Package org.eclipse.gef.layout.algorithms

Class TreeLayoutHelper.TreeNode

java.lang.Object
org.eclipse.gef.layout.algorithms.TreeLayoutHelper.TreeNode
Enclosing class:
TreeLayoutHelper
public static class TreeLayoutHelper.TreeNode extends Object
Represents a node in a tree structure and stores all information related to it. May be subclassed if additional data and behavior is necessary.

  • Field Details

    • node

      protected final org.eclipse.gef.graph.Node node
      The wrapped Node.

    • owner

      protected final TreeLayoutHelper owner
      The TreeLayoutHelper that controls this TreeLayoutHelper.TreeNode.

    • height

      protected int height
      The height of the node.

    • depth

      protected int depth
      The depth of the node.

    • numOfLeaves

      protected int numOfLeaves
      The number of leaves.

    • numOfDescendants

      protected int numOfDescendants
      The number of descendants.

    • order

      protected int order
      The order of this node.

    • children

      protected final List<TreeLayoutHelper.TreeNode> children
      The children of this node.

    • parent

      protected TreeLayoutHelper.TreeNode parent
      The parent of this node.

    • firstChild

      protected boolean firstChild
      true if this node is the first child, otherwise false.

    • lastChild

      protected boolean lastChild
      true if this node is the last child, otherwise false.

  • Constructor Details

    • TreeNode

      protected TreeNode(org.eclipse.gef.graph.Node node, TreeLayoutHelper owner)
      Creates a tree node related to given layout node
      Parameters:
      node - the layout node
      owner - TreeLayoutObserver owning created node

  • Method Details

    • getNode

      public org.eclipse.gef.graph.Node getNode()
      Returns:
      node layout related to this tree node (null for Super Root)

    • getOwner

      public TreeLayoutHelper getOwner()
      Returns:
      TreeLayoutObserver owning this tree node

    • getHeight

      public int getHeight()
      Returns:
      height of this node in the tree (the longest distance to a leaf, 0 for a leaf itself)

    • getDepth

      public int getDepth()
      Returns:
      depth of this node in the tree (distance from root, 0 for a root and -1 for Super Root

    • getNumOfLeaves

      public int getNumOfLeaves()
      Returns:
      number of all leaves descending from this node (1 for a leaf itself)

    • getNumOfDescendants

      public int getNumOfDescendants()
      Returns:
      total number of descendants of this node (0 for leafs)

    • getOrder

      public int getOrder()
      Returns order in which nodes are visited during Deep First Search. Children are visited in the same order as they were added to their layout context, unless TreeLayoutHelper.computeTree(Node[]) was called after the nodes were added. In that case the order is determined by order of nodes returned by Node.getAllSuccessorNodes(). Leaves are assigned successive numbers starting from 0, other nodes have order equal to the smallest order of their children.
      Returns:
      order of this node

    • getChildren

      public List<TreeLayoutHelper.TreeNode> getChildren()
      Returns:
      an unmodifiable list of this node's children

    • getParent

      public TreeLayoutHelper.TreeNode getParent()
      Returns:
      this node's parent

    • isFirstChild

      public boolean isFirstChild()
      Returns:
      true if this node is the first child of its parent (has the smallest order)

    • isLastChild

      public boolean isLastChild()
      Returns:
      true if this node is the last child of its parent (has the highest order)

    • addChild

      protected void addChild(TreeLayoutHelper.TreeNode child)
      Adds given node to the list of this node's children and set its parent to this node.
      Parameters:
      child - node to add

    • precomputeTree

      protected void precomputeTree()
      Performs a DFS on the tree structure and calculates all parameters of its nodes. Should be called on Super Root. Uses recurrence to go through all the nodes.

    • findNewParent

      protected void findNewParent()
      Finds a node that is the best parent for this node. Add this node as a child of the found node.

    • isBetterParent

      protected boolean isBetterParent(TreeLayoutHelper.TreeNode potentialParent)
      Checks if a potential parent would be better for this node than its current parent. A better parent has smaller depth (with exception to Super Root, which has depth equal to -1 but is never a better parent than any other node).
      Parameters:
      potentialParent - potential parent to check
      Returns:
      true if potentialParent can be a parent of this node and is better than its current parent

    • isAncestorOf

      public boolean isAncestorOf(TreeLayoutHelper.TreeNode descendant)
      Parameters:
      descendant - The TreeLayoutHelper.TreeNode in question.
      Returns:
      true if this node is an ancestor if given descendant node