SignpostImg class Images
Vector signpost image for directional navigation signs.
SDK-generated vector image representing directional road signs (exit signs, destination boards, etc.) in navigation UI. Supports lossless scaling to any size (isScalable returns true). Cannot be instantiated by users - only provided via SignpostDetails.image in navigation instructions.
Customize appearance using SignpostImageRenderSettings to control layout
(border width, row height, max rows). Set allowResize to true to let the SDK
choose optimal aspect ratio based on requested height.
Important note on navigation sessions
At creation time, each SignpostImg is tagged by the native layer with
its source: if the underlying signpost matched the one carried by the
currently-active NavigationInstruction
(NavigationService.getNavigationInstruction()), the handle is flagged
as "live". Calls on a live handle render from whatever
NavigationInstruction is currently published by NavigationService,
not from the memory captured when the handle was created. This means
a SignpostImg retained across instruction updates (next step, rematch,
route recalculation, arrival) keeps rendering the active instruction's
signpost rather than use-after-freeing into recycled native memory.
Handles obtained from a RouteInstructionBase or from a SignpostDetails that did not correspond to the active instruction at creation time (route preview, static route-instruction list, off-map inspection) render from the image captured when the handle was produced, as before.
See also:
- SignpostImageRenderSettings - Customize layout and borders
- SignpostDetails.image - The accessor that produces this handle
Properties
- hashCode → int
-
The hash code for this object.
no setterinherited
- hasRegisteredAutoReleaseObject ↔ bool
-
getter/setter pairinherited
- imageType → ImageType
-
Category of this image indicating its source and purpose.
no setterinherited
- isCacheable → bool
-
Whether renders of this image may be memoized by
ImgCache.no setteroverride - isScalable → bool
-
Whether the image uses a vector format and supports lossless scaling.
no setteroverride
- isValid → bool
-
Whether the SDK has valid image data available.
no setterinherited
- pointerId → int
-
The pointer ID of the native object
no setterinherited
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
- uid → int
-
Unique identifier for this image instance.
no setterinherited
Methods
-
cachedFlutterImgCall(
{required int widthPx, required int heightPx, required ImageFileFormat format, required String? arg, required int settingsHash, required bool allowResize}) → RenderableImg? -
Memoized variant of
GemKitPlatform.callGetFlutterImg.inherited -
dispose(
) → void -
Disposes the native object.
inherited
-
getRenderableImage(
{Size? size, ImageFileFormat format = ImageFileFormat.png, SignpostImageRenderSettings? renderSettings, bool allowResize = false}) → RenderableImg? -
Retrieves image with bytes and actual rendered dimensions.
override
-
getRenderableImageBytes(
{Size? size, ImageFileFormat format = ImageFileFormat.png, SignpostImageRenderSettings? renderSettings, bool allowResize = false}) → Uint8List? -
Retrieves image bytes suitable for display with
Image.memory.override -
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
registerAutoReleaseObject(
int pointerId) → void -
Registers an object for auto release.
inherited
-
toString(
) → String -
A string representation of this object.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited