Module javafx.graphics
Package javafx.scene.text

Class TextFlow

  • All Implemented Interfaces:
    Styleable, EventTarget
    public class TextFlow
extends Pane
    TextFlow is special layout designed to lay out rich text. It can be used to layout several Text nodes in a single text flow. The TextFlow uses the text and the font of each Text node inside of it plus its own width and text alignment to determine the location for each child. A single Text node can span over several lines due to wrapping, and the visual location of Text node can differ from the logical location due to bidi reordering.

    Any Node, other than Text, will be treated as an embedded object in the text layout. It will be inserted in the content using its preferred width, height, and baseline offset.

    When a Text node is inside of a TextFlow, some of its properties are ignored. For example, the x and y properties of the Text node are ignored since the location of the node is determined by the parent. Likewise, the wrapping width in the Text node is ignored since the width used for wrapping is the TextFlow's width. The value of the pickOnBounds property of a Text is set to false when it is laid out by the TextFlow. This happens because the content of a single Text node can divided and placed in the different locations on the TextFlow (usually due to line breaking and bidi reordering).

    The wrapping width of the layout is determined by the region's current width. It can be specified by the application by setting the textflow's preferred width. If no wrapping is desired, the application can either set the preferred with to Double.MAX_VALUE or Region.USE_COMPUTED_SIZE.

    Paragraphs are separated by '\n' present in any Text child.

    Example of a TextFlow: 

    
     Text text1 = new Text("Big italic red text");
     text1.setFill(Color.RED);
     text1.setFont(Font.font("Helvetica", FontPosture.ITALIC, 40));
     Text text2 = new Text(" little bold blue text");
     text2.setFill(Color.BLUE);
     text2.setFont(Font.font("Helvetica", FontWeight.BOLD, 10));
     TextFlow textFlow = new TextFlow(text1, text2);

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

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

    Resizable Range

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

    TextFlow Resize Table
    widthheight
    minimum left/right insets top/bottom insets plus the height of the text content
    preferred left/right insets plus the width of the text content top/bottom insets plus the height of the text content
    maximum Double.MAX_VALUEDouble.MAX_VALUE

    A textflow'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.

    TextFlow 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: 

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

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

    Since:
    JavaFX 8.0

    • Constructor Detail

      • TextFlow

        public TextFlow()
        Creates an empty TextFlow layout.

      • TextFlow

        public TextFlow​(Node... children)
        Creates a TextFlow layout with the given children.
        Parameters:
        children - children.

    • Method Detail

      • hitTest

        public final HitInfo hitTest​(Point2D point)
        Maps local point to index in the content.
        Parameters:
        point - the specified point to be tested
        Returns:
        a HitInfo representing the character index found
        Since:
        9

      • caretShape

        public PathElement[] caretShape​(int charIndex,
                                boolean leading)
        Returns shape of caret in local coordinates.
        Parameters:
        charIndex - the character index for the caret
        leading - whether the caret is biased on the leading edge of the character
        Returns:
        an array of PathElement which can be used to create a Shape
        Since:
        9

      • rangeShape

        public final PathElement[] rangeShape​(int start,
                                      int end)
        Returns shape for the range of the text in local coordinates.
        Parameters:
        start - the beginning character index for the range
        end - the end character index (non-inclusive) for the range
        Returns:
        an array of PathElement which can be used to create a Shape
        Since:
        9

      • usesMirroring

        public boolean usesMirroring()
        Description copied from class: Node
        Determines whether a node should be mirrored when node orientation is right-to-left.

        When a node is mirrored, the origin is automatically moved to the top right corner causing the node to layout children and draw from right to left using a mirroring transformation. Some nodes may wish to draw from right to left without using a transformation. These nodes will will answer false and implement right-to-left orientation without using the automatic transformation.

        Overrides:
        usesMirroring in class Node
        Returns:
        true if this Node should be mirrored

      • setWidth

        protected void setWidth​(double value)
        Description copied from class: Region
        Sets the value of the property width.
        Overrides:
        setWidth in class 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

      • 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

      • 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

      • setTextAlignment

        public final void setTextAlignment​(TextAlignment value)
        Sets the value of the property textAlignment.
        Property description:
        Defines horizontal text alignment.
        Default value:
        TextAlignment.LEFT

      • getTextAlignment

        public final TextAlignment getTextAlignment()
        Gets the value of the property textAlignment.
        Property description:
        Defines horizontal text alignment.
        Default value:
        TextAlignment.LEFT

      • setLineSpacing

        public final void setLineSpacing​(double spacing)
        Sets the value of the property lineSpacing.
        Property description:
        Defines the vertical space in pixel between lines.
        Default value:
        0
        Since:
        JavaFX 8.0

      • getLineSpacing

        public final double getLineSpacing()
        Gets the value of the property lineSpacing.
        Property description:
        Defines the vertical space in pixel between lines.
        Default value:
        0
        Since:
        JavaFX 8.0

      • getBaselineOffset

        public final double getBaselineOffset()
        Description copied from class: Parent
        Calculates the baseline offset based on the first managed child. If there is no such child, returns Node.getBaselineOffset().
        Overrides:
        getBaselineOffset in class Parent
        Returns:
        baseline offset

      • getClassCssMetaData

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

      • queryAccessibleAttribute

        public Object queryAccessibleAttribute​(AccessibleAttribute attribute,
                                       Object... parameters)
        This method is called by the assistive technology to request the value for an attribute.

        This method is commonly overridden by subclasses to implement attributes that are required for a specific role.
        If a particular attribute is not handled, the superclass implementation must be called.

        Overrides:
        queryAccessibleAttribute in class Parent
        Parameters:
        attribute - the requested attribute
        parameters - optional list of parameters
        Returns:
        the value for the requested attribute
        See Also:
        AccessibleAttribute