| /******************************************************************************* |
| * 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.bpel.common.ui.details; |
| |
| import org.eclipse.bpel.common.ui.command.ICommandFramework; |
| import org.eclipse.swt.SWT; |
| import org.eclipse.swt.custom.CCombo; |
| import org.eclipse.swt.widgets.Control; |
| import org.eclipse.swt.widgets.Event; |
| import org.eclipse.swt.widgets.Listener; |
| import org.eclipse.swt.widgets.Text; |
| |
| /** |
| * An abstract IOngoingChange that is also a Listener. ChangeHelper notifies the |
| * details area of IOngoingChange lifecycle events on behalf of the widget(s) it |
| * listens to. |
| */ |
| public abstract class ChangeHelper implements IOngoingChange, Listener { |
| |
| protected ICommandFramework fCommandFramework; |
| protected int fNonUserChange = 0; |
| |
| /** |
| * Marks the start of a programmatic change to the widget contents. Clients must |
| * call startNonUserChange() before directly setting the widget contents to avoid |
| * unwanted IOngoingChange lifecycle events. (Only some widgets/viewers will send the |
| * unwanted notifications, but all clients should use this pattern anyway). |
| * Currently, changes may not be nested. |
| * |
| */ |
| |
| public void startNonUserChange() { |
| fNonUserChange += 1; |
| } |
| |
| /** |
| * Clients who call startNonUserChange() should call finishNonUserChange() as soon |
| * as possible after the change is done. |
| * |
| * @throws IllegalArgumentException if no change is in progress. |
| */ |
| @SuppressWarnings("nls") |
| public void finishNonUserChange() { |
| if (fNonUserChange == 0) { |
| throw new IllegalStateException("Non-matching call to finishNonUserChange()") ; |
| } |
| fNonUserChange -= 1; |
| } |
| |
| /** |
| * @return true if a programmatic change is in progress. |
| */ |
| public boolean isNonUserChange() { |
| return fNonUserChange > 0; |
| } |
| |
| /** |
| * |
| * @param commandFramework |
| */ |
| public ChangeHelper (ICommandFramework commandFramework) { |
| fCommandFramework = commandFramework; |
| } |
| |
| |
| /** |
| * @see org.eclipse.swt.widgets.Listener#handleEvent(org.eclipse.swt.widgets.Event) |
| */ |
| public void handleEvent(Event event) { |
| if (isNonUserChange()) { |
| return ; |
| } |
| |
| switch (event.type) { |
| case SWT.KeyDown: |
| if (event.character == SWT.CR) { |
| finish(); |
| } |
| break; |
| case SWT.FocusOut: |
| finish(); |
| break; |
| case SWT.Modify: |
| case SWT.Selection: |
| case SWT.DefaultSelection: |
| modify(); |
| break; |
| case SWT.Dispose : |
| abort(); |
| break; |
| } |
| } |
| |
| /** |
| * |
| */ |
| void finish() { |
| fCommandFramework.notifyChangeDone(this); |
| } |
| |
| /** |
| * |
| */ |
| void modify() { |
| fCommandFramework.notifyChangeInProgress(this); |
| } |
| |
| void abort () { |
| fCommandFramework.abortCurrentChange(); |
| } |
| |
| protected boolean isModifyBasedControl(Control c) { |
| if (c instanceof CCombo) { |
| return (c.getStyle() & SWT.READ_ONLY) == 0; // if not read only |
| } |
| return (c instanceof Text); |
| } |
| |
| protected boolean isSelectionBasedControl(Control c) { |
| return !(c instanceof Text); |
| } |
| |
| /** |
| * Registers this ChangeHelper with the given control to listen for events |
| * which indicate that a change is in progress (or done). |
| * |
| * @param controls |
| */ |
| |
| public void startListeningTo (Control ... controls ) { |
| |
| for (Control control : controls) { |
| |
| control.addListener(SWT.FocusOut, this); |
| control.addListener(SWT.Dispose, this); |
| if (isModifyBasedControl(control)) { |
| control.addListener(SWT.Modify, this); |
| } |
| if (isSelectionBasedControl(control)) { |
| control.addListener(SWT.Selection, this); |
| control.addListener(SWT.DefaultSelection, this); |
| } |
| } |
| } |
| |
| /** |
| * Registers this ChangeHelper with the given control to listen for the |
| * Enter key. When Enter is pressed, the change is considered done (this |
| * is appropriate for single-line Text widgets). |
| * @param controls |
| */ |
| public void startListeningForEnter (Control ... controls) { |
| // NOTE: KeyDown rather than KeyUp, because of similar usage in CCombo. |
| for(Control control : controls) { |
| control.addListener(SWT.KeyDown, this); |
| } |
| } |
| |
| /** |
| * Unregisters this ChangeHelper from a control previously passed to |
| * startListeningTo() and/or startListeningForEnter(). |
| * @param controls |
| */ |
| public void stopListeningTo (Control ...controls ) { |
| for(Control control : controls) { |
| |
| control.removeListener(SWT.FocusOut, this); |
| if (isModifyBasedControl(control)) { |
| control.removeListener(SWT.Modify, this); |
| } |
| if (isSelectionBasedControl(control)) { |
| control.removeListener(SWT.Selection, this); |
| control.removeListener(SWT.DefaultSelection, this); |
| } |
| control.removeListener(SWT.KeyDown, this); |
| |
| } |
| |
| } |
| } |