org.eclipse.jdt.debug.ui/ui/org/eclipse/jdt/internal/debug/ui/jres/JREsComboBlock.java - jdt/eclipse.jdt.debug - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2004 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Common Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/cpl-v10.html
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.jdt.internal.debug.ui.jres;

 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.Iterator;
 import java.util.List;

 import org.eclipse.debug.internal.ui.SWTUtil;
 import org.eclipse.jdt.internal.debug.ui.actions.ControlAccessibleListener;
 import org.eclipse.jdt.internal.debug.ui.launcher.DefineSystemLibraryQuickFix;
 import org.eclipse.jdt.launching.IVMInstall;
 import org.eclipse.jdt.launching.IVMInstallType;
 import org.eclipse.jdt.launching.JavaRuntime;
 import org.eclipse.jdt.launching.VMStandin;
 import org.eclipse.jface.util.ListenerList;
 import org.eclipse.jface.viewers.ISelection;
 import org.eclipse.jface.viewers.ISelectionChangedListener;
 import org.eclipse.jface.viewers.ISelectionProvider;
 import org.eclipse.jface.viewers.IStructuredSelection;
 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.graphics.Font;
 import org.eclipse.swt.layout.GridData;
 import org.eclipse.swt.layout.GridLayout;
 import org.eclipse.swt.widgets.Button;
 import org.eclipse.swt.widgets.Combo;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
 import org.eclipse.swt.widgets.Event;
 import org.eclipse.swt.widgets.Group;
 import org.eclipse.swt.widgets.Listener;
 import org.eclipse.swt.widgets.Shell;

 /**
  * A composite that displays installed JRE's in a combo box, with a 'manage...'
  * button to modify installed JREs.
  * <p>
  * This block implements ISelectionProvider - it sends selection change events
  * when the checked JRE in the table changes, or when the "use default" button
  * check state changes.
  * </p>
  */
 public class JREsComboBlock implements ISelectionProvider {

 	/**
 	 * This block's control
 	 */
 	private Composite fControl;

 	/**
 	 * VMs being displayed
 	 */
 	private List fVMs = new ArrayList();

 	/**
 	 * The main control
 	 */
 	private Combo fCombo;

 	// Action buttons
 	private Button fManageButton;

 	/**
 	 * Selection listeners (checked JRE changes)
 	 */
 	private ListenerList fSelectionListeners = new ListenerList();

 	/**
 	 * Previous selection
 	 */
 	private ISelection fPrevSelection = new StructuredSelection();

 	/**
 	 * Default JRE descriptor or <code>null</code> if none.
 	 */
 	private JREDescriptor fDefaultDescriptor = null;

 	/**
 	 * Specific JRE descriptor or <code>null</code> if none.
 	 */
 	private JREDescriptor fSpecificDescriptor = null;

 	/**
 	 * Default JRE radio button or <code>null</code> if none
 	 */
 	private Button fDefaultButton = null;

 	/**
 	 * Selected JRE radio button
 	 */
 	private Button fSpecificButton = null;

 	/**
 	 * The title used for the JRE block
 	 */
 	private String fTitle = null;

 	/* (non-Javadoc)
 	 * @see org.eclipse.jface.viewers.ISelectionProvider#addSelectionChangedListener(org.eclipse.jface.viewers.ISelectionChangedListener)
 	 */
 	public void addSelectionChangedListener(ISelectionChangedListener listener) {
 		fSelectionListeners.add(listener);
 	}

 	/* (non-Javadoc)
 	 * @see org.eclipse.jface.viewers.ISelectionProvider#getSelection()
 	 */
 	public ISelection getSelection() {
 		IVMInstall vm = getJRE();
 		if (vm == null) {
 			return new StructuredSelection();
 		}
 		return new StructuredSelection(vm);
 	}

 	/* (non-Javadoc)
 	 * @see org.eclipse.jface.viewers.ISelectionProvider#removeSelectionChangedListener(org.eclipse.jface.viewers.ISelectionChangedListener)
 	 */
 	public void removeSelectionChangedListener(ISelectionChangedListener listener) {
 		fSelectionListeners.remove(listener);
 	}

