Module javafx.graphics
Package javafx.scene.layout

# Class HBox

java.lang.Object
javafx.scene.Node
javafx.scene.Parent
javafx.scene.layout.Region
javafx.scene.layout.Pane
javafx.scene.layout.HBox

All Implemented Interfaces:
  `Styleable`, `EventTarget`

public class HBox extends Pane
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);

Since:
  JavaFX 2.0

- ## Property Summary

  Properties
  Type
  Property
  Description
  `final ObjectProperty<Pos>`
  `alignment`
  The overall alignment of children within the hbox's width and height.
  `final BooleanProperty`
  `fillHeight`
  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.
  `final DoubleProperty`
  `spacing`
  The amount of horizontal space between each child in the hbox.

  ### Properties declared in class javafx.scene.layout.Region

  `background, border, cacheShape, centerShape, height, insets, maxHeight, maxWidth, minHeight, minWidth, opaqueInsets, padding, prefHeight, prefWidth, scaleShape, shape, snapToPixel, width`

  ### Properties declared in class javafx.scene.Parent

  `needsLayout`

  ### Properties declared in class javafx.scene.Node

  `accessibleHelp, accessibleRoleDescription, accessibleRole, accessibleText, blendMode, boundsInLocal, boundsInParent, cacheHint, cache, clip, cursor, depthTest, disabled, disable, effectiveNodeOrientation, effect, eventDispatcher, focused, focusTraversable, hover, id, inputMethodRequests, layoutBounds, layoutX, layoutY, localToParentTransform, localToSceneTransform, managed, mouseTransparent, nodeOrientation, onContextMenuRequested, onDragDetected, onDragDone, onDragDropped, onDragEntered, onDragExited, onDragOver, onInputMethodTextChanged, onKeyPressed, onKeyReleased, onKeyTyped, onMouseClicked, onMouseDragEntered, onMouseDragExited, onMouseDragged, onMouseDragOver, onMouseDragReleased, onMouseEntered, onMouseExited, onMouseMoved, onMousePressed, onMouseReleased, onRotate, onRotationFinished, onRotationStarted, onScrollFinished, onScroll, onScrollStarted, onSwipeDown, onSwipeLeft, onSwipeRight, onSwipeUp, onTouchMoved, onTouchPressed, onTouchReleased, onTouchStationary, onZoomFinished, onZoom, onZoomStarted, opacity, parent, pickOnBounds, pressed, rotate, rotationAxis, scaleX, scaleY, scaleZ, scene, style, translateX, translateY, translateZ, viewOrder, visible`

- ## Field Summary

  ### Fields declared in class javafx.scene.layout.Region

  `USE_COMPUTED_SIZE, USE_PREF_SIZE`

  ### Fields declared in class javafx.scene.Node

  `BASELINE_OFFSET_SAME_AS_HEIGHT`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `HBox()`
  Creates an `HBox` layout with `spacing = 0`.
  `HBox(double spacing)`
  Creates an `HBox` layout with the specified spacing between children.
  `HBox(double spacing, Node... children)`
  Creates an `HBox` layout with the specified spacing between children.
  `HBox(Node... children)`
  Creates an `HBox` layout with `spacing = 0`.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `final ObjectProperty<Pos>`
  `alignmentProperty()`
  The overall alignment of children within the hbox's width and height.
  `static void`
  `clearConstraints(Node child)`
  Removes all hbox constraints from the child node.
  `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.
  `final Pos`
  `getAlignment()`
  Gets the value of the property alignment.
  `static List<CssMetaData<? extends Styleable,?>>`
  `getClassCssMetaData()`
  `Orientation`
  `getContentBias()`
  Returns the orientation of a node's resizing bias for layout purposes.
  `List<CssMetaData<? extends Styleable,?>>`
  `getCssMetaData()`
  This method should delegate to `Node.getClassCssMetaData()` so that a Node's CssMetaData can be accessed without the need for reflection.
  `static Priority`
  `getHgrow(Node child)`
  Returns the child's hgrow constraint if set.
  `static Insets`
  `getMargin(Node child)`
  Returns the child's margin constraint if set.
  `final double`
  `getSpacing()`
  Gets the value of the property spacing.
  `final boolean`
  `isFillHeight()`
  Gets the value of the property fillHeight.
  `final void`
  `setAlignment(Pos value)`
  Sets the value of the property alignment.
  `final void`
  `setFillHeight(boolean value)`
  Sets the value of the property fillHeight.
  `static void`
  `setHgrow(Node child, Priority value)`
  Sets the horizontal grow priority for the child when contained by an hbox.
  `static void`
  `setMargin(Node child, Insets value)`
  Sets the margin for the child when contained by an hbox.
  `final void`
  `setSpacing(double value)`
  Sets the value of the property spacing.
  `final DoubleProperty`
  `spacingProperty()`
  The amount of horizontal space between each child in the hbox.

