Stage class

The Stage is the root display container for a GraphX scene. It extends the GDisplayObjectContainer class and provides a canvas to which you can draw objects, as well as handling resize and tick events.

The Stage has a ScenePainter that defines the scene's SceneController. It is responsible for updating the scene and painting the display tree. It also mixes in various signal mix-ins to enable the dispatching of resize, tick and mouse input events to the scene and display tree.

The Stage has a size (stageWidth and stageHeight) that can be set by the parent container.

The Stage class overrides the hitTest method to ensure that mouse events are only dispatched to visible and mouse-enabled objects within the stage's bounds.

The Stage class provides the mouseX and mouseY properties to get the current mouse position within the stage's bounds. It also overrides various properties and methods from GDisplayObject that are not applicable to the stage, such as width, height, x, y, scaleX, scaleY, pivotX, pivotY, skewX, skewY, and rotation.

Inheritance
Mixed in types
Available Extensions

Constructors

Stage(ScenePainter scene)
Initializes a new instance of the Stage class. Should only be initialized by the ScenePainter.

Properties

$alpha ↔ double
(Internal usage) The alpha (transparency) value of this object, a value between 0.0 (fully transparent) and 1.0 (fully opaque).
getter/setter pairinherited
$colorize ↔ Color?
(Internal usage) The color to apply to this object.
getter/setter pairinherited
$debugBounds ↔ bool
(Internal usage) Whether to show debug bounds for this object.
getter/setter pairinherited
$debugBoundsPaint ↔ Paint?
(Internal usage) Defines the debug paint used to show the bounds of this display object when debug mode is enabled. By default, it uses a magenta stroke with a width of 1. Override this property to use a custom debug paint.
getter/setter pairinherited
$debugLastLayerBounds ↔ GRect?
(Internal usage) Tracks the last layer bounds used for rendering this display object using getBounds($parent).
getter/setter pairinherited
$filters ↔ List<GBaseFilter>?
(Internal usage) The filters applied to this object.
getter/setter pairinherited
$hasColorize → bool
(Internal usage) Whether this object has a color applied to it.
no setterinherited
$hasTouchableArea ↔ bool
(Internal usage) Optimization flag indicating whether this object has a touchable area.
getter/setter pairinherited
$hasVisibleArea ↔ bool
(Internal usage) Optimization flag indicating whether this object has a visible area.
getter/setter pairinherited
$lastClickTime ↔ double
(Internal usage) The time of the last mouse click.
getter/setter pairinherited
$mask ↔ GShape?
(Internal usage) The mask of this object, used for masking.
getter/setter pairinherited
$maskee ↔ GDisplayObject?
(Internal usage) The display object that acts as a mask of this object.
getter/setter pairinherited
$matrixDirty ↔ bool
(Internal usage) Indicates whether the matrix of this object needs to be recalculated.
getter/setter pairinherited
$mouseDownObj ↔ GDisplayObject?
(Internal usage) The object that the mouse was last pressed on.
getter/setter pairinherited
$mouseOverObj ↔ GDisplayObject?
(Internal usage) The object that the mouse is currently over.
getter/setter pairinherited
$onAdded ↔ Signal?
(Internal)
getter/setter pairinherited
$onAddedToStage ↔ Signal?
(Internal)
getter/setter pairinherited
$onEnterFrame ↔ EventSignal<double>?
(Internal)
getter/setter pairinherited
$onMouseClick ↔ EventSignal<MouseInputData>?
(Internal)
getter/setter pairinherited
$onMouseDoubleClick ↔ EventSignal<MouseInputData>?
(Internal)
getter/setter pairinherited
$onMouseDown ↔ EventSignal<MouseInputData>?
(Internal)
getter/setter pairinherited
$onMouseEnter ↔ EventSignal<MouseInputData>?
(Internal)
getter/setter pairinherited
$onMouseLeave ↔ EventSignal<MouseInputData>?
(Internal)
getter/setter pairinherited
$onMouseMove ↔ EventSignal<MouseInputData>?
(Internal)
getter/setter pairinherited
$onMouseOut ↔ EventSignal<MouseInputData>?
(Internal)
