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, 2015 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
  * which accompanies this distribution, and is available at
  * https://www.eclipse.org/legal/epl-2.0/
  *
  * SPDX-License-Identifier: EPL-2.0
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.jdt.internal.debug.ui.jres;

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

 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.ListenerList;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.debug.internal.ui.SWTFactory;
 import org.eclipse.jdt.debug.ui.IJavaDebugUIConstants;
 import org.eclipse.jdt.internal.debug.ui.JDIDebugUIPlugin;
 import org.eclipse.jdt.internal.debug.ui.actions.ControlAccessibleListener;
 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.jdt.launching.environments.IExecutionEnvironment;
 import org.eclipse.jdt.launching.environments.IExecutionEnvironmentsManager;
 import org.eclipse.jface.util.IPropertyChangeListener;
 import org.eclipse.jface.util.PropertyChangeEvent;
 import org.eclipse.osgi.util.NLS;
 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.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 JREs 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 {

 	public static final String PROPERTY_JRE = "PROPERTY_JRE"; //$NON-NLS-1$

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

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

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

 	// Action buttons
 	private Button fManageButton;

 	/**
 	 * JRE change listeners
 	 */
 	private ListenerList<IPropertyChangeListener> fListeners = new ListenerList<>();

 	/**
 	 * Whether the default JRE should be in first position (if <code>false</code>, it becomes last).
 	 */
 	private boolean fDefaultFirst;

 	/**
 	 * 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;

 	/**
 	 * Selected JRE profile radio button
 	 */
 	private Button fEnvironmentsButton = null;

 	/**
 	 * Combo box of JRE profiles
 	 */
 	private Combo fEnvironmentsCombo = null;

 	private Button fManageEnvironmentsButton = null;

 	// a path to an unavailable JRE
 	private IPath fErrorPath;

 	/**
 	 * List of execution environments
 	 */
 	private List<Object> fEnvironments = new ArrayList<>();

 	private IStatus fStatus = OK_STATUS;

 	private static IStatus OK_STATUS = new Status(IStatus.OK, JDIDebugUIPlugin.getUniqueIdentifier(), 0, "", null); //$NON-NLS-1$

 	/**
 	 * Creates a JREs combo block.
 	 *
 	 * @param defaultFirst whether the default JRE should be in first position (if <code>false</code>, it becomes last)
 	 */
 	public JREsComboBlock(boolean defaultFirst) {
 		fDefaultFirst= defaultFirst;
 	}

 	public void addPropertyChangeListener(IPropertyChangeListener listener) {
 		fListeners.add(listener);
 	}

 	public void removePropertyChangeListener(IPropertyChangeListener listener) {
 		fListeners.remove(listener);
 	}

 	private void firePropertyChange() {
 		PropertyChangeEvent event = new PropertyChangeEvent(this, PROPERTY_JRE, null, getPath());
 		for (IPropertyChangeListener listener : fListeners) {
 			listener.propertyChange(event);
 		}
 	}

 	/**
 	 * Creates this block's control in the given control.
 	 *
 	 * @param anscestor containing control
 	 */
 	public void createControl(Composite ancestor) {
 		fControl = SWTFactory.createComposite(ancestor, 1, 1, GridData.FILL_BOTH);
 		if (fTitle == null) {
 			fTitle = JREMessages.JREsComboBlock_3;
 		}
 		Group group = SWTFactory.createGroup(fControl, fTitle, 1, 1, GridData.FILL_HORIZONTAL);
 		Composite comp = SWTFactory.createComposite(group, group.getFont(), 3, 1, GridData.FILL_BOTH, 0, 0);

 		if (fDefaultFirst) {
 			createDefaultJREControls(comp);
 		}
 		createEEControls(comp);
 		createAlternateJREControls(comp);
 		if (!fDefaultFirst) {
 			createDefaultJREControls(comp);
 		}
 	}

 	private void createEEControls(Composite comp) {
 		fEnvironmentsButton = SWTFactory.createRadioButton(comp, JREMessages.JREsComboBlock_4);
 		fEnvironmentsButton.addSelectionListener(new SelectionAdapter() {
 			@Override
 			public void widgetSelected(SelectionEvent e) {
 				if (fEnvironmentsButton.getSelection()) {
 					fCombo.setEnabled(false);
 					if (fEnvironmentsCombo.getText().length() == 0 && !fEnvironments.isEmpty()) {
 						fEnvironmentsCombo.select(0);
 					}
 					fEnvironmentsCombo.setEnabled(true);
 					if (fEnvironments.isEmpty()) {
 						setError(JREMessages.JREsComboBlock_5);
 					} else {
 						setStatus(OK_STATUS);
 					}
 					firePropertyChange();
 				}
 			}
 		});

 		fEnvironmentsCombo = SWTFactory.createCombo(comp, SWT.DROP_DOWN | SWT.READ_ONLY, 1, null);
 		fEnvironmentsCombo.addSelectionListener(new SelectionAdapter() {
 			@Override
 			public void widgetSelected(SelectionEvent e) {
 				setPath(JavaRuntime.newJREContainerPath(getEnvironment()));
 				firePropertyChange();
 			}
 		});

 		fManageEnvironmentsButton = SWTFactory.createPushButton(comp, JREMessages.JREsComboBlock_14, null);
 		fManageEnvironmentsButton.addListener(SWT.Selection, new Listener() {
 			@Override
 			public void handleEvent(Event event) {
 				showPrefPage(ExecutionEnvironmentsPreferencePage.ID);
 			}
 		});

 		fillWithWorkspaceProfiles();
 	}

 	private void createAlternateJREControls(Composite comp) {
 		String text = JREMessages.JREsComboBlock_1;
 		if (fSpecificDescriptor != null) {
 			text = fSpecificDescriptor.getDescription();
 		}
 		fSpecificButton = SWTFactory.createRadioButton(comp, text, 1);
 		fSpecificButton.addSelectionListener(new SelectionAdapter() {
 			@Override
 			public void widgetSelected(SelectionEvent e) {
 				if (fSpecificButton.getSelection()) {
 					fCombo.setEnabled(true);
 					if (fCombo.getText().length() == 0 && !fVMs.isEmpty()) {
 						fCombo.select(0);
 					}
 					if (fVMs.isEmpty()) {
 						setError(JREMessages.JREsComboBlock_0);
 					} else {
 						setStatus(OK_STATUS);
 					}
 					fEnvironmentsCombo.setEnabled(false);
 					firePropertyChange();
 				}
 			}
 		});
 		fCombo = SWTFactory.createCombo(comp, SWT.DROP_DOWN | SWT.READ_ONLY, 1, null);
 		ControlAccessibleListener.addListener(fCombo, fSpecificButton.getText());
 		fCombo.addSelectionListener(new SelectionAdapter() {
 			@Override
 			public void widgetSelected(SelectionEvent e) {
 				setStatus(OK_STATUS);
 				firePropertyChange();
 			}
 		});

 		fManageButton = SWTFactory.createPushButton(comp, JREMessages.JREsComboBlock_2, null);
 		fManageButton.addListener(SWT.Selection, new Listener() {
 			@Override
 			public void handleEvent(Event event) {
 				showPrefPage(JREsPreferencePage.ID);
 			}
 		});
 		fillWithWorkspaceJREs();
 	}

 	private void createDefaultJREControls(Composite comp) {
 		if (fDefaultDescriptor != null) {
 			fDefaultButton = SWTFactory.createRadioButton(comp, fDefaultDescriptor.getDescription(), 3);
 			fDefaultButton.addSelectionListener(new SelectionAdapter() {
 				@Override
 				public void widgetSelected(SelectionEvent e) {
 					if (fDefaultButton.getSelection()) {
 						setUseDefaultJRE();
 						setStatus(OK_STATUS);
 						firePropertyChange();
 					}
 				}
 			});
 		}
 	}

 	/**
 	 * Opens the given preference page, and updates when closed.
 	 *
 	 * @param id pref page id
 	 * @param page pref page
 	 */
 	private void showPrefPage(String id/*, IPreferencePage page*/) {
 		IVMInstall prevJRE = getJRE();
 		IExecutionEnvironment prevEnv = getEnvironment();
 		JDIDebugUIPlugin.showPreferencePage(id);
 		fillWithWorkspaceJREs();
 		fillWithWorkspaceProfiles();
 		restoreCombo(fVMs, prevJRE, fCombo);
 		restoreCombo(fEnvironments, prevEnv, fEnvironmentsCombo);
 		// update text
 		setDefaultJREDescriptor(fDefaultDescriptor);
 		if (isDefaultJRE()) {
 			// reset in case default has changed
 			setUseDefaultJRE();
 		}
 		setPath(getPath());
 		firePropertyChange();
 	}

 	private void restoreCombo(List<Object> elements, Object element, Combo combo) {
 		int index = -1;
 		if (element != null) {
 			index = elements.indexOf(element);
 		}
 		if (index >= 0) {
 			combo.select(index);
 		} else {
 			combo.select(0);
 		}
 	}

