JavaFX 27 · javafx.scene.layout.FlowPane · APIdia, the JavaDoc alternative

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
	width	height
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_VALUE	Double.MAX_VALUE

Vertical
	width	height
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_VALUE	Double.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.

Nested and Inner Type Summary

Modifier and Type	Class and Description
private static class	FlowPane.LayoutRect
private static class	FlowPane.Run
private static class	FlowPane.StyleableProperties

Field Summary

Modifier and Type	Field and Description
private ObjectProperty<Pos>	alignment
private ObjectProperty<HPos>	columnHalignment
pack-priv boolean	computingRuns
private DoubleProperty	hgap
private double	lastMaxRunLength
private static final String	MARGIN_CONSTRAINT
private static final Callback<Node, Insets>	marginAccessor
private ObjectProperty<Orientation>	orientation
private DoubleProperty	prefWrapLength
private ObjectProperty<VPos>	rowValignment
private List<FlowPane.Run>	runs
private DoubleProperty	vgap

Constructor Summary

Access	Constructor and Description
public	FlowPane() Creates a horizontal FlowPane layout with hgap/vgap = 0.
public	FlowPane(Orientation the direction the tiles should flow & wrap orientation) Creates a FlowPane layout with the specified orientation and hgap/vgap = 0.
public	FlowPane(double the amount of horizontal space between each tile hgap, double the amount of vertical space between each tile vgap) Creates a horizontal FlowPane layout with the specified hgap/vgap.
public	FlowPane(Orientation the direction the tiles should flow & wrap orientation, double the amount of horizontal space between each tile hgap, double the amount of vertical space between each tile vgap) Creates a FlowPane layout with the specified orientation and hgap/vgap.
public	FlowPane(Node... The initial set of children for this pane. children) Creates a horizontal FlowPane layout with hgap/vgap = 0.
public	FlowPane(Orientation the direction the tiles should flow & wrap orientation, Node... The initial set of children for this pane. children) Creates a FlowPane layout with the specified orientation and hgap/vgap = 0.
public	FlowPane(double the amount of horizontal space between each tile hgap, double the amount of vertical space between each tile vgap, Node... The initial set of children for this pane. children) Creates a horizontal FlowPane layout with the specified hgap/vgap.
public	FlowPane(Orientation the direction the tiles should flow & wrap orientation, double the amount of horizontal space between each tile hgap, double the amount of vertical space between each tile vgap, Node... The initial set of children for this pane. children) Creates a FlowPane layout with the specified orientation and hgap/vgap.

