javaandroidcollision-detectioncollision

Collision detection between ImageViews


I need help getting two ImageViews to collide, I looked around on this website and many youtube videos and think I have found one solution to my problem. I found some code from another person post,

how to detect when a ImageView is in collision with another ImageView?

and I'm just wondering where I should place that code in my program because when it's at the bottom i try to log.d to show if I was succesful on trying to detect whether the imageViews collided and nothing shows. Anyways here is my code and the code I used from the other question is at the very bottom and used as a comment. YOUR HELP IS EXTREMELY APPRECIATED, THANK YOU IF YOU HELPED ME!

Main.java

package com.example.admin.basketball;

import android.graphics.Point;


import android.os.Handler;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import android.view.Display;
import android.view.MotionEvent;
import android.view.View;
import android.view.WindowManager;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

//Layout
private RelativeLayout myLayout = null;

//Screen Size
private int screenWidth;
private int screenHeight;

//Position
private float ballDownY;
private float ballDownX;

//Initialize Class
private Handler handler = new Handler();
private Timer timer = new Timer();

//Images
private ImageView net = null;
private ImageView ball = null;

//for net movement along x-axis
float x;
float y;

//points
private int points = 0;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    myLayout = (RelativeLayout) findViewById(R.id.myLayout);

    //score
    final TextView score = (TextView) findViewById(R.id.score);


    //imageviews
    net = (ImageView) findViewById(R.id.net);
    ball = (ImageView) findViewById(R.id.ball);


    //retrieving screen size
    WindowManager wm = getWindowManager();
    Display disp = wm.getDefaultDisplay();
    Point size = new Point();
    disp.getSize(size);
    screenWidth = size.x;
    screenHeight = size.y;

    //move to out of screen
    ball.setX(-80.0f);
    ball.setY(screenHeight + 80.0f);


    //start timer
    timer.schedule(new TimerTask() {
        @Override
        public void run() {
            handler.post(new Runnable() {
                @Override
                public void run() {
                    changePos();
                }
            });
        }
    }, 0, 20);
}


public void changePos() {
    //down

    ballDownY += 10;
    if (ball.getY() > screenHeight) {
        ballDownX = (float) Math.floor((Math.random() * (screenWidth - 
ball.getWidth())));
        ballDownY = -100.0f;

    }
    ball.setY(ballDownY);
    ball.setX(ballDownX);


    //make net follow finger
    myLayout.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View view, MotionEvent event) {
            MainActivity.this.x = event.getX();
            y = event.getY();

            if (event.getAction() == MotionEvent.ACTION_MOVE) {
                net.setX(MainActivity.this.x);
                net.setY(y);

            }
            return true;
        }
    });
}

}



/*
private boolean viewsOverlap(ImageView net, ImageView ball) {

    int[] net_coords = new int[2];
    net.getLocationOnScreen(net_coords);
    int net_w = net.getWidth();
    int net_h = net.getHeight();
    Rect net_rect = new Rect(net_coords[0], net_coords[1], net_coords[0] + 
net_w, net_coords[1] + net_h);

    int[] ball_coords = new int[2];
    ball.getLocationOnScreen(ball_coords);
    int ball_w = ball.getWidth();
    int ball_h = ball.getHeight();
    Rect ball_rect = new Rect(ball_coords[0], ball_coords[1], ball_coords[0] 
+ ball_w, ball_coords[1] + ball_h);

    return net_rect.intersect(ball_rect) || net_rect.contains(ball_rect) || 
ball_rect.contains(net_rect);

}*/

Solution

  • Collision detection and score increase:

    public class MainActivity extends AppCompatActivity 
    {
       //Layout
       private RelativeLayout myLayout = null;
    
       //Screen Size
       private int screenWidth;
       private int screenHeight;
    
       //Position
       private float ballDownY;
       private float ballDownX;
    
       //Initialize Class
       private Handler handler = new Handler();
       private Timer timer = new Timer();
    
       //Images
       private ImageView net = null;
       private ImageView ball = null;
    
       //score
       private TextView score = null;
    
       //for net movement along x-axis
       public float x = 0;
       public float y = 0;
    
       //points
       private int points = 0;
    
    
       @Override
        protected void onCreate(Bundle savedInstanceState) 
        {
             super.onCreate(savedInstanceState);
    
             this.setContentView(R.layout.activity_main);
             this.myLayout = (RelativeLayout) findViewById(R.id.myLayout);
    
             this.score = (TextView) findViewById(R.id.score);
    
             this.net = (ImageView) findViewById(R.id.net);
             this.ball = (ImageView) findViewById(R.id.ball);
    
             //retrieving screen size
             WindowManager wm = getWindowManager();
             Display disp = wm.getDefaultDisplay();
             Point size = new Point();
             disp.getSize(size);
             screenWidth = size.x;
             screenHeight = size.y;
    
             //move to out of screen
             this.ball.setX(-80.0f);
             this.ball.setY(screenHeight + 80.0f);
    
              //Error here
             /*//Run constantly
             new Handler().postDelayed(new Runnable()
             {
               @Override
               public void run()
               {
                  Render();
               }
             }, 100); //100 is miliseconds interval than sleep this process, 1000 miliseconds is 1 second*/
    
         Thread t = new Thread() {
         @Override
         public void run() {
         try {
            while (!isInterrupted()) {
                 Thread.sleep(100);
                 runOnUiThread(new Runnable() {
                 @Override
                 public void run(){Render();}});}
                 }catch (InterruptedException e) {}}};
    
         t.start();
    
        }
    
        public void Render()
        {
            changePos();
            if(Collision(net, ball))
            {
              points++; //You dont need findView Textview score for that exists in OnCreate Method
              this.score.setText("Score:" + points);
            }
        }
    
        public void changePos() 
        {
    
            //down
            ballDownY += 10;
            if (ball.getY() > screenHeight) {
            ballDownX = (float) Math.floor((Math.random() * (screenWidth - ball.getWidth())));
            ballDownY = -100.0f;
    
        }
        ball.setY(ballDownY);
        ball.setX(ballDownX);
    
          //make net follow finger
          myLayout.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View view, MotionEvent event) {
                x = event.getX();
                y = event.getY();
    
                if (event.getAction() == MotionEvent.ACTION_MOVE) {
                    net.setX(x);
                    net.setY(y);
                }
                return true;
            }
    
        });
    
        public boolean Collision(ImageView net, ImageView ball)
        {
           Rect BallRect = new Rect();
           ball.getHitRect(BallRect);
           Rect NetRect = new Rect();
           net.getHitRect(NetRect);
           return BallRect.intersect(NetRect);
        }
    }