CanvasWatchFaceService.Engine

public class CanvasWatchFaceService.Engine
extends WatchFaceService.Engine

java.lang.Object
   ↳ android.service.wallpaper.WallpaperService.Engine
     ↳ android.support.wearable.watchface.WatchFaceService.Engine
       ↳ android.support.wearable.watchface.CanvasWatchFaceService.Engine


This class is deprecated.
Use androidx.wear.watchface.WatchFaceService, androidx.wear.watchface.Renderer.CanvasRenderer and androidx.wear.watchface.complications.rendering.CanvasComplicationDrawable from the Jetpack Wear Watch Face libraries instead.

The actual implementation of a watch face that draws on a Canvas. You must implement CanvasWatchFaceService.onCreateEngine() to return your concrete Engine implementation.

Summary

Public constructors

Engine()
Engine(boolean useHardwareCanvas)

Public methods

void invalidate()

Schedules a call to onDraw(Canvas, Rect) to draw the next frame.

void onDestroy()
void onDraw(Canvas canvas, Rect bounds)

Draws the watch face.

void onSurfaceChanged(SurfaceHolder holder, int format, int width, int height)
void onSurfaceCreated(SurfaceHolder holder)
void onSurfaceRedrawNeeded(SurfaceHolder holder)
void onVisibilityChanged(boolean visible)

Called to inform you of the watch face becoming visible or hidden.

void postInvalidate()

Posts a message to schedule a call to onDraw(Canvas, Rect) to draw the next frame.

Inherited methods

Public constructors

Engine

public Engine ()

Engine

public Engine (boolean useHardwareCanvas)

Parameters
useHardwareCanvas boolean

Public methods

invalidate

public void invalidate ()

Schedules a call to onDraw(Canvas, Rect) to draw the next frame. Must be called on the main thread.

onDestroy

public void onDestroy ()

onDraw

public void onDraw (Canvas canvas, 
                Rect bounds)

Draws the watch face.

Parameters
canvas Canvas: the canvas to draw into. Canvas.isHardwareAccelerated() can be used to confirm if it is hardware accelerated.

bounds Rect: the bounds in which the watch face should be drawn

onSurfaceChanged

public void onSurfaceChanged (SurfaceHolder holder, 
                int format, 
                int width, 
                int height)

Parameters
holder SurfaceHolder

format int

width int

height int

onSurfaceCreated

public void onSurfaceCreated (SurfaceHolder holder)

Parameters
holder SurfaceHolder

onSurfaceRedrawNeeded

public void onSurfaceRedrawNeeded (SurfaceHolder holder)

Parameters
holder SurfaceHolder

onVisibilityChanged

public void onVisibilityChanged (boolean visible)

Called to inform you of the watch face becoming visible or hidden. If you decide to override this method, you must call super.onVisibilityChanged(visible) as the first statement in your override.

Parameters
visible boolean

postInvalidate

public void postInvalidate ()

Posts a message to schedule a call to onDraw(Canvas, Rect) to draw the next frame. Unlike invalidate(), this method is thread-safe and may be called on any thread.