| /******************************************************************************* |
| * Copyright (c) 2007, 2009 Oracle. 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: |
| * Oracle - initial API and implementation |
| ******************************************************************************/ |
| package org.eclipse.jpt.ui.internal.utility.swt; |
| |
| import org.eclipse.jpt.ui.internal.listeners.SWTPropertyChangeListenerWrapper; |
| import org.eclipse.jpt.utility.internal.StringTools; |
| import org.eclipse.jpt.utility.model.event.PropertyChangeEvent; |
| import org.eclipse.jpt.utility.model.listener.PropertyChangeListener; |
| import org.eclipse.jpt.utility.model.value.PropertyValueModel; |
| import org.eclipse.jpt.utility.model.value.WritablePropertyValueModel; |
| import org.eclipse.swt.events.DisposeEvent; |
| import org.eclipse.swt.events.DisposeListener; |
| import org.eclipse.swt.events.SelectionAdapter; |
| import org.eclipse.swt.events.SelectionEvent; |
| import org.eclipse.swt.events.SelectionListener; |
| import org.eclipse.swt.widgets.Button; |
| |
| /** |
| * This binding can be used to keep a check-box, toggle button, or radio button |
| * "selection" synchronized with a model boolean. |
| * |
| * @see WritablePropertyValueModel |
| * @see Button |
| */ |
| @SuppressWarnings("nls") |
| final class BooleanButtonModelBinding { |
| |
| // ***** model |
| /** A value model on the underlying model boolean. */ |
| private final WritablePropertyValueModel<Boolean> booleanHolder; |
| |
| /** |
| * A listener that allows us to synchronize the button's selection state with |
| * the model boolean. |
| */ |
| private final PropertyChangeListener booleanChangeListener; |
| |
| /** |
| * The default setting for the check-box/toggle button/radio button; |
| * for when the underlying model is <code>null</code>. |
| * The default [default value] is <code>false</code> (i.e. the check-box |
| * is unchecked/toggle button popped out/radio button unchecked). |
| */ |
| private final boolean defaultValue; |
| |
| // ***** UI |
| /** The check-box/toggle button/radio button we synchronize with the model boolean. */ |
| private final Button button; |
| |
| /** |
| * A listener that allows us to synchronize the model boolean with |
| * the button's selection state. |
| */ |
| private final SelectionListener buttonSelectionListener; |
| |
| /** |
| * A listener that allows us to stop listening to stuff when the button |
| * is disposed. (Critical for preventing memory leaks.) |
| */ |
| private final DisposeListener buttonDisposeListener; |
| |
| |
| // ********** constructor ********** |
| |
| /** |
| * Constructor - the boolean holder and button are required. |
| */ |
| BooleanButtonModelBinding(WritablePropertyValueModel<Boolean> booleanHolder, Button button, boolean defaultValue) { |
| super(); |
| if ((booleanHolder == null) || (button == null)) { |
| throw new NullPointerException(); |
| } |
| this.booleanHolder = booleanHolder; |
| this.button = button; |
| this.defaultValue = defaultValue; |
| |
| this.booleanChangeListener = this.buildBooleanChangeListener(); |
| this.booleanHolder.addPropertyChangeListener(PropertyValueModel.VALUE, this.booleanChangeListener); |
| |
| this.buttonSelectionListener = this.buildButtonSelectionListener(); |
| this.button.addSelectionListener(this.buttonSelectionListener); |
| |
| this.buttonDisposeListener = this.buildButtonDisposeListener(); |
| this.button.addDisposeListener(this.buttonDisposeListener); |
| |
| this.setButtonSelection(this.booleanHolder.getValue()); |
| } |
| |
| |
| // ********** initialization ********** |
| |
| private PropertyChangeListener buildBooleanChangeListener() { |
| return new SWTPropertyChangeListenerWrapper(this.buildBooleanChangeListener_()); |
| } |
| |
| private PropertyChangeListener buildBooleanChangeListener_() { |
| return new PropertyChangeListener() { |
| public void propertyChanged(PropertyChangeEvent event) { |
| BooleanButtonModelBinding.this.booleanChanged(event); |
| } |
| @Override |
| public String toString() { |
| return "boolean listener"; |
| } |
| }; |
| } |
| |
| private SelectionListener buildButtonSelectionListener() { |
| return new SelectionAdapter() { |
| @Override |
| public void widgetSelected(SelectionEvent event) { |
| BooleanButtonModelBinding.this.buttonSelected(event); |
| } |
| @Override |
| public String toString() { |
| return "button selection listener"; |
| } |
| }; |
| } |
| |
| private DisposeListener buildButtonDisposeListener() { |
| return new DisposeListener() { |
| public void widgetDisposed(DisposeEvent event) { |
| BooleanButtonModelBinding.this.buttonDisposed(event); |
| } |
| @Override |
| public String toString() { |
| return "button dispose listener"; |
| } |
| }; |
| } |
| |
| |
| // ********** behavior ********** |
| |
| /** |
| * The model has changed - synchronize the button. |
| * If the new model value is null, use the binding's default value |
| * (which is typically false). |
| */ |
| void booleanChanged(PropertyChangeEvent event) { |
| this.setButtonSelection((Boolean) event.getNewValue()); |
| } |
| |
| private void setButtonSelection(Boolean b) { |
| if ( ! this.button.isDisposed()) { |
| this.button.setSelection(this.booleanValue(b)); |
| } |
| } |
| |
| private boolean booleanValue(Boolean b) { |
| return (b != null) ? b.booleanValue() : this.getDefaultValue(); |
| } |
| |
| private boolean getDefaultValue() { |
| return this.defaultValue; |
| } |
| |
| /** |
| * The button has been "selected" - synchronize the model. |
| */ |
| void buttonSelected(@SuppressWarnings("unused") SelectionEvent event) { |
| if ( ! this.button.isDisposed()) { |
| this.booleanHolder.setValue(Boolean.valueOf(this.button.getSelection())); |
| } |
| } |
| |
| |
| // ********** dispose ********** |
| |
| void buttonDisposed(@SuppressWarnings("unused") DisposeEvent event) { |
| // the button is not yet "disposed" when we receive this event |
| // so we can still remove our listeners |
| this.button.removeSelectionListener(this.buttonSelectionListener); |
| this.button.removeDisposeListener(this.buttonDisposeListener); |
| this.booleanHolder.removePropertyChangeListener(PropertyValueModel.VALUE, this.booleanChangeListener); |
| } |
| |
| |
| // ********** standard methods ********** |
| |
| @Override |
| public String toString() { |
| return StringTools.buildToStringFor(this, this.booleanHolder); |
| } |
| |
| } |