  ### Methods declared in class javafx.scene.layout.Pane

  `getChildren`

  ### Methods declared in class javafx.scene.layout.Region

  `backgroundProperty, borderProperty, cacheShapeProperty, centerShapeProperty, computeMaxHeight, computeMaxWidth, computeMinHeight, computeMinWidth, computePrefHeight, computePrefWidth, getBackground, getBorder, getHeight, getInsets, getMaxHeight, getMaxWidth, getMinHeight, getMinWidth, getOpaqueInsets, getPadding, getPrefHeight, getPrefWidth, getShape, getUserAgentStylesheet, getWidth, heightProperty, insetsProperty, isCacheShape, isCenterShape, isResizable, isScaleShape, isSnapToPixel, layoutInArea, layoutInArea, layoutInArea, layoutInArea, maxHeight, maxHeightProperty, maxWidth, maxWidthProperty, minHeight, minHeightProperty, minWidth, minWidthProperty, opaqueInsetsProperty, paddingProperty, positionInArea, positionInArea, prefHeight, prefHeightProperty, prefWidth, prefWidthProperty, resize, scaleShapeProperty, setBackground, setBorder, setCacheShape, setCenterShape, setHeight, setMaxHeight, setMaxSize, setMaxWidth, setMinHeight, setMinSize, setMinWidth, setOpaqueInsets, setPadding, setPrefHeight, setPrefSize, setPrefWidth, setScaleShape, setShape, setSnapToPixel, setWidth, shapeProperty, snappedBottomInset, snappedLeftInset, snappedRightInset, snappedTopInset, snapPosition, snapPositionX, snapPositionY, snapSize, snapSizeX, snapSizeY, snapSpace, snapSpaceX, snapSpaceY, snapToPixelProperty, widthProperty`

  ### Methods declared in class javafx.scene.Parent

  `getBaselineOffset, getChildrenUnmodifiable, getManagedChildren, getStylesheets, isNeedsLayout, layout, layoutChildren, needsLayoutProperty, requestLayout, requestParentLayout, setNeedsLayout, updateBounds`

