Module javafx.graphics
Package javafx.scene.layout

Class FlowPane

  • All Implemented Interfaces:
    Styleable, EventTarget
    public class FlowPane
extends Pane
    FlowPane lays out its children in a flow that wraps at the flowpane's boundary.

    A horizontal flowpane (the default) will layout nodes in rows, wrapping at the flowpane's width. A vertical flowpane lays out nodes in columns, wrapping at the flowpane's height. If the flowpane has a border and/or padding set, the content will be flowed within those insets.

    FlowPane's prefWrapLength property establishes its preferred width (for horizontal) or preferred height (for vertical). Applications should set prefWrapLength if the default value (400) doesn't suffice. Note that prefWrapLength is used only for calculating the preferred size and may not reflect the actual wrapping dimension, which tracks the actual size of the flowpane.

    The alignment property controls how the rows and columns are aligned within the bounds of the flowpane and defaults to Pos.TOP_LEFT. It is also possible to control the alignment of nodes within the rows and columns by setting rowValignment for horizontal or columnHalignment for vertical.

    Example of a horizontal flowpane: 

    
     Image images[] = { ... };
     FlowPane flow = new FlowPane();
     flow.setVgap(8);
     flow.setHgap(4);
     flow.setPrefWrapLength(300); // preferred width = 300
     for (int i = 0; i < images.length; i++) {
         flow.getChildren().add(new ImageView(image[i]);
     }

    Example of a vertical flowpane: 

    
     FlowPane flow = new FlowPane(Orientation.VERTICAL);
     flow.setColumnHalignment(HPos.LEFT); // align labels on left
     flow.setPrefWrapLength(200); // preferred height = 200
     for (int i = 0; i < titles.size(); i++) {
         flow.getChildren().add(new Label(titles[i]);
     }

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

    FlowPane may be styled with backgrounds and borders using CSS. See Region superclass for details.

    Resizable Range

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

    Horizontal
    widthheight
    minimum left/right insets plus largest of children's pref widths top/bottom insets plus height required to display all children at their preferred heights when wrapped at a specified width
    preferred left/right insets plus prefWrapLength top/bottom insets plus height required to display all children at their pref heights when wrapped at a specified width
    maximum Double.MAX_VALUEDouble.MAX_VALUE

    Vertical
    widthheight
    minimum left/right insets plus width required to display all children at their preferred widths when wrapped at a specified height top/bottom insets plus largest of children's pref heights
    preferred left/right insets plus width required to display all children at their pref widths when wrapped at the specified height top/bottom insets plus prefWrapLength
    maximum Double.MAX_VALUEDouble.MAX_VALUE

    A flowpane'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.

    FlowPane 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: 

    
     flowPane.setMaxWidth(500);
    Applications may restore the computed values by setting these properties back to Region.USE_COMPUTED_SIZE.

    FlowPane does not clip its content by default, so it is possible that children's bounds may extend outside its own bounds if a child's pref size is larger than the space flowpane has to allocate for it.

    Since:
    JavaFX 2.0

    • Property Detail

      • orientation

        public final ObjectProperty<Orientation> orientationProperty
        The orientation of this flowpane. A horizontal flowpane lays out children left to right, wrapping at the flowpane's width boundary. A vertical flowpane lays out children top to bottom, wrapping at the flowpane's height. The default is horizontal.
        See Also:
        getOrientation(), setOrientation(Orientation)

      • hgap

        public final DoubleProperty hgapProperty
        The amount of horizontal space between each node in a horizontal flowpane or the space between columns in a vertical flowpane.
        See Also:
        getHgap(), setHgap(double)

      • vgap

        public final DoubleProperty vgapProperty
        The amount of vertical space between each node in a vertical flowpane or the space between rows in a horizontal flowpane.
        See Also:
        getVgap(), setVgap(double)

      • prefWrapLength

        public final DoubleProperty prefWrapLengthProperty
        The preferred width where content should wrap in a horizontal flowpane or the preferred height where content should wrap in a vertical flowpane.

        This value is used only to compute the preferred size of the flowpane and may not reflect the actual width or height, which may change if the flowpane is resized to something other than its preferred size.

        Applications should initialize this value to define a reasonable span for wrapping the content.

        See Also:
        getPrefWrapLength(), setPrefWrapLength(double)

      • alignment

        public final ObjectProperty<Pos> alignmentProperty
        The overall alignment of the flowpane's content within its width and height.

