Background
There are some nice apps out there that show some layout on top , while the user is making a call or answering one (like "current caller id").
I need to create an app with the ability to show something on top , during a call, and allow it to be interactive.
The problem
Using broadcastReceiver ,foreground service and SYSTEM_ALERT permission, I've succeeded showing something on the screen during calls.
As long as the content being shown is static, I have no problems.
However, I've noticed that when I try to make the content being shown to be interactive , I face some problems:
Everything is jumpy and this includes not only animations, but also setting visibility to visible/gone. I hate to think how it would work like when I need to make things draggable.
Not sure if this is the reason, but using the SlidingDrawer make the entire width belong to the SlidingDrawer and you cannot click through it. This means that if its location is at the bottom, you can't touch the "answer" button when someone calls you.
The question
What is the reason for those problems?
How can I fix them and be able to show things right?
How do other apps handle it right ?
EDIT: about the SlidingDrawer , it seems that it has terrible bugs about its location and size, and the content area, even when it's not shown to the user and the user can see through, it cannot be touched through. Still, I don't know why, and how to fix it, and I also don't know why things are so jumpy compared to normal apps (probably because of over-drawing, but it's really really slow).
Maybe this question should be more general: how to make a floating window like on AirCalc, that can be moved easily yet still be quite fast.
For the dragging functionality, I've tried to get the layoutParams of the root view (which is of type WindowManager.LayoutParams ) that I show, update it and set it again, but for some reason it didn't do anything. Wonder what I'm doing wrong.
EDIT: it seems that i should be using windowManager.updateViewLayout for updating the layoutParams. Using this post , I've made it perfectly draggable.
Ok, I've come up to some conclusions about this, first to answer my original questions:
it's probably because of overdraw and the views i've used. I wanted to try out libraries that could replace the slidingDrawer , but each had a different problem. using simple views proved that the idea in general works.
in the case of visibility changes, it was jumpy because the size of the view wasn't able to fit using the current WindowManager.LayoutParams size.
slidingDrawaer does have issues since it uses the whole size it get when closed or opened.
now to the rest of the issues :
unable to drag ? instead of the regular setLayoutParams , use windowManager.updateViewLayout .
unable to touch outside of the view ? set its minimal size according to your needs. you can also set the window flags so that touch event would go through .
want to listen to calls events ? you can use the broadcastReceiver for triggering the showing of the app, but I suspect that hanging the call might cause the intent be received later sometimes. I think you can use telephonyManager and listen to events there, using the service you run in the foreground (that i've created just to make sure the app won't close in the middle).
if anyone else has questions, i can help.