Merge "Update TrustedPresentationListener docs and update exceptions" into main (f5d37c93) · Commits · e / os / android_frameworks_base

core/java/android/view/WindowManager.java

+55 −8

Original line number	Original line	Diff line number	Diff line
	@@ -6016,16 +6016,63 @@ public interface WindowManager extends ViewManager {
	}		}

	/**		/**
	* Add a trusted presentation listener associated with a window.		* Sets a callback to receive feedback about the presentation of a {@link Window}.
	*		* When the {@link Window} is presented according to the passed in
	* <p> If this listener is already registered then the window and thresholds will be updated.		* {@link TrustedPresentationThresholds}, it is said to "enter the state", and receives the
			* callback with {@code true}. When the conditions fall out of thresholds, it is then
			* said to leave the state and the caller will receive a callback with {@code false}. The
			* callbacks be sent for every state transition thereafter.
			* <p>
			* There are a few simple thresholds:
			* <ul>
			* <li>minAlpha: Lower bound on computed alpha</li>
			* <li>minFractionRendered: Lower bounds on fraction of pixels that were rendered</li>
			* <li>stabilityThresholdMs: A time that alpha and fraction rendered must remain within
			* bounds before we can "enter the state" </li>
			* </ul>
			* <p>
			* The fraction of pixels rendered is a computation based on scale, crop
			* and occlusion. The calculation may be somewhat counterintuitive, so we
			* can work through an example. Imagine we have a Window with a 100x100 buffer
			* which is occluded by (10x100) pixels on the left, and cropped by (100x10) pixels
			* on the top. Furthermore imagine this Window is scaled by 0.9 in both dimensions.
			* (c=crop,o=occluded,b=both,x=none)
			*
			* <blockquote>
			* <table>
			* <caption></caption>
			* <tr><td>b</td><td>c</td><td>c</td><td>c</td></tr>
			* <tr><td>o</td><td>x</td><td>x</td><td>x</td></tr>
			* <tr><td>o</td><td>x</td><td>x</td><td>x</td></tr>
			* <tr><td>o</td><td>x</td><td>x</td><td>x</td></tr>
			* </table>
			* </blockquote>
	*		*
	* @param window The Window to add the trusted presentation listener for		*<p>
	* @param thresholds The {@link TrustedPresentationThresholds} that will specify		* We first start by computing fr=xscaleyscale=0.90.9=0.81, indicating
	* when the to invoke the callback.		* that "81%" of the pixels were rendered. This corresponds to what was 100
			* pixels being displayed in 81 pixels. This is somewhat of an abuse of
			* language, as the information of merged pixels isn't totally lost, but
			* we err on the conservative side.
			* <p>
			* We then repeat a similar process for the crop and covered regions and
			* accumulate the results: fr = fr * (fractionNotCropped) * (fractionNotCovered)
			* So for this example we would get 0.90.90.9*0.9=0.65...
			* <p>
			* Notice that this is not completely accurate, as we have double counted
			* the region marked as b. However we only wanted a "lower bound" and so it
			* is ok to err in this direction. Selection of the threshold will ultimately
			* be somewhat arbitrary, and so there are some somewhat arbitrary decisions in
			* this API as well.
			* <p>
			* @param window The Window to add the trusted presentation listener for. This can be
			* retrieved from {@link View#getWindowToken()}.
			* @param thresholds The {@link TrustedPresentationThresholds} that will specify when the to
			* invoke the callback.
	* @param executor The {@link Executor} where the callback will be invoked on.		* @param executor The {@link Executor} where the callback will be invoked on.
	* @param listener The {@link Consumer} that will receive the callbacks		* @param listener The {@link Consumer} that will receive the callbacks
	* when entered or exited trusted presentation per the thresholds.		* when entered or exited trusted presentation per the thresholds.
			* @see TrustedPresentationThresholds
	*/		*/
	@FlaggedApi(Flags.FLAG_TRUSTED_PRESENTATION_LISTENER_FOR_WINDOW)		@FlaggedApi(Flags.FLAG_TRUSTED_PRESENTATION_LISTENER_FOR_WINDOW)
	default void registerTrustedPresentationListener(@NonNull IBinder window,		default void registerTrustedPresentationListener(@NonNull IBinder window,

core/java/android/view/WindowManagerGlobal.java

+2 −2

Original line number	Original line	Diff line number	Diff line
	@@ -950,7 +950,7 @@ public final class WindowManagerGlobal {
	WindowManagerGlobal.getWindowManagerService()		WindowManagerGlobal.getWindowManagerService()
	.registerTrustedPresentationListener(window, this, thresholds, id);		.registerTrustedPresentationListener(window, this, thresholds, id);
	} catch (RemoteException e) {		} catch (RemoteException e) {
	e.rethrowAsRuntimeException();		e.rethrowFromSystemServer();
	}		}
	}		}
	}		}
	@@ -967,7 +967,7 @@ public final class WindowManagerGlobal {
	WindowManagerGlobal.getWindowManagerService()		WindowManagerGlobal.getWindowManagerService()
	.unregisterTrustedPresentationListener(this, removedListener.first);		.unregisterTrustedPresentationListener(this, removedListener.first);
	} catch (RemoteException e) {		} catch (RemoteException e) {
	e.rethrowAsRuntimeException();		e.rethrowFromSystemServer();
	}		}
	}		}
	}		}