  ### Methods declared in class javafx.scene.Node

  `accessibleHelpProperty, accessibleRoleDescriptionProperty, accessibleRoleProperty, accessibleTextProperty, addEventFilter, addEventHandler, applyCss, autosize, blendModeProperty, boundsInLocalProperty, boundsInParentProperty, buildEventDispatchChain, cacheHintProperty, cacheProperty, clipProperty, computeAreaInScreen, contains, contains, cursorProperty, depthTestProperty, disabledProperty, disableProperty, effectiveNodeOrientationProperty, effectProperty, eventDispatcherProperty, executeAccessibleAction, fireEvent, focusedProperty, focusTraversableProperty, getAccessibleHelp, getAccessibleRole, getAccessibleRoleDescription, getAccessibleText, getBlendMode, getBoundsInLocal, getBoundsInParent, getCacheHint, getClip, getCursor, getDepthTest, getEffect, getEffectiveNodeOrientation, getEventDispatcher, getId, getInitialCursor, getInitialFocusTraversable, getInputMethodRequests, getLayoutBounds, getLayoutX, getLayoutY, getLocalToParentTransform, getLocalToSceneTransform, getNodeOrientation, getOnContextMenuRequested, getOnDragDetected, getOnDragDone, getOnDragDropped, getOnDragEntered, getOnDragExited, getOnDragOver, getOnInputMethodTextChanged, getOnKeyPressed, getOnKeyReleased, getOnKeyTyped, getOnMouseClicked, getOnMouseDragEntered, getOnMouseDragExited, getOnMouseDragged, getOnMouseDragOver, getOnMouseDragReleased, getOnMouseEntered, getOnMouseExited, getOnMouseMoved, getOnMousePressed, getOnMouseReleased, getOnRotate, getOnRotationFinished, getOnRotationStarted, getOnScroll, getOnScrollFinished, getOnScrollStarted, getOnSwipeDown, getOnSwipeLeft, getOnSwipeRight, getOnSwipeUp, getOnTouchMoved, getOnTouchPressed, getOnTouchReleased, getOnTouchStationary, getOnZoom, getOnZoomFinished, getOnZoomStarted, getOpacity, getParent, getProperties, getPseudoClassStates, getRotate, getRotationAxis, getScaleX, getScaleY, getScaleZ, getScene, getStyle, getStyleableParent, getStyleClass, getTransforms, getTranslateX, getTranslateY, getTranslateZ, getTypeSelector, getUserData, getViewOrder, hasProperties, hoverProperty, idProperty, inputMethodRequestsProperty, intersects, intersects, isCache, isDisable, isDisabled, isFocused, isFocusTraversable, isHover, isManaged, isMouseTransparent, isPickOnBounds, isPressed, isVisible, layoutBoundsProperty, layoutXProperty, layoutYProperty, localToParent, localToParent, localToParent, localToParent, localToParent, localToParentTransformProperty, localToScene, localToScene, localToScene, localToScene, localToScene, localToScene, localToScene, localToScene, localToScene, localToScene, localToSceneTransformProperty, localToScreen, localToScreen, localToScreen, localToScreen, localToScreen, lookup, lookupAll, managedProperty, mouseTransparentProperty, nodeOrientationProperty, notifyAccessibleAttributeChanged, onContextMenuRequestedProperty, onDragDetectedProperty, onDragDoneProperty, onDragDroppedProperty, onDragEnteredProperty, onDragExitedProperty, onDragOverProperty, onInputMethodTextChangedProperty, onKeyPressedProperty, onKeyReleasedProperty, onKeyTypedProperty, onMouseClickedProperty, onMouseDragEnteredProperty, onMouseDragExitedProperty, onMouseDraggedProperty, onMouseDragOverProperty, onMouseDragReleasedProperty, onMouseEnteredProperty, onMouseExitedProperty, onMouseMovedProperty, onMousePressedProperty, onMouseReleasedProperty, onRotateProperty, onRotationFinishedProperty, onRotationStartedProperty, onScrollFinishedProperty, onScrollProperty, onScrollStartedProperty, onSwipeDownProperty, onSwipeLeftProperty, onSwipeRightProperty, onSwipeUpProperty, onTouchMovedProperty, onTouchPressedProperty, onTouchReleasedProperty, onTouchStationaryProperty, onZoomFinishedProperty, onZoomProperty, onZoomStartedProperty, opacityProperty, parentProperty, parentToLocal, parentToLocal, parentToLocal, parentToLocal, parentToLocal, pickOnBoundsProperty, pressedProperty, pseudoClassStateChanged, queryAccessibleAttribute, relocate, removeEventFilter, removeEventHandler, requestFocus, resizeRelocate, rotateProperty, rotationAxisProperty, scaleXProperty, scaleYProperty, scaleZProperty, sceneProperty, sceneToLocal, sceneToLocal, sceneToLocal, sceneToLocal, sceneToLocal, sceneToLocal, sceneToLocal, sceneToLocal, screenToLocal, screenToLocal, screenToLocal, setAccessibleHelp, setAccessibleRole, setAccessibleRoleDescription, setAccessibleText, setBlendMode, setCache, setCacheHint, setClip, setCursor, setDepthTest, setDisable, setDisabled, setEffect, setEventDispatcher, setEventHandler, setFocused, setFocusTraversable, setHover, setId, setInputMethodRequests, setLayoutX, setLayoutY, setManaged, setMouseTransparent, setNodeOrientation, setOnContextMenuRequested, setOnDragDetected, setOnDragDone, setOnDragDropped, setOnDragEntered, setOnDragExited, setOnDragOver, setOnInputMethodTextChanged, setOnKeyPressed, setOnKeyReleased, setOnKeyTyped, setOnMouseClicked, setOnMouseDragEntered, setOnMouseDragExited, setOnMouseDragged, setOnMouseDragOver, setOnMouseDragReleased, setOnMouseEntered, setOnMouseExited, setOnMouseMoved, setOnMousePressed, setOnMouseReleased, setOnRotate, setOnRotationFinished, setOnRotationStarted, setOnScroll, setOnScrollFinished, setOnScrollStarted, setOnSwipeDown, setOnSwipeLeft, setOnSwipeRight, setOnSwipeUp, setOnTouchMoved, setOnTouchPressed, setOnTouchReleased, setOnTouchStationary, setOnZoom, setOnZoomFinished, setOnZoomStarted, setOpacity, setPickOnBounds, setPressed, setRotate, setRotationAxis, setScaleX, setScaleY, setScaleZ, setStyle, setTranslateX, setTranslateY, setTranslateZ, setUserData, setViewOrder, setVisible, snapshot, snapshot, startDragAndDrop, startFullDrag, styleProperty, toBack, toFront, toString, translateXProperty, translateYProperty, translateZProperty, usesMirroring, viewOrderProperty, visibleProperty`