        For a horizontal flowpane, each row will be aligned within the flowpane's width using the alignment's hpos value, and the rows will be aligned within the flowpane's height using the alignment's vpos value.

        For a vertical flowpane, each column will be aligned within the flowpane's height using the alignment's vpos value, and the columns will be aligned within the flowpane's width using the alignment's hpos value.

        See Also:
        getAlignment(), setAlignment(Pos)

      • rowValignment

        public final ObjectProperty<VPos> rowValignmentProperty
        The vertical alignment of nodes within each row of a horizontal flowpane. If this property is set to VPos.BASELINE, then the flowpane will always resize children to their preferred heights, rather than expanding heights to fill the row height. The property is ignored for vertical flowpanes.
        See Also:
        getRowValignment(), setRowValignment(VPos)

    • Constructor Detail

      • FlowPane

        public FlowPane()
        Creates a horizontal FlowPane layout with hgap/vgap = 0.

      • FlowPane

        public FlowPane​(Orientation orientation)
        Creates a FlowPane layout with the specified orientation and hgap/vgap = 0.
        Parameters:
        orientation - the direction the tiles should flow & wrap

      • FlowPane

        public FlowPane​(double hgap,
                double vgap)
        Creates a horizontal FlowPane layout with the specified hgap/vgap.
        Parameters:
        hgap - the amount of horizontal space between each tile
        vgap - the amount of vertical space between each tile

      • FlowPane

        public FlowPane​(Orientation orientation,
                double hgap,
                double vgap)
        Creates a FlowPane layout with the specified orientation and hgap/vgap.
        Parameters:
        orientation - the direction the tiles should flow & wrap
        hgap - the amount of horizontal space between each tile
        vgap - the amount of vertical space between each tile

      • FlowPane

        public FlowPane​(Node... children)
        Creates a horizontal FlowPane layout with hgap/vgap = 0.
        Parameters:
        children - The initial set of children for this pane.
        Since:
        JavaFX 8.0

      • FlowPane

        public FlowPane​(Orientation orientation,
                Node... children)
        Creates a FlowPane layout with the specified orientation and hgap/vgap = 0.
        Parameters:
        orientation - the direction the tiles should flow & wrap
        children - The initial set of children for this pane.
        Since:
        JavaFX 8.0

      • FlowPane

        public FlowPane​(double hgap,
                double vgap,
                Node... children)
        Creates a horizontal FlowPane layout with the specified hgap/vgap.
        Parameters:
        hgap - the amount of horizontal space between each tile
        vgap - the amount of vertical space between each tile
        children - The initial set of children for this pane.
        Since:
        JavaFX 8.0

      • FlowPane

        public FlowPane​(Orientation orientation,
                double hgap,
                double vgap,
                Node... children)
        Creates a FlowPane layout with the specified orientation and hgap/vgap.
        Parameters:
        orientation - the direction the tiles should flow & wrap
        hgap - the amount of horizontal space between each tile
        vgap - the amount of vertical space between each tile
        children - The initial set of children for this pane.
        Since:
        JavaFX 8.0

    • Method Detail

      • setMargin

        public static void setMargin​(Node child,
                             Insets value)
        Sets the margin for the child when contained by a flowpane. If set, the flowpane will layout it out with the margin space around it. Setting the value to null will remove the constraint.
        Parameters:
        child - the child node of a flowpane
        value - the margin of space around the child

      • getMargin

        public static Insets getMargin​(Node child)
        Returns the child's margin constraint if set.
        Parameters:
        child - the child node of a flowpane
        Returns:
        the margin for the child or null if no margin was set

      • clearConstraints

        public static void clearConstraints​(Node child)
        Removes all flowpane constraints from the child node.
        Parameters:
        child - the child node

      • orientationProperty

        public final ObjectProperty<Orientation> orientationProperty()
        The orientation of this flowpane. A horizontal flowpane lays out children left to right, wrapping at the flowpane's width boundary. A vertical flowpane lays out children top to bottom, wrapping at the flowpane's height. The default is horizontal.
        See Also:
        getOrientation(), setOrientation(Orientation)

      • setOrientation

        public final void setOrientation​(Orientation value)
        Sets the value of the property orientation.
        Property description:
        The orientation of this flowpane. A horizontal flowpane lays out children left to right, wrapping at the flowpane's width boundary. A vertical flowpane lays out children top to bottom, wrapping at the flowpane's height. The default is horizontal.

