JavaFX 25 · javafx.scene.layout.HBox · APIdia, the JavaDoc alternative

HBox lays out its children in a single horizontal row. If the hbox has a border and/or padding set, then the contents will be laid out within those insets.

HBox example:

HBox hbox = new HBox(8); // spacing = 8
    hbox.getChildren().addAll(new Label("Name:), new TextBox());

HBox will resize children (if resizable) to their preferred widths and uses its fillHeight property to determine whether to resize their heights to fill its own height or keep their heights to their preferred (fillHeight defaults to true). The alignment of the content is controlled by the alignment property, which defaults to Pos.TOP_LEFT.

If an hbox is resized larger than its preferred width, by default it will keep children to their preferred widths, leaving the extra space unused. If an application wishes to have one or more children be allocated that extra space it may optionally set an hgrow constraint on the child. See "Optional Layout Constraints" for details.

HBox lays out each managed child regardless of the child's visible property value; unmanaged children are ignored.

Resizable Range

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

HBox Resize Table
	width	height
minimum	left/right insets plus the sum of each child's min width plus spacing between each child.	top/bottom insets plus the largest of the children's min heights.
preferred	left/right insets plus the sum of each child's pref width plus spacing between each child.	top/bottom insets plus the largest of the children's pref heights.
maximum	Double.MAX_VALUE	Double.MAX_VALUE

An hbox'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.

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


    hbox.setPrefWidth(400);

Applications may restore the computed values by setting these properties back to USE_COMPUTED_SIZE.

HBox 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 min size prevents it from being fit within the hbox.

Optional Layout Constraints

An application may set constraints on individual children to customize HBox's layout. For each constraint, HBox provides a static method for setting it on the child.

HBox Constraint Table
Constraint	Type	Description
hgrow	javafx.scene.layout.Priority	The horizontal grow priority for the child.
margin	javafx.geometry.Insets	Margin space around the outside of the child.

For example, if an hbox needs the TextField to be allocated all extra space:


    HBox hbox = new HBox();
    TextField field = new TextField();
    HBox.setHgrow(field, Priority.ALWAYS);
    hbox.getChildren().addAll(new Label("Search:"), field, new Button("Go"));

If more than one child has the same grow priority set, then the hbox will allocate equal amounts of space to each. HBox will only grow a child up to its maximum width, so if the child has a max width other than Double.MAX_VALUE, the application may need to override the max to allow it to grow. For example:


    HBox hbox = new HBox();
    Button button1 = new Button("Add");
    Button button2 = new Button("Remove");
    HBox.setHgrow(button1, Priority.ALWAYS);
    HBox.setHgrow(button2, Priority.ALWAYS);
    button1.setMaxWidth(Double.MAX_VALUE);
    button2.setMaxWidth(Double.MAX_VALUE);
    hbox.getChildren().addAll(button1, button2);

Nested and Inner Type Summary

Modifier and Type	Class and Description
private static class	HBox.StyleableProperties

Field Summary

Modifier and Type	Field and Description
private ObjectProperty<Pos>	alignment
private double	baselineOffset
private Orientation	bias
private boolean	biasDirty
private BooleanProperty	fillHeight
private static final String	HGROW_CONSTRAINT
private static final String	MARGIN_CONSTRAINT
private static final Callback<Node, Insets>	marginAccessor
private double	minBaselineComplement
private double	prefBaselineComplement
private DoubleProperty	spacing
private double[][]	tempArray

Constructor Summary

Access	Constructor and Description
public	HBox() Creates an `HBox` layout with `spacing = 0`.
public	HBox(double the amount of horizontal space between each child spacing) Creates an `HBox` layout with the specified spacing between children.
public	HBox(Node... the initial set of children for this pane children) Creates an `HBox` layout with `spacing = 0`.
public	HBox(double the amount of horizontal space between each child spacing, Node... the initial set of children for this pane children) Creates an `HBox` layout with the specified spacing between children.

