Renderer
sealed class Renderer
Renderer.CanvasRenderer |
This class is deprecated. CanvasRenderer is deprecated |
Renderer.GlesRenderer |
This class is deprecated. GlesRenderer is deprecated |
ListenableCanvasRenderer2 |
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ListenableCanvasRenderer |
This class is deprecated. Use ListenableCanvasRenderer2 instead |
ListenableGlesRenderer2 |
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ListenableGlesRenderer |
This class is deprecated. Use ListenableGlesRenderer2 instead |
Renderer.CanvasRenderer2 |
Watch faces that require |
Renderer.GlesRenderer2 |
Watch faces that require |
The base class for CanvasRenderer, CanvasRenderer2, GlesRenderer, GlesRenderer2. Where possible it is recommended to use CanvasRenderer2 or GlesRenderer2 which allow memory to be saved during editing because there can be more than one watchface instance during editing.
Renderers are constructed on a background thread but all rendering is done on the UiThread. There is a memory barrier between construction and rendering so no special threading primitives are required.
It is recommended to set watchfaceColors with representative WatchFaceColors this is used by compatible systems to influence the system's color scheme.
Please note android.graphics.drawable.AnimatedImageDrawable and similar classes which rely on android.graphics.drawable.Drawable.Callback do not animate properly out of the box unless you register an implementation with android.graphics.drawable.Drawable.setCallback that calls invalidate. Even then these classes are not recommend because the ZonedDateTime passed to Renderer.CanvasRenderer.render or Renderer.GlesRenderer.render is not guaranteed to match the system time (e.g. for taking screenshots). In addition care is needed when implementing android.graphics.drawable.Drawable.Callback to ensure it does not animate in ambient mode which could lead to a significant power regression.
Summary
Nested types |
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abstract class Renderer.CanvasRenderer : RendererThis class is deprecated. CanvasRenderer is deprecated |
abstract class Renderer.CanvasRenderer2<SharedAssetsT : Renderer.SharedAssets> : Renderer.CanvasRendererWatch faces that require |
abstract class Renderer.GlesRenderer : RendererThis class is deprecated. GlesRenderer is deprecated |
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Exception thrown if a GL call fails |
abstract class Renderer.GlesRenderer2<SharedAssetsT : Renderer.SharedAssets> : Renderer.GlesRendererWatch faces that require |
interface Renderer.SharedAssetsMultiple |
Protected constructors |
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@WorkerThread |
Public functions |
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open Rect |
This method is used for accessibility support to describe the portion of the screen containing the main clock element. |
Unit |
Schedules a call to either |
open Unit |
Called when the Renderer is destroyed. |
abstract Unit |
@UiThreadCalled when adb shell dumpsys is invoked for the WatchFaceService, allowing the renderer to optionally record state for debugging purposes. |
Unit |
Posts a message to schedule a call to either |
Unit |
Sends a request to the system asking it to update the preview image. |
open Boolean |
The system periodically (at least once per minute) calls onTimeTick() to trigger a display update. |
Protected functions |
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open Unit |
@UiThreadCalled when the |
Public properties |
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Collection<Pair<Int, ContentDescriptionLabel>> |
Accessibility |
@Px Float |
The center x coordinate of the |
@Px Float |
The center y coordinate of the |
Long |
The interval in milliseconds between frames in interactive |
RenderParameters |
The current |
Rect |
The bounds of the |
SurfaceHolder |
The |
WatchFaceColors? |
Representative |
Protected constructors
Renderer
@WorkerThread
protected Renderer(
surfaceHolder: SurfaceHolder,
currentUserStyleRepository: CurrentUserStyleRepository,
watchState: WatchState,
interactiveDrawModeUpdateDelayMillis: @IntRange(from = 0, to = 60000) Long
)
| Parameters | |
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surfaceHolder: SurfaceHolder |
The |
currentUserStyleRepository: CurrentUserStyleRepository |
The associated |
watchState: WatchState |
The associated |
interactiveDrawModeUpdateDelayMillis: @IntRange(from = 0, to = 60000) Long |
The interval in milliseconds between frames in interactive |
Public functions
getMainClockElementBounds
@UiThread
open fun getMainClockElementBounds(): Rect
This method is used for accessibility support to describe the portion of the screen containing the main clock element. By default we assume this is contained in the central half of the watch face. Watch faces should override this to return the correct bounds for the main clock element.