getter/setter pairinherited
$onMouseOver ↔ EventSignal<MouseInputData>?
(Internal)
getter/setter pairinherited
$onMouseUp ↔ EventSignal<MouseInputData>?
(Internal)
getter/setter pairinherited
$onMouseWheel ↔ EventSignal<MouseInputData>?
(Internal)
getter/setter pairinherited
$onPostPaint ↔ EventSignal<Canvas>?
(Internal)
getter/setter pairinherited
$onPrePaint ↔ EventSignal<Canvas>?
(Internal)
getter/setter pairinherited
$onPreTransform ↔ EventSignal<Canvas>?
(Internal)
getter/setter pairinherited
$onRemoved ↔ Signal?
(Internal)
getter/setter pairinherited
$onRemovedFromStage ↔ Signal?
(Internal)
getter/setter pairinherited
$onResized ↔ Signal?
(Internal)
getter/setter pairinherited
$onRightMouseDown ↔ EventSignal<MouseInputData>?
(Internal)
getter/setter pairinherited
$onZoomPan ↔ EventSignal<MouseInputData>?
(Internal)
getter/setter pairinherited
$parent ↔ GDisplayObjectContainer?
(Internal usage) The parent display object container that this object is a child of.
getter/setter pairinherited
$useSaveLayerBounds ↔ bool
(Internal usage) When enabled, a rectangle is created to save the layer for better rendering performance.
getter/setter pairinherited
allowSaveLayer ↔ bool
When enabled, the saveLayer() feature is used for better rendering performance. Disabling it may provide better performance for certain display objects. Childless DisplayObjects, like GShape and GBitmap, have their own Paint() so no need to use an expensive saveLayer().
getter/setter pairinherited
alpha ↔ double
Returns the alpha (transparency) value of this object.
getter/setter pairinherited
base → GDisplayObject
Returns the base object, i.e. the topmost parent in the display hierarchy.
no setterinherited
bounds → GRect?
TODO: should be cached. Returns the bounds of this object in its local coordinate space.
no setterinherited
children → List<GDisplayObject>
The list of children that this container holds.
finalinherited
color ↔ Color?
Gets the background color of the stage.
getter/setter pair
colorize ↔ Color?
Gets the color applied to this object.
getter/setter pairinherited
controller → SceneController
Gets the owner SceneController for the stage.
no setter
filterPaint ↔ Paint
The paint to use for filters that require a paint.
getter/setter pairinherited
filters ↔ List<GBaseFilter>?
Gets the filters applied to this object.
getter/setter pairinherited
hasChildren → bool
Whether this container has any children.
no setterinherited
hasFilters → bool
Returns true if this object has any filters applied.
no setterinherited
hashCode → int
The hash code for this object.
no setterinherited
height ↔ double
Indicates the height of the display object, in dp. The height is calculated based on the bounds of the content of the display object. When you set the height property, the scaleX property is adjusted accordingly, as shown in the following code:
getter/setter pairoverride
inStage → bool
Returns true if this object is on the stage.
no setterinherited
isMask → bool
Returns whether this object is currently being used as a mask for another object.
no setterinherited
isMouseInside → bool
Returns a boolean indicating whether the mouse pointer is inside the stage. So if it's available to detect events.
no setter
isRotated → bool
Returns whether this object has any rotation or skew transformation.
no setterinherited
keyboard → KeyboardManager<KeyboardEventData>?
Access the keyboard instance of the owner SceneController, Only available when SceneConfig.useKeyboard is true.
no setter
mask ↔ GShape?
Returns the mask of this object.
getter/setter pairinherited
maskBounds ↔ bool
The native canvas bounds will be clipped to the bounds of the stage if maskBounds is set to true.
getter/setter pair
maskInverted ↔ bool
Whether the object should apply an inverted mask. can be set on the Shape mask, or the maskee DisplayObject.
getter/setter pairinherited
maskRect ↔ GRect?
The rectangular area of the mask.
getter/setter pairinherited
maskRectCornerRadius ↔ double?
The corner radius of the mask.
getter/setter pairinherited
maskRectInverted ↔ bool
Whether the mask is inverted or not.
getter/setter pairinherited
mouseChildren ↔ bool
Whether this container will capture mouse input events for its children.
getter/setter pairinherited
mouseEnabled ↔ bool
Indicates whether this object can receive mouse and touch input events.
getter/setter pairinherited
mouseEnableStillEvents ↔ bool
If set to true, mouse events will be dispatched to objects that are not directly below the mouse pointer but still receive mouse events (like mouse move events).
getter/setter pair
mousePosition → GPoint
Returns the position of the mouse in the local coordinate system of this object. The mouse position is updated every frame, so this method returns the current mouse position relative to the top-left corner of this object.
no setterinherited
mouseUseShape ↔ bool
Whether to use the shape of the object for mouse event detection.
getter/setter pairinherited
mouseX → double
Returns the current x-coordinate of the mouse pointer on the stage.
no setteroverride
mouseY → double
Returns the current y-coordinate of the mouse pointer on the stage.
no setteroverride
name ↔ String?
Name to reference this object.
getter/setter pairinherited
numChildren → int
The number of children of this container.
no setterinherited
onAdded → Signal
Returns the Signal that is triggered when an object is added to the display list.
no setterinherited
onAddedToStage → Signal
Returns the Signal that is triggered when an object is added to the stage.
no setterinherited
onEnterFrame → EventSignal<double>
Returns the EventSignal that is triggered on every frame update.
no setterinherited
onHotReload → Signal
A signal that is dispatched when the scene is reloaded (for hot-reloading purposes).
no setter
onMouseClick → EventSignal<MouseInputData>
A signal that is dispatched when the mouse is clicked.
no setterinherited
onMouseDoubleClick → EventSignal<MouseInputData>
A signal that is dispatched when the mouse is double clicked.
no setterinherited
onMouseDown → EventSignal<MouseInputData>
A signal that is dispatched when the mouse button is pressed down.
no setterinherited
onMouseEnter → EventSignal<MouseInputData>
A signal that is dispatched when the mouse enters the stage.
no setterinherited
onMouseLeave → EventSignal<MouseInputData>
A signal that is dispatched when the mouse leaves the stage.
no setterinherited
onMouseMove → EventSignal<MouseInputData>
A signal that is dispatched when the mouse is moved.
no setterinherited
onMouseOut → EventSignal<MouseInputData>
A signal that is dispatched when the mouse leaves a component.
no setterinherited
onMouseOver → EventSignal<MouseInputData>
A signal that is dispatched when the mouse is over a component.
no setterinherited
onMouseScroll → EventSignal<MouseInputData>
A signal that is dispatched when the mouse wheel is scrolled.
no setterinherited
onMouseUp → EventSignal<MouseInputData>
A signal that is dispatched when the mouse button is released.
no setterinherited
onPostPaint → EventSignal<Canvas>
A signal that runs right after GDisplayObject.$applyPaint is called.
no setterinherited
onPrePaint → EventSignal<Canvas>
A signal that runs before GDisplayObject.$applyPaint, which is the render method to subclass.
no setterinherited
onPreTransform → EventSignal<Canvas>
A signal that runs right away when GDisplayObject.paint is called, before any mask or filters are applied. This is the first signal to run on rendering.
no setterinherited
onRemoved → Signal
Returns the Signal that is triggered when an object is removed from the display list.
no setterinherited
onRemovedFromStage → Signal
Returns the Signal that is triggered when an object is removed from the stage.
no setterinherited
onResized → Signal
Returns the Signal that is triggered when the size of an object changes.
no setterinherited
onRightMouseDown → EventSignal<MouseInputData>
A signal that is dispatched when the right mouse button is pressed down.
no setterinherited
onZoomPan → EventSignal<MouseInputData>
A signal that is dispatched when a zoom/pan gesture is performed.
no setterinherited
parent → GDisplayObjectContainer?
Returns the parent container.
no setterinherited
pivotX ↔ double
Returns the x coordinate of the pivot point, the center of scaling and rotation.
getter/setter pairinherited-getteroverride-setter
pivotY ↔ double
Returns the y coordinate of the pivot point, the center of scaling and rotation.
getter/setter pairinherited-getteroverride-setter
pointer → PointerManager<PointerEventData>?
Access the pointer (mouse or touch info) instance of the owner SceneController, Only available when SceneConfig.usePointer is true.
no setter
root → GDisplayObject?
Returns the root GDisplayObject that is the ancestor of this object (either a Stage or a null).
no setterinherited
rotation ↔ double
Returns the angle of rotation in radians.
getter/setter pairinherited-getteroverride-setter
rotationX ↔ double
The rotation angle in radians about the x-axis for 3d transformation.
getter/setter pairinherited
rotationY ↔ double
The rotation angle in radians about the y-axis for 3d transformation.
getter/setter pairinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
scale ↔ double
Shortcut for setting proportional X and Y scale values.
getter/setter pairinherited
scaleX ↔ double
Returns the horizontal scale of the object.
getter/setter pairinherited-getteroverride-setter
scaleY ↔ double
Returns the vertical scale of the object.
getter/setter pairinherited-getteroverride-setter
scene → ScenePainter
The scene painter that defines the scene's SceneController.
final
showBoundsRect ↔ bool
Determines whether to display the bounds of the stage area drawing a 2px black line square around it. Useful to debug if the mouse touches are not working because the widget is not covering the whole screen.
getter/setter pair
skewX ↔ double
Returns the angle of skew on the x-axis in radians.
getter/setter pairinherited-getteroverride-setter
skewY ↔ double
Returns the angle of skew on the y-axis in radians.
getter/setter pairinherited-getteroverride-setter
stage → Stage?
Returns the stage this object is on or null if it's not on a stage.
no setterinherited
stageHeight → double
The current height of the Stage.
no setter
stageRect → GRect
Returns the bounds of the stage as a GRect.
no setter
stageWidth → double
The current width of the Stage.
no setter
transformationMatrix ↔ GMatrix
Gets the transformation matrix that represents the object's position, scale, rotation and skew.
getter/setter pairinherited
useCursor ↔ bool
Whether to use a custom cursor for this object.
getter/setter pairinherited
userData ↔ Object?
You can store any user defined data in this property for easy access.
getter/setter pairinherited
visible ↔ bool
Returns whether the display object is visible or not.
getter/setter pairinherited
width ↔ double
Indicates the width of the display object, in dp. The width is calculated based on the bounds of the content of the display object. When you set the width property, the scaleX property is adjusted accordingly, as shown in the following code:
getter/setter pairoverride
worldAlpha → double
Returns the alpha value of the object relative to its parent and all its ancestors.
no setterinherited
worldScaleX → double
Returns the horizontal scaling factor of the object relative to its parent and all its ancestors.
no setterinherited
worldScaleY → double
Returns the vertical scaling factor of the object relative to its parent and all its ancestors.
no setterinherited
worldX → double
Returns the x coordinate of the object relative to the stage and all its ancestors.
no setterinherited
worldY → double
Returns the y coordinate of the object relative to the stage and all its ancestors.
no setterinherited
x ↔ double
The x coordinate of the display object relative to its parent's coordinate system.
getter/setter pairinherited-getteroverride-setter
y ↔ double
The y coordinate of the display object relative to its parent's coordinate system.
getter/setter pairinherited-getteroverride-setter
z ↔ double
(Experimental) The z-coordinate of this object in 3D space.
getter/setter pairinherited

Methods

$applyMaskRect(Canvas? canvas) → void
Applies the current mask to the provided Canvas.
inherited
$applyPaint(Canvas canvas) → void
(Internal usage) Applies the container's paint to the specified canvas.
inherited
$dispatchMouseCallback(MouseInputType type, GDisplayObject object, MouseInputData input) → void
(Internal usage) Dispatches a mouse event to the appropriate callback functions.
inherited
$disposeDisplayListSignals() → void
Removes all registered listeners and frees all display list signals.
inherited
$disposePointerSignals() → void
Disposes all mouse signals to free up memory.
inherited
$disposeRenderSignals() → void
Disposes all render-related signals and clears all callbacks for this instance. This method should be called when the instance is no longer needed, to prevent memory leaks.
inherited
$disposeResizeSignals() → void
(Internal) Removes all registered listeners and frees the onResized signal.
inherited
$disposeStagePointerSignals() → void
Disposes all stage mouse signals to free up memory.
inherited
$disposeTickerSignals() → void
(Internal) Removes all registered listeners and frees the onEnterFrame signal.
inherited
$initFrameSize(Size value) → void
(Internal usage) Initializes the size of the stage.
$setParent(GDisplayObjectContainer? value) → void
(Internal usage) Sets the GDisplayObjectContainer that contains this GDisplayObject.
inherited
$setTransformationChanged() → void
(Internal usage) Sets the transformationChanged flag and updates the 3D flag based on whether the object has 3D properties set.
inherited
$tick(double delta) → void
TODO: need to find a way to reference the window. (Internal usage) Updates the Stage object and dispatches the enterFrame event with the delta time since the last frame, in seconds.
$updateTransformationMatrices(double? x, double? y, double pivotX, double pivotY, double scaleX, double scaleY, double skewX, double skewY, double rotation, GMatrix out) → void
(Internal usage) Updates the transformation matrices of a display object based on the given parameters.
inherited
addChild<T extends GDisplayObject>(T child) → T
Adds a child to the end of the list of children of this container.
inherited
addChildAt<T extends GDisplayObject>(T child, int index) → T
Adds a child to the list of children of this container at a specific index.
inherited
addedToStage() → void
Called when the object is added to the stage. Should be overridden by subclasses as entry point.
inherited
alignPivot([Alignment alignment = painting.Alignment.center]) → void
Adjusts the pivot point of this display object to a new location defined by the given alignment parameter, which defaults to Alignment.center. This method calculates the bounds of the object and aligns the pivot point based on the provided alignment parameter. The alignment is represented by an Alignment object, where the x and y values range from -1.0 to 1.0. For example, an Alignment of (-1.0, -1.0) represents the top left corner, while an Alignment of (1.0, 1.0) represents the bottom right corner. The pivot point represents the center point for rotations and scaling, and by default it is set to (0,0), which means that the object is rotated and scaled around the top-left corner. This method is useful to adjust the pivot point to a more suitable location before performing rotations or scaling operations. If the bounds of the object are empty, no adjustment is made to the pivot point. The resulting pivot point is stored in the pivotX and pivotY properties of this display object.
inherited
captureMouseInput(MouseInputData input) → void
Captures the MouseInputData and processes it to update mouse input state and dispatch MouseEvent signals on this Stage or its children.
override
contains(GDisplayObject? child, [bool recursive = true]) → bool
Returns true if a given child is a descendant of this container, or false otherwise.
inherited
createImage([bool adjustOffset = true, double resolution = 1, GRect? rect]) → Future<Image>
Creates an image representation of the current state of the GDisplayObject. If adjustOffset is true, the resulting image will be offset so that its top-left corner corresponds to the top-left corner of the current bounds. If resolution is provided and is different than 1, the image will be scaled by this factor before being returned. If rect is provided, it defines a rectangle that will be used as the bounds for the image instead of the getFilterBounds of the GDisplayObject. Returns a Future that resolves to a ui.Image representing the current state of the GDisplayObject in the form of an image.
inherited
createImageSync([bool adjustOffset = true, double resolution = 1, GRect? rect]) → Image
Creates a synchronous image from this display object.
inherited
createImageTexture([bool adjustOffset = true, double resolution = 1, GRect? rect]) → Future<GTexture>
Creates a new GTexture asynchronously from the display object's image. The image is retrieved using the createImage method, and a new texture is created from the image with the specified resolution. If a rect is specified, only the portion of the image within the bounds of the rectangle will be used to create the texture. If adjustOffset is true, the image will be adjusted to remove any offsets from the top left corner.
inherited
createImageTextureSync([bool adjustOffset = true, double resolution = 1, GRect? rect]) → GTexture
Creates a texture from the synchronous image generated from this display object.
inherited
