org.eclipse.jface.viewers.TreeNode Maven / Gradle / Ivy
The newest version!
/*******************************************************************************
* Copyright (c) 2005, 2015 IBM Corporation and others.
*
* This program and the accompanying materials
* are made available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution, and is available at
* https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.jface.viewers;
import java.util.Objects;
/**
* A simple data structure that is useful for implemented tree models. This can
* be returned by
* {@link org.eclipse.jface.viewers.IStructuredContentProvider#getElements(Object)}.
* It allows simple delegation of methods from
* {@link org.eclipse.jface.viewers.ITreeContentProvider} such as
* {@link org.eclipse.jface.viewers.ITreeContentProvider#getChildren(Object)},
* {@link org.eclipse.jface.viewers.ITreeContentProvider#getParent(Object)} and
* {@link org.eclipse.jface.viewers.ITreeContentProvider#hasChildren(Object)}
*
* @since 3.2
*/
public class TreeNode {
/**
* The array of child tree nodes for this tree node. If there are no
* children, then this value may either by an empty array or
* null. There should be no null children in
* the array.
*/
private TreeNode[] children;
/**
* The parent tree node for this tree node. This value may be
* null if there is no parent.
*/
private TreeNode parent;
/**
* The value contained in this node. This value may be anything.
*/
protected Object value;
/**
* Constructs a new instance of TreeNode.
*
* @param value
* The value held by this node; may be anything.
*/
public TreeNode(final Object value) {
this.value = value;
}
@Override
public boolean equals(final Object object) {
if (object instanceof TreeNode) {
return Objects.equals(this.value, ((TreeNode) object).value);
}
return false;
}
/**
* Returns the child nodes. Empty arrays are converted to null
* before being returned.
*
* @return The child nodes; may be null, but never empty.
* There should be no null children in the array.
*/
public TreeNode[] getChildren() {
if (children != null && children.length == 0) {
return null;
}
return children;
}
/**
* Returns the parent node.
*
* @return The parent node; may be null if there are no
* parent nodes.
*/
public TreeNode getParent() {
return parent;
}
/**
* Returns the value held by this node.
*
* @return The value; may be anything.
*/
public Object getValue() {
return value;
}
/**
* Returns whether the tree has any children.
*
* @return true if its array of children is not
* null and is non-empty; false
* otherwise.
*/
public boolean hasChildren() {
return children != null && children.length > 0;
}
@Override
public int hashCode() {
return Objects.hashCode(value);
}
/**
* Sets the children for this node.
*
* @param children
* The child nodes; may be null or empty. There
* should be no null children in the array.
*/
public void setChildren(final TreeNode[] children) {
this.children = children;
}
/**
* Sets the parent for this node.
*
* @param parent
* The parent node; may be null.
*/
public void setParent(final TreeNode parent) {
this.parent = parent;
}
}