Moving an ImageView located in a WindowManager doesn't work properly - android-layout

Question

I'm trying to draw an Icon over everything on the screen (TOP MOST) similar to the chathead of new Facebook messenger
I have create a service to work in the background and based on a specific condition my icon should appear on the screen (exactly like when someone sends you a message on facebook the messenger service will hook the message and shows the chathead on the screen to notify you about the new message)
What I did:
I have created the service and gave it the permission to show system alert windows (since the head is actually a system alert window)
[assembly: UsesPermission(Name = Android.Manifest.Permission.SystemAlertWindow)]
I have inherited a class (StickyHeadView) from ImageView and implemented OnTouchListener listener using the following way :
class StickyHeadView : ImageView, Android.Views.View.IOnTouchListener
{
private StickyHeadService OwnerService;
public StickyHeadView(StickyHeadService ContextService, Context context)
: base(context)
{
OwnerService = ContextService;
SetOnTouchListener(this);
}
float TouchMoveX;
float TouchMoveY;
public bool OnTouch(View v, MotionEvent e)
{
var windowService = OwnerService.GetSystemService(Android.Content.Context.WindowService);
var windowManager = windowService.JavaCast<Android.Views.IWindowManager>();
switch (e.Action & e.ActionMasked)
{
case MotionEventActions.Move:
TouchMoveX = (int)e.GetX();
TouchMoveY = (int)e.GetY();
OwnerService.LOParams.X = (int)(TouchMoveX);
OwnerService.LOParams.Y = (int)(TouchMoveY);
windowManager.UpdateViewLayout(this, OwnerService.LOParams);
Log.Debug("Point : ", "X: " + Convert.ToString(OwnerService.LOParams.X) + " Y: " + Convert.ToString(OwnerService.LOParams.Y));
return true;
case MotionEventActions.Down:
return true;
case MotionEventActions.Up:
return true;
}
return false;
}
}
The service has wiindow manager to show the Icon on it...in Service "OnStart" event I initialize the Head :
private StickyHeadView MyHead;
public Android.Views.WindowManagerLayoutParams LOParams;
public override void OnStart(Android.Content.Intent intent, int startId)
{
base.OnStart(intent, startId);
var windowService = this.GetSystemService(Android.Content.Context.WindowService);
var windowManager = windowService.JavaCast<Android.Views.IWindowManager>();
MyHead = new StickyHeadView(this, this);
MyHead.SetImageResource(Resource.Drawable.Icon);
LOParams = new Android.Views.WindowManagerLayoutParams(Android.Views.WindowManagerLayoutParams.WrapContent,
Android.Views.WindowManagerLayoutParams.WrapContent,
Android.Views.WindowManagerTypes.Phone,
Android.Views.WindowManagerFlags.NotFocusable,
Android.Graphics.Format.Translucent);
LOParams.Gravity = GravityFlags.Top | GravityFlags.Left;
LOParams.X = 10;
LOParams.Y = 10;
windowManager.AddView(MyHead, LOParams);
}
as you can see I have declared a WindowManager and added the view (MyHead) to it with special parameters
My Problem :
When ever I try to move the View (My head) it doesn't move in a stable way and keeps having a quake!
I'm testing it using android 4.0.4 on real HTC Phone
I'm using monodroid
Please help...if the implementation of the touch is not right please suggest a better way...thank you.

Answer 1

In your code just use...
TYPE_SYSTEM_ALERT
or
TYPE_PHONE
instead of
TYPE_SYSTEM_OVERLAY
Hope this will help you.
a working example:
#Override
public void onCreate() {
super.onCreate();
windowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
chatHead = new ImageView(this);
chatHead.setImageResource(R.drawable.ic_launcher);
final WindowManager.LayoutParams params = new WindowManager.LayoutParams(
WindowManager.LayoutParams.WRAP_CONTENT,
WindowManager.LayoutParams.WRAP_CONTENT,
WindowManager.LayoutParams.TYPE_SYSTEM_ALERT, //TYPE_PHONE
WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
PixelFormat.TRANSLUCENT);
params.gravity = Gravity.TOP | Gravity.LEFT;
params.x = 0;
params.y = 100;
windowManager.addView(chatHead, params);
chatHead.setOnTouchListener(new View.OnTouchListener() {
private int initialX;
private int initialY;
private float initialTouchX;
private float initialTouchY;
#Override public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
initialX = params.x;
initialY = params.y;
initialTouchX = event.getRawX();
initialTouchY = event.getRawY();
return true;
case MotionEvent.ACTION_UP:
return true;
case MotionEvent.ACTION_MOVE:
params.x = initialX + (int) (event.getRawX() - initialTouchX);
params.y = initialY + (int) (event.getRawY() - initialTouchY);
windowManager.updateViewLayout(chatHead, params);
return true;
}
return false;
}
});
}