Method Summary

Modifier and Type	Method and Description
public final ObjectProperty<Pos>	Returns: the overall alignment of the flowpane's content within its width and height alignmentProperty() The overall alignment of the flowpane's content within its width and height.
public static void	clearConstraints(Node the child node child) Removes all flowpane constraints from the child node.
public final ObjectProperty<HPos>	Returns: the horizontal alignment of nodes within each column of a vertical flowpane columnHalignmentProperty() The horizontal alignment of nodes within each column of a vertical flowpane.
private double	computeContentHeight(List<FlowPane.Run> runs)
private double	computeContentWidth(List<FlowPane.Run> runs)
protected double	computeMinHeight(double width) Overrides javafx.scene.layout.Region.computeMinHeight. Computes the minimum height of this region.
protected double	computeMinWidth(double height) Overrides javafx.scene.layout.Region.computeMinWidth. Computes the minimum width of this region.
protected double	computePrefHeight(double forWidth) Overrides javafx.scene.layout.Region.computePrefHeight. 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.
protected double	computePrefWidth(double forHeight) Overrides javafx.scene.layout.Region.computePrefWidth. Computes the preferred width of this region for the given height.
public final Pos	getAlignment()
private Pos	getAlignmentInternal()
public static List<CssMetaData<? extends Styleable, ?>>	Returns: the `CssMetaData` getClassCssMetaData() Hides javafx.scene.layout.Region.getClassCssMetaData. Gets the `CssMetaData` associated with this class, which may include the `CssMetaData` of its superclasses.
public final HPos	getColumnHalignment()
private HPos	getColumnHalignmentInternal()
public Orientation	getContentBias() Overrides javafx.scene.Node.getContentBias. Returns the orientation of a node's resizing bias for layout purposes.
public List<CssMetaData<? extends Styleable, ?>>	getCssMetaData() Overrides javafx.scene.layout.Region.getCssMetaData. Implements javafx.css.Styleable.getCssMetaData. This method should delegate to `Node#getClassCssMetaData()` so that a Node's CssMetaData can be accessed without the need for reflection.
public final double	getHgap()
public static Insets	Returns: the margin for the child or null if no margin was set getMargin(Node the child node of a flowpane child) Returns the child's margin constraint if set.
public final Orientation	getOrientation()
public final double	getPrefWrapLength()
public final VPos	getRowValignment()
private VPos	getRowValignmentInternal()
private List<FlowPane.Run>	getRuns(double maxRunLength)
public final double	getVgap()
public final DoubleProperty	Returns: the amount of horizontal space between each node in a horizontal flowpane or the space between columns in a vertical flowpane hgapProperty() The amount of horizontal space between each node in a horizontal flowpane or the space between columns in a vertical flowpane.
protected void	layoutChildren() Overrides javafx.scene.Parent.layoutChildren. Invoked during the layout pass to layout the children in this `Parent`.
private void	normalizeRun(final FlowPane.Run run, double runOffset)
public final ObjectProperty<Orientation>	Returns: the orientation of this flowpane orientationProperty() The orientation of this flowpane.
public final DoubleProperty	Returns: the preferred width where content should wrap in a horizontal flowpane or the preferred height where content should wrap in a vertical flowpane prefWrapLengthProperty() The preferred width where content should wrap in a horizontal flowpane or the preferred height where content should wrap in a vertical flowpane.
public void	requestLayout() Overrides javafx.scene.Parent.requestLayout. Requests a layout pass to be performed before the next scene is rendered.
public final ObjectProperty<VPos>	Returns: the vertical alignment of nodes within each row of a horizontal flowpane rowValignmentProperty() The vertical alignment of nodes within each row of a horizontal flowpane.
public final void	setAlignment(Pos value)
public final void	setColumnHalignment(HPos value)
public final void	setHgap(double value)
public static void	setMargin(Node the child node of a flowpane child, Insets the margin of space around the child value) Sets the margin for the child when contained by a flowpane.
public final void	setOrientation(Orientation value)
public final void	setPrefWrapLength(double value)
public final void	setRowValignment(VPos value)
public final void	setVgap(double value)
public final DoubleProperty	Returns: the amount of vertical space between each node in a vertical flowpane or the space between rows in a horizontal flowpane vgapProperty() The amount of vertical space between each node in a vertical flowpane or the space between rows in a horizontal flowpane.

Inherited from javafx.scene.layout.Pane:: getChildren getConstraint setConstraint

Field Detail

alignment	back to summary
private ObjectProperty<Pos> alignment

columnHalignment	back to summary
private ObjectProperty<HPos> columnHalignment

computingRuns	back to summary
pack-priv boolean computingRuns

hgap	back to summary
private DoubleProperty hgap

lastMaxRunLength	back to summary
private double lastMaxRunLength

MARGIN_CONSTRAINT	back to summary
private static final String MARGIN_CONSTRAINT

marginAccessor	back to summary
private static final Callback<Node, Insets> marginAccessor

orientation	back to summary
private ObjectProperty<Orientation> orientation

prefWrapLength	back to summary
private DoubleProperty prefWrapLength

rowValignment	back to summary
private ObjectProperty<VPos> rowValignment

runs	back to summary
private List<FlowPane.Run> runs

vgap	back to summary
private DoubleProperty vgap

Constructor Detail

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

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

FlowPane

Modifier and Type	Field and Description
pack-priv double	height
public Node	node
pack-priv double	width
pack-priv double	x
pack-priv double	y

Modifier and Type	Field and Description
pack-priv double	baselineOffset
pack-priv double	height
pack-priv ArrayList<FlowPane.LayoutRect>	rects
pack-priv double	width

Modifier and Type	Field and Description
private static final CssMetaData<FlowPane, Pos>	ALIGNMENT
private static final CssMetaData<FlowPane, HPos>	COLUMN_HALIGNMENT
private static final CssMetaData<FlowPane, Number>	HGAP
private static final CssMetaData<FlowPane, Orientation>	ORIENTATION
private static final CssMetaData<FlowPane, VPos>	ROW_VALIGNMENT
private static final List<CssMetaData<? extends Styleable, ?>>	STYLEABLES
private static final CssMetaData<FlowPane, Number>	VGAP

public Class FlowPane

Resizable Range

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private Class FlowPane.LayoutRect

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private Class FlowPane.Run

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private Class FlowPane.StyleableProperties

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