| /******************************************************************************* |
| * Copyright (c) 2000, 2016 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.swt.snippets; |
| |
| /* |
| * ScrolledComposite snippet: use a ScrolledComposite to scroll a disabled |
| * control. Note that this goes against conventional UI behaviour, where |
| * disabling a control typically disables its scrollbars as well. |
| * |
| * For a list of all SWT example snippets see |
| * http://www.eclipse.org/swt/snippets/ |
| */ |
| import static org.eclipse.swt.events.SelectionListener.*; |
| |
| import org.eclipse.swt.*; |
| import org.eclipse.swt.custom.*; |
| import org.eclipse.swt.events.*; |
| import org.eclipse.swt.graphics.*; |
| import org.eclipse.swt.widgets.*; |
| |
| public class Snippet322 { |
| |
| public static void main (String[] args) { |
| final Display display = new Display (); |
| Shell shell = new Shell (display); |
| shell.setBounds (10, 10, 300, 300); |
| final ScrolledComposite sc = new ScrolledComposite (shell, SWT.VERTICAL); |
| sc.setBounds (10, 10, 280, 200); |
| final int clientWidth = sc.getClientArea ().width; |
| |
| final Tree tree = new Tree (sc, SWT.NONE); |
| for (int i = 0; i < 99; i++) { |
| TreeItem item = new TreeItem (tree, SWT.NONE); |
| item.setText ("item " + i); |
| new TreeItem (item, SWT.NONE).setText ("child"); |
| } |
| sc.setContent (tree); |
| int prefHeight = tree.computeSize (SWT.DEFAULT, SWT.DEFAULT).y; |
| tree.setSize (clientWidth, prefHeight); |
| /* |
| * The following listener ensures that the Tree is always large |
| * enough to not need to show its own vertical scrollbar. |
| */ |
| tree.addTreeListener (new TreeListener () { |
| @Override |
| public void treeExpanded (TreeEvent e) { |
| int prefHeight = tree.computeSize (SWT.DEFAULT, SWT.DEFAULT).y; |
| tree.setSize (clientWidth, prefHeight); |
| } |
| @Override |
| public void treeCollapsed (TreeEvent e) { |
| int prefHeight = tree.computeSize (SWT.DEFAULT, SWT.DEFAULT).y; |
| tree.setSize (clientWidth, prefHeight); |
| } |
| }); |
| /* |
| * The following listener ensures that a newly-selected item |
| * in the Tree is always visible. |
| */ |
| tree.addSelectionListener(widgetSelectedAdapter(e -> { |
| TreeItem [] selectedItems = tree.getSelection(); |
| if (selectedItems.length > 0) { |
| Rectangle itemRect = selectedItems[0].getBounds(); |
| Rectangle area = sc.getClientArea(); |
| Point origin = sc.getOrigin(); |
| if (itemRect.x < origin.x || itemRect.y < origin.y |
| || itemRect.x + itemRect.width > origin.x + area.width |
| || itemRect.y + itemRect.height > origin.y + area.height) { |
| sc.setOrigin(itemRect.x, itemRect.y); |
| } |
| } |
| })); |
| /* |
| * The following listener scrolls the Tree one item at a time |
| * in response to MouseWheel events. |
| */ |
| tree.addListener(SWT.MouseWheel, event -> { |
| Point origin = sc.getOrigin(); |
| if (event.count < 0) { |
| origin.y = Math.min(origin.y + tree.getItemHeight(), tree.getSize().y); |
| } else { |
| origin.y = Math.max(origin.y - tree.getItemHeight(), 0); |
| } |
| sc.setOrigin(origin); |
| }); |
| |
| Button disableButton = new Button (shell, SWT.PUSH); |
| disableButton.setBounds (10, 220, 120, 30); |
| disableButton.setText ("Disable"); |
| disableButton.addListener (SWT.Selection, event -> tree.setEnabled(false)); |
| Button enableButton = new Button (shell, SWT.PUSH); |
| enableButton.setBounds (140, 220, 120, 30); |
| enableButton.setText ("Enable"); |
| enableButton.addListener (SWT.Selection, event -> tree.setEnabled(true)); |
| |
| shell.open (); |
| while (!shell.isDisposed ()) { |
| if (!display.readAndDispatch ()) display.sleep (); |
| } |
| display.dispose (); |
| } |
| } |