Answer 2

The e.GetX()/eGetY() you are using is relative to view position so when you move the view with UpdateViewLayout the next values will be relative to the move. It works using GetRawX()/GetRawY(), but you have to keep track of the initial Down rawX and rawY also.
Here is my JAVA that works:
#Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_MOVE:
layoutParams.x = Math.round(event.getRawX() - downX);
layoutParams.y = Math.round(event.getRawY() - downY);
windowManager.updateViewLayout(floatingView, layoutParams);
return true;
case MotionEvent.ACTION_DOWN:
downX = event.getRawX() - layoutParams.x;
downY = event.getRawY() - layoutParams.y;
return true;
case MotionEvent.ACTION_UP:
return true;
}
return false;
}
One comment, there's a big downside in using windowManager.updateViewLayout(...) this method will call onLayout on the floating view for each move, and that might be a performance issue, anyway until now I haven't found another method to move the floating view.

Answer 3

Try this might be help ful
first add global variable on your activity:
WindowManager wm;
LinearLayout lay;
float downX,downY;
after put in code to oncreate on your activity
Button btnstart=(Button)findViewById(R.id.button1);
Button btnstop=(Button)findViewById(R.id.button2);
btnstart.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(lay==null)
{
wm = (WindowManager) getApplicationContext().getSystemService(
Context.WINDOW_SERVICE);
final WindowManager.LayoutParams params = new WindowManager.LayoutParams(
LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT,
WindowManager.LayoutParams.TYPE_SYSTEM_ALERT
| WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY,
WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL
| WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
PixelFormat.TRANSLUCENT);
params.x = (int) wm.getDefaultDisplay().getWidth();
params.y = 0;
// params.height = wm.getDefaultDisplay().getHeight()/2;
params.width = LayoutParams.WRAP_CONTENT;
params.format = PixelFormat.TRANSLUCENT;
params.gravity = Gravity.TOP | Gravity.LEFT;
params.setTitle("Info");
lay = null;
lay = new LinearLayout(getApplicationContext());
lay.setOrientation(LinearLayout.VERTICAL);
// lay.setAlpha(0.5f);
TextView txt_no = new TextView(getApplicationContext());
txt_no.setTextSize(10.0f);
txt_no.setText("Moving view by stack user!");
txt_no.setTextColor(Color.BLACK);
// txt_no.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT,
// LayoutParams.WRAP_CONTENT));
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
layoutParams.setMargins(0, 0, 0, 0); // margins as you wish
txt_no.setGravity(Gravity.RIGHT);
txt_no.setBackgroundColor(Color.WHITE);
txt_no.setLayoutParams(layoutParams);
txt_no.setPadding(10, 10, 10, 10);
lay.addView(txt_no);
AlphaAnimation alpha = new AlphaAnimation(0.5F, 0.5F);
alpha.setDuration(0); // Make animation instant
alpha.setFillAfter(true); // Tell it to persist after the animation ends
// And then on your layout
wm.addView(lay, params);
txt_no.startAnimation(alpha);
downX=params.x;
downY=params.y;
Log.v("MSES>", "x="+ downX +",y="+ downY);
lay.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
switch (event.getAction()) {
case MotionEvent.ACTION_MOVE:
params.x = Math.round(event.getRawX() - downX);
params.y = Math.round(event.getRawY() - downY);
wm.updateViewLayout(lay, params);
Log.v("MSES EVENT>", "x="+ event.getRawX() +",y="+ event.getRawY());
Log.v("MSES MOVE>", "x="+ params.x +",y="+ params.y);
return true;
case MotionEvent.ACTION_DOWN:
downX = event.getRawX() - params.x;
downY = event.getRawY() - params.y;
Log.v("MSES DOWN>", "x="+ params.x +",y="+ params.y);
return true;
case MotionEvent.ACTION_UP:
//params.x = Math.round(event.getRawX() - downX);
//params.y = Math.round(event.getRawY() - downY);
//wm.updateViewLayout(lay, params);
return true;
}
return false;
}
});
}
}
});
btnstop.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (lay != null) {
lay.removeAllViews();
wm.removeViewImmediate(lay);
lay = null;
}
}
});