 	/* (non-Javadoc)
 	 * @see org.eclipse.jface.viewers.ISelectionProvider#setSelection(org.eclipse.jface.viewers.ISelection)
 	 */
 	public void setSelection(ISelection selection) {
 		if (selection instanceof IStructuredSelection) {
 			if (!selection.equals(fPrevSelection)) {
 				fPrevSelection = selection;
 				if (selection.isEmpty()) {
 					fCombo.setText(""); //$NON-NLS-1$
 					fCombo.select(-1);
 					// need to do this to clear the old text
 					fCombo.setItems(new String[]{});
 					fillWithWorkspaceJREs();
 				} else {
 					Object jre = ((IStructuredSelection)selection).getFirstElement();
 					int index = fVMs.indexOf(jre);
 					if (index >= 0) {
 						fCombo.select(index);
 					}
 				}
 				fireSelectionChanged();
 			}
 		}
 	}

 	/**
 	 * Creates this block's control in the given control.
 	 *
 	 * @param anscestor containing control
 	 */
 	public void createControl(Composite ancestor) {
 		Font font = ancestor.getFont();
 		Composite comp = new Composite(ancestor, SWT.NONE);
 		GridLayout layout= new GridLayout();
 		comp.setLayout(new GridLayout());
 		comp.setLayoutData(new GridData(GridData.FILL_BOTH));
 		fControl = comp;
 		comp.setFont(font);

 		Group group= new Group(comp, SWT.NULL);
 		layout= new GridLayout();
 		layout.numColumns= 3;
 		group.setLayout(layout);
 		group.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
 		group.setFont(font);

 		GridData data;

 		if (fTitle == null) {
 			fTitle = JREMessages.getString("JREsComboBlock.3"); //$NON-NLS-1$
 		}
 		group.setText(fTitle);

 		// display a 'use default JRE' check box
 		if (fDefaultDescriptor != null) {
 			fDefaultButton = new Button(group, SWT.RADIO);
 			fDefaultButton.setText(fDefaultDescriptor.getDescription());
 			fDefaultButton.addSelectionListener(new SelectionAdapter() {
 				public void widgetSelected(SelectionEvent e) {
 					if (fDefaultButton.getSelection()) {
 						setUseDefaultJRE();
 					}
 				}
 			});
 			data = new GridData();
 			data.horizontalSpan = 3;
 			fDefaultButton.setLayoutData(data);
 			fDefaultButton.setFont(font);
 		}

 		fSpecificButton = new Button(group, SWT.RADIO);
 		if (fSpecificDescriptor != null) {
 			fSpecificButton.setText(fSpecificDescriptor.getDescription());
 		} else {
 			fSpecificButton.setText(JREMessages.getString("JREsComboBlock.1")); //$NON-NLS-1$
 		}
 		fSpecificButton.addSelectionListener(new SelectionAdapter() {
 			public void widgetSelected(SelectionEvent e) {
 				if (fSpecificButton.getSelection()) {
 					fCombo.setEnabled(true);
 					fManageButton.setEnabled(true);
 					fireSelectionChanged();
 				}
 			}
 		});
 		fSpecificButton.setFont(font);
 		data = new GridData(GridData.BEGINNING);
 		fSpecificButton.setLayoutData(data);

 		fCombo = new Combo(group, SWT.DROP_DOWN | SWT.READ_ONLY);
 		fCombo.setFont(font);
 		data= new GridData(GridData.FILL_HORIZONTAL);
 		data.horizontalSpan = 1;
 		fCombo.setLayoutData(data);
 		ControlAccessibleListener.addListener(fCombo, fSpecificButton.getText());

 		fCombo.addSelectionListener(new SelectionAdapter() {
 			public void widgetSelected(SelectionEvent e) {
 				setJRE(getJRE());
 			}
 		});

 		fManageButton = createPushButton(group, JREMessages.getString("JREsComboBlock.2")); //$NON-NLS-1$
 		fManageButton.addListener(SWT.Selection, new Listener() {
 			public void handleEvent(Event event) {
 				IVMInstall oldSelection = getJRE();
 				int oldIndex = -1;
 				if (oldSelection != null) {
 					oldIndex = fVMs.indexOf(oldSelection);
 				}
 				DefineSystemLibraryQuickFix fix = new DefineSystemLibraryQuickFix();
 				fix.run(null);
 				fillWithWorkspaceJREs();
 				int newIndex = -1;
 				if (oldSelection != null) {
 					newIndex = fVMs.indexOf(oldSelection);
 				}
 				if (newIndex != oldIndex) {
 					// clear the old selection so that a selection changed is fired
 					fPrevSelection = null;
 				}
 				// update text
 				setDefaultJREDescriptor(fDefaultDescriptor);
 				if (isDefaultJRE()) {
 					// reset in case default has changed
 					setUseDefaultJRE();
 				} else {
 					// restore selection
 					if (newIndex >= 0) {
 						fCombo.select(newIndex);
 					} else {
 						// select the first JRE
 						fCombo.select(0);
 					}
 					setJRE(getJRE());
 				}
 			}
 		});

 		fillWithWorkspaceJREs();
 	}

 	/**
 	 * Fire current selection
 	 */
 	private void fireSelectionChanged() {
 		SelectionChangedEvent event = new SelectionChangedEvent(this, getSelection());
 		Object[] listeners = fSelectionListeners.getListeners();
 		for (int i = 0; i < listeners.length; i++) {
 			ISelectionChangedListener listener = (ISelectionChangedListener)listeners[i];
 			listener.selectionChanged(event);
 		}
 	}

 	protected Button createPushButton(Composite parent, String label) {
 		return SWTUtil.createPushButton(parent, label, null);
 	}

 	/**
 	 * Returns this block's control
 	 *
 	 * @return control
 	 */
 	public Control getControl() {
 		return fControl;
 	}

 	/**
 	 * Sets the JREs to be displayed in this block
 	 *
 	 * @param vms JREs to be displayed
 	 */
 	protected void setJREs(List jres) {
 		fVMs.clear();
 		fVMs.addAll(jres);
 		// sort by name
 		Collections.sort(fVMs, new Comparator() {
 			public int compare(Object o1, Object o2) {
 				IVMInstall left = (IVMInstall)o1;
 				IVMInstall right = (IVMInstall)o2;
 				return left.getName().compareToIgnoreCase(right.getName());
 			}

 			public boolean equals(Object obj) {
 				return obj == this;
 			}
 		});
 		// now make an array of names
 		String[] names = new String[fVMs.size()];
 		Iterator iter = fVMs.iterator();
 		int i = 0;
 		while (iter.hasNext()) {
 			IVMInstall vm = (IVMInstall)iter.next();
 			names[i] = vm.getName();
 			i++;
 		}
 		fCombo.setItems(names);
 	}

 	/**
 	 * Returns the JREs currently being displayed in this block
 	 *
 	 * @return JREs currently being displayed in this block
 	 */
 	public IVMInstall[] getJREs() {
 		return (IVMInstall[])fVMs.toArray(new IVMInstall[fVMs.size()]);
 	}

 	protected Shell getShell() {
 		return getControl().getShell();
 	}

 	/**
 	 * Sets the selected JRE, or <code>null</code>
 	 *
 	 * @param vm JRE or <code>null</code>
 	 */
 	public void setJRE(IVMInstall vm) {
 		fSpecificButton.setSelection(true);
 		fDefaultButton.setSelection(false);
 		fCombo.setEnabled(true);
 		fManageButton.setEnabled(true);
 		if (vm == null) {
 			setSelection(new StructuredSelection());
 		} else {
 			setSelection(new StructuredSelection(vm));
 		}
 	}

 	/**
 	 * Returns the selected JRE or <code>null</code> if none.
 	 *
 	 * @return the selected JRE or <code>null</code> if none
 	 */
 	public IVMInstall getJRE() {
 		int index = fCombo.getSelectionIndex();
 		if (index >= 0) {
 			return (IVMInstall)fVMs.get(index);
 		}
 		return null;
 	}

 	/**
 	 * Populates the JRE table with existing JREs defined in the workspace.
 	 */
 	protected void fillWithWorkspaceJREs() {
 		// fill with JREs
 		List standins = new ArrayList();
 		IVMInstallType[] types = JavaRuntime.getVMInstallTypes();
 		for (int i = 0; i < types.length; i++) {
 			IVMInstallType type = types[i];
 			IVMInstall[] installs = type.getVMInstalls();
 			for (int j = 0; j < installs.length; j++) {
 				IVMInstall install = installs[j];
 				standins.add(new VMStandin(install));
 			}
 		}
 		setJREs(standins);
 	}

 	/**
 	 * Sets the Default JRE Descriptor for this block.
 	 *
 	 * @param descriptor default JRE descriptor
 	 */
 	public void setDefaultJREDescriptor(JREDescriptor descriptor) {
 		fDefaultDescriptor = descriptor;
 		setButtonTextFromDescriptor(fDefaultButton, descriptor);
 	}

 	private void setButtonTextFromDescriptor(Button button, JREDescriptor descriptor) {
 		if (button != null) {
 			//update the description & JRE in case it has changed
 			String currentText = button.getText();
 			String newText = descriptor.getDescription();
 			if (!newText.equals(currentText)) {
 				button.setText(newText);
 				fControl.layout();
 			}
 		}
 	}

 	/**
 	 * Sets the specific JRE Descriptor for this block.
 	 *
 	 * @param descriptor specific JRE descriptor
 	 */
 	public void setSpecificJREDescriptor(JREDescriptor descriptor) {
 		fSpecificDescriptor = descriptor;
 		setButtonTextFromDescriptor(fSpecificButton, descriptor);
 	}

 	/**
 	 * Returns whether the 'use default JRE' button is checked.
 	 *
 	 * @return whether the 'use default JRE' button is checked
 	 */
 	public boolean isDefaultJRE() {
 		if (fDefaultButton != null) {
 			return fDefaultButton.getSelection();
 		}
 		return false;
 	}

 	/**
 	 * Sets this control to use the 'default' JRE.
 	 */
 	public void setUseDefaultJRE() {
 		if (fDefaultDescriptor != null) {
 			fDefaultButton.setSelection(true);
 			fSpecificButton.setSelection(false);
 			fCombo.setEnabled(false);
 			fManageButton.setEnabled(false);
 			fPrevSelection = null;
 			fireSelectionChanged();
 		}
 	}

 	/**
 	 * Sets the title used for this JRE block
 	 *
 	 * @param title title for this JRE block
 	 */
 	public void setTitle(String title) {
 		fTitle = title;
 	}

 	/**
 	 * Refresh the default JRE description.
 	 */
 	public void refresh() {
 		setDefaultJREDescriptor(fDefaultDescriptor);
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2000, 2004 IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Common Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/cpl-v10.html
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.jdt.internal.debug.ui.jres;

	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.Comparator;
	import java.util.Iterator;
	import java.util.List;

	import org.eclipse.debug.internal.ui.SWTUtil;
	import org.eclipse.jdt.internal.debug.ui.actions.ControlAccessibleListener;
	import org.eclipse.jdt.internal.debug.ui.launcher.DefineSystemLibraryQuickFix;
	import org.eclipse.jdt.launching.IVMInstall;
	import org.eclipse.jdt.launching.IVMInstallType;
	import org.eclipse.jdt.launching.JavaRuntime;
	import org.eclipse.jdt.launching.VMStandin;
	import org.eclipse.jface.util.ListenerList;
	import org.eclipse.jface.viewers.ISelection;
	import org.eclipse.jface.viewers.ISelectionChangedListener;
	import org.eclipse.jface.viewers.ISelectionProvider;
	import org.eclipse.jface.viewers.IStructuredSelection;
	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.graphics.Font;
	import org.eclipse.swt.layout.GridData;
	import org.eclipse.swt.layout.GridLayout;
	import org.eclipse.swt.widgets.Button;
	import org.eclipse.swt.widgets.Combo;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Control;
	import org.eclipse.swt.widgets.Event;
	import org.eclipse.swt.widgets.Group;
	import org.eclipse.swt.widgets.Listener;
	import org.eclipse.swt.widgets.Shell;

