isStarted()) {
            animator.start();
        }
    }

    private void stopAnimation(Animator animator, View view) {
        if (animator.isStarted()) {
            animator.cancel();
            setDropScale(view);
        }
    }
}