bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/ContentProposalPopup.java - platform/eclipse.platform.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2005 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.jface.fieldassist;

 import java.util.ArrayList;

 import org.eclipse.core.runtime.Assert;
 import org.eclipse.jface.dialogs.Dialog;
 import org.eclipse.jface.dialogs.PopupDialog;
 import org.eclipse.jface.viewers.ILabelProvider;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.events.DisposeEvent;
 import org.eclipse.swt.events.DisposeListener;
 import org.eclipse.swt.events.FocusAdapter;
 import org.eclipse.swt.events.FocusEvent;
 import org.eclipse.swt.events.SelectionEvent;
 import org.eclipse.swt.events.SelectionListener;
 import org.eclipse.swt.graphics.FontMetrics;
 import org.eclipse.swt.graphics.GC;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.graphics.Rectangle;
 import org.eclipse.swt.layout.GridData;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
 import org.eclipse.swt.widgets.Event;
 import org.eclipse.swt.widgets.Listener;
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.swt.widgets.Table;
 import org.eclipse.swt.widgets.TableItem;
 import org.eclipse.swt.widgets.Text;

 /**
  * A lightweight popup used to show content proposals for a text field. If
  * additional information exists for a proposal, then selecting that proposal
  * will result in the information being displayed in a secondary popup.
  *
  * <p>
  * This API is considered experimental. It is still evolving during 3.2 and is
  * subject to change. It is being released to obtain feedback from early
  * adopters. For now, there is limited API to control how the popup is sized or
  * placed relative to the control, or whether it is resizable. The intention is
  * that standard techniques will be implemented to "do the right thing"
  * depending on the associated control's size/location and the content size, and
  * API added if we discover there are additional choices to be made.
  *
  * @since 3.2
  */
 public class ContentProposalPopup extends PopupDialog {

 	/*
 	 * Set to <code>true</code> to use a Table with SWT.VIRTUAL. This is a
 	 * workaround for https://bugs.eclipse.org/bugs/show_bug.cgi?id=98585#c40
 	 * The corresponding SWT bug is
 	 * https://bugs.eclipse.org/bugs/show_bug.cgi?id=90321
 	 */
 	private static final boolean USE_VIRTUAL = !"motif".equals(SWT.getPlatform()); //$NON-NLS-1$

 	/*
 	 * The delay before showing a secondary popup.
 	 */
 	private static final int POPUP_DELAY = 500;

 	/*
 	 * The character height hint for the popup.
 	 */
 	private static final int POPUP_CHARHEIGHT = 10;

 	/*
 	 * Empty string.
 	 */
 	private static final String EMPTY = ""; //$NON-NLS-1$

 	/*
 	 * The listener we will install on the target control.
 	 */
 	private final class TargetControlListener implements Listener {
 		// Key events from the control
 		public void handleEvent(Event e) {
 			if (!isValid())
 				return;

 			if (!(e.type == SWT.KeyDown || e.type == SWT.Traverse))
 				return;

 			// Traverse events will be blocked when the popup is open, but
 			// we will interpret their characters as navigation within the
 			// popup.
 			if (e.type == SWT.Traverse) {
 				e.detail = SWT.TRAVERSE_NONE;
 				e.doit = true;
 			}

 			char key = e.character;

 			// No character. Check for navigation keys.

 			if (key == 0) {
 				int newSelection = proposalTable.getSelectionIndex();
 				int visibleRows = (proposalTable.getSize().y / proposalTable
 						.getItemHeight()) - 1;
 				switch (e.keyCode) {
 				case SWT.ARROW_UP:
 					newSelection -= 1;
 					if (newSelection < 0)
 						newSelection = proposalTable.getItemCount() - 1;
 					break;

 				case SWT.ARROW_DOWN:
 					newSelection += 1;
 					if (newSelection > proposalTable.getItemCount() - 1)
 						newSelection = 0;
 					break;

 				case SWT.PAGE_DOWN:
 					newSelection += visibleRows;
 					if (newSelection >= proposalTable.getItemCount())
 						newSelection = proposalTable.getItemCount() - 1;
 					break;

 				case SWT.PAGE_UP:
 					newSelection -= visibleRows;
 					if (newSelection < 0)
 						newSelection = 0;
 					break;

 				case SWT.HOME:
 					newSelection = 0;
 					break;

 				case SWT.END:
 					newSelection = proposalTable.getItemCount() - 1;
 					break;

 				// Any unknown keycodes will cause the popup to close.
 				// Modifier keys are explicitly checked and ignored because
 				// they are not complete yet (no character).
 				default:
 					if (e.keyCode != SWT.CAPS_LOCK && e.keyCode != SWT.MOD1
 							&& e.keyCode != SWT.MOD2 && e.keyCode != SWT.MOD3
 							&& e.keyCode != SWT.MOD4)
 						close();
 					return;
 				}

 				// If any of these navigation events caused a new selection,
 				// then handle that now and return.
 				if (newSelection >= 0)
 					selectProposal(newSelection);
 				return;
 			}

 			// key != 0
 			// Check for special keys involved in cancelling, accepting, or
 			// filtering the proposals.
 			switch (key) {
 			case SWT.ESC: // Esc
 				e.doit = false;
 				close();
 				break;

 			case SWT.LF:
 			case SWT.CR:
 				e.doit = false;
 				Object p = getSelectedProposal();
 				if (p != null)
 					acceptCurrentProposal();
 				close();
 				break;

 			case SWT.TAB:
 				e.doit = false;
 				getShell().setFocus();
 				return;

 			case SWT.BS:
 				// Backspace should back out of any stored filter text
 				if (filter) {
 					filterText = filterText.substring(0,
 							filterText.length() - 1);
 					recomputeProposals(filterText);
 					return;
 				}

 			default:
 				// If the key is a defined unicode character, and not one of the
 				// special cases processed above, update the filter text and
 				// filter the proposals.
 				if (filter && Character.isDefined(key)) {
 					filterText = filterText + String.valueOf(key);
 					recomputeProposals(filterText);
 				}
 				break;
 			}
 		}
 	}

 	/*
 	 * Internal class used to implement the secondary popup.
 	 */
 	private class InfoPopupDialog extends PopupDialog {

 		/*
 		 * The text control that displays the text.
 		 */
 		private Text text;

 		/*
 		 * The String shown in the popup.
 		 */
 		private String contents = EMPTY;

 		/*
 		 * Construct an info-popup with the specified parent.
 		 */
 		InfoPopupDialog(Shell parent) {
 			super(parent, PopupDialog.HOVER_SHELLSTYLE, false, false, false,
 					false, null, null);
 		}

 		/*
 		 * Create a text control for showing the info about a proposal.
 		 */
 		protected Control createDialogArea(Composite parent) {
 			text = new Text(parent, SWT.MULTI | SWT.READ_ONLY | SWT.WRAP
 					| SWT.NO_FOCUS);

 			// Use the compact margins employed by PopupDialog.
 			GridData gd = new GridData(GridData.BEGINNING | GridData.FILL_BOTH);
 			gd.horizontalIndent = PopupDialog.POPUP_HORIZONTALSPACING;
 			gd.verticalIndent = PopupDialog.POPUP_VERTICALSPACING;
 			text.setLayoutData(gd);
 			text.setText(contents);

 			// since SWT.NO_FOCUS is only a hint...
 			text.addFocusListener(new FocusAdapter() {
 				public void focusGained(FocusEvent event) {
 					ContentProposalPopup.this.close();
 				}
 			});
 			return text;
 		}

 		/*
 		 * Adjust the bounds so that we appear adjacent to our parent shell
 		 */
 		protected void adjustBounds() {
 			Rectangle parentBounds = getParentShell().getBounds();
 			getShell().setBounds(
 					new Rectangle(parentBounds.x + parentBounds.width
 							+ PopupDialog.POPUP_HORIZONTALSPACING,
 							parentBounds.y + PopupDialog.POPUP_VERTICALSPACING,
 							parentBounds.width, parentBounds.height));

 		}

 		/*
 		 * Set the text contents of the popup.
 		 */
 		void setContents(String newContents) {
 			if (newContents == null)
 				newContents = EMPTY;
 			this.contents = newContents;
 			if (text != null && !text.isDisposed()) {
 				text.setText(contents);
 			}
 		}
 	}

 	/*
 	 * The adapter on the target control.
 	 */
 	private ContentProposalAdapter adapter;

 	/*
 	 * The listener installed on the target control.
 	 */
 	private Listener controlListener;

 	/*
 	 * The control on which we are proposing content.
 	 */
 	private Control control;

 	/*
 	 * The table used to show the list of proposals.
 	 */
 	private Table proposalTable;

 	/*
 	 * The provider of proposals and proposal descriptions
 	 */
 	private IContentProposalProvider proposalProvider;

 	/*
 	 * The proposals to be shown (cached to avoid repeated requests).
 	 */
 	private IContentProposal[] proposals;

 	/*
 	 * A label provider used to show the proposals in the table.
 	 */
 	private ILabelProvider labelProvider;

 	/*
 	 * Secondary popup used to show detailed information about the selected
 	 * proposal..
 	 */
 	private InfoPopupDialog infoPopup;

 	/*
 	 * Filter text - tracked while popup is open, only if we are told to filter
 	 */
 	private String filterText = EMPTY;

 	/*
 	 * Boolean that indicates whether we are filtering.
 	 */
 	private boolean filter = false;

 	/**
 	 * Constructs a new instance of this popup, specifying the control for which
 	 * this popup is showing content, and how the proposals should be obtained
 	 * and displayed.
 	 *
 	 * @param adapter
 	 *            the content proposal adapter that opened this dialog.
 	 * @param control
 	 *            the control whose content is being proposed.
 	 * @param proposalProvider
 	 *            the provider of content proposals
 	 * @param infoText
 	 *            Text to be shown in a lower info area, or <code>null</code>
 	 *            if there is no info area.
 	 * @param labelProvider
 	 *            the {@link ILabelProvider} used to obtain visual content for
 	 *            the proposals. Must never be <code>null</code>.
 	 * @param filter
 	 *            a boolean indicating whether proposals should be filtered as
 	 *            keys are typed in the popup.
 	 */
 	public ContentProposalPopup(ContentProposalAdapter adapter,
 			Control control, IContentProposalProvider proposalProvider,
 			String infoText, ILabelProvider labelProvider, boolean filter) {
 		super(control.getShell(), PopupDialog.INFOPOPUPRESIZE_SHELLSTYLE,
 				false, false, false, false, null, infoText);
 		this.adapter = adapter;
 		this.control = control;
 		this.labelProvider = labelProvider;
 		this.proposalProvider = proposalProvider;
 		this.proposals = getProposals(filterText);
 		this.filter = filter;
 	}

 	/*
 	 * Creates the content area for the proposal popup. This creates a table and
 	 * places it inside the composite. The table will contain a list of all the
 	 * proposals.
 	 *
 	 * @param parent The parent composite to contain the dialog area; must not
 	 * be <code>null</code>.
 	 */
 	protected final Control createDialogArea(final Composite parent) {
 		// Use virtual where appropriate (see flag definition).
 		if (USE_VIRTUAL) {
 			proposalTable = new Table(parent, SWT.H_SCROLL | SWT.V_SCROLL
 					| SWT.VIRTUAL);

 			Listener listener = new Listener() {
 				public void handleEvent(Event event) {
 					handleSetData(event);
 				}
 			};
 			proposalTable.addListener(SWT.SetData, listener);
 		} else {
 			proposalTable = new Table(parent, SWT.H_SCROLL | SWT.V_SCROLL);
 		}

 		// compute the proposals to force population of the table.
 		recomputeProposals(filterText);

 		proposalTable.setHeaderVisible(false);
 		proposalTable.addSelectionListener(new SelectionListener() {

 			public void widgetSelected(SelectionEvent e) {
 				// If a proposal has been selected, show it in the popup.
 				// Otherwise close the popup.
 				if (e.item == null) {
 					if (infoPopup != null)
 						infoPopup.close();
 				} else {
 					TableItem item = (TableItem) e.item;
 					IContentProposal proposal = (IContentProposal) item
 							.getData();
 					showProposalDescription(proposal.getDescription());
 				}
 			}

 			// Default selection was made. Accept the current proposal.
 			public void widgetDefaultSelected(SelectionEvent e) {
 				acceptCurrentProposal();
 			}
 		});

 		// Compute a height and width for the table.
 		GridData data = new GridData(GridData.FILL_BOTH);
 		GC gc = new GC(proposalTable);
 		gc.setFont(proposalTable.getFont());
 		FontMetrics fontMetrics = gc.getFontMetrics();
 		gc.dispose();
 		data.widthHint = control.getBounds().width;
 		data.heightHint = Dialog.convertHeightInCharsToPixels(fontMetrics,
 				POPUP_CHARHEIGHT);
 		proposalTable.setLayoutData(data);
 		return proposalTable;
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.jface.dialogs.PopupDialog.adjustBounds()
 	 */
 	protected void adjustBounds() {
 		// Get our control's location in display coordinates.
 		Point location = control.getDisplay().map(control.getParent(), null,
 				control.getLocation());
 		getShell().setLocation(location.x + 3,
 				location.y + control.getSize().y + 3);
 	}

 	/*
 	 * Handle the set data event. Set the item data of the requested item to the
 	 * corresponding proposal in the proposal cache.
 	 */
 	private void handleSetData(Event event) {
 		TableItem item = (TableItem) event.item;
 		int index = proposalTable.indexOf(item);

 		if (0 <= index && index < proposals.length) {
 			IContentProposal current = proposals[index];
 			item.setText(getString(current));
 			item.setImage(getImage(current));
 			item.setData(current);
 		} else {
 			// this should not happen, but does on win32
 		}
 	}

 	/*
 	 * Caches the specified proposals and repopulates the table if it has been
 	 * created.
 	 */
 	private void setProposals(IContentProposal[] newProposals) {
 		if (newProposals == null || newProposals.length == 0) {
 			newProposals = getEmptyProposalArray();
 		}
 		this.proposals = newProposals;

 		// If there is a table
 		if (isValid()) {
 			final int newSize = newProposals.length;
 			if (USE_VIRTUAL) {
 				// Set and clear the virtual table. Data will be
 				// provided in the SWT.SetData event handler.
 				proposalTable.setItemCount(newSize);
 				proposalTable.clearAll();
 			} else {
 				// Populate the table manually
 				proposalTable.setRedraw(false);
 				proposalTable.setItemCount(newSize);
 				TableItem[] items = proposalTable.getItems();
 				for (int i = 0; i < items.length; i++) {
 					TableItem item = items[i];
 					IContentProposal proposal = newProposals[i];
 					item.setText(getString(proposal));
 					item.setImage(getImage(proposal));
 					item.setData(proposal);
 				}
 				proposalTable.setRedraw(true);
 			}
 			// Default to the first selection if there is content.
 			if (newProposals.length > 0) {
 				selectProposal(0);
 			} else {
 				// No selection, close the secondary popup if it was open
 				if (infoPopup != null)
 					infoPopup.close();

 			}
 		}
 	}

 	/*
 	 * Get the string for the specified proposal. Always return a String of some
 	 * kind.
 	 */
 	private String getString(IContentProposal proposal) {
 		if (proposal == null)
 			return EMPTY;
 		if (labelProvider == null)
 			return proposal.getLabel() == null ? proposal.getContent()
 					: proposal.getLabel();
 		return labelProvider.getText(proposal);
 	}

 	/*
 	 * Get the image for the specified proposal. If there is no image available,
 	 * return null.
 	 */
 	private Image getImage(IContentProposal proposal) {
 		if (proposal == null || labelProvider == null)
 			return null;
 		return labelProvider.getImage(proposal);
 	}

 	/*
 	 * Return an empty array. Used so that something always shows in the
 	 * proposal popup, even if no proposal provider was specified.
 	 */
 	private IContentProposal[] getEmptyProposalArray() {
 		return new IContentProposal[0];
 	}

 	/*
 	 * Add a listener to the target control. We monitor key and traverse events
 	 * in the target control while we are open, in order to handle traversal and
 	 * navigation requests.
 	 */
 	private void addControlListener() {
 		controlListener = new TargetControlListener();
 		control.addListener(SWT.KeyDown, controlListener);
 		control.addListener(SWT.Traverse, controlListener);
 	}

 	/*
 	 * Remove any listeners installed on the control.
 	 */
 	private void removeControlListener() {
 		control.removeListener(SWT.KeyDown, controlListener);
 		control.removeListener(SWT.Traverse, controlListener);
 	}

 	/*
 	 * Answer true if the popup is valid, which means the table has been created
 	 * and not disposed.
 	 */
 	private boolean isValid() {
 		return proposalTable != null && !proposalTable.isDisposed();
 	}

 	/*
 	 * Return the current selected proposal.
 	 */
 	private IContentProposal getSelectedProposal() {
 		if (isValid()) {
 			int i = proposalTable.getSelectionIndex();
 			if (proposals == null || i < 0 || i >= proposals.length)
 				return null;
 			return proposals[i];
 		}
 		return null;
 	}

 	/*
 	 * Select the proposal at the given index.
 	 */
 	private void selectProposal(int index) {
 		Assert.isTrue(index >= 0, "Proposal index should never be negative"); //$NON-NLS-1$
 		if (!isValid() || proposals == null || index >= proposals.length)
 			return;
 		proposalTable.setSelection(index);
 		proposalTable.showSelection();

 		showProposalDescription(proposals[index].getDescription());
 	}

 	/**
 	 * Opens this ContentProposalPopup. This method is extended in order to add
 	 * the control listener when the popup is opened and to invoke the secondary
 	 * popup if applicable.
 	 *
 	 * @return the return code
 	 *
 	 * @see org.eclipse.jface.window.Window#open()
 	 */
 	public int open() {
 		addControlListener();
 		int value = super.open();
 		showProposalDescription(getSelectedProposal().getDescription());
 		return value;
 	}

 	/**
 	 * Closes this popup. This method is extended to remove the control
 	 * listener.
 	 *
 	 * @return <code>true</code> if the window is (or was already) closed, and
 	 *         <code>false</code> if it is still open
 	 */
 	public boolean close() {
 		removeControlListener();
 		return super.close();
 	}

 	/*
 	 * Get the proposals from the proposal provider. The provider may or may not
 	 * filter the proposals based on the specified filter text.
 	 */
 	private IContentProposal[] getProposals(String filterString) {
 		if (proposalProvider == null)
 			return null;
 		int position = adapter.getControlContentAdapter().getCursorPosition(
 				adapter.getControl());
 		String contents = adapter.getControlContentAdapter()
 				.getControlContents(adapter.getControl());
 		IContentProposal[] proposals = proposalProvider.getProposals(contents,
 				position);
 		if (filter) {
 			return filterProposals(proposals, filterString);
 		}
 		return proposals;
 	}

 	/*
 	 * Show the proposal description in a secondary popup.
 	 */
 	private void showProposalDescription(String description) {
 		// If we have not created an info popup yet, do so now.
 		if (infoPopup == null && description != null) {
 			// Create a thread that will sleep for the specified delay
 			// before creating the popup. We do not use Jobs since this
 			// code must be able to run independently of the Eclipse runtime.
 			Runnable runnable = new Runnable() {
 				public void run() {
 					try {
 						Thread.sleep(POPUP_DELAY);
 					} catch (InterruptedException e) {
 					}
 					if (!isValid())
 						return;
 					getShell().getDisplay().syncExec(new Runnable() {
 						public void run() {
 							// The selection may have changed by the time we
 							// open, so double check it.
 							IContentProposal p = getSelectedProposal();
 							if (p != null) {
 								if (infoPopup == null) {
 									infoPopup = new InfoPopupDialog(getShell());
 									infoPopup.open();
 								}
 								infoPopup.setContents(p.getDescription());
 								infoPopup.getShell().addDisposeListener(
 										new DisposeListener() {
 											public void widgetDisposed(
 													DisposeEvent event) {
 												infoPopup = null;
 											}
 										});
 							}
 						}
 					});
 				}
 			};
 			Thread t = new Thread(runnable);
 			t.start();
 		} else if (infoPopup != null) {
 			// We already have a popup, so just reset the contents.
 			infoPopup.setContents(description);
 		}
 	}

 	/*
 	 * Accept the current proposal.
 	 */
 	private void acceptCurrentProposal() {
 		adapter.proposalAccepted(getSelectedProposal());
 		close();
 	}

 	/*
 	 * Request the proposals from the proposal provider, and recompute any
 	 * caches. Repopulate the popup if it is open.
 	 */
 	private void recomputeProposals(String filterText) {
 		setProposals(getProposals(filterText));
 	}