Method Summary

Modifier and Type	Method and Description
private double	adjustAreaWidths(List<Node> managed, double[][] areaWidths, double width, double height)
public final ObjectProperty<Pos>	Returns: the overall alignment of children within the hbox's width and height alignmentProperty() The overall alignment of children within the hbox's width and height.
public static void	clearConstraints(Node the child node child) Removes all hbox constraints from the child node.
private double	computeContentWidth(List<Node> managedChildren, double height, boolean minimum)
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 width) 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 height) Overrides javafx.scene.layout.Region.computePrefWidth. Computes the preferred width of this region for the given height.
public final BooleanProperty	Returns: true if resizable children will be resized to fill the full height of the hbox fillHeightProperty() Whether or not resizable children will be resized to fill the full height of the hbox or be resized to their preferred height and aligned according to the `alignment` vpos value.
public final Pos	getAlignment()
private Pos	getAlignmentInternal()
private double[][]	getAreaWidths(List<Node> managed, double height, boolean minimum)
public double	getBaselineOffset() Overrides javafx.scene.Parent.getBaselineOffset. Calculates the baseline offset based on the first managed child.
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 Orientation	Returns: null unless one of its children has a content bias. 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 static Priority	Returns: the horizontal grow priority for the child or null if no priority was set getHgrow(Node the child node of an hbox child) Returns the child's hgrow constraint if set.
public static Insets	Returns: the margin for the child or null if no margin was set getMargin(Node the child node of an hbox child) Returns the child's margin constraint if set.
private double	getMinBaselineComplement()
private double	getPrefBaselineComplement()
public final double	getSpacing()
private double[][]	getTempArray(int size)
private double	growOrShrinkAreaWidths(List<Node> managed, double[][] areaWidths, Priority priority, double extraWidth, double height)
public final boolean	isFillHeight()
protected void	layoutChildren() Overrides javafx.scene.Parent.layoutChildren. Invoked during the layout pass to layout the children in this `Parent`.
public void	requestLayout() Overrides javafx.scene.Parent.requestLayout. Requests a layout pass to be performed before the next scene is rendered.
public final void	setAlignment(Pos value)
public final void	setFillHeight(boolean value)
public static void	setHgrow(Node the child of an hbox child, Priority the horizontal grow priority for the child value) Sets the horizontal grow priority for the child when contained by an hbox.
public static void	setMargin(Node the child mode of the hbox child, Insets the margin of space around the child value) Sets the margin for the child when contained by an hbox.
public final void	setSpacing(double value)
private boolean	shouldFillHeight()
public final DoubleProperty	Returns: the amount of horizontal space between each child in the hbox spacingProperty() The amount of horizontal space between each child in the hbox.
private static double	sum(double[] array, int size)

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

Field Detail

alignment	back to summary
private ObjectProperty<Pos> alignment

baselineOffset	back to summary
private double baselineOffset

bias	back to summary
private Orientation bias

biasDirty	back to summary
private boolean biasDirty

fillHeight	back to summary
private BooleanProperty fillHeight

HGROW_CONSTRAINT	back to summary
private static final String HGROW_CONSTRAINT

MARGIN_CONSTRAINT	back to summary
private static final String MARGIN_CONSTRAINT

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

minBaselineComplement	back to summary
private double minBaselineComplement

prefBaselineComplement	back to summary
private double prefBaselineComplement

spacing	back to summary
private DoubleProperty spacing

tempArray	back to summary
private double[][] tempArray

Constructor Detail

HBox	back to summary
public HBox() Creates an `HBox` layout with `spacing = 0`.

HBox back to summary

HBox	back to summary
public HBox(double spacing) Creates an `HBox` layout with the specified spacing between children. Parameters spacing:double the amount of horizontal space between each child

public HBox(double spacing)

Creates an HBox layout with the specified spacing between children.

Parameters

spacing:double: the amount of horizontal space between each child

HBox back to summary

HBox	back to summary
public HBox(Node... children) Creates an `HBox` layout with `spacing = 0`. Parameters children:Node[] the initial set of children for this pane Since JavaFX 8.0

public HBox(Node... children)

Creates an HBox layout with spacing = 0.

Parameters

children:Node[]: the initial set of children for this pane

Since

JavaFX 8.0

HBox back to summary

HBox	back to summary
public HBox(double spacing, Node... children) Creates an `HBox` layout with the specified spacing between children. Parameters spacing:double the amount of horizontal space between each child children:Node[] the initial set of children for this pane Since JavaFX 8.0

public HBox(double spacing, Node... children)

Creates an HBox layout with the specified spacing between children.

Parameters

spacing:double: the amount of horizontal space between each child
children:Node[]: the initial set of children for this pane

Since

JavaFX 8.0

Method Detail

adjustAreaWidths	back to summary
private double adjustAreaWidths(List<Node> managed, double[][] areaWidths, double width, double height)

alignmentProperty	back to summary
public final ObjectProperty<Pos> alignmentProperty() The overall alignment of children within the hbox's width and height. Returns:ObjectProperty<Pos> the overall alignment of children within the hbox's width and height

alignmentProperty

back to summary

public final ObjectProperty<Pos> alignmentProperty()

The overall alignment of children within the hbox's width and height.

Returns:ObjectProperty<Pos>: the overall alignment of children within the hbox's width and height

clearConstraints	back to summary
public static void clearConstraints(Node child) Removes all hbox constraints from the child node. Parameters child:Node the child node

clearConstraints

back to summary

public static void clearConstraints(Node child)

Removes all hbox constraints from the child node.

