atmob-task/src/main/java/com/atmob/task/view/TwinklingRecyclerView.java

package com.atmob.task.view;

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.ValueAnimator;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.recyclerview.widget.RecyclerView;

public class TwinklingRecyclerView extends RecyclerView {

    private Paint paint;

    private boolean twinkling;
    private ValueAnimator valueAnimator;

    public TwinklingRecyclerView(@NonNull Context context) {
        this(context, null);
    }

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

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

    private void init() {
        paint = new Paint(Paint.ANTI_ALIAS_FLAG);
        paint.setColor(Color.parseColor("#ccff7c7c"));
        addItemDecoration(new ItemDecoration() {
            @Override
            public void onDrawOver(@NonNull Canvas c, @NonNull RecyclerView parent, @NonNull State state) {
                super.onDrawOver(c, parent, state);
                if (!twinkling) {
                    return;
                }
                for (int i = 0; i < parent.getChildCount(); i++) {
                    View childAt = parent.getChildAt(i);
                    int left = childAt.getLeft();
                    int top = childAt.getTop();
                    int right = childAt.getRight();
                    int bottom = childAt.getBottom();
                    c.drawRoundRect(left, top, right, bottom, 10, 10, paint);
                }
            }
        });
    }

    public void twinkling() {
        if (valueAnimator == null) {
            valueAnimator = new ValueAnimator();
            valueAnimator.setFloatValues(0, 1);
            valueAnimator.setRepeatCount(2);
            valueAnimator.setRepeatMode(ValueAnimator.RESTART);
            valueAnimator.setDuration(500);
            valueAnimator.addUpdateListener(animation -> {
                float value = (float) animation.getAnimatedValue();
                twinkling = value > 0.5;
                invalidate();
            });
            valueAnimator.addListener(new AnimatorListenerAdapter() {
                @Override
                public void onAnimationEnd(Animator animation) {
                    super.onAnimationEnd(animation);
                    twinkling = false;
                    invalidate();
                }
            });
        }
        if (valueAnimator.isRunning()) {
            valueAnimator.cancel();
        }
        valueAnimator.start();
    }

    @Override
    protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();
        if (valueAnimator != null) {
            valueAnimator.cancel();
        }
    }
}