      • getOrientation

        public final Orientation getOrientation()
        Gets the value of the property orientation.
        Property description:
        The orientation of this flowpane. A horizontal flowpane lays out children left to right, wrapping at the flowpane's width boundary. A vertical flowpane lays out children top to bottom, wrapping at the flowpane's height. The default is horizontal.

      • hgapProperty

        public final DoubleProperty hgapProperty()
        The amount of horizontal space between each node in a horizontal flowpane or the space between columns in a vertical flowpane.
        See Also:
        getHgap(), setHgap(double)

      • setHgap

        public final void setHgap​(double value)
        Sets the value of the property hgap.
        Property description:
        The amount of horizontal space between each node in a horizontal flowpane or the space between columns in a vertical flowpane.

      • getHgap

        public final double getHgap()
        Gets the value of the property hgap.
        Property description:
        The amount of horizontal space between each node in a horizontal flowpane or the space between columns in a vertical flowpane.

      • vgapProperty

        public final DoubleProperty vgapProperty()
        The amount of vertical space between each node in a vertical flowpane or the space between rows in a horizontal flowpane.
        See Also:
        getVgap(), setVgap(double)

      • setVgap

        public final void setVgap​(double value)
        Sets the value of the property vgap.
        Property description:
        The amount of vertical space between each node in a vertical flowpane or the space between rows in a horizontal flowpane.

      • getVgap

        public final double getVgap()
        Gets the value of the property vgap.
        Property description:
        The amount of vertical space between each node in a vertical flowpane or the space between rows in a horizontal flowpane.

      • prefWrapLengthProperty

        public final DoubleProperty prefWrapLengthProperty()
        The preferred width where content should wrap in a horizontal flowpane or the preferred height where content should wrap in a vertical flowpane.

        This value is used only to compute the preferred size of the flowpane and may not reflect the actual width or height, which may change if the flowpane is resized to something other than its preferred size.

        Applications should initialize this value to define a reasonable span for wrapping the content.

        See Also:
        getPrefWrapLength(), setPrefWrapLength(double)

      • setPrefWrapLength

        public final void setPrefWrapLength​(double value)
        Sets the value of the property prefWrapLength.
        Property description:
        The preferred width where content should wrap in a horizontal flowpane or the preferred height where content should wrap in a vertical flowpane.

        This value is used only to compute the preferred size of the flowpane and may not reflect the actual width or height, which may change if the flowpane is resized to something other than its preferred size.

        Applications should initialize this value to define a reasonable span for wrapping the content.

      • getPrefWrapLength

        public final double getPrefWrapLength()
        Gets the value of the property prefWrapLength.
        Property description:
        The preferred width where content should wrap in a horizontal flowpane or the preferred height where content should wrap in a vertical flowpane.

        This value is used only to compute the preferred size of the flowpane and may not reflect the actual width or height, which may change if the flowpane is resized to something other than its preferred size.

        Applications should initialize this value to define a reasonable span for wrapping the content.

      • alignmentProperty

        public final ObjectProperty<Pos> alignmentProperty()
        The overall alignment of the flowpane's content within its width and height.

        For a horizontal flowpane, each row will be aligned within the flowpane's width using the alignment's hpos value, and the rows will be aligned within the flowpane's height using the alignment's vpos value.

        For a vertical flowpane, each column will be aligned within the flowpane's height using the alignment's vpos value, and the columns will be aligned within the flowpane's width using the alignment's hpos value.

        See Also:
        getAlignment(), setAlignment(Pos)

      • setAlignment

        public final void setAlignment​(Pos value)
        Sets the value of the property alignment.
        Property description:
        The overall alignment of the flowpane's content within its width and height.

        For a horizontal flowpane, each row will be aligned within the flowpane's width using the alignment's hpos value, and the rows will be aligned within the flowpane's height using the alignment's vpos value.

        For a vertical flowpane, each column will be aligned within the flowpane's height using the alignment's vpos value, and the columns will be aligned within the flowpane's width using the alignment's hpos value.

      • getAlignment

        public final Pos getAlignment()
        Gets the value of the property alignment.
        Property description:
        The overall alignment of the flowpane's content within its width and height.

        For a horizontal flowpane, each row will be aligned within the flowpane's width using the alignment's hpos value, and the rows will be aligned within the flowpane's height using the alignment's vpos value.

        For a vertical flowpane, each column will be aligned within the flowpane's height using the alignment's vpos value, and the columns will be aligned within the flowpane's width using the alignment's hpos value.

