org.eclipse.egerrit.ui/src/org/eclipse/egerrit/internal/ui/tabs/HyperLinkPresenter.java - egerrit/org.eclipse.egerrit - Git at Google

 /*******************************************************************************
  * Copyright (c) 2016 Ericsson AB.
  * 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:
  *     Ericsson - initial API and implementation
  *******************************************************************************/

 package org.eclipse.egerrit.internal.ui.tabs;

 import org.eclipse.core.runtime.Assert;
 import org.eclipse.egerrit.internal.core.GerritClient;
 import org.eclipse.egerrit.internal.model.ChangeInfo;
 import org.eclipse.jface.preference.IPreferenceStore;
 import org.eclipse.jface.preference.PreferenceConverter;
 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.DocumentEvent;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.IDocumentListener;
 import org.eclipse.jface.text.IRegion;
 import org.eclipse.jface.text.ITextInputListener;
 import org.eclipse.jface.text.ITextPresentationListener;
 import org.eclipse.jface.text.ITextViewer;
 import org.eclipse.jface.text.ITextViewerExtension2;
 import org.eclipse.jface.text.ITextViewerExtension4;
 import org.eclipse.jface.text.ITextViewerExtension6;
 import org.eclipse.jface.text.Position;
 import org.eclipse.jface.text.Region;
 import org.eclipse.jface.text.TextPresentation;
 import org.eclipse.jface.text.hyperlink.IHyperlink;
 import org.eclipse.jface.text.hyperlink.IHyperlinkPresenter;
 import org.eclipse.jface.text.hyperlink.IHyperlinkPresenterExtension2;
 import org.eclipse.jface.text.source.ISourceViewer;
 import org.eclipse.jface.util.IPropertyChangeListener;
 import org.eclipse.jface.util.PropertyChangeEvent;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.custom.StyleRange;
 import org.eclipse.swt.custom.StyledText;
 import org.eclipse.swt.graphics.Color;
 import org.eclipse.swt.graphics.RGB;

 /**
  * The default hyperlink presenter underlines the link and colors the line and the text with the given color.
  * <p>
  * It can only be used together with the {@link EGerritHyperlinkManager#FIRST} or the
  * {@link EGerritHyperlinkManager#LONGEST_REGION_FIRST} hyperlink strategy.
  * </p>
  *
  * @since 3.1
  */

 /* Change the IHyperlinkPresenterExtension by IHyperlinkPresenterExtension2 for multi hyperlink */

 class HyperLinkPresenter implements IHyperlinkPresenter, IHyperlinkPresenterExtension2, ITextPresentationListener,
 		ITextInputListener, IDocumentListener, IPropertyChangeListener {

 	private ISourceViewer fSourceViewer;

 	private GerritClient fGerritClient;

 	private ChangeInfo fChangeInfo;

 	/**
 	 * A named preference that holds the color used for hyperlinks.
 	 * <p>
 	 * Value is of type <code>String</code>. A RGB color value encoded as a string using class
 	 * <code>PreferenceConverter</code>.
 	 * </p>
 	 *
 	 * @see org.eclipse.jface.resource.StringConverter
 	 * @see org.eclipse.jface.preference.PreferenceConverter
 	 */
 	private static final String HYPERLINK_COLOR = "hyperlinkColor"; //$NON-NLS-1$

 	/**
 	 * A named preference that holds the preference whether to use the native link color.
 	 * <p>
 	 * The preference value is of type <code>Boolean</code>.
 	 * </p>
 	 *
 	 * @since 3.5
 	 */
 	private static final String HYPERLINK_COLOR_SYSTEM_DEFAULT = "hyperlinkColor.SystemDefault"; //$NON-NLS-1$

 	/** The text viewer. */
 	private ITextViewer fTextViewer;

 	/** The link color. */
 	private Color fColor;

 	/**
 	 * Tells whether to use native link color.
 	 *
 	 * @since 3.5
 	 */
 	private boolean fIsUsingNativeLinkColor;

 	/** The link color specification. May be <code>null</code>. */
 	private RGB fRGB;

 	/** Tells whether to dispose the color on uninstall. */
 	private boolean fDisposeColor;

 	/** The currently active region. */
 	private IRegion fActiveRegion;

 	/** The currently active style range as position. */
 	private Position fRememberedPosition;

 	/** The optional preference store. May be <code>null</code>. */
 	private IPreferenceStore fPreferenceStore;

 	private int fClickedOffset;

 	/**
 	 * Creates a new default hyperlink presenter which uses {@link #HYPERLINK_COLOR} to read the color from the given
 	 * preference store.
 	 *
 	 * @param store
 	 *            the preference store
 	 */
 	public HyperLinkPresenter(IPreferenceStore store) {
 		fPreferenceStore = store;
 		fDisposeColor = true;
 	}

 	/**
 	 * Creates a new default hyperlink presenter.
 	 *
 	 * @param color
 	 *            the hyperlink color or <code>null</code> if the existing text color should be preserved; to be
 	 *            disposed by the caller
 	 */
 	public HyperLinkPresenter(Color color) {
 		fColor = color;
 	}

 	/**
 	 * Creating the presenter for EGerrit viewer
 	 *
 	 * @param rgb
 	 * @param sourceViewer
 	 * @param tableViewer
 	 * @param gerritClient
 	 * @param changeInfo
 	 */
 	HyperLinkPresenter(RGB rgb, ISourceViewer sourceViewer, GerritClient gerritClient, ChangeInfo changeInfo) {
 		fRGB = rgb;
 		fDisposeColor = true;
 		fSourceViewer = sourceViewer;
 		fGerritClient = gerritClient;
 		fChangeInfo = changeInfo;

 	}

 	/*
 	 * @see org.eclipse.jdt.internal.ui.javaeditor.IHyperlinkControl#canShowMultipleHyperlinks()
 	 */
 	public boolean canShowMultipleHyperlinks() {
 		return true;
 	}

 	/*
 	 * @see org.eclipse.jdt.internal.ui.javaeditor.IHyperlinkControl#activate(org.eclipse.jdt.internal.ui.javaeditor.IHyperlink[])
 	 */
 	public void showHyperlinks(IHyperlink[] hyperlinks) {
 		Assert.isLegal(hyperlinks != null && hyperlinks.length >= 1);
 		for (IHyperlink hyperlink : hyperlinks) {
 			highlightRegion(hyperlink.getHyperlinkRegion());
 		}
 		if (hyperlinks != null && hyperlinks.length > 1) {
 			for (IHyperlink hyperlink : hyperlinks) {
 				if (isWithinRegion(hyperlink.getHyperlinkRegion()) && fClickedOffset != -1) {
 					hyperlink.open();
 				}
 			}
 		}
 		setOffset(-1);
 	}

 	/**
 	 * {@inheritDoc}
 	 *
 	 * @since 3.4
 	 */
 	public boolean canHideHyperlinks() {
 		return true;
 	}

 	/*
 	 * @see org.eclipse.jdt.internal.ui.javaeditor.IHyperlinkControl#deactivate()
 	 */
 	public void hideHyperlinks() {
 		repairRepresentation();
 		fRememberedPosition = null;
 	}

 	/*
 	 * @see org.eclipse.jdt.internal.ui.javaeditor.IHyperlinkControl#install(org.eclipse.jface.text.ITextViewer)
 	 */
 	public void install(ITextViewer textViewer) {
 		Assert.isNotNull(textViewer);
 		fTextViewer = textViewer;
 		fTextViewer.addTextInputListener(this);
 		if (fTextViewer instanceof ITextViewerExtension4) {
 			((ITextViewerExtension4) fTextViewer).addTextPresentationListener(this);
 		}

 		if (fPreferenceStore != null) {
 			fIsUsingNativeLinkColor = fPreferenceStore.getBoolean(HYPERLINK_COLOR_SYSTEM_DEFAULT);
 			if (!fIsUsingNativeLinkColor) {
 				fColor = createColorFromPreferenceStore();
 			}
 			fPreferenceStore.addPropertyChangeListener(this);
 		} else if (fRGB != null) {
 			StyledText text = fTextViewer.getTextWidget();
 			if (text != null && !text.isDisposed()) {
 				fColor = new Color(text.getDisplay(), fRGB);
 			}
 		}
 	}

