SceneController class

Mutable controller that owns the scene editing state and tool logic.

The controller is the primary integration point for apps:

  • It mutates scene in response to pointer input and commands.
  • It exposes selection state and marquee selection rectangle.
  • It emits actions for app-level undo/redo integration.
  • It emits editTextRequests when a text node should be edited.
Inheritance

Constructors

SceneController({Scene? scene, PointerInputSettings? pointerSettings, double? dragStartSlop, NodeId nodeIdGenerator()?})
Creates a controller that edits scene.

Properties

actions → Stream<ActionCommitted>
Synchronous broadcast stream of committed actions.
no setter
debugContractsSelectionRectRevision → int
no setter
debugMoveGestureBuildCount → int
no setter
debugMoveGestureNodes → List<SceneNode>?
no setter
debugSceneRevision → int
no setter
debugSelectionRectRevision → int
no setter
debugSelectionRevision → int
no setter
dragStartSlop → double
Pointer slop threshold used to treat a drag as a move.
no setter
drawColor → Color
no setter
drawTool → DrawTool
no setter
editTextRequests → Stream<EditTextRequested>
Synchronous broadcast stream of text edit requests.
no setter
eraserThickness ↔ double
getter/setter pair
hashCode → int
The hash code for this object.
no setterinherited
hasListeners → bool
Whether any listeners are currently registered.
no setterinherited
hasPendingLineStart → bool
Whether a two-tap line start is waiting for the second tap.
no setter
highlighterOpacity ↔ double
getter/setter pair
highlighterThickness ↔ double
getter/setter pair
lineThickness ↔ double
getter/setter pair
mode → CanvasMode
no setter
pendingLineStart → Offset?
Pending first point for a two-tap line gesture, if any.
no setter
pendingLineTimestampMs → int?
Timestamp for the pending two-tap line start, if any.
no setter
penThickness ↔ double
getter/setter pair
pointerSettings → PointerInputSettings
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
scene → Scene
final
selectedNodeIds → Set<NodeId>
Current selection snapshot.
no setter
selectionBoundsWorld → Rect?
Axis-aligned world bounds of the current transformable selection.
no setter
selectionCenterWorld → Offset?
Center of selectionBoundsWorld when selection is non-empty.
no setter
selectionRect → Rect?
Current marquee selection rectangle in scene coordinates.
no setter

Methods

addListener(VoidCallback listener) → void
Register a closure to be called when the object changes.
inherited
addNode(SceneNode node, {int layerIndex = 0}) → void
Adds node to the target layer and notifies listeners.
clearScene({int? timestampMs}) → void
Clears all non-background layers and emits an action.
clearSelection() → void
Clears the current selection.
debugSetSelection(Iterable<NodeId> nodeIds) → void
debugSetSelectionRect(Rect? rect) → void
deleteSelection({int? timestampMs}) → void
Deletes deletable selected nodes and emits an action.
dispose() → void
Discards any resources used by the object. After this is called, the object is not in a usable state and should be discarded (calls to addListener will throw after the object is disposed).
override
findNode(NodeId id) → ({int layerIndex, SceneNode node, int nodeIndex})?
Finds a node by id and returns its location in the scene.
flipSelectionHorizontal({int? timestampMs}) → void
Flips the transformable selection vertically around its center.
flipSelectionVertical({int? timestampMs}) → void
Flips the transformable selection horizontally around its center.
getNode(NodeId id) → SceneNode?
Returns the first node with id, or null if it does not exist.
handlePointer(PointerSample sample) → void
Handles a pointer sample and updates the controller state.
handlePointerSignal(PointerSignal signal) → void
Handles pointer signals such as double-tap text edit requests.
moveNode(NodeId id, {required int targetLayerIndex, int? timestampMs}) → void
Moves a node by id to another layer and emits an action.
mutate(void fn(Scene scene), {bool structural = false}) → void
Runs fn to mutate scene and schedules the appropriate updates.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
notifyListeners() → void
Call all the registered listeners.
inherited
notifySceneChanged() → void
Restores minimal invariants after external mutations to scene.
removeListener(VoidCallback listener) → void
Remove a previously registered closure from the list of closures that are notified when the object changes.
inherited
removeNode(NodeId id, {int? timestampMs}) → void
Removes a node by id, clears its selection, and emits an action.
requestRepaintOncePerFrame() → void
rotateSelection({required bool clockwise, int? timestampMs}) → void
Rotates the transformable selection by 90 degrees.
selectAll({bool onlySelectable = true}) → void
Selects all nodes in the scene.
setBackgroundColor(Color value) → void
Updates the scene background color.
setCameraOffset(Offset value) → void
Updates the scene camera offset.
setDrawColor(Color value) → void
Sets the current drawing color.
setDrawTool(DrawTool tool) → void
Changes the active drawing tool and resets draw state.
setGridCellSize(double value) → void
Sets the grid cell size in scene units.
setGridEnabled(bool value) → void
Enables or disables the background grid.
setMode(CanvasMode value) → void
Switches between move and draw modes.
setSelection(Iterable<NodeId> nodeIds) → void
Replaces the selection with nodeIds.
toggleSelection(NodeId id) → void
Toggles selection for a single node id.
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited