/*******************************************************************************
* Copyright (c) 2004, 2006 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.internal;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.MenuItem;
/**
* Represents a group of radio buttons in a menu. Each menu item
* is mapped onto a particular value. The RadioMenu reports its state
* using the attached Model object. That is, Model.getState() will
* return the value of the currently selected radio button and Model.setState(value)
* will select the radio button associated with the given value.
*/
public class RadioMenu implements IChangeListener {
private Model data;
private Menu parent;
private List items = new ArrayList();
SelectionAdapter selectionAdapter = new SelectionAdapter() {
public void widgetSelected(SelectionEvent e) {
Object newState = e.widget.getData();
data.setState(newState, RadioMenu.this);
}
};
/**
* Creates a set of radio menu items on the given menu.
*
* @param parent menu that will contain the menu items
* @param newData the model that will store the value of the currently selected item
*/
public RadioMenu(Menu parent, Model newData) {
this.parent = parent;
this.data = newData;
newData.addChangeListener(this);
}
/**
* Returns true iff the given values are considered equal.
*
* @param value1
* @param value2
* @return
*/
private static boolean isEqual(Object value1, Object value2) {
if (value1 == null) {
return value2 == null;
} else if (value2 == null) {
return false;
}
return value1.equals(value2);
}
/**
* Creates a new menu item with the given text and value. When
* the item is selected, the state of the model will change to
* match the given value.
*
* @param text
* @param value
*/
public void addMenuItem(String text, Object value) {
MenuItem newItem = new MenuItem(parent, SWT.RADIO);
newItem.setSelection(isEqual(data.getState(), value));
newItem.setText(text);
newItem.setData(value);
items.add(newItem);
newItem.addSelectionListener(selectionAdapter);
}
/**
* Disposes all menu items
*/
public void dispose() {
Iterator iter = items.iterator();
while (iter.hasNext()) {
MenuItem next = (MenuItem) iter.next();
if (!next.isDisposed()) {
next.removeSelectionListener(selectionAdapter);
next.dispose();
}
}
items.clear();
}
/**
* Refreshes the selected menu items to match the current state of the model.
*/
private void refreshSelection() {
Iterator iter = items.iterator();
while (iter.hasNext()) {
MenuItem next = (MenuItem) iter.next();
if (!next.isDisposed()) {
next.setSelection(isEqual(data.getState(), next.getData()));
}
}
}
/* (non-Javadoc)
* @see org.eclipse.ui.internal.controls.IView#changed()
*/
public void update(boolean changed) {
refreshSelection();
}
}