Module javafx.graphics
Package javafx.scene.layout

Class Pane

  • All Implemented Interfaces:
    Styleable, EventTarget
    Direct Known Subclasses:
    AnchorPane, BorderPane, DialogPane, FlowPane, GridPane, HBox, PopupControl.CSSBridge, StackPane, TextFlow, TilePane, VBox

    @DefaultProperty("children")
public class Pane
extends Region
    Base class for layout panes which need to expose the children list as public so that users of the subclass can freely add/remove children.

    This class may be used directly in cases where absolute positioning of children is required since it does not perform layout beyond resizing resizable children to their preferred sizes. It is the application's responsibility to position the children since the pane leaves the positions alone during layout. For example: 

    
     Pane canvas = new Pane();
     canvas.setStyle("-fx-background-color: black;");
     canvas.setPrefSize(200,200);
     Circle circle = new Circle(50,Color.BLUE);
     circle.relocate(20, 20);
     Rectangle rectangle = new Rectangle(100,100,Color.RED);
     rectangle.relocate(70,70);
     canvas.getChildren().addAll(circle,rectangle);

    Note: if an application needs children to be kept aligned within a parent (centered, positioned at top-left, etc), it should use a StackPane instead.

    Pane resizes each managed child regardless of the child's visible property value; unmanaged children are ignored for all layout calculations.

    Resizable Range

    A pane's parent will resize the pane within the pane's resizable range during layout. By default the pane computes this range based on its content as outlined in the table below:

    Pane Resize Table
    widthheight
    minimum left plus right insets. top plus bottom insets.
    preferred width required to encompass each child at its current x location and preferred width. height required to encompass each child at its current y location and preferred height.
    maximum Double.MAX_VALUEDouble.MAX_VALUE

    A pane's unbounded maximum width and height are an indication to the parent that it may be resized beyond its preferred size to fill whatever space is assigned to it.

    Pane provides properties for setting the size range directly. These properties default to the sentinel value Region.USE_COMPUTED_SIZE, however the application may set them to other values as needed: 

    
     pane.setPrefSize(500,400);
    Applications may restore the computed values by setting these properties back to Region.USE_COMPUTED_SIZE.

    Pane does not clip its content by default, so it is possible that childrens' bounds may extend outside its own bounds, either if children are positioned at negative coordinates or the pane is resized smaller than its preferred size.

    Since:
    JavaFX 2.0

    • Constructor Detail

      • Pane

        public Pane​()
        Creates a Pane layout.

      • Pane

        public Pane​(Node... children)
        Creates a Pane layout.
        Parameters:
        children - The initial set of children for this pane.
        Since:
        JavaFX 8.0

    • Method Detail

      • getChildren

        public ObservableList<Node> getChildren​()
        Description copied from class: Parent
        Gets the list of children of this Parent.

        See the class documentation for Node for scene graph structure restrictions on setting a Parent's children list. If these restrictions are violated by a change to the list of children, the change is ignored and the previous value of the children list is restored. An IllegalArgumentException is thrown in this case.

        If this Parent node is attached to a Scene attached to a Window that is showning (Window.isShowing()), then its list of children must only be modified on the JavaFX Application Thread. An IllegalStateException is thrown if this restriction is violated.

        Note to subclasses: if you override this method, you must return from your implementation the result of calling this super method. The actual list instance returned from any getChildren() implementation must be the list owned and managed by this Parent. The only typical purpose for overriding this method is to promote the method to be public.

        Overrides:
        getChildren in class Parent
        Returns:
        modifiable list of children.