 	/*
 	 * Filter the provided list of content proposals according to the filter
 	 * text.
 	 */
 	private IContentProposal[] filterProposals(IContentProposal[] proposals,
 			String filterString) {
 		if (filterString.length() == 0)
 			return proposals;

 		// Check each string for a match. Use the string displayed to the user,
 		// not the proposal content.
 		ArrayList list = new ArrayList();
 		for (int i = 0; i < proposals.length; i++) {
 			String string = getString(proposals[i]);
 			if (string.length() >= filterString.length()
 					&& string.substring(0, filterString.length())
 							.equalsIgnoreCase(filterString))
 				list.add(proposals[i]);

 		}
 		return (IContentProposal[]) list.toArray(new IContentProposal[list
 				.size()]);
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2005 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.jface.fieldassist;

	import java.util.ArrayList;

	import org.eclipse.core.runtime.Assert;
	import org.eclipse.jface.dialogs.Dialog;
	import org.eclipse.jface.dialogs.PopupDialog;
	import org.eclipse.jface.viewers.ILabelProvider;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.events.DisposeEvent;
	import org.eclipse.swt.events.DisposeListener;
	import org.eclipse.swt.events.FocusAdapter;
	import org.eclipse.swt.events.FocusEvent;
	import org.eclipse.swt.events.SelectionEvent;
	import org.eclipse.swt.events.SelectionListener;
	import org.eclipse.swt.graphics.FontMetrics;
	import org.eclipse.swt.graphics.GC;
	import org.eclipse.swt.graphics.Image;
	import org.eclipse.swt.graphics.Point;
	import org.eclipse.swt.graphics.Rectangle;
	import org.eclipse.swt.layout.GridData;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Control;
	import org.eclipse.swt.widgets.Event;
	import org.eclipse.swt.widgets.Listener;
	import org.eclipse.swt.widgets.Shell;
	import org.eclipse.swt.widgets.Table;
	import org.eclipse.swt.widgets.TableItem;
	import org.eclipse.swt.widgets.Text;

	/**
	* A lightweight popup used to show content proposals for a text field. If
	* additional information exists for a proposal, then selecting that proposal
	* will result in the information being displayed in a secondary popup.
	*
	* <p>
	* This API is considered experimental. It is still evolving during 3.2 and is
	* subject to change. It is being released to obtain feedback from early
	* adopters. For now, there is limited API to control how the popup is sized or
	* placed relative to the control, or whether it is resizable. The intention is
	* that standard techniques will be implemented to "do the right thing"
	* depending on the associated control's size/location and the content size, and
	* API added if we discover there are additional choices to be made.
	*
	* @since 3.2
	*/
	public class ContentProposalPopup extends PopupDialog {

	/*
	* Set to <code>true</code> to use a Table with SWT.VIRTUAL. This is a
	* workaround for https://bugs.eclipse.org/bugs/show_bug.cgi?id=98585#c40
	* The corresponding SWT bug is
	* https://bugs.eclipse.org/bugs/show_bug.cgi?id=90321
	*/
	private static final boolean USE_VIRTUAL = !"motif".equals(SWT.getPlatform()); //$NON-NLS-1$

	/*
	* The delay before showing a secondary popup.
	*/
	private static final int POPUP_DELAY = 500;

	/*
	* The character height hint for the popup.
	*/
	private static final int POPUP_CHARHEIGHT = 10;

	/*
	* Empty string.
	*/
	private static final String EMPTY = ""; //$NON-NLS-1$

	/*
	* The listener we will install on the target control.
	*/
	private final class TargetControlListener implements Listener {
	// Key events from the control
	public void handleEvent(Event e) {
	if (!isValid())
	return;

	if (!(e.type == SWT.KeyDown \|\| e.type == SWT.Traverse))
	return;

	// Traverse events will be blocked when the popup is open, but
	// we will interpret their characters as navigation within the
	// popup.
	if (e.type == SWT.Traverse) {
	e.detail = SWT.TRAVERSE_NONE;
	e.doit = true;
	}

	char key = e.character;

	// No character. Check for navigation keys.

	if (key == 0) {
	int newSelection = proposalTable.getSelectionIndex();
	int visibleRows = (proposalTable.getSize().y / proposalTable
	.getItemHeight()) - 1;
	switch (e.keyCode) {
	case SWT.ARROW_UP:
	newSelection -= 1;
	if (newSelection < 0)
	newSelection = proposalTable.getItemCount() - 1;
	break;

	case SWT.ARROW_DOWN:
	newSelection += 1;
	if (newSelection > proposalTable.getItemCount() - 1)
	newSelection = 0;
	break;

	case SWT.PAGE_DOWN:
	newSelection += visibleRows;
	if (newSelection >= proposalTable.getItemCount())
	newSelection = proposalTable.getItemCount() - 1;
	break;

	case SWT.PAGE_UP:
	newSelection -= visibleRows;
	if (newSelection < 0)
	newSelection = 0;
	break;

	case SWT.HOME:
	newSelection = 0;
	break;

	case SWT.END:
	newSelection = proposalTable.getItemCount() - 1;
	break;

	// Any unknown keycodes will cause the popup to close.
	// Modifier keys are explicitly checked and ignored because
	// they are not complete yet (no character).
	default:
	if (e.keyCode != SWT.CAPS_LOCK && e.keyCode != SWT.MOD1
	&& e.keyCode != SWT.MOD2 && e.keyCode != SWT.MOD3
	&& e.keyCode != SWT.MOD4)
	close();
	return;
	}

	// If any of these navigation events caused a new selection,
	// then handle that now and return.
	if (newSelection >= 0)
	selectProposal(newSelection);
	return;
	}

	// key != 0
	// Check for special keys involved in cancelling, accepting, or
	// filtering the proposals.
	switch (key) {
	case SWT.ESC: // Esc
	e.doit = false;
	close();
	break;

	case SWT.LF:
	case SWT.CR:
	e.doit = false;
	Object p = getSelectedProposal();
	if (p != null)
	acceptCurrentProposal();
	close();
	break;

	case SWT.TAB:
	e.doit = false;
	getShell().setFocus();
	return;

	case SWT.BS:
	// Backspace should back out of any stored filter text
	if (filter) {
	filterText = filterText.substring(0,
	filterText.length() - 1);
	recomputeProposals(filterText);
	return;
	}

	default:
	// If the key is a defined unicode character, and not one of the
	// special cases processed above, update the filter text and
	// filter the proposals.
	if (filter && Character.isDefined(key)) {
	filterText = filterText + String.valueOf(key);
	recomputeProposals(filterText);
	}
	break;
	}
	}
	}

	/*
	* Internal class used to implement the secondary popup.
	*/
	private class InfoPopupDialog extends PopupDialog {

	/*
	* The text control that displays the text.
	*/
	private Text text;

	/*
	* The String shown in the popup.
	*/
	private String contents = EMPTY;

	/*
	* Construct an info-popup with the specified parent.
	*/
	InfoPopupDialog(Shell parent) {
	super(parent, PopupDialog.HOVER_SHELLSTYLE, false, false, false,
	false, null, null);
	}

	/*
	* Create a text control for showing the info about a proposal.
	*/
	protected Control createDialogArea(Composite parent) {
	text = new Text(parent, SWT.MULTI \| SWT.READ_ONLY \| SWT.WRAP
	\| SWT.NO_FOCUS);

	// Use the compact margins employed by PopupDialog.
	GridData gd = new GridData(GridData.BEGINNING \| GridData.FILL_BOTH);
	gd.horizontalIndent = PopupDialog.POPUP_HORIZONTALSPACING;
	gd.verticalIndent = PopupDialog.POPUP_VERTICALSPACING;
	text.setLayoutData(gd);
	text.setText(contents);

	// since SWT.NO_FOCUS is only a hint...
	text.addFocusListener(new FocusAdapter() {
	public void focusGained(FocusEvent event) {
	ContentProposalPopup.this.close();
	}
	});
	return text;
	}

	/*
	* Adjust the bounds so that we appear adjacent to our parent shell
	*/
	protected void adjustBounds() {
	Rectangle parentBounds = getParentShell().getBounds();
	getShell().setBounds(
	new Rectangle(parentBounds.x + parentBounds.width
	+ PopupDialog.POPUP_HORIZONTALSPACING,
	parentBounds.y + PopupDialog.POPUP_VERTICALSPACING,
	parentBounds.width, parentBounds.height));

	}

	/*
	* Set the text contents of the popup.
	*/
	void setContents(String newContents) {
	if (newContents == null)
	newContents = EMPTY;
	this.contents = newContents;
	if (text != null && !text.isDisposed()) {
	text.setText(contents);
	}
	}
	}

	/*
	* The adapter on the target control.
	*/
	private ContentProposalAdapter adapter;

	/*
	* The listener installed on the target control.
	*/
	private Listener controlListener;

	/*
	* The control on which we are proposing content.
	*/
	private Control control;

	/*
	* The table used to show the list of proposals.
	*/
	private Table proposalTable;

	/*
	* The provider of proposals and proposal descriptions
	*/
	private IContentProposalProvider proposalProvider;

	/*
	* The proposals to be shown (cached to avoid repeated requests).
	*/
	private IContentProposal[] proposals;

	/*
	* A label provider used to show the proposals in the table.
	*/
	private ILabelProvider labelProvider;

	/*
	* Secondary popup used to show detailed information about the selected
	* proposal..
	*/
	private InfoPopupDialog infoPopup;

	/*
	* Filter text - tracked while popup is open, only if we are told to filter
	*/
	private String filterText = EMPTY;

	/*
	* Boolean that indicates whether we are filtering.
	*/
	private boolean filter = false;

	/**
	* Constructs a new instance of this popup, specifying the control for which
	* this popup is showing content, and how the proposals should be obtained
	* and displayed.
	*
	* @param adapter
	* the content proposal adapter that opened this dialog.
	* @param control
	* the control whose content is being proposed.
	* @param proposalProvider
	* the provider of content proposals
	* @param infoText
	* Text to be shown in a lower info area, or <code>null</code>
	* if there is no info area.
	* @param labelProvider
	* the {@link ILabelProvider} used to obtain visual content for
	* the proposals. Must never be <code>null</code>.
	* @param filter
	* a boolean indicating whether proposals should be filtered as
	* keys are typed in the popup.
	*/
	public ContentProposalPopup(ContentProposalAdapter adapter,
	Control control, IContentProposalProvider proposalProvider,
	String infoText, ILabelProvider labelProvider, boolean filter) {
	super(control.getShell(), PopupDialog.INFOPOPUPRESIZE_SHELLSTYLE,
	false, false, false, false, null, infoText);
	this.adapter = adapter;
	this.control = control;
	this.labelProvider = labelProvider;
	this.proposalProvider = proposalProvider;
	this.proposals = getProposals(filterText);
	this.filter = filter;
	}