Parameters

child:Node: the child node

computeContentWidth	back to summary
private double computeContentWidth(List<Node> managedChildren, double height, boolean minimum)

computeMinHeight	back to summary
protected double computeMinHeight(double width) Overrides javafx.scene.layout.Region.computeMinHeight. Doc from javafx.scene.layout.Region.computeMinHeight. 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. Annotations @Override

computeMinHeight

back to summary

protected double computeMinHeight(double width)

Overrides javafx.scene.layout.Region.computeMinHeight.

Doc from javafx.scene.layout.Region.computeMinHeight.

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.

Annotations

@Override

computeMinWidth	back to summary
protected double computeMinWidth(double height) Overrides javafx.scene.layout.Region.computeMinWidth. Doc from javafx.scene.layout.Region.computeMinWidth. 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. Annotations @Override

computeMinWidth

back to summary

protected double computeMinWidth(double height)

Overrides javafx.scene.layout.Region.computeMinWidth.

Doc from javafx.scene.layout.Region.computeMinWidth.

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.

Annotations

@Override

computePrefHeight	back to summary
protected double computePrefHeight(double width) Overrides javafx.scene.layout.Region.computePrefHeight. Doc from 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. If the subclass doesn't have a HORIZONTAL content bias, then the width parameter can be ignored. Annotations @Override

computePrefHeight

back to summary

protected double computePrefHeight(double width)

Overrides javafx.scene.layout.Region.computePrefHeight.

Doc from 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. If the subclass doesn't have a HORIZONTAL content bias, then the width parameter can be ignored.

Annotations

@Override

computePrefWidth	back to summary
protected double computePrefWidth(double height) Overrides javafx.scene.layout.Region.computePrefWidth. Doc from javafx.scene.layout.Region.computePrefWidth. 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. Annotations @Override

computePrefWidth

back to summary

protected double computePrefWidth(double height)

Overrides javafx.scene.layout.Region.computePrefWidth.

Doc from javafx.scene.layout.Region.computePrefWidth.

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.

Annotations

@Override

fillHeightProperty back to summary

fillHeightProperty	back to summary
public final BooleanProperty fillHeightProperty() Whether or not resizable children will be resized to fill the full height of the hbox or be resized to their preferred height and aligned according to the `alignment` vpos value. Note that if the hbox vertical alignment is set to BASELINE, then this property will be ignored and children will be resized to their preferred heights. Returns:BooleanProperty true if resizable children will be resized to fill the full height of the hbox

public final BooleanProperty fillHeightProperty()

Whether or not resizable children will be resized to fill the full height of the hbox or be resized to their preferred height and aligned according to the alignment vpos value. Note that if the hbox vertical alignment is set to BASELINE, then this property will be ignored and children will be resized to their preferred heights.

Returns:BooleanProperty: true if resizable children will be resized to fill the full height of the hbox

getAlignment	back to summary
public final Pos getAlignment()

getAlignmentInternal	back to summary
private Pos getAlignmentInternal()

getAreaWidths	back to summary
private double[][] getAreaWidths(List<Node> managed, double height, boolean minimum)

getBaselineOffset back to summary

getBaselineOffset	back to summary
public double getBaselineOffset() Overrides javafx.scene.Parent.getBaselineOffset. Doc from javafx.scene.Parent.getBaselineOffset. Calculates the baseline offset based on the first managed child. If there is no such child, returns `Node#getBaselineOffset()`. Annotations @Override

public double getBaselineOffset()

Overrides javafx.scene.Parent.getBaselineOffset.

Doc from javafx.scene.Parent.getBaselineOffset.

Calculates the baseline offset based on the first managed child. If there is no such child, returns Node#getBaselineOffset().

Annotations

@Override

getClassCssMetaData back to summary

public static List<CssMetaData<? extends Styleable, ?>> getClassCssMetaData()

Hides javafx.scene.layout.Region.getClassCssMetaData.

Gets the CssMetaData associated with this class, which may include the CssMetaData of its superclasses.

Returns:List<CssMetaData<? extends Styleable, ?>>: the CssMetaData
Since: JavaFX 8.0

getContentBias	back to summary
public Orientation getContentBias() Overrides javafx.scene.Node.getContentBias. Doc from javafx.scene.Node.getContentBias. Returns the orientation of a node's resizing bias for layout purposes. If the node type has no bias, returns null. If the node is resizable and it's height depends on its width, returns HORIZONTAL, else if its width depends on its height, returns VERTICAL. Resizable subclasses should override this method to return an appropriate value. Returns:Orientation null unless one of its children has a content bias. Annotations @Override

getContentBias

back to summary

public Orientation getContentBias()

Overrides javafx.scene.Node.getContentBias.

Doc from javafx.scene.Node.getContentBias.

