025 Java Android Program to Demonstrate Touch Listener
Posted by Superadmin on December 21 2015 05:36:08

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This Android Java Program demonstrates on Touch Listener.
Here is source code of the Program to demonstrates on Touch Listener. The program is successfully compiled and run on a Windows system using Eclipse Ide. The program output is also shown below.

Main Activity

package com.example.on_touch_listener;


import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.View.OnTouchListener;

public class MainActivity extends Activity implements OnTouchListener {


Ourview v;
Bitmap bm;
float x,y;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
v = new Ourview(this);
v.setOnTouchListener(this);
bm = BitmapFactory.decodeResource(getResources(), R.drawable.image4);
x=0;y=0;
setContentView(v);
}

@Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
v.pause();
}

@Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
v.resume();
}

// surface view is going to be a thread now
class Ourview extends SurfaceView implements Runnable {

Thread th = null;
SurfaceHolder holder;
boolean var = false;

public Ourview(Context context) {
super(context);
// TODO Auto-generated constructor stub
holder = getHolder();
}

@Override
public void run() {
// TODO Auto-generated method stub
while (var = true) {
// do stuff
if (!holder.getSurface().isValid()) {
continue;
}
Canvas c = holder.lockCanvas();// while drawing on a canvas we
// lock it and after drawing on
// it we unlock it

c.drawARGB(255, 250, 150, 20);//rgb values
c.drawBitmap(bm, x -(bm.getWidth()/2), y -(bm.getHeight()/2), null );
holder.unlockCanvasAndPost(c);
}
}

public void pause() {

var = false;
while (true) {
try {
th.join();// would pause the currently executing thread till
// the user finishes its job
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
break;
}
th = null;
}

public void resume() {
var = true;
th = new Thread(this);
th.start();
}
}

@Override
public boolean onTouch(View v, MotionEvent me) {
// TODO Auto-generated method stub
//update the value of x and y on every touch so that our bitmap gets drawn with that x and y position which we just changed on clicking
x=me.getX();//ontouch listener
y=me.getY();

return true;
}

}