 	/*
 	 * @see org.eclipse.jdt.internal.ui.javaeditor.IHyperlinkControl#uninstall()
 	 */
 	public void uninstall() {
 		fTextViewer.removeTextInputListener(this);
 		IDocument document = fTextViewer.getDocument();
 		if (document != null) {
 			document.removeDocumentListener(this);
 		}

 		if (fColor != null) {
 			if (fDisposeColor) {
 				fColor.dispose();
 			}
 			fColor = null;
 		}

 		if (fTextViewer instanceof ITextViewerExtension4) {
 			((ITextViewerExtension4) fTextViewer).removeTextPresentationListener(this);
 		}
 		fTextViewer = null;

 		if (fPreferenceStore != null) {
 			fPreferenceStore.removePropertyChangeListener(this);
 			fPreferenceStore = null;
 		}
 	}

 	/**
 	 * Sets the hyperlink foreground color.
 	 *
 	 * @param color
 	 *            the hyperlink foreground color or <code>null</code> if the existing text color should be preserved
 	 */
 	public void setColor(Color color) {
 		Assert.isNotNull(fTextViewer);
 		Assert.isTrue(fPreferenceStore == null, "Cannot set color if preference store is set"); //$NON-NLS-1$
 		if (fColor != null && fDisposeColor) {
 			fColor.dispose();
 		}
 		fColor = color;
 	}

 	/*
 	 * @see org.eclipse.jface.text.ITextPresentationListener#applyTextPresentation(org.eclipse.jface.text.TextPresentation)
 	 */
 	public void applyTextPresentation(TextPresentation textPresentation) {
 		if (fActiveRegion == null) {
 			return;
 		}
 		IRegion region = textPresentation.getExtent();
 		if (fActiveRegion.getOffset() + fActiveRegion.getLength() >= region.getOffset()
 				&& region.getOffset() + region.getLength() > fActiveRegion.getOffset()) {
 			Color color = null;
 			if (!fIsUsingNativeLinkColor) {
 				color = fColor;
 			}
 			StyleRange styleRange = new StyleRange(fActiveRegion.getOffset(), fActiveRegion.getLength(), color, null);
 			styleRange.underlineStyle = SWT.UNDERLINE_LINK;
 			styleRange.underline = true;
 			textPresentation.mergeStyleRange(styleRange);
 		}
 	}

 	private void highlightRegion(IRegion region) {

 		if (region.equals(fActiveRegion)) {
 			return;
 		}

 		StyledText text = fTextViewer.getTextWidget();
 		if (text == null || text.isDisposed()) {
 			return;
 		}

 		// Invalidate region ==> apply text presentation
 		fActiveRegion = region;
 		if (fTextViewer instanceof ITextViewerExtension6) {
 			((ITextViewerExtension2) fTextViewer).invalidateTextPresentation(region.getOffset(), region.getLength());
 		} else {
 			fTextViewer.invalidateTextPresentation();
 		}
 	}

 	private void repairRepresentation() {

 		if (fActiveRegion == null) {
 			return;
 		}

 		int offset = fActiveRegion.getOffset();
 		int length = fActiveRegion.getLength();
 		fActiveRegion = null;

 		// Invalidate ==> remove applied text presentation
 		if (fTextViewer instanceof ITextViewerExtension2) {
 			((ITextViewerExtension2) fTextViewer).invalidateTextPresentation(offset, length);
 		} else {
 			fTextViewer.invalidateTextPresentation();
 		}

 	}

 	/*
 	 * @see org.eclipse.jface.text.IDocumentListener#documentAboutToBeChanged(org.eclipse.jface.text.DocumentEvent)
 	 */
 	public void documentAboutToBeChanged(DocumentEvent event) {
 		if (fActiveRegion != null) {
 			fRememberedPosition = new Position(fActiveRegion.getOffset(), fActiveRegion.getLength());
 			try {
 				event.getDocument().addPosition(fRememberedPosition);
 			} catch (BadLocationException x) {
 				fRememberedPosition = null;
 			}
 		}
 	}

