org.eclipse.ui.dialogs.ContainerCheckedTreeViewer Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of org.eclipse.ui.workbench Show documentation
This is org.eclipse.ui.workbench jar used by Scout SDK
There is a newer version: 3.108.0.v20160602-1232
Show newest version
/*******************************************************************************
 * 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() {
            @Override
			public void checkStateChanged(CheckStateChangedEvent event) {
                doCheckStateChanged(event.getElement());
            }
        });
        addTreeListener(new ITreeViewerListener() {
            @Override
			public void treeCollapsed(TreeExpansionEvent event) {
            }

            @Override
			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());
        }
    }


    @Override
	public boolean setChecked(Object element, boolean state) {
        if (super.setChecked(element, state)) {
            doCheckStateChanged(element);
            return true;
        }
        return false;
    }


    @Override
	public void setCheckedElements(Object[] elements) {
        super.setCheckedElements(elements);
        for (int i = 0; i < elements.length; i++) {
            doCheckStateChanged(elements[i]);
        }
    }


    @Override
	protected void setExpanded(Item item, boolean expand) {
        super.setExpanded(item, expand);
        if (expand && item instanceof TreeItem) {
            initializeItem((TreeItem) item);
        }
    }


    @Override
	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);
        }
    }

}