Android水波纹效果

 <declare-styleable name="RippleAnimationView">
        <attr name="ripple_anim_color" format="color" />
        <!--   水波纹填充类型     -->
        <attr name="ripple_anim_type" format="enum">
            <enum name="fillRipple" value="0" />
            <enum name="strokeRipple" value="1" />
        </attr>
        <!--    水波纹的半径    -->
        <attr name="radius" format="integer" />
        <!--    水波纹边框大小    -->
        <attr name="stroeWidth" format="integer" />
    </declare-styleable>

public class RippleAnimationView extends RelativeLayout {

    private Paint paint;
    private int radius;
    private int strokeWidth;
    private int rippleColor;

    private AnimatorSet animatorSet;

    public RippleAnimationView(Context context) {
        this(context, null);
    }

    public RippleAnimationView(Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public RippleAnimationView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context, attrs);
    }

    private void init(Context context, AttributeSet attrs) {

        paint = new Paint();
        paint.setAntiAlias(true);

        TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.RippleAnimationView);
        // 水波纹填充类型
        int rippleType = array.getInt(R.styleable.RippleAnimationView_ripple_anim_type, 0);
        radius = array.getInteger(R.styleable.RippleAnimationView_radius, 54);
        strokeWidth = array.getInteger(R.styleable.RippleAnimationView_stroeWidth, 2);
        rippleColor = array.getColor(R.styleable.RippleAnimationView_ripple_anim_color, ContextCompat.getColor(context,
                R.color.colorAccent));
        array.recycle();

        // 设置画笔线宽
        paint.setStrokeWidth(UIUtils.getInstance().getWidth(strokeWidth));
        if (rippleType == 0) {
            paint.setStyle(Paint.Style.FILL);
        } else {
            paint.setStyle(Paint.Style.STROKE);
        }
        paint.setColor(rippleColor);

        LayoutParams params = new LayoutParams(
                UIUtils.getInstance().getWidth(radius + strokeWidth),
                UIUtils.getInstance().getWidth(radius + strokeWidth));
        params.addRule(CENTER_IN_PARENT, TRUE);
        // 缩放系数
        float maxScale =   UIUtils.getInstance().displayMetricsWidth / (2 * UIUtils.getInstance().getWidth(
                radius + strokeWidth
        ));
        // 延迟时间
        int rippleDuration = 3500;
        int singleDelay = rippleDuration / 4; // 时间间隔

        // 动画集合
        List<Animator> animatorList = new ArrayList<>();
        // 实例化水波纹view
        for (int i = 0;i<4;i++){
            RippleCircleView rippleCircleView = new RippleCircleView(this);
            addView(rippleCircleView,params);
            // 添加水波纹到集合
            viewList.add(rippleCircleView);

            // 初始化属性动画
            // x
            ObjectAnimator scaleXAnimator = ObjectAnimator.ofFloat(rippleCircleView,"ScaleX",
                    1.0f,maxScale);
            scaleXAnimator.setRepeatCount(ObjectAnimator.INFINITE);// 无限循环
            scaleXAnimator.setRepeatMode(ObjectAnimator.RESTART);
            scaleXAnimator.setStartDelay(i*singleDelay);
            scaleXAnimator.setDuration(rippleDuration);
            animatorList.add(scaleXAnimator);
            // y
            ObjectAnimator scaleYAnimator = ObjectAnimator.ofFloat(rippleCircleView,"ScaleY",
                    1.0f,maxScale);
            scaleYAnimator.setRepeatCount(ObjectAnimator.INFINITE);// 无限循环
            scaleYAnimator.setRepeatMode(ObjectAnimator.RESTART);
            scaleYAnimator.setStartDelay(i*singleDelay);
            scaleYAnimator.setDuration(rippleDuration);
            animatorList.add(scaleYAnimator);
            // alpha
            ObjectAnimator alphaAnimator = ObjectAnimator.ofFloat(rippleCircleView,"Alpha",
                    1.0f,0f);
            alphaAnimator.setRepeatCount(ObjectAnimator.INFINITE);// 无限循环
            alphaAnimator.setRepeatMode(ObjectAnimator.RESTART);
            alphaAnimator.setStartDelay(i*singleDelay);
            alphaAnimator.setDuration(rippleDuration);
            animatorList.add(alphaAnimator);
        }

        animatorSet = new AnimatorSet();
        animatorSet.setInterpolator(new AccelerateDecelerateInterpolator()); // 差值器:先加速，后减速
        animatorSet.playTogether(animatorList);
    }

    private boolean animationRunning;
    private List<RippleCircleView> viewList = new ArrayList<>();
    /**
     * 开启动画
     */
    public void startRippleAnimation(){
        if (!animationRunning){
            for (RippleCircleView  rippleCircleView: viewList) {
                rippleCircleView.setVisibility(VISIBLE);
            }
            animatorSet.start();
            animationRunning = true;
        }
    }
    /**
     *  结束动画
     */
    public void stopRippleAnimation(){
        if (animationRunning){
            // 逆序播放（从外向内播放动画）
            Collections.reverse(viewList);
            for (RippleCircleView  rippleCircleView: viewList) {
                rippleCircleView.setVisibility(INVISIBLE);
            }
            animatorSet.end();
            animationRunning = false;
        }
    }

    public int getStrokeWidth() {
        return strokeWidth;
    }

    public Paint getPaint() {
        return paint;
    }

    public boolean isAnimationRunning() {
        return animationRunning;
    }
}

public class RippleCircleView extends View {

    private RippleAnimationView rippleAnimationView;

    public RippleCircleView(RippleAnimationView rippleAnimationView) {
        this(rippleAnimationView.getContext(),null);
        this.rippleAnimationView = rippleAnimationView;
        // 一开始隐藏
        this.setVisibility(INVISIBLE);
    }

    public RippleCircleView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    public RippleCircleView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        int radius = Math.min(getWidth(),getHeight()) / 2;

        // 画圆
        canvas.drawCircle(radius,radius,radius - rippleAnimationView.getStrokeWidth(),
                rippleAnimationView.getPaint());
    }
}

<com.wangyi.course.lession4.RippleAnimationView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/ripple_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:ripple_anim_color="#c0362e"
    app:stroeWidth="18"
    app:ripple_anim_type="strokeRipple"
    app:radius="150">
    <ImageView
        android:id="@+id/iv_play"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:src="@drawable/ic_play"
        />
</com.wangyi.course.lession4.RippleAnimationView>

 RippleAnimationView rippleAnimationView = findViewById(R.id.ripple_view);
        findViewById(R.id.iv_play)
                .setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        if (rippleAnimationView.isAnimationRunning()) {
                            rippleAnimationView.stopRippleAnimation();
                        } else {
                            rippleAnimationView.startRippleAnimation();
                        }
                    }
                });