 	/*
 	 * @see org.eclipse.jface.text.IDocumentListener#documentChanged(org.eclipse.jface.text.DocumentEvent)
 	 */
 	public void documentChanged(DocumentEvent event) {
 		if (fRememberedPosition != null) {
 			if (!fRememberedPosition.isDeleted()) {
 				event.getDocument().removePosition(fRememberedPosition);
 				fActiveRegion = new Region(fRememberedPosition.getOffset(), fRememberedPosition.getLength());
 			} else {
 				fActiveRegion = new Region(event.getOffset(), event.getLength());
 			}
 			fRememberedPosition = null;

 			StyledText widget = fTextViewer.getTextWidget();
 			if (widget != null && !widget.isDisposed()) {
 				widget.getDisplay().asyncExec(new Runnable() {
 					public void run() {
 						hideHyperlinks();
 					}
 				});
 			}
 		}
 	}

 	/*
 	 * @see org.eclipse.jface.text.ITextInputListener#inputDocumentAboutToBeChanged(org.eclipse.jface.text.IDocument, org.eclipse.jface.text.IDocument)
 	 */
 	public void inputDocumentAboutToBeChanged(IDocument oldInput, IDocument newInput) {
 		if (oldInput == null) {
 			return;
 		}
 		hideHyperlinks();
 		oldInput.removeDocumentListener(this);
 	}

 	/*
 	 * @see org.eclipse.jface.text.ITextInputListener#inputDocumentChanged(org.eclipse.jface.text.IDocument, org.eclipse.jface.text.IDocument)
 	 */
 	public void inputDocumentChanged(IDocument oldInput, IDocument newInput) {
 		if (newInput == null) {
 			return;
 		}
 		newInput.addDocumentListener(this);

 		IHyperlink[] links = null;
 		if (fSourceViewer != null) {
 			links = new HyperLinkDetector(fGerritClient, fChangeInfo).detectHyperlinks(fSourceViewer, null, true);
 		}
 		if (links != null) {
 			showHyperlinks(links);
 		}
 	}

 	/**
 	 * Creates a color from the information stored in the given preference store.
 	 *
 	 * @return the color or <code>null</code> if there is no such information available or i f the text widget is not
 	 *         available
 	 */
 	private Color createColorFromPreferenceStore() {
 		StyledText textWidget = fTextViewer.getTextWidget();
 		if (textWidget == null || textWidget.isDisposed()) {
 			return null;
 		}

 		RGB rgb = null;

 		if (fPreferenceStore.contains(HYPERLINK_COLOR)) {

 			if (fPreferenceStore.isDefault(HYPERLINK_COLOR)) {
 				rgb = PreferenceConverter.getDefaultColor(fPreferenceStore, HYPERLINK_COLOR);
 			} else {
 				rgb = PreferenceConverter.getColor(fPreferenceStore, HYPERLINK_COLOR);
 			}

 			if (rgb != null) {
 				return new Color(textWidget.getDisplay(), rgb);
 			}
 		}

 		return null;
 	}

 	/*
 	 * @see org.eclipse.jface.util.IPropertyChangeListener#propertyChange(org.eclipse.jface.util.PropertyChangeEvent)
 	 */
 	public void propertyChange(PropertyChangeEvent event) {
 		if (HYPERLINK_COLOR.equals(event.getProperty())) {
 			if (fColor != null && fDisposeColor) {
 				fColor.dispose();
 			}
 			fColor = createColorFromPreferenceStore();
 			return;
 		}

 		if (HYPERLINK_COLOR_SYSTEM_DEFAULT.equals(event.getProperty())) {
 			fIsUsingNativeLinkColor = fPreferenceStore.getBoolean(HYPERLINK_COLOR_SYSTEM_DEFAULT);
 			if (!fIsUsingNativeLinkColor && fColor == null) {
 				fColor = createColorFromPreferenceStore();
 			}
 			return;
 		}
 	}

 	/**
 	 * ShowHyperLinks come with IHyperlinkPresenterExtension2
 	 */
 	@Override
 	public void showHyperlinks(IHyperlink[] activeHyperlinks, boolean takesFocusWhenVisible) {
 		if (activeHyperlinks != null && activeHyperlinks.length == 1) {
 			return;
 		}

