Class UITreeLayout

public class UITreeLayout extends UILayoutManager
{
  // Constructors
  public UITreeLayout();
  public UITreeLayout(int indent);
  public UITreeLayout(int indent, int vgap);

  // Methods
  public Dimension adjustLayoutSize(IUIContainer parent,
        Dimension oldParentSize, IUIComponent comp,
        Dimension oldSize, Dimension newSize);
  public void drawLine(FxGraphics g, int x1, int y1, int x2,
        int y2);
  public Dimension getMinimumSize(IUIContainer target);
  public Dimension getPreferredSize(IUIContainer target);
  public boolean isHeightRelative();
  public boolean isOverlapping();
  public boolean isWidthRelative();
  public void layout(IUIContainer target, Rectangle bounds);
  public void paintContainer(IUIContainer target, FxGraphics g);
}

This class implements a layout manager for tree nodes. UITreeLayout handles the drawing of the lines that connect a tree node to its children. UITree typically uses UITreeLayout for its default layout manager.

By default, UISystem defines UITreeLayout at the TREE_LAYOUT index.

UILayoutManager
  |
  +--UITreeLayout

Constructors

UITreeLayout

public UITreeLayout();

Creates a tree layout manager.

Remarks:

By default, the vertical spacing between all components is 2 pixels. A tree node's child components will be laid out with an indent of 16 pixels.

UITreeLayout

public UITreeLayout(int indent);

Creates a tree layout manager with the specified indent.

Parameter	Description
indent	The indent (in pixels) used when laying out child components.

Remarks:

By default, the vertical spacing between all components is 2 pixels.

UITreeLayout

public UITreeLayout(int indent, int vgap);

Creates a tree layout manager with the specified indent and vertical gap.

Parameter	Description
indent	The indent (in pixels) used when laying out child components.
vgap	The vertical spacing (in pixels) between components.

Methods

adjustLayoutSize

public Dimension adjustLayoutSize(IUIContainer parent,
        Dimension oldParentSize, IUIComponent comp, Dimension oldSize,
        Dimension newSize);

Called to adjust the layout size of the specified component in the specified container.

Return Value:

Returns a Dimension object containing the new preferred size of the container.

Parameter	Description
parent	The container of the component.
oldParentSize	The previous layout size of the container.
comp	The component being sized.
oldSize	The previous layout size of the component.
newSize	The new layout size of the component.

Overrides:

adjustLayoutSize(IUIContainer,Dimension,IUIComponent,Dimension,Dimension) in UILayoutManager.

drawLine

public void drawLine(FxGraphics g, int x1, int y1, int x2, int y2);

Draws a line from one point to another.

Return Value:

No return value.

Parameter	Description
g	The graphics context.
x1	The x coordinate of the line's starting point.
y1	The y coordinate of the line's starting point.
x2	The x coordinate of the line's ending point.
y2	The y coordinate of the line's ending point.

Remarks:

This method is called by paintContainer to draw the lines that connect a tree node to its children.

getMinimumSize

public Dimension getMinimumSize(IUIContainer target);

Determines the minimum dimensions (in pixels) needed to lay out the child components in the specified container.

Return Value:

Returns a Dimension object containing the minimum layout size.

Parameter	Description
target	The container of the components.

Remarks:

The height of the returned Dimension object is the sum of the minimum heights of each item displayed by the tree node and all its children, plus the vertical gaps between each item. The Dimension object's width is the largest of the minimum widths of the items (including the indent).

Overrides:

getMinimumSize(IUIContainer) in UILayoutManager.

See Also: getPreferredSize

getPreferredSize

public Dimension getPreferredSize(IUIContainer target);

Determines the preferred dimensions (in pixels) for laying out the child components in the specified container.

Return Value:

Returns a Dimension object containing the preferred layout size.

Parameter	Description
target	The container of the components.

Remarks:

The height of the returned Dimension object is the sum of the preferred heights of each item displayed by the tree node and all its children, plus the vertical gaps between each item. The Dimension object's width is the largest of the preferred widths of the items (including the indent).

Overrides:

getPreferredSize(IUIContainer) in UILayoutManager.

See Also: getMinimumSize

isHeightRelative

public boolean isHeightRelative();

This method simply returns false, indicating that the UITreeLayout does not lay out its components based on the height of the container.

Return Value:

Returns false.

Overrides:

isHeightRelative() in UILayoutManager.

See Also: isWidthRelative

isOverlapping

public boolean isOverlapping();

This method simply returns false, indicating that the UITreeLayout lays out its components such that they never overlap.

Return Value:

Returns false.

Overrides:

isOverlapping() in UILayoutManager.

isWidthRelative

public boolean isWidthRelative();

This method simply returns false, indicating that the UITreeLayout does not lay out its components based on the width of the container.

Return Value:

Returns false.

Overrides:

isWidthRelative() in UILayoutManager.

See Also: isHeightRelative

layout

public void layout(IUIContainer target, Rectangle bounds);

Lays out the components in the specified container.

Return Value:

No return value.

Parameter	Description
target	The container being laid out.
bounds	The bounding rectangle in which to lay out the components.

Remarks:

The height and width of each component is based on the component's respective preferred height and width. The vertical gap (defined when the layout manager was created) is used for vertical spacing between each component.

For each tree node's expand button, layoutContainer determines where the attaching line must be drawn from the node to its parent, based on the node's getAttachRect method and the layout manager's defined indent. The paintContainer method is then invoked to draw all connecting lines between a node and its children.

Overrides:

layout(IUIContainer,Rectangle) in UILayoutManager.

paintContainer

public void paintContainer(IUIContainer target, FxGraphics g);

Draws the container.

Return Value:

No return value.

Parameter	Description
target	The container.
g	The graphics context of the container.

Remarks:

This method is automatically invoked during a call to the container's paint method. If the tree node is expanded, paintContainer calls drawLine to connect the node to its children.

Overrides:

paintContainer(IUIContainer,FxGraphics) in UILayoutManager.