  ### Methods declared in class java.lang.Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

  ### Methods declared in interface javafx.css.Styleable

  `getStyleableNode`

- ## Property Details

  - ### spacing

    public final DoubleProperty spacingProperty
    The amount of horizontal space between each child in the hbox.
    See Also:
      - `getSpacing()`
      - `setSpacing(double)`

  - ### alignment

    public final ObjectProperty<Pos> alignmentProperty
    The overall alignment of children within the hbox's width and height.
    See Also:
      - `getAlignment()`
      - `setAlignment(Pos)`

  - ### fillHeight

    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.
    See Also:
      - `isFillHeight()`
      - `setFillHeight(boolean)`

- ## Constructor Details

  - ### HBox

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

  - ### HBox

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

  - ### HBox

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

  - ### HBox

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

- ## Method Details

  - ### setHgrow

    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` - the child of an hbox
      `value` - the horizontal grow priority for the child

  - ### getHgrow

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

  - ### setMargin

    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` - the child mode of the hbox
      `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 an hbox
    Returns:
      the margin for the child or null if no margin was set

  - ### clearConstraints

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

  - ### spacingProperty

    public final DoubleProperty spacingProperty()
    The amount of horizontal space between each child in the hbox.
    See Also:
      - `getSpacing()`
      - `setSpacing(double)`

  - ### setSpacing

    public final void setSpacing(double value)
    Sets the value of the property spacing.
    Property description:
      The amount of horizontal space between each child in the hbox.

  - ### getSpacing

    public final double getSpacing()
    Gets the value of the property spacing.
    Property description:
      The amount of horizontal space between each child in the hbox.

  - ### alignmentProperty

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

  - ### getAlignment

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

  - ### fillHeightProperty

    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.
    See Also:
      - `isFillHeight()`
      - `setFillHeight(boolean)`

  - ### setFillHeight

    public final void setFillHeight(boolean value)
    Sets the value of the property fillHeight.
    Property description:
      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.

  - ### isFillHeight

    public final boolean isFillHeight()
    Gets the value of the property fillHeight.
    Property description:
      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.

  - ### getContentBias

    public Orientation getContentBias()
    Description copied from class: `Node`
    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.

    Overrides:
      `getContentBias` in class `Node`
    Returns:
      null unless one of its children has a content bias.
    See Also:
      - `Node.isResizable()`
      - `Node.minWidth(double)`
      - `Node.minHeight(double)`
      - `Node.prefWidth(double)`
      - `Node.prefHeight(double)`
      - `Node.maxWidth(double)`
      - `Node.maxHeight(double)`

  - ### 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

  - ### getCssMetaData

    public List<CssMetaData<? extends Styleable,?>> getCssMetaData()
    This method should delegate to `Node.getClassCssMetaData()` so that a Node's CssMetaData can be accessed without the need for reflection.
    Specified by:
      `getCssMetaData` in interface `Styleable`
    Overrides:
      `getCssMetaData` in class `Region`
    Returns:
      The CssMetaData associated with this node, which may include the CssMetaData of its superclasses.
    Since:
      JavaFX 8.0