start method

GemError start({ required GemMapController controller, required Path track, required String outputPath, ActivityVideoPreviewSettings settings = const ActivityVideoPreviewSettings(), required void onComplete(GemError error), void onProgress(int progress)?, })

Starts rendering the fly-over video of track on the map of controller.

The render runs asynchronously: onProgress reports its progress and onComplete its outcome. A failed or cancelled render leaves the partial file at outputPath in place.

Parameters

• controller: The map used for rendering. It must stay mounted and visible until the render completes.
• track: The recorded track to fly over.
• outputPath: The path of the MP4 file to write.
• settings: The render settings. Defaults to the native defaults.
• onComplete: Callback invoked once when the render finishes, unless the renderer is disposed first. The function is called with:
  • error - GemError.success when the video was written, GemError.cancel after cancel, GemError.invalidated when the map was removed, GemError.operationTimeout when the map stopped rendering, or another GemError on failure (see lastErrorDetails).
• onProgress: Optional callback invoked with the render progress, from 0 to 100.

Returns

• GemError.success when the render started. Any other value means nothing started and onComplete is not called:
  • GemError.inUse when the previous render of this renderer has not called its onComplete yet, or another renderer is rendering on the same map.
  • GemError.invalidInput when the track is unusable (a single point or shorter than 20 meters) or the map is not available.
  • GemError.notSupported when the platform has no video encoder.
  • GemError.missingCapability when the renderer is not available in this SDK.
  • GemError.internalAbort when the render could not be scheduled.

See also:

• startIntroImage - Render only the opening overview as a picture.
• cancel - Cancel the render in progress.
• lastErrorDetails - Platform detail about a failed render.

Implementation

GemError start({
  required GemMapController controller,
  required Path track,
  required String outputPath,
  ActivityVideoPreviewSettings settings =
      const ActivityVideoPreviewSettings(),
  required void Function(GemError error) onComplete,
  void Function(int progress)? onProgress,
}) {
  return _start(
    'start',
    _renderArgs(controller, track, outputPath, settings),
    onComplete,
    onProgress,
  );
}