 		Assert.isLegal(activeHyperlinks != null && activeHyperlinks.length >= 1);
 		for (IHyperlink hyperlink : activeHyperlinks) {
 			highlightRegion(hyperlink.getHyperlinkRegion());
 		}
 	}

 	private boolean isWithinRegion(IRegion region) {

 		if (fClickedOffset != -1 && fClickedOffset >= region.getOffset()
 				&& fClickedOffset <= (region.getLength() + region.getOffset())) {
 			return true;
 		}

 		return false;
 	}

 	/**
 	 * save the location where the user clicked in the text area
 	 */
 	public void setOffset(int offset) {
 		fClickedOffset = offset;
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2016 Ericsson AB.
	* 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:
	* Ericsson - initial API and implementation
	*******************************************************************************/

	package org.eclipse.egerrit.internal.ui.tabs;

	import org.eclipse.core.runtime.Assert;
	import org.eclipse.egerrit.internal.core.GerritClient;
	import org.eclipse.egerrit.internal.model.ChangeInfo;
	import org.eclipse.jface.preference.IPreferenceStore;
	import org.eclipse.jface.preference.PreferenceConverter;
	import org.eclipse.jface.text.BadLocationException;
	import org.eclipse.jface.text.DocumentEvent;
	import org.eclipse.jface.text.IDocument;
	import org.eclipse.jface.text.IDocumentListener;
	import org.eclipse.jface.text.IRegion;
	import org.eclipse.jface.text.ITextInputListener;
	import org.eclipse.jface.text.ITextPresentationListener;
	import org.eclipse.jface.text.ITextViewer;
	import org.eclipse.jface.text.ITextViewerExtension2;
	import org.eclipse.jface.text.ITextViewerExtension4;
	import org.eclipse.jface.text.ITextViewerExtension6;
	import org.eclipse.jface.text.Position;
	import org.eclipse.jface.text.Region;
	import org.eclipse.jface.text.TextPresentation;
	import org.eclipse.jface.text.hyperlink.IHyperlink;
	import org.eclipse.jface.text.hyperlink.IHyperlinkPresenter;
	import org.eclipse.jface.text.hyperlink.IHyperlinkPresenterExtension2;
	import org.eclipse.jface.text.source.ISourceViewer;
	import org.eclipse.jface.util.IPropertyChangeListener;
	import org.eclipse.jface.util.PropertyChangeEvent;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.custom.StyleRange;
	import org.eclipse.swt.custom.StyledText;
	import org.eclipse.swt.graphics.Color;
	import org.eclipse.swt.graphics.RGB;

	/**
	* The default hyperlink presenter underlines the link and colors the line and the text with the given color.
	* <p>
	* It can only be used together with the {@link EGerritHyperlinkManager#FIRST} or the
	* {@link EGerritHyperlinkManager#LONGEST_REGION_FIRST} hyperlink strategy.
	* </p>
	*
	* @since 3.1
	*/

	/* Change the IHyperlinkPresenterExtension by IHyperlinkPresenterExtension2 for multi hyperlink */

	class HyperLinkPresenter implements IHyperlinkPresenter, IHyperlinkPresenterExtension2, ITextPresentationListener,
	ITextInputListener, IDocumentListener, IPropertyChangeListener {

	private ISourceViewer fSourceViewer;

	private GerritClient fGerritClient;

	private ChangeInfo fChangeInfo;

	/**
	* A named preference that holds the color used for hyperlinks.
	* <p>
	* Value is of type <code>String</code>. A RGB color value encoded as a string using class
	* <code>PreferenceConverter</code>.
	* </p>
	*
	* @see org.eclipse.jface.resource.StringConverter
	* @see org.eclipse.jface.preference.PreferenceConverter
	*/
	private static final String HYPERLINK_COLOR = "hyperlinkColor"; //$NON-NLS-1$

	/**
	* A named preference that holds the preference whether to use the native link color.
	* <p>
	* The preference value is of type <code>Boolean</code>.
	* </p>
	*
	* @since 3.5
	*/
	private static final String HYPERLINK_COLOR_SYSTEM_DEFAULT = "hyperlinkColor.SystemDefault"; //$NON-NLS-1$

	/** The text viewer. */
	private ITextViewer fTextViewer;

	/** The link color. */
	private Color fColor;

