[Android Q&A, Help & Troubleshooting] jitin_s:
Hi All! I'm trying to create an always-op-top button/clickable-image which stays on top of all the windows all the time. The proof of concept is here http://www.appbrain.com/app/smart-taskbar-(sidebar)/com.smart.taskbar and here http://xdaforums.com/showthread.php?t=865525 I'm following this example code http://android.git.kernel.org/?p=pl...6429aaa5ccf6ecf311dfb3af0f3ccbf5f8d29;hb=HEAD

I have been successful and have a running service now. The service displays some text on top left corner of screen all the time while user can freely interact with rest of apps in normal manner. What I'm doing is subclass ViewGroup and add it to root window manager with flag TYPE_SYSTEM_OVERLAY. Now I want to add a button/clickable-image in place of this text which can receive touch events on itself. I tried overriding "onTouchEvent" for the whole ViewGroup but it does not receive any event. How can I receive events only on certain parts of my always-on-top view group? Kindly suggest.

import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.os.IBinder;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.ViewGroup;
import android.view.WindowManager;
import android.widget.AbsoluteLayout;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.widget.Toast;

public class HUD extends Service {
HUDView mView;

@Override
public IBinder onBind(Intent intent) {
return null;
}

@Override
public void onCreate() {
super.onCreate();
Toast.makeText(getBaseContext(),"onCreate", Toast.LENGTH_LONG).show();
mView = new HUDView(this);
WindowManager.LayoutParams params = new WindowManager.LayoutParams(
WindowManager.LayoutParams.WRAP_CONTENT,
WindowManager.LayoutParams.WRAP_CONTENT,
WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY,
0,
// WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
// | WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE,
PixelFormat.TRANSLUCENT);
params.gravity = Gravity.RIGHT | Gravity.TOP;
params.setTitle("Load Average");
WindowManager wm = (WindowManager) getSystemService(WINDOW_SERVICE);
wm.addView(mView, params);
}

@Override
public void onDestroy() {
super.onDestroy();
Toast.makeText(getBaseContext(),"onDestroy", Toast.LENGTH_LONG).show();
if(mView != null)
{
((WindowManager) getSystemService(WINDOW_SERVICE)).removeView(mView);
mView = null;
}
}
}

class HUDView extends ViewGroup {
private Paint mLoadPaint;

public HUDView(Context context) {
super(context);
Toast.makeText(getContext(),"HUDView", Toast.LENGTH_LONG).show();

mLoadPaint = new Paint();
mLoadPaint.setAntiAlias(true);
mLoadPaint.setTextSize(10);
mLoadPaint.setARGB(255, 255, 0, 0);
}

@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawText("Hello World", 5, 15, mLoadPaint);
}

@Override
protected void onLayout(boolean arg0, int arg1, int arg2, int arg3, int arg4) {
}

@Override
public boolean onTouchEvent(MotionEvent event) {
//return super.onTouchEvent(event);
Toast.makeText(getContext(),"onTouchEvent", Toast.LENGTH_LONG).show();
return true;
}
}