	/*
	* Creates the content area for the proposal popup. This creates a table and
	* places it inside the composite. The table will contain a list of all the
	* proposals.
	*
	* @param parent The parent composite to contain the dialog area; must not
	* be <code>null</code>.
	*/
	protected final Control createDialogArea(final Composite parent) {
	// Use virtual where appropriate (see flag definition).
	if (USE_VIRTUAL) {
	proposalTable = new Table(parent, SWT.H_SCROLL \| SWT.V_SCROLL
	\| SWT.VIRTUAL);

	Listener listener = new Listener() {
	public void handleEvent(Event event) {
	handleSetData(event);
	}
	};
	proposalTable.addListener(SWT.SetData, listener);
	} else {
	proposalTable = new Table(parent, SWT.H_SCROLL \| SWT.V_SCROLL);
	}

	// compute the proposals to force population of the table.
	recomputeProposals(filterText);

	proposalTable.setHeaderVisible(false);
	proposalTable.addSelectionListener(new SelectionListener() {

	public void widgetSelected(SelectionEvent e) {
	// If a proposal has been selected, show it in the popup.
	// Otherwise close the popup.
	if (e.item == null) {
	if (infoPopup != null)
	infoPopup.close();
	} else {
	TableItem item = (TableItem) e.item;
	IContentProposal proposal = (IContentProposal) item
	.getData();
	showProposalDescription(proposal.getDescription());
	}
	}

	// Default selection was made. Accept the current proposal.
	public void widgetDefaultSelected(SelectionEvent e) {
	acceptCurrentProposal();
	}
	});

	// Compute a height and width for the table.
	GridData data = new GridData(GridData.FILL_BOTH);
	GC gc = new GC(proposalTable);
	gc.setFont(proposalTable.getFont());
	FontMetrics fontMetrics = gc.getFontMetrics();
	gc.dispose();
	data.widthHint = control.getBounds().width;
	data.heightHint = Dialog.convertHeightInCharsToPixels(fontMetrics,
	POPUP_CHARHEIGHT);
	proposalTable.setLayoutData(data);
	return proposalTable;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.jface.dialogs.PopupDialog.adjustBounds()
	*/
	protected void adjustBounds() {
	// Get our control's location in display coordinates.
	Point location = control.getDisplay().map(control.getParent(), null,
	control.getLocation());
	getShell().setLocation(location.x + 3,
	location.y + control.getSize().y + 3);
	}

	/*
	* Handle the set data event. Set the item data of the requested item to the
	* corresponding proposal in the proposal cache.
	*/
	private void handleSetData(Event event) {
	TableItem item = (TableItem) event.item;
	int index = proposalTable.indexOf(item);

	if (0 <= index && index < proposals.length) {
	IContentProposal current = proposals[index];
	item.setText(getString(current));
	item.setImage(getImage(current));
	item.setData(current);
	} else {
	// this should not happen, but does on win32
	}
	}

	/*
	* Caches the specified proposals and repopulates the table if it has been
	* created.
	*/
	private void setProposals(IContentProposal[] newProposals) {
	if (newProposals == null \|\| newProposals.length == 0) {
	newProposals = getEmptyProposalArray();
	}
	this.proposals = newProposals;

	// If there is a table
	if (isValid()) {
	final int newSize = newProposals.length;
	if (USE_VIRTUAL) {
	// Set and clear the virtual table. Data will be
	// provided in the SWT.SetData event handler.
	proposalTable.setItemCount(newSize);
	proposalTable.clearAll();
	} else {
	// Populate the table manually
	proposalTable.setRedraw(false);
	proposalTable.setItemCount(newSize);
	TableItem[] items = proposalTable.getItems();
	for (int i = 0; i < items.length; i++) {
	TableItem item = items[i];
	IContentProposal proposal = newProposals[i];
	item.setText(getString(proposal));
	item.setImage(getImage(proposal));
	item.setData(proposal);
	}
	proposalTable.setRedraw(true);
	}
	// Default to the first selection if there is content.
	if (newProposals.length > 0) {
	selectProposal(0);
	} else {
	// No selection, close the secondary popup if it was open
	if (infoPopup != null)
	infoPopup.close();

	}
	}
	}

	/*
	* Get the string for the specified proposal. Always return a String of some
	* kind.
	*/
	private String getString(IContentProposal proposal) {
	if (proposal == null)
	return EMPTY;
	if (labelProvider == null)
	return proposal.getLabel() == null ? proposal.getContent()
	: proposal.getLabel();
	return labelProvider.getText(proposal);
	}

	/*
	* Get the image for the specified proposal. If there is no image available,
	* return null.
	*/
	private Image getImage(IContentProposal proposal) {
	if (proposal == null \|\| labelProvider == null)
	return null;
	return labelProvider.getImage(proposal);
	}

