/*******************************************************************************
* Copyright (c) 2005 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.ui.dialogs;
import java.util.ArrayList;
import org.eclipse.jface.viewers.CheckStateChangedEvent;
import org.eclipse.jface.viewers.CheckboxTreeViewer;
import org.eclipse.jface.viewers.ICheckStateListener;
import org.eclipse.jface.viewers.ITreeViewerListener;
import org.eclipse.jface.viewers.TreeExpansionEvent;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Item;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.swt.widgets.TreeItem;
import org.eclipse.swt.widgets.Widget;
/**
* CheckboxTreeViewer with special behaviour of the checked / gray state on
* container (non-leaf) nodes:
* The grayed state is used to visualize the checked state of its children.
* Containers are checked and non-gray if all contained leafs are checked. The
* container is grayed if some but not all leafs are checked.
* @since 3.1
*/
public class ContainerCheckedTreeViewer extends CheckboxTreeViewer {
/**
* Constructor for ContainerCheckedTreeViewer.
* @see CheckboxTreeViewer#CheckboxTreeViewer(Composite)
*/
public ContainerCheckedTreeViewer(Composite parent) {
super(parent);
initViewer();
}
/**
* Constructor for ContainerCheckedTreeViewer.
* @see CheckboxTreeViewer#CheckboxTreeViewer(Composite,int)
*/
public ContainerCheckedTreeViewer(Composite parent, int style) {
super(parent, style);
initViewer();
}
/**
* Constructor for ContainerCheckedTreeViewer.
* @see CheckboxTreeViewer#CheckboxTreeViewer(Tree)
*/
public ContainerCheckedTreeViewer(Tree tree) {
super(tree);
initViewer();
}
private void initViewer() {
setUseHashlookup(true);
addCheckStateListener(new ICheckStateListener() {
public void checkStateChanged(CheckStateChangedEvent event) {
doCheckStateChanged(event.getElement());
}
});
addTreeListener(new ITreeViewerListener() {
public void treeCollapsed(TreeExpansionEvent event) {
}
public void treeExpanded(TreeExpansionEvent event) {
Widget item = findItem(event.getElement());
if (item instanceof TreeItem) {
initializeItem((TreeItem) item);
}
}
});
}
/**
* Update element after a checkstate change.
* @param element
*/
protected void doCheckStateChanged(Object element) {
Widget item = findItem(element);
if (item instanceof TreeItem) {
TreeItem treeItem = (TreeItem) item;
treeItem.setGrayed(false);
updateChildrenItems(treeItem);
updateParentItems(treeItem.getParentItem());
}
}
/**
* The item has expanded. Updates the checked state of its children.
*/
private void initializeItem(TreeItem item) {
if (item.getChecked() && !item.getGrayed()) {
updateChildrenItems(item);
}
}
/**
* Updates the check state of all created children
*/
private void updateChildrenItems(TreeItem parent) {
Item[] children = getChildren(parent);
boolean state = parent.getChecked();
for (int i = 0; i < children.length; i++) {
TreeItem curr = (TreeItem) children[i];
if (curr.getData() != null
&& ((curr.getChecked() != state) || curr.getGrayed())) {
curr.setChecked(state);
curr.setGrayed(false);
updateChildrenItems(curr);
}
}
}
/**
* Updates the check / gray state of all parent items
*/
private void updateParentItems(TreeItem item) {
if (item != null) {
Item[] children = getChildren(item);
boolean containsChecked = false;
boolean containsUnchecked = false;
for (int i = 0; i < children.length; i++) {
TreeItem curr = (TreeItem) children[i];
containsChecked |= curr.getChecked();
containsUnchecked |= (!curr.getChecked() || curr.getGrayed());
}
item.setChecked(containsChecked);
item.setGrayed(containsChecked && containsUnchecked);
updateParentItems(item.getParentItem());
}
}
/* (non-Javadoc)
* @see org.eclipse.jface.viewers.ICheckable#setChecked(java.lang.Object, boolean)
*/
public boolean setChecked(Object element, boolean state) {
if (super.setChecked(element, state)) {
doCheckStateChanged(element);
return true;
}
return false;
}
/* (non-Javadoc)
* @see org.eclipse.jface.viewers.CheckboxTreeViewer#setCheckedElements(java.lang.Object[])
*/
public void setCheckedElements(Object[] elements) {
super.setCheckedElements(elements);
for (int i = 0; i < elements.length; i++) {
doCheckStateChanged(elements[i]);
}
}
/* (non-Javadoc)
* @see org.eclipse.jface.viewers.AbstractTreeViewer#setExpanded(org.eclipse.swt.widgets.Item, boolean)
*/
protected void setExpanded(Item item, boolean expand) {
super.setExpanded(item, expand);
if (expand && item instanceof TreeItem) {
initializeItem((TreeItem) item);
}
}
/* (non-Javadoc)
* @see org.eclipse.jface.viewers.CheckboxTreeViewer#getCheckedElements()
*/
public Object[] getCheckedElements() {
Object[] checked = super.getCheckedElements();
// add all items that are children of a checked node but not created yet
ArrayList result = new ArrayList();
for (int i = 0; i < checked.length; i++) {
Object curr = checked[i];
result.add(curr);
Widget item = findItem(curr);
if (item != null) {
Item[] children = getChildren(item);
// check if contains the dummy node
if (children.length == 1 && children[0].getData() == null) {
// not yet created
collectChildren(curr, result);
}
}
}
return result.toArray();
}
/**
* Recursively add the filtered children of element to the result.
* @param element
* @param result
*/
private void collectChildren(Object element, ArrayList result) {
Object[] filteredChildren = getFilteredChildren(element);
for (int i = 0; i < filteredChildren.length; i++) {
Object curr = filteredChildren[i];
result.add(curr);
collectChildren(curr, result);
}
}
}