ScreenShade
Current Design
ScreenShade is an app I created to experiment with overlays and animations. The effect is most pronounced on phones with OLED screens, which provide deeper blacks.
I implemented the TapTargetView library for guiding the user through the basic elements of the app.
Getting Started
To enable the overlay, single tap the floating button.
Once the overlay is covering the screen, double tap the screen or hit the back button to hide the overlay.
You can peek behind the shade overlay by tapping and holding the screen.
The floating button can be removed by dragging it to the bottom of the screen.
App Details
The minimum Android SDK version is 23.
The "draw over apps" permission is required to run.
How it works
Screen Shade is able to create Views that persist between apps by adding Views to the Window Manager system service. When the enable button in the main activity is clicked, a service is started that handles all of the logic and overlay creation.
The Window Manager
The WindowManager is an extension of the ViewManager, which has three methods available for use:
- addView()
- updateViewLayout()
- removeView()
These methods provide no exception/error handling by themselves (ex: in the case of adding a view twice, or removing a view that is not yet added to the window manager). For this reason, I created an Overlay class that would handle these methods safely and abstract away functionality shared between the various overlays in this app.
OverlayService and OverlayManager
When the app is started, an instance of an OverlayService is created, which holds an instance of OverlayManager, which supervises the various overlays and handles their interactions.