	/*
	* Return an empty array. Used so that something always shows in the
	* proposal popup, even if no proposal provider was specified.
	*/
	private IContentProposal[] getEmptyProposalArray() {
	return new IContentProposal[0];
	}

	/*
	* Add a listener to the target control. We monitor key and traverse events
	* in the target control while we are open, in order to handle traversal and
	* navigation requests.
	*/
	private void addControlListener() {
	controlListener = new TargetControlListener();
	control.addListener(SWT.KeyDown, controlListener);
	control.addListener(SWT.Traverse, controlListener);
	}

	/*
	* Remove any listeners installed on the control.
	*/
	private void removeControlListener() {
	control.removeListener(SWT.KeyDown, controlListener);
	control.removeListener(SWT.Traverse, controlListener);
	}

	/*
	* Answer true if the popup is valid, which means the table has been created
	* and not disposed.
	*/
	private boolean isValid() {
	return proposalTable != null && !proposalTable.isDisposed();
	}

	/*
	* Return the current selected proposal.
	*/
	private IContentProposal getSelectedProposal() {
	if (isValid()) {
	int i = proposalTable.getSelectionIndex();
	if (proposals == null \|\| i < 0 \|\| i >= proposals.length)
	return null;
	return proposals[i];
	}
	return null;
	}

	/*
	* Select the proposal at the given index.
	*/
	private void selectProposal(int index) {
	Assert.isTrue(index >= 0, "Proposal index should never be negative"); //$NON-NLS-1$
	if (!isValid() \|\| proposals == null \|\| index >= proposals.length)
	return;
	proposalTable.setSelection(index);
	proposalTable.showSelection();

	showProposalDescription(proposals[index].getDescription());
	}

	/**
	* Opens this ContentProposalPopup. This method is extended in order to add
	* the control listener when the popup is opened and to invoke the secondary
	* popup if applicable.
	*
	* @return the return code
	*
	* @see org.eclipse.jface.window.Window#open()
	*/
	public int open() {
	addControlListener();
	int value = super.open();
	showProposalDescription(getSelectedProposal().getDescription());
	return value;
	}

	/**
	* Closes this popup. This method is extended to remove the control
	* listener.
	*
	* @return <code>true</code> if the window is (or was already) closed, and
	* <code>false</code> if it is still open
	*/
	public boolean close() {
	removeControlListener();
	return super.close();
	}

	/*
	* Get the proposals from the proposal provider. The provider may or may not
	* filter the proposals based on the specified filter text.
	*/
	private IContentProposal[] getProposals(String filterString) {
	if (proposalProvider == null)
	return null;
	int position = adapter.getControlContentAdapter().getCursorPosition(
	adapter.getControl());
	String contents = adapter.getControlContentAdapter()
	.getControlContents(adapter.getControl());
	IContentProposal[] proposals = proposalProvider.getProposals(contents,
	position);
	if (filter) {
	return filterProposals(proposals, filterString);
	}
	return proposals;
	}

	/*
	* Show the proposal description in a secondary popup.
	*/
	private void showProposalDescription(String description) {
	// If we have not created an info popup yet, do so now.
	if (infoPopup == null && description != null) {
	// Create a thread that will sleep for the specified delay
	// before creating the popup. We do not use Jobs since this
	// code must be able to run independently of the Eclipse runtime.
	Runnable runnable = new Runnable() {
	public void run() {
	try {
	Thread.sleep(POPUP_DELAY);
	} catch (InterruptedException e) {
	}
	if (!isValid())
	return;
	getShell().getDisplay().syncExec(new Runnable() {
	public void run() {
	// The selection may have changed by the time we
	// open, so double check it.
	IContentProposal p = getSelectedProposal();
	if (p != null) {
	if (infoPopup == null) {
	infoPopup = new InfoPopupDialog(getShell());
	infoPopup.open();
	}
	infoPopup.setContents(p.getDescription());
	infoPopup.getShell().addDisposeListener(
	new DisposeListener() {
	public void widgetDisposed(
	DisposeEvent event) {
	infoPopup = null;
	}
	});
	}
	}
	});
	}
	};
	Thread t = new Thread(runnable);
	t.start();
	} else if (infoPopup != null) {
	// We already have a popup, so just reset the contents.
	infoPopup.setContents(description);
	}
	}

	/*
	* Accept the current proposal.
	*/
	private void acceptCurrentProposal() {
	adapter.proposalAccepted(getSelectedProposal());
	close();
	}

	/*
	* Request the proposals from the proposal provider, and recompute any
	* caches. Repopulate the popup if it is open.
	*/
	private void recomputeProposals(String filterText) {
	setProposals(getProposals(filterText));
	}

	/*
	* Filter the provided list of content proposals according to the filter
	* text.
	*/
	private IContentProposal[] filterProposals(IContentProposal[] proposals,
	String filterString) {
	if (filterString.length() == 0)
	return proposals;

	// Check each string for a match. Use the string displayed to the user,
	// not the proposal content.
	ArrayList list = new ArrayList();
	for (int i = 0; i < proposals.length; i++) {
	String string = getString(proposals[i]);
	if (string.length() >= filterString.length()
	&& string.substring(0, filterString.length())
	.equalsIgnoreCase(filterString))
	list.add(proposals[i]);

	}
	return (IContentProposal[]) list.toArray(new IContentProposal[list
	.size()]);
	}
	}