You won't deal with this type directly, but every class in the Canvas2D Feature extends this type (at the exception of Brushes), so it's good to know about the features it offers.
As these feature are pretty important, most of them have dedicated documentation page.
When creating a primitive you can set the id field in the settings object, the id is a string and will be stored in the primitive, so it can be omitted at creation. From a given primitive you can look for a child primitive from its id using the findById method.
The default value is null, so there's no value set. The id is considered to be immutable, you can only set it at creation time and can't change it afterward.
You will find more info on the position, transformation and hierarchy page.
To summarize, a Base Primitive have the following properties:
owner, which points to the owner Canvas.parent which points to the direct parent that owns it.children an array of the direct children Primitives.hierarchyDepth a number given the depth in the hierarchy tree of the Primitive. The Canvas being 0, its direct children being 1, their children 2, and so on.zOrder, enables to override the default Z behavior. See this page for more information.You will find more info on the position, transformation and hierarchy page.
To summarize, a Base Primitive have the following properties:
position, a 2D Vector which give the position of the primitive bottom/left corner, relative from its parent's bottom/left corner.x, which is a shortcut to position.x, use it instead of changing the x of position in order to trigger value change.y, which is a shortcut to position.y, same remark as above.rotation, a angle in radian of the primitive's rotation around the Z axis.scale, a number which represent the uniform scale to apply on the primitive.actuaPosition the 'final' position, after layout and positioning engines were processed. Will be equal to position if no layout/positioning are used.actualX, which is a shortcut to actualPosition.x. use it instead of changing the x of actualPostition in order to trigger value change.actualY, which is a shortcut to actualPosition.y, same remark as above.globalTransform, invGlobalTransform and localTransform are all Matrix typed properties.Rotation and Scaling properties behave in regard of the origin property set for the Primitive. See the origin page for more information.
More information can be found in the Visibility page.
To summarize:
levelVisible is get/set property to define the visibility at the primitive's level. Default being true, but it won't necessarily means the primitive is visible, if one of its parent is hidden the primitive will be hidden.isVisible is a get only property, it defines if the primitive is actually visible or not, based on the levelVisible of this primitive and its parents.More information can be found in the dedicated page
The ActualSize property of type Size gives the actual bounding size of the property formed by an axis-aligned bounding rectangle.
the levelBoundingInfo property give as its name suggest the bounding information of the primitive without considering its children, it's about the primitive itself, that's all.
The boundingInfo property gives bounding information of the primitive and its children.
The bounding info is defined by:
You will find more information in the dedicated page.
To summarize:
isPickable, defines if the primitive can be picked/selected or not.pointerEventObservable is the main Observable to subscribe for all interaction related events.You can subscribe to the propertyChanged observable to be notified each time a property (defined with a @xxxLevelProperty decorator) has its value changing.