	/**
	* Tells whether to use native link color.
	*
	* @since 3.5
	*/
	private boolean fIsUsingNativeLinkColor;

	/** The link color specification. May be <code>null</code>. */
	private RGB fRGB;

	/** Tells whether to dispose the color on uninstall. */
	private boolean fDisposeColor;

	/** The currently active region. */
	private IRegion fActiveRegion;

	/** The currently active style range as position. */
	private Position fRememberedPosition;

	/** The optional preference store. May be <code>null</code>. */
	private IPreferenceStore fPreferenceStore;

	private int fClickedOffset;

	/**
	* Creates a new default hyperlink presenter which uses {@link #HYPERLINK_COLOR} to read the color from the given
	* preference store.
	*
	* @param store
	* the preference store
	*/
	public HyperLinkPresenter(IPreferenceStore store) {
	fPreferenceStore = store;
	fDisposeColor = true;
	}

	/**
	* Creates a new default hyperlink presenter.
	*
	* @param color
	* the hyperlink color or <code>null</code> if the existing text color should be preserved; to be
	* disposed by the caller
	*/
	public HyperLinkPresenter(Color color) {
	fColor = color;
	}

	/**
	* Creating the presenter for EGerrit viewer
	*
	* @param rgb
	* @param sourceViewer
	* @param tableViewer
	* @param gerritClient
	* @param changeInfo
	*/
	HyperLinkPresenter(RGB rgb, ISourceViewer sourceViewer, GerritClient gerritClient, ChangeInfo changeInfo) {
	fRGB = rgb;
	fDisposeColor = true;
	fSourceViewer = sourceViewer;
	fGerritClient = gerritClient;
	fChangeInfo = changeInfo;

	}

	/*
	* @see org.eclipse.jdt.internal.ui.javaeditor.IHyperlinkControl#canShowMultipleHyperlinks()
	*/
	public boolean canShowMultipleHyperlinks() {
	return true;
	}

	/*
	* @see org.eclipse.jdt.internal.ui.javaeditor.IHyperlinkControl#activate(org.eclipse.jdt.internal.ui.javaeditor.IHyperlink[])
	*/
	public void showHyperlinks(IHyperlink[] hyperlinks) {
	Assert.isLegal(hyperlinks != null && hyperlinks.length >= 1);
	for (IHyperlink hyperlink : hyperlinks) {
	highlightRegion(hyperlink.getHyperlinkRegion());
	}
	if (hyperlinks != null && hyperlinks.length > 1) {
	for (IHyperlink hyperlink : hyperlinks) {
	if (isWithinRegion(hyperlink.getHyperlinkRegion()) && fClickedOffset != -1) {
	hyperlink.open();
	}
	}
	}
	setOffset(-1);
	}

	/**
	* {@inheritDoc}
	*
	* @since 3.4
	*/
	public boolean canHideHyperlinks() {
	return true;
	}

	/*
	* @see org.eclipse.jdt.internal.ui.javaeditor.IHyperlinkControl#deactivate()
	*/
	public void hideHyperlinks() {
	repairRepresentation();
	fRememberedPosition = null;
	}

	/*
	* @see org.eclipse.jdt.internal.ui.javaeditor.IHyperlinkControl#install(org.eclipse.jface.text.ITextViewer)
	*/
	public void install(ITextViewer textViewer) {
	Assert.isNotNull(textViewer);
	fTextViewer = textViewer;
	fTextViewer.addTextInputListener(this);
	if (fTextViewer instanceof ITextViewerExtension4) {
	((ITextViewerExtension4) fTextViewer).addTextPresentationListener(this);
	}

	if (fPreferenceStore != null) {
	fIsUsingNativeLinkColor = fPreferenceStore.getBoolean(HYPERLINK_COLOR_SYSTEM_DEFAULT);
	if (!fIsUsingNativeLinkColor) {
	fColor = createColorFromPreferenceStore();
	}
	fPreferenceStore.addPropertyChangeListener(this);
	} else if (fRGB != null) {
	StyledText text = fTextViewer.getTextWidget();
	if (text != null && !text.isDisposed()) {
	fColor = new Color(text.getDisplay(), fRGB);
	}
	}
	}