invalidate
@UiThread
fun invalidate(): Unit
Schedules a call to either CanvasRenderer.render or GlesRenderer.render to draw the next frame.
onDump
@UiThread
abstract fun onDump(writer: PrintWriter): Unit
Called when adb shell dumpsys is invoked for the WatchFaceService, allowing the renderer to optionally record state for debugging purposes.
postInvalidate
fun postInvalidate(): Unit
Posts a message to schedule a call to either CanvasRenderer.render or GlesRenderer.render to draw the next frame. Unlike invalidate, this method is thread-safe and may be called on any thread.
sendPreviewImageNeedsUpdateRequest
fun sendPreviewImageNeedsUpdateRequest(): Unit
Sends a request to the system asking it to update the preview image. This is useful for watch faces with configuration outside of the UserStyleSchema E.g. a watchface with a selectable background.
The system may choose to rate limit this method for performance reasons and the system is free to schedule when the update occurs.
Requires a compatible system to work (if the system is incompatible this does nothing). This can be called from any thread.
shouldAnimate
@UiThread
open fun shouldAnimate(): Boolean
The system periodically (at least once per minute) calls onTimeTick() to trigger a display update. If the watch face needs to animate with an interactive frame rate, calls to invalidate must be scheduled. This method controls whether or not we should do that and if shouldAnimate returns true we inhibit entering DrawMode.AMBIENT.
By default we remain at an interactive frame rate when the watch face is visible and we're not in ambient mode. Watch faces with animated transitions for entering ambient mode may need to override this to ensure they play smoothly.
| Returns | |
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Boolean |
Whether we should schedule an onDraw call to maintain an interactive frame rate |
Protected functions
onRenderParametersChanged
@UiThread
protected open fun onRenderParametersChanged(renderParameters: RenderParameters): Unit
Called when the RenderParameters has been updated. Will always be called before the first call to CanvasRenderer.render or GlesRenderer.render.
Public properties
additionalContentDescriptionLabels
var additionalContentDescriptionLabels: Collection<Pair<Int, ContentDescriptionLabel>>
Accessibility ContentDescriptionLabel for any rendered watch face elements other than the time and ComplicationSlots which are generated automatically.
The Int in the Pair<Int, ContentDescriptionLabel> is used to sort the ContentDescriptionLabels. Note the time piece has an accessibility traversal index of -1 and each ComplicationSlot's index is defined by its ComplicationSlot.accessibilityTraversalIndex.
centerX
val centerX: @Px Float
The center x coordinate of the SurfaceHolder this Renderer renders into.
centerY
val centerY: @Px Float
The center y coordinate of the SurfaceHolder this Renderer renders into.
interactiveDrawModeUpdateDelayMillis
var interactiveDrawModeUpdateDelayMillis: Long
The interval in milliseconds between frames in interactive DrawModes. To render at 60hz set to 16. Note when battery is low, the frame rate will be clamped to 10fps. Watch faces are recommended to use lower frame rates if possible for better battery life. Variable frame rates can also help preserve battery life, e.g. if a watch face has a short animation once per second it can adjust the frame rate inorder to sleep when not animating. In ambient mode the watch face will be rendered once per minute.
renderParameters
val renderParameters: RenderParameters
The current RenderParameters. Updated before every onDraw call.
screenBounds
val screenBounds: Rect
The bounds of the SurfaceHolder this Renderer renders into. Depending on the shape of the device's screen not all of these pixels may be visible to the user (see Configuration.isScreenRound). Note also that API level 27+ devices draw indicators in the top and bottom 24dp of the screen, avoid rendering anything important there.
surfaceHolder
var surfaceHolder: SurfaceHolder
The SurfaceHolder that renderInternal will draw into.
watchfaceColors
@WatchFaceExperimental
var watchfaceColors: WatchFaceColors?
Representative WatchFaceColors which are made available to system clients via androidx.wear.watchface.client.InteractiveWatchFaceClient.OnWatchFaceColorsListener.
Initially this value is null signifying that the colors are unknown. When possible the watchFace should assign non null WatchFaceColors and keep this updated when the colors change (e.g. due to a style change).