Class TreeLayoutAlgorithm

java.lang.Object
org.eclipse.gef.layout.algorithms.TreeLayoutAlgorithm
All Implemented Interfaces:
ILayoutAlgorithm

public class TreeLayoutAlgorithm extends Object implements ILayoutAlgorithm
The TreeLayoutAlgorithm class implements a simple algorithm to arrange graph nodes in a layered tree-like layout.
  • Field Details

    • TOP_DOWN

      public static final int TOP_DOWN
      Tree direction constant for which root is placed at the top and branches spread downwards
      See Also:
    • BOTTOM_UP

      public static final int BOTTOM_UP
      Tree direction constant for which root is placed at the bottom and branches spread upwards
      See Also:
    • LEFT_RIGHT

      public static final int LEFT_RIGHT
      Tree direction constant for which root is placed at the left and branches spread to the right
      See Also:
    • RIGHT_LEFT

      public static final int RIGHT_LEFT
      Tree direction constant for which root is placed at the right and branches spread to the left
      See Also:
  • Constructor Details

    • TreeLayoutAlgorithm

      public TreeLayoutAlgorithm()
      Create a default Tree Layout.
    • TreeLayoutAlgorithm

      public TreeLayoutAlgorithm(int direction)
      Create a Tree Layout with a specified direction.
      Parameters:
      direction - The direction, one of BOTTOM_UP, LEFT_RIGHT, RIGHT_LEFT, TOP_DOWN
    • TreeLayoutAlgorithm

      public TreeLayoutAlgorithm(int direction, Dimension nodeSpace)
      Create a Tree Layout with fixed size spacing around nodes. If nodeSpace is not null, the layout will size the container to the ideal space to just contain all nodes of fixed size without any overlap. Otherwise, the algorithm will size for the container's available space.
      Parameters:
      direction - The direction, one of BOTTOM_UP, LEFT_RIGHT, RIGHT_LEFT, TOP_DOWN
      nodeSpace - the size to make each node. May be null.
  • Method Details

    • setNodeSpace

      public void setNodeSpace(Dimension nodeSpace)
      Parameters:
      nodeSpace - the nodeSpace size to set
    • getDirection

      public int getDirection()
      Returns the direction of this TreeLayoutAlgorithm.
      Returns:
      The direction of this TreeLayoutAlgorithm.
    • setDirection

      public void setDirection(int direction)
      Changes the direction of this TreeLayoutAlgorithm to the given value. The direction may either be TOP_DOWN, BOTTOM_UP, LEFT_RIGHT, or RIGHT_LEFT.
      Parameters:
      direction - The new direction for this TreeLayoutAlgorithm.
    • isResizing

      public boolean isResizing()
      Returns:
      true if this algorithm is set to resize elements
    • setResizing

      public void setResizing(boolean resizing)
      Parameters:
      resizing - true if this algorithm should resize elements (default is false)
    • applyLayout

      public void applyLayout(LayoutContext layoutContext, boolean clean)
      Description copied from interface: ILayoutAlgorithm
      Makes this algorithm perform layout computation and apply it to its context.
      Specified by:
      applyLayout in interface ILayoutAlgorithm
      Parameters:
      layoutContext - The LayoutContext that provides all relevant information about what to layout.
      clean - if true the receiver should assume that the layout context has changed significantly and recompute the whole layout even if it keeps track of changes with listeners. False can be used after dynamic layout in a context is turned back on so that layout algorithm working in background can apply accumulated changes. Static layout algorithm can ignore this call entirely if clean is false.
    • toString

      public String toString()
      Overrides:
      toString in class Object