Package javafx.scene
Provides the core set of base classes for the JavaFX Scene Graph API. A scene graph is a tree-like data structure, where each item in the tree has zero or one parent and zero or more children.
The two primary classes in this package are:
Scene
– Defines the scene to be rendered. It contains afill
variable that specifies the background of the scene,width
andheight
variables that specify the size of the scene, and acontent
sequence that contains a list of "root"Nodes
to be rendered onto the scene. This sequence ofNodes
is the scene graph for thisScene
. AScene
is rendered onto aStage
, which is the top-level container for JavaFX content.Node
– Abstract base class for all nodes in the scene graph. Each node is either a "leaf" node with no child nodes or a "branch" node with zero or more child nodes. Each node in the tree has zero or one parent. Only a single node within each tree in the scene graph will have no parent, which is often referred to as the "root" node. There may be several trees in the scene graph. Some trees may be part of aScene
, in which case they are eligible to be displayed. Other trees might not be part of anyScene
.
Branch nodes are of type Parent
or
subclasses thereof.
Leaf nodes are classes such as
Rectangle
, Text
,
ImageView
, MediaView
,
or other such leaf classes which cannot have children.
A node may occur at most once anywhere in the scene
graph. Specifically, a node must appear no more than once in the children
list of a Parent
or as the clip of a
Node
.
See the Node
class for more details on these restrictions.
Example
An example JavaFX scene graph is as follows:
package example; import javafx.application.Application; import javafx.stage.Stage; import javafx.scene.Scene; import javafx.scene.Group; import javafx.scene.paint.Color; import javafx.scene.shape.Circle; import javafx.scene.text.Text; import javafx.scene.text.Font; public class Example extends Application { @Override public void start(Stage stage) { Group root = new Group(); Scene scene = new Scene(root, 200, 150); scene.setFill(Color.LIGHTGRAY); Circle circle = new Circle(60, 40, 30, Color.GREEN); Text text = new Text(10, 90, "JavaFX Scene"); text.setFill(Color.DARKRED); Font font = new Font(20); text.setFont(font); root.getChildren().add(circle); root.getChildren().add(text); stage.setScene(scene); stage.show(); } public static void main(String[] args) { Application.launch(args); } }
The above example will generate the following image:
Coordinate System and Transformations
The Node
class defines a traditional computer graphics "local"
coordinate system in which the x
axis increases to the right and the
y
axis increases downwards. The concrete node classes for shapes
provide variables for defining the geometry and location of the shape
within this local coordinate space. For example,
Rectangle
provides x
, y
,
width
, height
variables while
Circle
provides centerX
, centerY
,
and radius
.
Any Node
can have transformations applied to it. These include
translation, rotation, scaling, or shearing transformations. A transformation
will change the position, orientation, or size of the coordinate system as
viewed from the parent of the node that has been transformed.
See the Node
class for more information on transformations.
Bounding Rectangle
Since every Node
has transformations, every Node's geometric
bounding rectangle can be described differently depending on whether
transformations are accounted for or not.
Each Node
has the following properties which
specifies these bounding rectangles:
boundsInLocal
– specifies the bounds of theNode
in untransformed local coordinates.boundsInParent
– specifies the bounds of theNode
after all transformations have been applied. It is called "boundsInParent" because the rectangle will be relative to the parent's coordinate system.layoutBounds
– specifies the rectangular bounds of theNode
that should be used as the basis for layout calculations, and may differ from the visual bounds of the node. For shapes, Text, and ImageView, the defaultlayoutBounds
includes only the shape geometry.
See the Node
class for more information on bounding rectangles.
CSS
The JavaFX Scene Graph provides the facility to style nodes using
CSS (Cascading Style Sheets).
The Node
class contains id
, styleClass
, and
style
variables are used by CSS selectors to find nodes
to which styles should be applied. The Scene
class contains
the stylesheets
variable which is a sequence of URLs that
reference CSS style sheets that are to be applied to the nodes within
that scene.
For further information about CSS, how to apply CSS styles to nodes, and what properties are available for styling, see the CSS Reference Guide.
-
Class Summary Class Description AmbientLight Defines an ambient light source object.Camera Base class for a camera used to render a scene.Cursor A class to encapsulate the bitmap representation of the mouse cursor.Group AGroup
node contains an ObservableList of children that are rendered in order whenever this node is rendered.ImageCursor A custom image representation of the mouse cursor.LightBase TheLightBase
class provides definitions of common properties for objects that represent a form of light source.Node Base class for scene graph nodes.ParallelCamera Specifies a parallel camera for rendering a scene without perspective correction.Parent The base class for all nodes that have children in the scene graph.PerspectiveCamera Specifies a perspective camera for rendering a scene.PointLight A light source that radiates light equally in all directions away from itself.Scene The JavaFXScene
class is the container for all content in a scene graph.SceneAntialiasing The JavaFXSceneAntialiasing
class specifies the level of anti-aliasing desired.SnapshotParameters Parameters used to specify the rendering attributes for Node snapshot.SnapshotResult This class holds the result of a snapshot operation.SubScene TheSubScene
class is the container for content in a scene graph. -
Enum Summary Enum Description AccessibleAction This enum describes the actions that an assistive technology such as a screen reader can request from the scene graph.AccessibleAttribute This enum describes the attributes that an assistive technology such as a screen reader can request from the scene graph.AccessibleRole This enum describes the accessible role for aNode
.CacheHint Cache hints for use withNode.cacheHint
DepthTest This enum defines the possible states for the depthTest flag in node.