	/**
	* A composite that displays installed JRE's in a combo box, with a 'manage...'
	* button to modify installed JREs.
	* <p>
	* This block implements ISelectionProvider - it sends selection change events
	* when the checked JRE in the table changes, or when the "use default" button
	* check state changes.
	* </p>
	*/
	public class JREsComboBlock implements ISelectionProvider {

	/**
	* This block's control
	*/
	private Composite fControl;

	/**
	* VMs being displayed
	*/
	private List fVMs = new ArrayList();

	/**
	* The main control
	*/
	private Combo fCombo;

	// Action buttons
	private Button fManageButton;

	/**
	* Selection listeners (checked JRE changes)
	*/
	private ListenerList fSelectionListeners = new ListenerList();

	/**
	* Previous selection
	*/
	private ISelection fPrevSelection = new StructuredSelection();

	/**
	* Default JRE descriptor or <code>null</code> if none.
	*/
	private JREDescriptor fDefaultDescriptor = null;

	/**
	* Specific JRE descriptor or <code>null</code> if none.
	*/
	private JREDescriptor fSpecificDescriptor = null;

	/**
	* Default JRE radio button or <code>null</code> if none
	*/
	private Button fDefaultButton = null;

	/**
	* Selected JRE radio button
	*/
	private Button fSpecificButton = null;

	/**
	* The title used for the JRE block
	*/
	private String fTitle = null;

	/* (non-Javadoc)
	* @see org.eclipse.jface.viewers.ISelectionProvider#addSelectionChangedListener(org.eclipse.jface.viewers.ISelectionChangedListener)
	*/
	public void addSelectionChangedListener(ISelectionChangedListener listener) {
	fSelectionListeners.add(listener);
	}

	/* (non-Javadoc)
	* @see org.eclipse.jface.viewers.ISelectionProvider#getSelection()
	*/
	public ISelection getSelection() {
	IVMInstall vm = getJRE();
	if (vm == null) {
	return new StructuredSelection();
	}
	return new StructuredSelection(vm);
	}

	/* (non-Javadoc)
	* @see org.eclipse.jface.viewers.ISelectionProvider#removeSelectionChangedListener(org.eclipse.jface.viewers.ISelectionChangedListener)
	*/
	public void removeSelectionChangedListener(ISelectionChangedListener listener) {
	fSelectionListeners.remove(listener);
	}

	/* (non-Javadoc)
	* @see org.eclipse.jface.viewers.ISelectionProvider#setSelection(org.eclipse.jface.viewers.ISelection)
	*/
	public void setSelection(ISelection selection) {
	if (selection instanceof IStructuredSelection) {
	if (!selection.equals(fPrevSelection)) {
	fPrevSelection = selection;
	if (selection.isEmpty()) {
	fCombo.setText(""); //$NON-NLS-1$
	fCombo.select(-1);
	// need to do this to clear the old text
	fCombo.setItems(new String[]{});
	fillWithWorkspaceJREs();
	} else {
	Object jre = ((IStructuredSelection)selection).getFirstElement();
	int index = fVMs.indexOf(jre);
	if (index >= 0) {
	fCombo.select(index);
	}
	}
	fireSelectionChanged();
	}
	}
	}

	/**
	* Creates this block's control in the given control.
	*
	* @param anscestor containing control
	*/
	public void createControl(Composite ancestor) {
	Font font = ancestor.getFont();
	Composite comp = new Composite(ancestor, SWT.NONE);
	GridLayout layout= new GridLayout();
	comp.setLayout(new GridLayout());
	comp.setLayoutData(new GridData(GridData.FILL_BOTH));
	fControl = comp;
	comp.setFont(font);

	Group group= new Group(comp, SWT.NULL);
	layout= new GridLayout();
	layout.numColumns= 3;
	group.setLayout(layout);
	group.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
	group.setFont(font);

	GridData data;

	if (fTitle == null) {
	fTitle = JREMessages.getString("JREsComboBlock.3"); //$NON-NLS-1$
	}
	group.setText(fTitle);

