Attachment 149671 Details for Bug 292448 – Tree snippet

Tree snippet

SnippetNonSelectableTreeItems.java (text/plain), 5.46 KB, created by Elias Volanakis

on 2009-10-15 14:49:45 EDT

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Creator: Elias Volanakis

Created: 2009-10-15 14:49:45 EDT

Size: 5.46 KB

patch

obsolete

>/*******************************************************************************
> * Copyright (c) 2000, 2009 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
> *     compeople AG    - created this example based on Snippet15
> *******************************************************************************/
>package org.eclipse.riena.navigation.ui.swt.views;
>
>import java.util.ArrayList;
>import java.util.Arrays;
>import java.util.List;
>
>import org.eclipse.swt.SWT;
>import org.eclipse.swt.events.KeyAdapter;
>import org.eclipse.swt.events.KeyEvent;
>import org.eclipse.swt.events.MouseEvent;
>import org.eclipse.swt.events.MouseListener;
>import org.eclipse.swt.events.SelectionEvent;
>import org.eclipse.swt.events.SelectionListener;
>import org.eclipse.swt.layout.FillLayout;
>import org.eclipse.swt.widgets.Display;
>import org.eclipse.swt.widgets.Shell;
>import org.eclipse.swt.widgets.Tree;
>import org.eclipse.swt.widgets.TreeItem;
>
>/**
> * Create a tree with non-selectable items.
> */
>public class SnippetNonSelectableTreeItems {
>
>	public static void main(String[] args) {
>		Display display = new Display();
>		Shell shell = new Shell(display);
>		shell.setLayout(new FillLayout());
>		final Tree tree = new Tree(shell, SWT.BORDER | SWT.SINGLE);
>		for (int i = 0; i < 4; i++) {
>			TreeItem iItem = new TreeItem(tree, 0);
>			iItem.setText("TreeItem (0) -" + i);
>			if (i % 2 == 1) {
>				markNonSelectable(iItem);
>				iItem.setText("not selectable");
>			}
>			for (int j = 0; j < 4; j++) {
>				TreeItem jItem = new TreeItem(iItem, 0);
>				jItem.setText("TreeItem (1) -" + j);
>				if (j % 2 == 0) {
>					markNonSelectable(jItem);
>					jItem.setText("not selectable");
>				}
>				for (int k = 0; k < 4; k++) {
>					TreeItem kItem = new TreeItem(jItem, 0);
>					kItem.setText("TreeItem (2) -" + k);
>					for (int l = 0; l < 4; l++) {
>						TreeItem lItem = new TreeItem(kItem, 0);
>						lItem.setText("TreeItem (3) -" + l);
>					}
>				}
>			}
>		}
>
>		new TreeListener(tree);
>
>		shell.setSize(200, 200);
>		shell.open();
>		while (!shell.isDisposed()) {
>			if (!display.readAndDispatch())
>				display.sleep();
>		}
>		display.dispose();
>	}
>
>	/**
>	 * Prevent selection of certain items. Find a matching alternative is
>	 * possible.
>	 */
>	private static final class TreeListener extends KeyAdapter implements SelectionListener, MouseListener {
>
>		private int lastKey;
>		private int lastButton;
>		private TreeItem lastItem;
>
>		public TreeListener(Tree tree) {
>			tree.addKeyListener(this);
>			tree.addSelectionListener(this);
>			tree.addMouseListener(this);
>		}
>
>		@Override
>		public void keyPressed(KeyEvent e) {
>			if (e.stateMask == 0) {
>				lastKey = e.keyCode;
>			}
>		}
>
>		@Override
>		public void keyReleased(KeyEvent e) {
>			lastKey = 0;
>		}
>
>		public void mouseDown(MouseEvent e) {
>			lastButton = e.button;
>		}
>
>		public void mouseUp(MouseEvent e) {
>			lastButton = 0;
>		}
>
>		public void widgetSelected(SelectionEvent e) {
>			System.out.println(e);
>			Tree tree = (Tree) e.widget;
>			TreeItem[] sel = tree.getSelection();
>			if (sel.length > 0) {
>				TreeItem item = sel[0];
>				if (!isSelectable(item)) {
>					if (lastKey == SWT.ARROW_UP || lastKey == SWT.ARROW_LEFT) {
>						item = findPrevious(item);
>					} else if (lastKey == SWT.ARROW_DOWN || lastKey == SWT.ARROW_RIGHT || lastButton != 0) {
>						item = findNext(item);
>					}
>					if (item != null) {
>						item.getParent().select(item);
>					} else {
>						lastItem.getParent().setSelection(lastItem);
>					}
>				}
>				if (item != null) {
>					lastItem = item;
>				}
>			}
>		}
>
>		public void widgetDefaultSelected(SelectionEvent e) {
>			// unused
>		}
>
>		public void mouseDoubleClick(MouseEvent e) {
>			// unused
>		}
>
>	};
>
>	private static boolean isSelectable(TreeItem item) {
>		return item == null ? true : !Boolean.FALSE.equals(item.getData("s"));
>	}
>
>	/**
>	 * Mark this item as 'non-selectable'.
>	 */
>	private static void markNonSelectable(TreeItem item) {
>		item.setData("s", Boolean.FALSE);
>	}
>
>	private static TreeItem findPrevious(TreeItem item) {
>		List<TreeItem> siblings = sequentialize(item.getParent().getItems());
>		int index = siblings.indexOf(item);
>		TreeItem result = index > 0 ? siblings.get(index - 1) : null;
>		if (!isSelectable(result)) {
>			result = findPrevious(result);
>		}
>		return result;
>	}
>
>	private static TreeItem findNext(TreeItem item) {
>		List<TreeItem> siblings = sequentialize(item.getParent().getItems());
>		int index = siblings.indexOf(item);
>		TreeItem result = index != -1 && index < siblings.size() - 1 ? siblings.get(index + 1) : null;
>		if (!isSelectable(result)) {
>			result = findNext(result);
>		}
>		return result;
>	}
>
>	/**
>	 * Do a DFS traversal and return all reachable nodes starting from root
>	 * (excluded).
>	 */
>	private static List<TreeItem> sequentialize(TreeItem[] siblings) {
>		List<TreeItem> stack = new ArrayList<TreeItem>(Arrays.asList(siblings));
>		List<TreeItem> result = new ArrayList<TreeItem>();
>		while (!stack.isEmpty()) {
>			TreeItem item = stack.remove(0);
>			result.add(item);
>			if (item.getExpanded()) {
>				stack.addAll(0, Arrays.asList(item.getItems()));
>			}
>		}
>		return result;
>	}
>}

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Attachments on bug 292448: 149671