 	/**
 	 * 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<VMStandin> jres) {
 		fVMs.clear();
 		fVMs.addAll(jres);
 		// sort by name
 		Collections.sort(fVMs, new Comparator<Object>() {
 			@Override
 			public int compare(Object o1, Object o2) {
 				IVMInstall left = (IVMInstall)o1;
 				IVMInstall right = (IVMInstall)o2;
 				return left.getName().compareToIgnoreCase(right.getName());
 			}

 			@Override
 			public boolean equals(Object obj) {
 				return obj == this;
 			}
 		});
 		// now make an array of names
 		String[] names = new String[fVMs.size()];
 		Iterator<Object> iter = fVMs.iterator();
 		int i = 0;
 		while (iter.hasNext()) {
 			IVMInstall vm = (IVMInstall)iter.next();
 			names[i] = vm.getName();
 			i++;
 		}
 		fCombo.setItems(names);
 		fCombo.setVisibleItemCount(Math.min(names.length, 20));
 	}

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

 	/**
 	 * Selects a specific JRE based on type/name.
 	 *
 	 * @param vm JRE or <code>null</code>
 	 */
 	private void selectJRE(IVMInstall vm) {
 		fSpecificButton.setSelection(true);
 		fDefaultButton.setSelection(false);
 		fEnvironmentsButton.setSelection(false);
 		fCombo.setEnabled(true);
 		fEnvironmentsCombo.setEnabled(false);
 		if (vm != null) {
 			int index = fVMs.indexOf(vm);
 			if (index >= 0) {
 				fCombo.select(index);
 			}
 		}
 		firePropertyChange();
 	}

 	/**
 	 * Selects a JRE based environment.
 	 *
 	 * @param env environment or <code>null</code>
 	 */
 	private void selectEnvironment(IExecutionEnvironment env) {
 		fSpecificButton.setSelection(false);
 		fDefaultButton.setSelection(false);
 		fCombo.setEnabled(false);
 		fEnvironmentsButton.setSelection(true);
 		fEnvironmentsCombo.setEnabled(true);
 		if (env != null) {
 			int index = fEnvironments.indexOf(env);
 			if (index >= 0) {
 				fEnvironmentsCombo.select(index);
 			}
 		}
 		firePropertyChange();
 	}

 	/**
 	 * 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;
 	}

 	/**
 	 * Returns the selected Environment or <code>null</code> if none.
 	 *
 	 * @return the selected Environment or <code>null</code> if none
 	 */
 	private IExecutionEnvironment getEnvironment() {
 		int index = fEnvironmentsCombo.getSelectionIndex();
 		if (index >= 0) {
 			return (IExecutionEnvironment)fEnvironments.get(index);
 		}
 		return null;
 	}

 	/**
 	 * Populates the JRE table with existing JREs defined in the workspace.
 	 */
 	protected void fillWithWorkspaceJREs() {
 		// fill with JREs
 		List<VMStandin> 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);
 	}

 	/**
 	 * Populates the JRE profile combo with profiles defined in the workspace.
 	 */
 	protected void fillWithWorkspaceProfiles() {
 		fEnvironments.clear();
 		IExecutionEnvironment[] environments = JavaRuntime.getExecutionEnvironmentsManager().getExecutionEnvironments();
 		for (int i = 0; i < environments.length; i++) {
 			fEnvironments.add(environments[i]);
 		}

 		String[] names = new String[fEnvironments.size()];
 		Iterator<Object> iter = fEnvironments.iterator();
 		int i = 0;
 		while (iter.hasNext()) {
 			IExecutionEnvironment env = (IExecutionEnvironment)iter.next();
 			IPath path = JavaRuntime.newJREContainerPath(env);
 			IVMInstall install = JavaRuntime.getVMInstall(path);
 			if (install != null) {
 				names[i] = NLS.bind(JREMessages.JREsComboBlock_15, new String[]{env.getId(), install.getName()});
 			} else {
 				names[i] = NLS.bind(JREMessages.JREsComboBlock_16, new String[]{env.getId()});
 			}
 			i++;
 		}
 		fEnvironmentsCombo.setItems(names);
 		fEnvironmentsCombo.setVisibleItemCount(Math.min(names.length, 20));
 	}

 	/**
 	 * 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.
 	 */
 	private void setUseDefaultJRE() {
 		if (fDefaultDescriptor != null) {
 			fDefaultButton.setSelection(true);
 			fSpecificButton.setSelection(false);
 			fEnvironmentsButton.setSelection(false);
 			fCombo.setEnabled(false);
 			fEnvironmentsCombo.setEnabled(false);
 			firePropertyChange();
 		}
 	}

 	/**
 	 * 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);
 	}

 	/**
 	 * Returns a classpath container path identifying the selected JRE.
 	 *
 	 * @return classpath container path or <code>null</code>
 	 * @since 3.2
 	 */
 	public IPath getPath() {
 		if (!getStatus().isOK() && fErrorPath != null) {
 			return fErrorPath;
 		}
 		if (fEnvironmentsButton.getSelection()) {
 			int index = fEnvironmentsCombo.getSelectionIndex();
 			if (index >= 0) {
 				IExecutionEnvironment env = (IExecutionEnvironment) fEnvironments.get(index);
 				return JavaRuntime.newJREContainerPath(env);
 			}
 			return null;
 		}
 		if (fSpecificButton.getSelection()) {
 			int index = fCombo.getSelectionIndex();
 			if (index >= 0) {
 				IVMInstall vm = (IVMInstall) fVMs.get(index);
 				return JavaRuntime.newJREContainerPath(vm);
 			}
 			return null;
 		}
 		return JavaRuntime.newDefaultJREContainerPath();
 	}

 	/**
 	 * Sets the selection based on the given container path and returns
 	 * a status indicating if the selection was successful.
 	 *
 	 * @param containerPath
 	 * @return status
 	 */
 	public void setPath(IPath containerPath) {
 		fErrorPath = null;
 		setStatus(OK_STATUS);
 		if (JavaRuntime.newDefaultJREContainerPath().equals(containerPath)) {
 			setUseDefaultJRE();
 		} else {
 			String envId = JavaRuntime.getExecutionEnvironmentId(containerPath);
 			if (envId != null) {
 				IExecutionEnvironmentsManager manager = JavaRuntime.getExecutionEnvironmentsManager();
 				IExecutionEnvironment environment = manager.getEnvironment(envId);
 				if (environment == null) {
 					fErrorPath = containerPath;
 					selectEnvironment(environment);
 					setError(NLS.bind(JREMessages.JREsComboBlock_6, new String[]{envId}));
 				} else {
 					selectEnvironment(environment);
 					IVMInstall[] installs = environment.getCompatibleVMs();
 					if (installs.length == 0) {
 						setError(NLS.bind(JREMessages.JREsComboBlock_7, new String[]{environment.getId()}));
 					}
 				}
 			} else {
 				IVMInstall install = JavaRuntime.getVMInstall(containerPath);
 				if (install == null) {
 					selectJRE(install);
 					fErrorPath = containerPath;
 					String installTypeId = JavaRuntime.getVMInstallTypeId(containerPath);
 					if (installTypeId == null) {
 						setError(JREMessages.JREsComboBlock_8);
 					} else {
 						IVMInstallType installType = JavaRuntime.getVMInstallType(installTypeId);
 						if (installType == null) {
 							setError(NLS.bind(JREMessages.JREsComboBlock_9, new String[]{installTypeId}));
 						} else {
 							String installName = JavaRuntime.getVMInstallName(containerPath);
 							if (installName == null) {
 								setError(NLS.bind(JREMessages.JREsComboBlock_10, new String[]{installType.getName()}));
 							} else {
 								setError(NLS.bind(JREMessages.JREsComboBlock_11, new String[]{installName, installType.getName()}));
 							}
 						}
 					}
 				} else {
 					selectJRE(install);
 					File location = install.getInstallLocation();
 					if (location == null) {
 						setError(JREMessages.JREsComboBlock_12);
 					} else if (!location.exists()) {
 						setError(JREMessages.JREsComboBlock_13);
 					}
 				}
 			}
 		}
 	}

 	private void setError(String message) {
 		setStatus(new Status(IStatus.ERROR, JDIDebugUIPlugin.getUniqueIdentifier(),
 				IJavaDebugUIConstants.INTERNAL_ERROR, message, null));
 	}

 	/**
 	 * Returns the status of the JRE selection.
 	 *
 	 * @return status
 	 */
 	public IStatus getStatus() {
 		return fStatus;
 	}

 	private void setStatus(IStatus status) {
 		fStatus = status;
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2015 IBM Corporation and others.
	*
	* This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License 2.0
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/legal/epl-2.0/
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.jdt.internal.debug.ui.jres;

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

	import org.eclipse.core.runtime.IPath;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.ListenerList;
	import org.eclipse.core.runtime.Status;
	import org.eclipse.debug.internal.ui.SWTFactory;
	import org.eclipse.jdt.debug.ui.IJavaDebugUIConstants;
	import org.eclipse.jdt.internal.debug.ui.JDIDebugUIPlugin;
	import org.eclipse.jdt.internal.debug.ui.actions.ControlAccessibleListener;
	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.jdt.launching.environments.IExecutionEnvironment;
	import org.eclipse.jdt.launching.environments.IExecutionEnvironmentsManager;
	import org.eclipse.jface.util.IPropertyChangeListener;
	import org.eclipse.jface.util.PropertyChangeEvent;
	import org.eclipse.osgi.util.NLS;
	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.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 JREs 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 {

	public static final String PROPERTY_JRE = "PROPERTY_JRE"; //$NON-NLS-1$

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

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

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

	// Action buttons
	private Button fManageButton;

	/**
	* JRE change listeners
	*/
	private ListenerList<IPropertyChangeListener> fListeners = new ListenerList<>();

	/**
	* Whether the default JRE should be in first position (if <code>false</code>, it becomes last).
	*/
	private boolean fDefaultFirst;

	/**
	* 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;

	/**
	* Selected JRE profile radio button
	*/
	private Button fEnvironmentsButton = null;

	/**
	* Combo box of JRE profiles
	*/
	private Combo fEnvironmentsCombo = null;

	private Button fManageEnvironmentsButton = null;

	// a path to an unavailable JRE
	private IPath fErrorPath;

	/**
	* List of execution environments
	*/
	private List<Object> fEnvironments = new ArrayList<>();

	private IStatus fStatus = OK_STATUS;

	private static IStatus OK_STATUS = new Status(IStatus.OK, JDIDebugUIPlugin.getUniqueIdentifier(), 0, "", null); //$NON-NLS-1$

	/**
	* Creates a JREs combo block.
	*
	* @param defaultFirst whether the default JRE should be in first position (if <code>false</code>, it becomes last)
	*/
	public JREsComboBlock(boolean defaultFirst) {
	fDefaultFirst= defaultFirst;
	}

	public void addPropertyChangeListener(IPropertyChangeListener listener) {
	fListeners.add(listener);
	}

	public void removePropertyChangeListener(IPropertyChangeListener listener) {
	fListeners.remove(listener);
	}

	private void firePropertyChange() {
	PropertyChangeEvent event = new PropertyChangeEvent(this, PROPERTY_JRE, null, getPath());
	for (IPropertyChangeListener listener : fListeners) {
	listener.propertyChange(event);
	}
	}

	/**
	* Creates this block's control in the given control.
	*
	* @param anscestor containing control
	*/
	public void createControl(Composite ancestor) {
	fControl = SWTFactory.createComposite(ancestor, 1, 1, GridData.FILL_BOTH);
	if (fTitle == null) {
	fTitle = JREMessages.JREsComboBlock_3;
	}
	Group group = SWTFactory.createGroup(fControl, fTitle, 1, 1, GridData.FILL_HORIZONTAL);
	Composite comp = SWTFactory.createComposite(group, group.getFont(), 3, 1, GridData.FILL_BOTH, 0, 0);

	if (fDefaultFirst) {
	createDefaultJREControls(comp);
	}
	createEEControls(comp);
	createAlternateJREControls(comp);
	if (!fDefaultFirst) {
	createDefaultJREControls(comp);
	}
	}

	private void createEEControls(Composite comp) {
	fEnvironmentsButton = SWTFactory.createRadioButton(comp, JREMessages.JREsComboBlock_4);
	fEnvironmentsButton.addSelectionListener(new SelectionAdapter() {
	@Override
	public void widgetSelected(SelectionEvent e) {
	if (fEnvironmentsButton.getSelection()) {
	fCombo.setEnabled(false);
	if (fEnvironmentsCombo.getText().length() == 0 && !fEnvironments.isEmpty()) {
	fEnvironmentsCombo.select(0);
	}
	fEnvironmentsCombo.setEnabled(true);
	if (fEnvironments.isEmpty()) {
	setError(JREMessages.JREsComboBlock_5);
	} else {
	setStatus(OK_STATUS);
	}
	firePropertyChange();
	}
	}
	});

	fEnvironmentsCombo = SWTFactory.createCombo(comp, SWT.DROP_DOWN \| SWT.READ_ONLY, 1, null);
	fEnvironmentsCombo.addSelectionListener(new SelectionAdapter() {
	@Override
	public void widgetSelected(SelectionEvent e) {
	setPath(JavaRuntime.newJREContainerPath(getEnvironment()));
	firePropertyChange();
	}
	});

	fManageEnvironmentsButton = SWTFactory.createPushButton(comp, JREMessages.JREsComboBlock_14, null);
	fManageEnvironmentsButton.addListener(SWT.Selection, new Listener() {
	@Override
	public void handleEvent(Event event) {
	showPrefPage(ExecutionEnvironmentsPreferencePage.ID);
	}
	});

	fillWithWorkspaceProfiles();
	}

	private void createAlternateJREControls(Composite comp) {
	String text = JREMessages.JREsComboBlock_1;
	if (fSpecificDescriptor != null) {
	text = fSpecificDescriptor.getDescription();
	}
	fSpecificButton = SWTFactory.createRadioButton(comp, text, 1);
	fSpecificButton.addSelectionListener(new SelectionAdapter() {
	@Override
	public void widgetSelected(SelectionEvent e) {
	if (fSpecificButton.getSelection()) {
	fCombo.setEnabled(true);
	if (fCombo.getText().length() == 0 && !fVMs.isEmpty()) {
	fCombo.select(0);
	}
	if (fVMs.isEmpty()) {
	setError(JREMessages.JREsComboBlock_0);
	} else {
	setStatus(OK_STATUS);
	}
	fEnvironmentsCombo.setEnabled(false);
	firePropertyChange();
	}
	}
	});
	fCombo = SWTFactory.createCombo(comp, SWT.DROP_DOWN \| SWT.READ_ONLY, 1, null);
	ControlAccessibleListener.addListener(fCombo, fSpecificButton.getText());
	fCombo.addSelectionListener(new SelectionAdapter() {
	@Override
	public void widgetSelected(SelectionEvent e) {
	setStatus(OK_STATUS);
	firePropertyChange();
	}
	});

	fManageButton = SWTFactory.createPushButton(comp, JREMessages.JREsComboBlock_2, null);
	fManageButton.addListener(SWT.Selection, new Listener() {
	@Override
	public void handleEvent(Event event) {
	showPrefPage(JREsPreferencePage.ID);
	}
	});
	fillWithWorkspaceJREs();
	}

	private void createDefaultJREControls(Composite comp) {
	if (fDefaultDescriptor != null) {
	fDefaultButton = SWTFactory.createRadioButton(comp, fDefaultDescriptor.getDescription(), 3);
	fDefaultButton.addSelectionListener(new SelectionAdapter() {
	@Override
	public void widgetSelected(SelectionEvent e) {
	if (fDefaultButton.getSelection()) {
	setUseDefaultJRE();
	setStatus(OK_STATUS);
	firePropertyChange();
	}
	}
	});
	}
	}

	/**
	* Opens the given preference page, and updates when closed.
	*
	* @param id pref page id
	* @param page pref page
	*/
	private void showPrefPage(String id/, IPreferencePage page/) {
	IVMInstall prevJRE = getJRE();
	IExecutionEnvironment prevEnv = getEnvironment();
	JDIDebugUIPlugin.showPreferencePage(id);
	fillWithWorkspaceJREs();
	fillWithWorkspaceProfiles();
	restoreCombo(fVMs, prevJRE, fCombo);
	restoreCombo(fEnvironments, prevEnv, fEnvironmentsCombo);
	// update text
	setDefaultJREDescriptor(fDefaultDescriptor);
	if (isDefaultJRE()) {
	// reset in case default has changed
	setUseDefaultJRE();
	}
	setPath(getPath());
	firePropertyChange();
	}

	private void restoreCombo(List<Object> elements, Object element, Combo combo) {
	int index = -1;
	if (element != null) {
	index = elements.indexOf(element);
	}
	if (index >= 0) {
	combo.select(index);
	} else {
	combo.select(0);
	}
	}

	/**
	* 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<VMStandin> jres) {
	fVMs.clear();
	fVMs.addAll(jres);
	// sort by name
	Collections.sort(fVMs, new Comparator<Object>() {
	@Override
	public int compare(Object o1, Object o2) {
	IVMInstall left = (IVMInstall)o1;
	IVMInstall right = (IVMInstall)o2;
	return left.getName().compareToIgnoreCase(right.getName());
	}

	@Override
	public boolean equals(Object obj) {
	return obj == this;
	}
	});
	// now make an array of names
	String[] names = new String[fVMs.size()];
	Iterator<Object> iter = fVMs.iterator();
	int i = 0;
	while (iter.hasNext()) {
	IVMInstall vm = (IVMInstall)iter.next();
	names[i] = vm.getName();
	i++;
	}
	fCombo.setItems(names);
	fCombo.setVisibleItemCount(Math.min(names.length, 20));
	}

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

	/**
	* Selects a specific JRE based on type/name.
	*
	* @param vm JRE or <code>null</code>
	*/
	private void selectJRE(IVMInstall vm) {
	fSpecificButton.setSelection(true);
	fDefaultButton.setSelection(false);
	fEnvironmentsButton.setSelection(false);
	fCombo.setEnabled(true);
	fEnvironmentsCombo.setEnabled(false);
	if (vm != null) {
	int index = fVMs.indexOf(vm);
	if (index >= 0) {
	fCombo.select(index);
	}
	}
	firePropertyChange();
	}

	/**
	* Selects a JRE based environment.
	*
	* @param env environment or <code>null</code>
	*/
	private void selectEnvironment(IExecutionEnvironment env) {
	fSpecificButton.setSelection(false);
	fDefaultButton.setSelection(false);
	fCombo.setEnabled(false);
	fEnvironmentsButton.setSelection(true);
	fEnvironmentsCombo.setEnabled(true);
	if (env != null) {
	int index = fEnvironments.indexOf(env);
	if (index >= 0) {
	fEnvironmentsCombo.select(index);
	}
	}
	firePropertyChange();
	}

	/**
	* 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;
	}

	/**
	* Returns the selected Environment or <code>null</code> if none.
	*
	* @return the selected Environment or <code>null</code> if none
	*/
	private IExecutionEnvironment getEnvironment() {
	int index = fEnvironmentsCombo.getSelectionIndex();
	if (index >= 0) {
	return (IExecutionEnvironment)fEnvironments.get(index);
	}
	return null;
	}

	/**
	* Populates the JRE table with existing JREs defined in the workspace.
	*/
	protected void fillWithWorkspaceJREs() {
	// fill with JREs
	List<VMStandin> 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);
	}

	/**
	* Populates the JRE profile combo with profiles defined in the workspace.
	*/
	protected void fillWithWorkspaceProfiles() {
	fEnvironments.clear();
	IExecutionEnvironment[] environments = JavaRuntime.getExecutionEnvironmentsManager().getExecutionEnvironments();
	for (int i = 0; i < environments.length; i++) {
	fEnvironments.add(environments[i]);
	}

	String[] names = new String[fEnvironments.size()];
	Iterator<Object> iter = fEnvironments.iterator();
	int i = 0;
	while (iter.hasNext()) {
	IExecutionEnvironment env = (IExecutionEnvironment)iter.next();
	IPath path = JavaRuntime.newJREContainerPath(env);
	IVMInstall install = JavaRuntime.getVMInstall(path);
	if (install != null) {
	names[i] = NLS.bind(JREMessages.JREsComboBlock_15, new String[]{env.getId(), install.getName()});
	} else {
	names[i] = NLS.bind(JREMessages.JREsComboBlock_16, new String[]{env.getId()});
	}
	i++;
	}
	fEnvironmentsCombo.setItems(names);
	fEnvironmentsCombo.setVisibleItemCount(Math.min(names.length, 20));
	}

	/**
	* 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.
	*/
	private void setUseDefaultJRE() {
	if (fDefaultDescriptor != null) {
	fDefaultButton.setSelection(true);
	fSpecificButton.setSelection(false);
	fEnvironmentsButton.setSelection(false);
	fCombo.setEnabled(false);
	fEnvironmentsCombo.setEnabled(false);
	firePropertyChange();
	}
	}

	/**
	* 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);
	}

	/**
	* Returns a classpath container path identifying the selected JRE.
	*
	* @return classpath container path or <code>null</code>
	* @since 3.2
	*/
	public IPath getPath() {
	if (!getStatus().isOK() && fErrorPath != null) {
	return fErrorPath;
	}
	if (fEnvironmentsButton.getSelection()) {
	int index = fEnvironmentsCombo.getSelectionIndex();
	if (index >= 0) {
	IExecutionEnvironment env = (IExecutionEnvironment) fEnvironments.get(index);
	return JavaRuntime.newJREContainerPath(env);
	}
	return null;
	}
	if (fSpecificButton.getSelection()) {
	int index = fCombo.getSelectionIndex();
	if (index >= 0) {
	IVMInstall vm = (IVMInstall) fVMs.get(index);
	return JavaRuntime.newJREContainerPath(vm);
	}
	return null;
	}
	return JavaRuntime.newDefaultJREContainerPath();
	}

	/**
	* Sets the selection based on the given container path and returns
	* a status indicating if the selection was successful.
	*
	* @param containerPath
	* @return status
	*/
	public void setPath(IPath containerPath) {
	fErrorPath = null;
	setStatus(OK_STATUS);
	if (JavaRuntime.newDefaultJREContainerPath().equals(containerPath)) {
	setUseDefaultJRE();
	} else {
	String envId = JavaRuntime.getExecutionEnvironmentId(containerPath);
	if (envId != null) {
	IExecutionEnvironmentsManager manager = JavaRuntime.getExecutionEnvironmentsManager();
	IExecutionEnvironment environment = manager.getEnvironment(envId);
	if (environment == null) {
	fErrorPath = containerPath;
	selectEnvironment(environment);
	setError(NLS.bind(JREMessages.JREsComboBlock_6, new String[]{envId}));
	} else {
	selectEnvironment(environment);
	IVMInstall[] installs = environment.getCompatibleVMs();
	if (installs.length == 0) {
	setError(NLS.bind(JREMessages.JREsComboBlock_7, new String[]{environment.getId()}));
	}
	}
	} else {
	IVMInstall install = JavaRuntime.getVMInstall(containerPath);
	if (install == null) {
	selectJRE(install);
	fErrorPath = containerPath;
	String installTypeId = JavaRuntime.getVMInstallTypeId(containerPath);
	if (installTypeId == null) {
	setError(JREMessages.JREsComboBlock_8);
	} else {
	IVMInstallType installType = JavaRuntime.getVMInstallType(installTypeId);
	if (installType == null) {
	setError(NLS.bind(JREMessages.JREsComboBlock_9, new String[]{installTypeId}));
	} else {
	String installName = JavaRuntime.getVMInstallName(containerPath);
	if (installName == null) {
	setError(NLS.bind(JREMessages.JREsComboBlock_10, new String[]{installType.getName()}));
	} else {
	setError(NLS.bind(JREMessages.JREsComboBlock_11, new String[]{installName, installType.getName()}));
	}
	}
	}
	} else {
	selectJRE(install);
	File location = install.getInstallLocation();
	if (location == null) {
	setError(JREMessages.JREsComboBlock_12);
	} else if (!location.exists()) {
	setError(JREMessages.JREsComboBlock_13);
	}
	}
	}
	}
	}

	private void setError(String message) {
	setStatus(new Status(IStatus.ERROR, JDIDebugUIPlugin.getUniqueIdentifier(),
	IJavaDebugUIConstants.INTERNAL_ERROR, message, null));
	}

	/**
	* Returns the status of the JRE selection.
	*
	* @return status
	*/
	public IStatus getStatus() {
	return fStatus;
	}

	private void setStatus(IStatus status) {
	fStatus = status;
	}
	}