RadioViewer.java

/*******************************************************************************
 * Copyright (c) 2008, 2011 Obeo.
 * 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:
 *     Obeo - initial API and implementation
 *******************************************************************************/
package org.eclipse.emf.eef.runtime.ui.widgets;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.eclipse.emf.common.util.Enumerator;
import org.eclipse.emf.eef.runtime.ui.utils.EditingUtils;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.ISelectionProvider;
import org.eclipse.jface.viewers.SelectionChangedEvent;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;

/**
 * A viewer composed of button to handles EEnum as Radio. It will display a radio for each element of the
 * enum.
 * 
 * @author <a href="mailto:stephane.bouchet@obeo.fr">Stephane Bouchet</a>
 */
public class RadioViewer extends Composite implements ISelectionProvider {

	/**
	 * Listeners for selection changes
	 */
	private List<ISelectionChangedListener> listeners;

	private RadioSelectionChangedListener radioSelectionChangedListener;

	/**
	 * the map of buttons used.
	 */
	private Map<Object, Button> buttons;

	public RadioViewer(Composite parent, int style) {
		super(parent, style);
		buttons = new HashMap<Object, Button>();
		this.setLayout(new GridLayout());
		listeners = new ArrayList<ISelectionChangedListener>();
		EditingUtils.setEEFtype(this, "eef::RadioViewer");
		radioSelectionChangedListener = new RadioSelectionChangedListener();
	}
	
	/**
	 * Clear all the graphical elements of the view
	 */
	private void clear() {
		while (this.getChildren().length > 0) {
			Control next = this.getChildren()[0];
			next.dispose();
		}
	}

	private void createButton(Object value) {
		Button b = new Button(this, SWT.RADIO);
		if (value instanceof Enumerator) {
			b.setText(((Enumerator)value).getLiteral());
		}
		GridData data = new GridData(GridData.FILL_BOTH);
		b.setLayoutData(data);
		b.addSelectionListener(radioSelectionChangedListener);
		buttons.put(value, b);
		EditingUtils.setEEFtype(b, "eef::RadioViewer::radio");
		if (EditingUtils.getID(this) != null)
			EditingUtils.setID(b, EditingUtils.getID(this));
	}

	/**
	 * {@inheritDoc}
	 * 
	 * @see org.eclipse.swt.widgets.Control#setEnabled(boolean)
	 */
	@Override
	public void setEnabled(boolean enabled) {
		for (Button button : buttons.values()) {
			button.setEnabled(enabled);
		}
		super.setEnabled(enabled);
	}

	/**
	 * @param newValue
	 */
	public void setSelection(ISelection selection) {
		if (selection instanceof StructuredSelection) {
			StructuredSelection sSelection = (StructuredSelection)selection;
			Object newValue = sSelection.getFirstElement();
			for (Object value : buttons.keySet()) {
				buttons.get(value).setSelection(false);
				if (value instanceof Enumerator && newValue instanceof Enumerator) {
					if (((Enumerator)value).getValue() == ((Enumerator)newValue).getValue()) {
						buttons.get(value).setSelection(true);
					}
				}
			}
		}
	}

	/**
	 * {@inheritDoc}
	 * 
	 * @see org.eclipse.jface.viewers.ISelectionProvider#getSelection()
	 */
	public ISelection getSelection() {
		for (Object value : buttons.keySet()) {
			if (buttons.get(value).getSelection())
				return new StructuredSelection(value);
		}
		return null;
	}

	public void setInput(Object input) {
		clear();
		if (input instanceof Collection) {
			for (Object value : (Collection<?>)input) {
				createButton(value);
			}
		}
		// refresh Layout
		GridLayout l = (GridLayout)this.getLayout();
		l.numColumns = buttons.size() == 0 ? 1 : buttons.size();
		this.setLayout(l);
		layout();
	}

	/**
	 * Sets the given ID to the EObjectFlatComboViewer
	 * 
	 * @param id
	 *            the id of the widget
	 */
	public void setID(Object id) {
		EditingUtils.setID(this, id);
		for (Control control : getChildren()) {
			EditingUtils.setID(control, id);
		}
	}

	/**
	 * @return the ID of the EObjectFlatComboViewer
	 */
	public Object getID() {
		return EditingUtils.getID(this);
	}

	/**
	 * Sets the tooltip text for the viewer
	 * 
	 * @param tooltip
	 *            the tooltip text
	 */
	public void setToolTipText(String tooltip) {
		for (Button button : buttons.values()) {
			button.setToolTipText(tooltip);
		}
	}

	/**
	 * Add a new SelectionChangedListener
	 * 
	 * @param listener
	 *            the listener to add
	 */
	public void addSelectionChangedListener(ISelectionChangedListener listener) {
		listeners.add(listener);
	}

	/**
	 * remove a SelectionChanged listener
	 * 
	 * @param listener
	 *            the listener to remove
	 */
	public void removeSelectionChangedListener(ISelectionChangedListener listener) {
		listeners.remove(listener);
	}

	private class RadioSelectionChangedListener extends SelectionAdapter {

		/**
		 * {@inheritDoc}
		 * 
		 * @see org.eclipse.swt.events.SelectionAdapter#widgetSelected(org.eclipse.swt.events.SelectionEvent)
		 */
		public void widgetSelected(SelectionEvent e) {
			Object value = null;
			for (Object tmp : buttons.keySet()) {
				if (buttons.get(tmp).getSelection())
					value = tmp;
			}
			if (value != null) {
				for (ISelectionChangedListener listener : listeners) {
					listener.selectionChanged(new SelectionChangedEvent(RadioViewer.this,
							new StructuredSelection(value)));
				}
			}
		}

	}
}