Drag and drop images in android

Question

I m working on a word scramble game which allows user to move the image to image..if the image doesn't match then it should come back to it's original position from where it was dragged.I have written a sample code to move the image but the problem here is if I move one image the neighbouring image also starts moving.. Here is the sample code.

 /** Touchmoveimage.java*/
     package com.examples.Touchmoveimage;
     import android.app.Activity;
     import android.content.Intent;
     import android.os.Bundle;
     import android.view.MotionEvent;
     import android.view.View;
     import android.view.View.OnTouchListener;
     import android.widget.ImageView;
     import android.widget.LinearLayout.LayoutParams;
     public class Touchmoveimage extends Activity implements OnTouchListener{

int windowwidth;
int windowheight;

   private LayoutParams layoutParams ;
   private LayoutParams layoutParams1 ;
   @Override
   public void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   setContentView(R.layout.main);

  windowwidth = getWindowManager().getDefaultDisplay().getWidth();
  windowheight = getWindowManager().getDefaultDisplay().getHeight();

  ImageView ball= (ImageView)findViewById(R.id.ball);
  ball.setOnTouchListener(this);

  ImageView ball1 = (ImageView)findViewById(R.id.ball1);
  ball1.setOnTouchListener(this); 

 }   
 public boolean onTouch(View v,MotionEvent event) {
 switch(v.getId())
 {
 case R.id.ball:
   ImageView ball= (ImageView)findViewById(R.id.ball);
   layoutParams = (LayoutParams) ball.getLayoutParams();
      switch(event.getAction())
      {
      case MotionEvent.ACTION_DOWN:   
             break;
      case MotionEvent.ACTION_MOVE:
                   int x_cord = (int)event.getRawX();
                   int y_cord = (int)event.getRawY();

                   if(x_cord>windowwidth){x_cord=windowwidth;}
                   if(y_cord>windowheight){y_cord=windowheight;}

                  layoutParams.leftMargin = x_cord -25;
                 layoutParams.topMargin = y_cord - 75;

                 ball.setLayoutParams(layoutParams);
             break;
             default : break;
      }
 case R.id.ball1:
     ImageView ball1= (ImageView)findViewById(R.id.ball1);
       layoutParams1 = (LayoutParams) ball1.getLayoutParams();
          switch(event.getAction())
          {
          case MotionEvent.ACTION_DOWN:   
                 break;
          case MotionEvent.ACTION_MOVE:
                       int x_cord = (int)event.getRawX();
                       int y_cord = (int)event.getRawY();

                       if(x_cord>windowwidth){x_cord=windowwidth;}
                       if(y_cord>windowheight){y_cord=windowheight;}

                      layoutParams1.leftMargin = x_cord -25;
                       layoutParams1.topMargin = y_cord - 75;

                       ball1.setLayoutParams(layoutParams1);
                 break;          
       default : break;
        }
      }
     return true;}

      }

     <!-- main.xml -->

       <?xml version="1.0" encoding="utf-8"?>
       <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
       android:orientation="vertical"
       android:layout_width="fill_parent"
      android:layout_height="fill_parent"
     >
     <ImageView 
     android:layout_width="50sp" 
     android:layout_height="50sp" 
     android:id="@+id/ball"
    android:src="@drawable/ball">
   </ImageView>

   <ImageView 
    android:layout_y="30dip" 
    android:layout_x="118dip" 
    android:layout_width="50sp" 
    android:layout_height="50sp" 
    android:id="@+id/ball1"
    android:src="@drawable/ball1">
   </ImageView>

    </LinearLayout>

Anyone plz help me out..Trying all possible thing to solve it..

Answer 1

You need to make sure the event is happening in the given ball. The onTouch event will be declared even if you are touching outside of the image object. So what you could do is to check in the ACTION_DOWN phases you've blocked off to make sure the touch is in the bounds of the object. You could then set a flag to tell the system which ball is being moved. I'll let you do the coding up, but hopefully this will let you get an idea as to what to do.