	// display a 'use default JRE' check box
	if (fDefaultDescriptor != null) {
	fDefaultButton = new Button(group, SWT.RADIO);
	fDefaultButton.setText(fDefaultDescriptor.getDescription());
	fDefaultButton.addSelectionListener(new SelectionAdapter() {
	public void widgetSelected(SelectionEvent e) {
	if (fDefaultButton.getSelection()) {
	setUseDefaultJRE();
	}
	}
	});
	data = new GridData();
	data.horizontalSpan = 3;
	fDefaultButton.setLayoutData(data);
	fDefaultButton.setFont(font);
	}

	fSpecificButton = new Button(group, SWT.RADIO);
	if (fSpecificDescriptor != null) {
	fSpecificButton.setText(fSpecificDescriptor.getDescription());
	} else {
	fSpecificButton.setText(JREMessages.getString("JREsComboBlock.1")); //$NON-NLS-1$
	}
	fSpecificButton.addSelectionListener(new SelectionAdapter() {
	public void widgetSelected(SelectionEvent e) {
	if (fSpecificButton.getSelection()) {
	fCombo.setEnabled(true);
	fManageButton.setEnabled(true);
	fireSelectionChanged();
	}
	}
	});
	fSpecificButton.setFont(font);
	data = new GridData(GridData.BEGINNING);
	fSpecificButton.setLayoutData(data);

	fCombo = new Combo(group, SWT.DROP_DOWN \| SWT.READ_ONLY);
	fCombo.setFont(font);
	data= new GridData(GridData.FILL_HORIZONTAL);
	data.horizontalSpan = 1;
	fCombo.setLayoutData(data);
	ControlAccessibleListener.addListener(fCombo, fSpecificButton.getText());

	fCombo.addSelectionListener(new SelectionAdapter() {
	public void widgetSelected(SelectionEvent e) {
	setJRE(getJRE());
	}
	});

	fManageButton = createPushButton(group, JREMessages.getString("JREsComboBlock.2")); //$NON-NLS-1$
	fManageButton.addListener(SWT.Selection, new Listener() {
	public void handleEvent(Event event) {
	IVMInstall oldSelection = getJRE();
	int oldIndex = -1;
	if (oldSelection != null) {
	oldIndex = fVMs.indexOf(oldSelection);
	}
	DefineSystemLibraryQuickFix fix = new DefineSystemLibraryQuickFix();
	fix.run(null);
	fillWithWorkspaceJREs();
	int newIndex = -1;
	if (oldSelection != null) {
	newIndex = fVMs.indexOf(oldSelection);
	}
	if (newIndex != oldIndex) {
	// clear the old selection so that a selection changed is fired
	fPrevSelection = null;
	}
	// update text
	setDefaultJREDescriptor(fDefaultDescriptor);
	if (isDefaultJRE()) {
	// reset in case default has changed
	setUseDefaultJRE();
	} else {
	// restore selection
	if (newIndex >= 0) {
	fCombo.select(newIndex);
	} else {
	// select the first JRE
	fCombo.select(0);
	}
	setJRE(getJRE());
	}
	}
	});

	fillWithWorkspaceJREs();
	}

	/**
	* Fire current selection
	*/
	private void fireSelectionChanged() {
	SelectionChangedEvent event = new SelectionChangedEvent(this, getSelection());
	Object[] listeners = fSelectionListeners.getListeners();
	for (int i = 0; i < listeners.length; i++) {
	ISelectionChangedListener listener = (ISelectionChangedListener)listeners[i];
	listener.selectionChanged(event);
	}
	}

	protected Button createPushButton(Composite parent, String label) {
	return SWTUtil.createPushButton(parent, label, null);
	}

	/**
	* Returns this block's control
	*
	* @return control
	*/
	public Control getControl() {
	return fControl;
	}

	/**
	* Sets the JREs to be displayed in this block
	*
	* @param vms JREs to be displayed
	*/
	protected void setJREs(List jres) {
	fVMs.clear();
	fVMs.addAll(jres);
	// sort by name
	Collections.sort(fVMs, new Comparator() {
	public int compare(Object o1, Object o2) {
	IVMInstall left = (IVMInstall)o1;
	IVMInstall right = (IVMInstall)o2;
	return left.getName().compareToIgnoreCase(right.getName());
	}

	public boolean equals(Object obj) {
	return obj == this;
	}
	});
	// now make an array of names
	String[] names = new String[fVMs.size()];
	Iterator iter = fVMs.iterator();
	int i = 0;
	while (iter.hasNext()) {
	IVMInstall vm = (IVMInstall)iter.next();
	names[i] = vm.getName();
	i++;
	}
	fCombo.setItems(names);
	}

