Module javafx.graphics
Package javafx.scene.layout

Class VBox

  • All Implemented Interfaces:
    Styleable, EventTarget

    public class VBox
extends Pane
    VBox lays out its children in a single vertical column. If the vbox has a border and/or padding set, then the contents will be layed out within those insets.

    VBox example: 

    
     VBox vbox = new VBox(8); // spacing = 8
     vbox.getChildren().addAll(new Button("Cut"), new Button("Copy"), new Button("Paste"));
    VBox will resize children (if resizable) to their preferred heights and uses its fillWidth property to determine whether to resize their widths to fill its own width or keep their widths to their preferred (fillWidth defaults to true). The alignment of the content is controlled by the alignment property, which defaults to Pos.TOP_LEFT.

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

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

    Resizable Range

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

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

    A vbox'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.

    VBox 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: 

    
     vbox.setPrefWidth(400);
    Applications may restore the computed values by setting these properties back to USE_COMPUTED_SIZE.

    VBox does not clip its content by default, so it is possible that childrens' bounds may extend outside its own bounds if a child's min size prevents it from being fit within the vbox.

    Optional Layout Constraints

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

    VBox Constraint Table
    ConstraintTypeDescription
    vgrowjavafx.scene.layout.PriorityThe vertical grow priority for the child.
    marginjavafx.geometry.InsetsMargin space around the outside of the child.

    For example, if a vbox needs the ListView to be allocated all extra space: 

    
     VBox vbox = new VBox();
     ListView list = new ListView();
     VBox.setVgrow(list, Priority.ALWAYS);
     vbox.getChildren().addAll(new Label("Names:"), list);
    If more than one child has the same grow priority set, then the vbox will allocate equal amounts of space to each. VBox will only grow a child up to its maximum height, so if the child has a max height other than Double.MAX_VALUE, the application may need to override the max to allow it to grow.
    Since:
    JavaFX 2.0

    • Constructor Detail

      • VBox

        public VBox​()
        Creates a VBox layout with spacing = 0 and alignment at TOP_LEFT.

      • VBox

        public VBox​(double spacing)
        Creates a VBox layout with the specified spacing between children.
        Parameters:
        spacing - the amount of vertical space between each child

      • VBox

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

      • VBox

        public VBox​(double spacing,
            Node... children)
        Creates an VBox 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 Detail

      • setVgrow

        public static void setVgrow​(Node child,
                            Priority value)
        Sets the vertical grow priority for the child when contained by an vbox. If set, the vbox will use the priority to allocate additional space if the vbox is resized larger than it's preferred height. If multiple vbox children have the same vertical grow priority, then the extra space will be split evenly between them. If no vertical grow priority is set on a child, the vbox will never allocate it additional vertical space if available. Setting the value to null will remove the constraint.
        Parameters:
        child - the child of a vbox
        value - the horizontal grow priority for the child

      • getVgrow

        public static Priority getVgrow​(Node child)
        Returns the child's vgrow property if set.
        Parameters:
        child - the child node of a vbox
        Returns:
        the vertical 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 a vbox. If set, the vbox will layout the child so that it has the margin space around it. Setting the value to null will remove the constraint.
        Parameters:
        child - the child mode of a vbox
        value - the margin of space around the child

      • getMargin

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

      • clearConstraints

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

      • setSpacing

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

      • getSpacing

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

      • setAlignment

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

      • fillWidthProperty

        public final BooleanProperty fillWidthProperty​()
        Whether or not resizable children will be resized to fill the full width of the vbox or be resized to their preferred width and aligned according to the alignment hpos value.
        See Also:
        isFillWidth(), setFillWidth(boolean)

      • setFillWidth

        public final void setFillWidth​(boolean value)
        Sets the value of the property fillWidth.
        Property description:
        Whether or not resizable children will be resized to fill the full width of the vbox or be resized to their preferred width and aligned according to the alignment hpos value.

      • isFillWidth

        public final boolean isFillWidth​()
        Gets the value of the property fillWidth.
        Property description:
        Whether or not resizable children will be resized to fill the full width of the vbox or be resized to their preferred width and aligned according to the alignment hpos value.

      • 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 height)
        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:
        height - 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 width)
        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:
        width - 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