createPicture([void prePaintCallback(Canvas)?, void postPaintCallback(Canvas)?]) → Picture
Creates a picture of the current state of the DisplayObject. To ensure the "original" form, call before applying any transformations (x, y, scale, etc).
inherited
dispose() → void
Disposes the Stage object, releasing any resources used by it and removing it from the display list.
override
getBounds(GDisplayObject? targetSpace, [GRect? out]) → GRect?
Returns the bounds of this container in the given targetSpace.
inherited
getChildAt<T extends GDisplayObject>(int index) → T
Returns the child at a specific index in the list of children of this container.
inherited
getChildByName<T extends GDisplayObject>(String name) → T?
Returns the child object that exists with the specified name.
inherited
getChildIndex(GDisplayObject child) → int
Returns the index of a child in the list of children of this container, or -1 if the child is not found.
inherited
getFilterBounds([GRect? layerBounds, Paint? alphaPaint]) → GRect?
Returns the bounds of this object after applying all its filters.
inherited
getObjectsUnderPoint(GPoint localPoint) → List<GDisplayObject>
Returns a list of display objects that are under the specified localPoint.
inherited
getStageBounds(GDisplayObject targetSpace, [GRect? out]) → GRect
Returns the bounds of the Stage object in the coordinate system specified by the targetSpace object. If the out parameter is provided, the result is stored in that object. Otherwise, a new GRect object is created and returned.
getTransformationMatrix(GDisplayObject? targetSpace, [GMatrix? out]) → GMatrix
Returns the transformation matrix that transforms coordinates from the local coordinate system to the coordinate system of the targetSpace.
inherited
globalToLocal(GPoint globalPoint, [GPoint? out]) → GPoint
Converts the given point from global coordinates to local coordinates.
inherited
hitTest(GPoint localPoint, [bool useShape = false]) → GDisplayObject?
Returns the deepest GDisplayObject that lies under the given point.
override
hitTestMask(GPoint localPoint) → bool
Determines whether the localPoint specified in the local coordinates of this object lies inside its mask.
inherited
hitTouch(GPoint localPoint, [bool useShape = false]) → bool
Checks whether a localPoint inside the object's boundary. This method always returns true for the Stage object, because it occupies the entire screen and it should always receive touch events.
override
localToGlobal(GPoint localPoint, [GPoint? out]) → GPoint
Transforms the given localPoint from the local coordinate system to the global coordinate system.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
paint(Canvas canvas) → void
Renders this stage on the given canvas.
override
removeChild<T extends GDisplayObject>(T child, [bool dispose = false]) → T?
Removes the specified child from this container.
inherited
removeChildAt<T extends GDisplayObject>(int index, [bool dispose = false]) → T
Removes the child at the specified index from this container.
inherited
removeChildren([int fromIndex = 0, int endIndex = -1, bool dispose = false]) → void
Removes a child from the list of children of this container based on its index.
inherited
removedFromStage() → void
Called when the object is removed to the stage.
inherited
removeFromParent([bool dispose = false]) → void
Removes this GDisplayObject from its parent GDisplayObjectContainer.
inherited
requiresRedraw() → void
Notifies the parent that the current state of this GDisplayObject has changed and it requires a redraw.
inherited
setChildIndex(GDisplayObject child, int index) → void
Sets the index of a child in the list of children of this container.
inherited
setPosition(double x, double y) → GDisplayObject
Sets the x and y transformation of the DisplayObject and returns it.
inherited
setScale(double scaleX, [double? scaleY]) → GDisplayObject
Sets the scaleX and scaleY transformation of the DisplayObject and returns it. If only one argument is provided, both scaleX and scaleY are set to the same value.
inherited
sortChildren(SortChildrenCallback compare) → void
Sorts the list of children of this container using a custom comparison function.
inherited
startDrag([bool lockCenter = false, GRect? bounds]) → void
Makes this object draggable. When this object is dragged, its x and y properties will be updated to match the mouse position. The lockCenter parameter, if set to true, will cause the object to be dragged from its center point. The bounds parameter can be used to restrict the movement of the object to a certain area. Throws an error if the object is not visible or touchable.
inherited
stopDrag() → void
Stops the current drag operation, if this DisplayObject is currently being dragged. Removes the mouse move event listener and sets the current drag object to null. Does nothing if this DisplayObject is not currently being dragged.
inherited
swapChildren(GDisplayObject child1, GDisplayObject child2) → void
Swaps the positions of two children. Throws an ArgumentError if child1 or child2 are not children of this container. If child1 and child2 are the same object, nothing happens.
inherited
swapChildrenAt(int index1, int index2) → void
Swaps the two children objects at the specified indexes.
inherited
toString() → String
Returns a string representation of this instance.
override
update(double delta) → void
Updates all children of this container.
inherited

Operators

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