      • setColumnHalignment

        public final void setColumnHalignment​(HPos value)
        Sets the value of the property columnHalignment.
        Property description:
        The horizontal alignment of nodes within each column of a vertical flowpane. The property is ignored for horizontal flowpanes.

      • getColumnHalignment

        public final HPos getColumnHalignment()
        Gets the value of the property columnHalignment.
        Property description:
        The horizontal alignment of nodes within each column of a vertical flowpane. The property is ignored for horizontal flowpanes.

      • rowValignmentProperty

        public final ObjectProperty<VPos> rowValignmentProperty()
        The vertical alignment of nodes within each row of a horizontal flowpane. If this property is set to VPos.BASELINE, then the flowpane will always resize children to their preferred heights, rather than expanding heights to fill the row height. The property is ignored for vertical flowpanes.
        See Also:
        getRowValignment(), setRowValignment(VPos)

      • setRowValignment

        public final void setRowValignment​(VPos value)
        Sets the value of the property rowValignment.
        Property description:
        The vertical alignment of nodes within each row of a horizontal flowpane. If this property is set to VPos.BASELINE, then the flowpane will always resize children to their preferred heights, rather than expanding heights to fill the row height. The property is ignored for vertical flowpanes.

      • getRowValignment

        public final VPos getRowValignment()
        Gets the value of the property rowValignment.
        Property description:
        The vertical alignment of nodes within each row of a horizontal flowpane. If this property is set to VPos.BASELINE, then the flowpane will always resize children to their preferred heights, rather than expanding heights to fill the row height. The property is ignored for vertical flowpanes.

      • computeMinWidth

        protected double computeMinWidth​(double height)
        Description copied from class: Region
        Computes the minimum width of this region. Returns the sum of the left and right insets by default. region subclasses should override this method to return an appropriate value based on their content and layout strategy. If the subclass doesn't have a VERTICAL content bias, then the height parameter can be ignored.
        Overrides:
        computeMinWidth in class Region
        Parameters:
        height - the height that should be used if min width depends on it
        Returns:
        the computed minimum width of this region

      • computeMinHeight

        protected double computeMinHeight​(double width)
        Description copied from class: Region
        Computes the minimum height of this region. Returns the sum of the top and bottom insets by default. Region subclasses should override this method to return an appropriate value based on their content and layout strategy. If the subclass doesn't have a HORIZONTAL content bias, then the width parameter can be ignored.
        Overrides:
        computeMinHeight in class Region
        Parameters:
        width - the width that should be used if min height depends on it
        Returns:
        the computed minimum height for this region

      • computePrefWidth

        protected double computePrefWidth​(double forHeight)
        Description copied from class: Region
        Computes the preferred width of this region for the given height. Region subclasses should override this method to return an appropriate value based on their content and layout strategy. If the subclass doesn't have a VERTICAL content bias, then the height parameter can be ignored.
        Overrides:
        computePrefWidth in class Region
        Parameters:
        forHeight - the height that should be used if preferred width depends on it
        Returns:
        the computed preferred width for this region

      • computePrefHeight

        protected double computePrefHeight​(double forWidth)
        Description copied from class: Region
        Computes the preferred height of this region for the given width; Region subclasses should override this method to return an appropriate value based on their content and layout strategy. If the subclass doesn't have a HORIZONTAL content bias, then the width parameter can be ignored.
        Overrides:
        computePrefHeight in class Region
        Parameters:
        forWidth - the width that should be used if preferred height depends on it
        Returns:
        the computed preferred height for this region

      • requestLayout

        public void requestLayout()
        Description copied from class: Parent
        Requests a layout pass to be performed before the next scene is rendered. This is batched up asynchronously to happen once per "pulse", or frame of animation.

        If this parent is either a layout root or unmanaged, then it will be added directly to the scene's dirty layout list, otherwise requestParentLayout will be invoked.

        Overrides:
        requestLayout in class Parent

      • layoutChildren

        protected void layoutChildren()
        Description copied from class: Parent
        Invoked during the layout pass to layout the children in this Parent. By default it will only set the size of managed, resizable content to their preferred sizes and does not do any node positioning.

        Subclasses should override this function to layout content as needed.

        Overrides:
        layoutChildren in class Parent

      • getClassCssMetaData

        public static List<CssMetaData<? extends Styleable,​?>> getClassCssMetaData()
        Returns:
        The CssMetaData associated with this class, which may include the CssMetaData of its superclasses.
        Since:
        JavaFX 8.0