Android Custom UI Particle Effect

In this article, we share the specific code of Android custom UI particle effect for your reference, the specific content is as follows

1. Explosive entity class

public class Ball {

  public int color;// Color 
  public float x;// Center of Circle x Coordinates 
  public float y;// Center of Circle y Coordinates 
  public float r;// Particle radius 

  public float vX;// Horizontal velocity of particles 
  public float vY;// Particle y Directional velocity 
  public float aX;// Horizontal acceleration of particles 
  public float ay;// Particle y Directional acceleration 
}

2. Customize the SplitView class

import android.animation.ValueAnimator;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.animation.LinearInterpolator;

import androidx.annotation.Nullable;

import java.util.ArrayList;
import java.util.List;

public class SplitView extends View {

  private Paint mPaint;
  private Bitmap mBitmap;
  private float d=3;// Particle diameter 
  private ValueAnimator mAnimator;
  private List<Ball> mBalls=new ArrayList<>();
  public SplitView(Context context) {
    super(context);
  }

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

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

  private void init() {
    mPaint=new Paint();
    mBitmap= BitmapFactory.decodeResource(getResources(),R.drawable.ic_launcher_background);
    for (int i=0;i<mBitmap.getWidth();i++){
      for (int j =0;j<mBitmap.getHeight();j++){
        Ball ball=new Ball();
        ball.color=mBitmap.getPixel(i,j);
        ball.x=i*d+d/2;
        ball.y=j*d+d/2;
        ball.r=d/2;

        // Speed ( -20 , 20 ) 
        ball.vX=(float)(Math.pow(-1,Math.ceil(Math.random()*1000))*20*Math.random());
        ball.vY=rangInt(-15,35);

        ball.aX=0;
        ball.ay=0.98f;
        mBalls.add(ball);
      }
    }
    mAnimator=ValueAnimator.ofFloat(0,1);
    mAnimator.setRepeatCount(-1);// Infinite number of repetitions 
    mAnimator.setDuration(2000);// Repetition time 
    mAnimator.setInterpolator(new LinearInterpolator());
    mAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
      @Override
      public void onAnimationUpdate(ValueAnimator animation) {
        upDateBall();
        invalidate();// Recall onMeasure,ondraw Method. 
      }
    });
  }

  private int rangInt(int x,int y){
    int max=Math.max(x,y);
    int min=Math.min(x,y);
    return (int)(min+Math.ceil(Math.random()*(max-min)));
  }

  private void upDateBall() {
    for (Ball ball:mBalls){
      ball.x=ball.x+ball.vX;
      ball.y=ball.y+ball.vY;
      ball.vX+=ball.aX;
      ball.vY+=ball.ay;

    }

  }

  @Override
  protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    canvas.translate(500,500);
    for (Ball ball:mBalls){
      mPaint.setColor(ball.color);
      canvas.drawCircle(ball.x,ball.y,ball.r,mPaint);
    }
  }

  @Override
  public boolean onTouchEvent(MotionEvent event) {
   if (event.getAction()==MotionEvent.ACTION_DOWN)
   {

     // Trigger animation 
     mAnimator.start();
   }
    return super.onTouchEvent(event);
  }
}