	/*
	* @see org.eclipse.jdt.internal.ui.javaeditor.IHyperlinkControl#uninstall()
	*/
	public void uninstall() {
	fTextViewer.removeTextInputListener(this);
	IDocument document = fTextViewer.getDocument();
	if (document != null) {
	document.removeDocumentListener(this);
	}

	if (fColor != null) {
	if (fDisposeColor) {
	fColor.dispose();
	}
	fColor = null;
	}

	if (fTextViewer instanceof ITextViewerExtension4) {
	((ITextViewerExtension4) fTextViewer).removeTextPresentationListener(this);
	}
	fTextViewer = null;

	if (fPreferenceStore != null) {
	fPreferenceStore.removePropertyChangeListener(this);
	fPreferenceStore = null;
	}
	}

	/**
	* Sets the hyperlink foreground color.
	*
	* @param color
	* the hyperlink foreground color or <code>null</code> if the existing text color should be preserved
	*/
	public void setColor(Color color) {
	Assert.isNotNull(fTextViewer);
	Assert.isTrue(fPreferenceStore == null, "Cannot set color if preference store is set"); //$NON-NLS-1$
	if (fColor != null && fDisposeColor) {
	fColor.dispose();
	}
	fColor = color;
	}

	/*
	* @see org.eclipse.jface.text.ITextPresentationListener#applyTextPresentation(org.eclipse.jface.text.TextPresentation)
	*/
	public void applyTextPresentation(TextPresentation textPresentation) {
	if (fActiveRegion == null) {
	return;
	}
	IRegion region = textPresentation.getExtent();
	if (fActiveRegion.getOffset() + fActiveRegion.getLength() >= region.getOffset()
	&& region.getOffset() + region.getLength() > fActiveRegion.getOffset()) {
	Color color = null;
	if (!fIsUsingNativeLinkColor) {
	color = fColor;
	}
	StyleRange styleRange = new StyleRange(fActiveRegion.getOffset(), fActiveRegion.getLength(), color, null);
	styleRange.underlineStyle = SWT.UNDERLINE_LINK;
	styleRange.underline = true;
	textPresentation.mergeStyleRange(styleRange);
	}
	}

	private void highlightRegion(IRegion region) {

	if (region.equals(fActiveRegion)) {
	return;
	}

	StyledText text = fTextViewer.getTextWidget();
	if (text == null \|\| text.isDisposed()) {
	return;
	}

	// Invalidate region ==> apply text presentation
	fActiveRegion = region;
	if (fTextViewer instanceof ITextViewerExtension6) {
	((ITextViewerExtension2) fTextViewer).invalidateTextPresentation(region.getOffset(), region.getLength());
	} else {
	fTextViewer.invalidateTextPresentation();
	}
	}

	private void repairRepresentation() {

	if (fActiveRegion == null) {
	return;
	}

	int offset = fActiveRegion.getOffset();
	int length = fActiveRegion.getLength();
	fActiveRegion = null;

	// Invalidate ==> remove applied text presentation
	if (fTextViewer instanceof ITextViewerExtension2) {
	((ITextViewerExtension2) fTextViewer).invalidateTextPresentation(offset, length);
	} else {
	fTextViewer.invalidateTextPresentation();
	}

	}

	/*
	* @see org.eclipse.jface.text.IDocumentListener#documentAboutToBeChanged(org.eclipse.jface.text.DocumentEvent)
	*/
	public void documentAboutToBeChanged(DocumentEvent event) {
	if (fActiveRegion != null) {
	fRememberedPosition = new Position(fActiveRegion.getOffset(), fActiveRegion.getLength());
	try {
	event.getDocument().addPosition(fRememberedPosition);
	} catch (BadLocationException x) {
	fRememberedPosition = null;
	}
	}
	}

	/*
	* @see org.eclipse.jface.text.IDocumentListener#documentChanged(org.eclipse.jface.text.DocumentEvent)
	*/
	public void documentChanged(DocumentEvent event) {
	if (fRememberedPosition != null) {
	if (!fRememberedPosition.isDeleted()) {
	event.getDocument().removePosition(fRememberedPosition);
	fActiveRegion = new Region(fRememberedPosition.getOffset(), fRememberedPosition.getLength());
	} else {
	fActiveRegion = new Region(event.getOffset(), event.getLength());
	}
	fRememberedPosition = null;