	/**
	* Returns the JREs currently being displayed in this block
	*
	* @return JREs currently being displayed in this block
	*/
	public IVMInstall[] getJREs() {
	return (IVMInstall[])fVMs.toArray(new IVMInstall[fVMs.size()]);
	}

	protected Shell getShell() {
	return getControl().getShell();
	}

	/**
	* Sets the selected JRE, or <code>null</code>
	*
	* @param vm JRE or <code>null</code>
	*/
	public void setJRE(IVMInstall vm) {
	fSpecificButton.setSelection(true);
	fDefaultButton.setSelection(false);
	fCombo.setEnabled(true);
	fManageButton.setEnabled(true);
	if (vm == null) {
	setSelection(new StructuredSelection());
	} else {
	setSelection(new StructuredSelection(vm));
	}
	}

	/**
	* Returns the selected JRE or <code>null</code> if none.
	*
	* @return the selected JRE or <code>null</code> if none
	*/
	public IVMInstall getJRE() {
	int index = fCombo.getSelectionIndex();
	if (index >= 0) {
	return (IVMInstall)fVMs.get(index);
	}
	return null;
	}

	/**
	* Populates the JRE table with existing JREs defined in the workspace.
	*/
	protected void fillWithWorkspaceJREs() {
	// fill with JREs
	List standins = new ArrayList();
	IVMInstallType[] types = JavaRuntime.getVMInstallTypes();
	for (int i = 0; i < types.length; i++) {
	IVMInstallType type = types[i];
	IVMInstall[] installs = type.getVMInstalls();
	for (int j = 0; j < installs.length; j++) {
	IVMInstall install = installs[j];
	standins.add(new VMStandin(install));
	}
	}
	setJREs(standins);
	}

	/**
	* Sets the Default JRE Descriptor for this block.
	*
	* @param descriptor default JRE descriptor
	*/
	public void setDefaultJREDescriptor(JREDescriptor descriptor) {
	fDefaultDescriptor = descriptor;
	setButtonTextFromDescriptor(fDefaultButton, descriptor);
	}

	private void setButtonTextFromDescriptor(Button button, JREDescriptor descriptor) {
	if (button != null) {
	//update the description & JRE in case it has changed
	String currentText = button.getText();
	String newText = descriptor.getDescription();
	if (!newText.equals(currentText)) {
	button.setText(newText);
	fControl.layout();
	}
	}
	}

	/**
	* Sets the specific JRE Descriptor for this block.
	*
	* @param descriptor specific JRE descriptor
	*/
	public void setSpecificJREDescriptor(JREDescriptor descriptor) {
	fSpecificDescriptor = descriptor;
	setButtonTextFromDescriptor(fSpecificButton, descriptor);
	}

	/**
	* Returns whether the 'use default JRE' button is checked.
	*
	* @return whether the 'use default JRE' button is checked
	*/
	public boolean isDefaultJRE() {
	if (fDefaultButton != null) {
	return fDefaultButton.getSelection();
	}
	return false;
	}

	/**
	* Sets this control to use the 'default' JRE.
	*/
	public void setUseDefaultJRE() {
	if (fDefaultDescriptor != null) {
	fDefaultButton.setSelection(true);
	fSpecificButton.setSelection(false);
	fCombo.setEnabled(false);
	fManageButton.setEnabled(false);
	fPrevSelection = null;
	fireSelectionChanged();
	}
	}

	/**
	* Sets the title used for this JRE block
	*
	* @param title title for this JRE block
	*/
	public void setTitle(String title) {
	fTitle = title;
	}

	/**
	* Refresh the default JRE description.
	*/
	public void refresh() {
	setDefaultJREDescriptor(fDefaultDescriptor);
	}

	}