Returns the orientation of a node's resizing bias for layout purposes. If the node type has no bias, returns null. If the node is resizable and it's height depends on its width, returns HORIZONTAL, else if its width depends on its height, returns VERTICAL.

Resizable subclasses should override this method to return an appropriate value.

Returns:Orientation

null unless one of its children has a content bias.

Annotations

@Override

getCssMetaData back to summary

public List<CssMetaData<? extends Styleable, ?>> getCssMetaData()

Overrides javafx.scene.layout.Region.getCssMetaData.

Implements javafx.css.Styleable.getCssMetaData.

Doc from javafx.scene.layout.Region.getCssMetaData.

This method should delegate to Node#getClassCssMetaData() so that a Node's CssMetaData can be accessed without the need for reflection.

Annotations

@Override

Since

JavaFX 8.0

getHgrow	back to summary
public static Priority getHgrow(Node child) Returns the child's hgrow constraint if set. Parameters child:Node the child node of an hbox Returns:Priority the horizontal grow priority for the child or null if no priority was set

getHgrow

back to summary

public static Priority getHgrow(Node child)

Returns the child's hgrow constraint if set.

Parameters

child:Node: the child node of an hbox

Returns:Priority

the horizontal grow priority for the child or null if no priority was set

getMargin	back to summary
public static Insets getMargin(Node child) Returns the child's margin constraint if set. Parameters child:Node the child node of an hbox Returns:Insets the margin for the child or null if no margin was set

getMargin

back to summary

public static Insets getMargin(Node child)

Returns the child's margin constraint if set.

Parameters

child:Node: the child node of an hbox

Returns:Insets

the margin for the child or null if no margin was set

getMinBaselineComplement	back to summary
private double getMinBaselineComplement()

getPrefBaselineComplement	back to summary
private double getPrefBaselineComplement()

getSpacing	back to summary
public final double getSpacing()

getTempArray	back to summary
private double[][] getTempArray(int size)

growOrShrinkAreaWidths	back to summary
private double growOrShrinkAreaWidths(List<Node> managed, double[][] areaWidths, Priority priority, double extraWidth, double height)

isFillHeight	back to summary
public final boolean isFillHeight()

layoutChildren back to summary

layoutChildren	back to summary
protected void layoutChildren() Overrides javafx.scene.Parent.layoutChildren. Doc from javafx.scene.Parent.layoutChildren. 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. Annotations @Override

protected void layoutChildren()

Overrides javafx.scene.Parent.layoutChildren.

Doc from javafx.scene.Parent.layoutChildren.

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.

Annotations

@Override

requestLayout	back to summary
public void requestLayout() Overrides javafx.scene.Parent.requestLayout. Doc from javafx.scene.Parent.requestLayout. 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. Annotations @Override

requestLayout

back to summary

public void requestLayout()

Overrides javafx.scene.Parent.requestLayout.

Doc from javafx.scene.Parent.requestLayout.

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.

Annotations

@Override

setAlignment	back to summary
public final void setAlignment(Pos value)

setFillHeight	back to summary
public final void setFillHeight(boolean value)

setHgrow back to summary

public static void setHgrow(Node child, Priority value)

Sets the horizontal grow priority for the child when contained by an hbox. If set, the hbox will use the priority value to allocate additional space if the hbox is resized larger than its preferred width. If multiple hbox children have the same horizontal grow priority, then the extra space will be split evenly between them. If no horizontal grow priority is set on a child, the hbox will never allocate any additional horizontal space for that child.

Setting the value to null will remove the constraint.

Parameters

child:Node: the child of an hbox
value:Priority: the horizontal grow priority for the child

setMargin

back to summary

public static void setMargin(Node child, Insets value)

Sets the margin for the child when contained by an hbox. If set, the hbox will layout the child with the margin space around it. Setting the value to null will remove the constraint.

Parameters

child:Node: the child mode of the hbox
value:Insets: the margin of space around the child

setSpacing	back to summary
public final void setSpacing(double value)

shouldFillHeight	back to summary
private boolean shouldFillHeight()

spacingProperty

back to summary

public final DoubleProperty spacingProperty()

The amount of horizontal space between each child in the hbox.

Returns:DoubleProperty: the amount of horizontal space between each child in the hbox

sum	back to summary
private static double sum(double[] array, int size)

Modifier and Type	Field and Description
private static final CssMetaData<HBox, Pos>	ALIGNMENT
private static final CssMetaData<HBox, Boolean>	FILL_HEIGHT
private static final CssMetaData<HBox, Number>	SPACING
private static final List<CssMetaData<? extends Styleable, ?>>	STYLEABLES

public Class HBox

Resizable Range

Optional Layout Constraints

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

private Class HBox.StyleableProperties

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail