MediaProjectionHolder

Holds the MediaProjection token obtained by the host Activity, plus the single VirtualDisplay + ImageReader pair mirroring the screen for it.

The host app must call set after the user grants screen-capture consent (e.g. via MediaProjectionManager.createScreenCaptureIntent()). CaptureScreenTool reads the token from here.

set registers a per-projection MediaProjection.Callback, required for two reasons: the platform requires a callback to be registered before createVirtualDisplay() can be called at all — without one, CaptureScreenTool throws IllegalStateException on every call; and onStop lets this holder clear itself when the user revokes consent via the system's screen-capture notification, instead of holding a dead token that looks valid but isn't. The callback only clears state if the stopping projection is still the current one, so a late onStop from a replaced projection can't wipe out its successor.

One virtual display per projection. On Android 14+ (targetSdk 34+) a MediaProjection may call createVirtualDisplay only once. The holder therefore creates the virtual display lazily on the first capture and keeps it (and its reader) alive for the projection's lifetime; each capture reads the most recent frame. Everything is released when the projection stops, on clear, or when set replaces it.