	StyledText widget = fTextViewer.getTextWidget();
	if (widget != null && !widget.isDisposed()) {
	widget.getDisplay().asyncExec(new Runnable() {
	public void run() {
	hideHyperlinks();
	}
	});
	}
	}
	}

	/*
	* @see org.eclipse.jface.text.ITextInputListener#inputDocumentAboutToBeChanged(org.eclipse.jface.text.IDocument, org.eclipse.jface.text.IDocument)
	*/
	public void inputDocumentAboutToBeChanged(IDocument oldInput, IDocument newInput) {
	if (oldInput == null) {
	return;
	}
	hideHyperlinks();
	oldInput.removeDocumentListener(this);
	}

	/*
	* @see org.eclipse.jface.text.ITextInputListener#inputDocumentChanged(org.eclipse.jface.text.IDocument, org.eclipse.jface.text.IDocument)
	*/
	public void inputDocumentChanged(IDocument oldInput, IDocument newInput) {
	if (newInput == null) {
	return;
	}
	newInput.addDocumentListener(this);

	IHyperlink[] links = null;
	if (fSourceViewer != null) {
	links = new HyperLinkDetector(fGerritClient, fChangeInfo).detectHyperlinks(fSourceViewer, null, true);
	}
	if (links != null) {
	showHyperlinks(links);
	}
	}

	/**
	* Creates a color from the information stored in the given preference store.
	*
	* @return the color or <code>null</code> if there is no such information available or i f the text widget is not
	* available
	*/
	private Color createColorFromPreferenceStore() {
	StyledText textWidget = fTextViewer.getTextWidget();
	if (textWidget == null \|\| textWidget.isDisposed()) {
	return null;
	}

	RGB rgb = null;

	if (fPreferenceStore.contains(HYPERLINK_COLOR)) {

	if (fPreferenceStore.isDefault(HYPERLINK_COLOR)) {
	rgb = PreferenceConverter.getDefaultColor(fPreferenceStore, HYPERLINK_COLOR);
	} else {
	rgb = PreferenceConverter.getColor(fPreferenceStore, HYPERLINK_COLOR);
	}

	if (rgb != null) {
	return new Color(textWidget.getDisplay(), rgb);
	}
	}

	return null;
	}

	/*
	* @see org.eclipse.jface.util.IPropertyChangeListener#propertyChange(org.eclipse.jface.util.PropertyChangeEvent)
	*/
	public void propertyChange(PropertyChangeEvent event) {
	if (HYPERLINK_COLOR.equals(event.getProperty())) {
	if (fColor != null && fDisposeColor) {
	fColor.dispose();
	}
	fColor = createColorFromPreferenceStore();
	return;
	}

	if (HYPERLINK_COLOR_SYSTEM_DEFAULT.equals(event.getProperty())) {
	fIsUsingNativeLinkColor = fPreferenceStore.getBoolean(HYPERLINK_COLOR_SYSTEM_DEFAULT);
	if (!fIsUsingNativeLinkColor && fColor == null) {
	fColor = createColorFromPreferenceStore();
	}
	return;
	}
	}

	/**
	* ShowHyperLinks come with IHyperlinkPresenterExtension2
	*/
	@Override
	public void showHyperlinks(IHyperlink[] activeHyperlinks, boolean takesFocusWhenVisible) {
	if (activeHyperlinks != null && activeHyperlinks.length == 1) {
	return;
	}

	Assert.isLegal(activeHyperlinks != null && activeHyperlinks.length >= 1);
	for (IHyperlink hyperlink : activeHyperlinks) {
	highlightRegion(hyperlink.getHyperlinkRegion());
	}
	}

	private boolean isWithinRegion(IRegion region) {

	if (fClickedOffset != -1 && fClickedOffset >= region.getOffset()
	&& fClickedOffset <= (region.getLength() + region.getOffset())) {
	return true;
	}

	return false;
	}

	/**
	* save the location where the user clicked in the text area
	*/
	public void setOffset(int offset) {
	fClickedOffset = offset;
	}

	}