bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StyledCellLabelProvider.java - platform/eclipse.platform.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2007, 2009 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
  *     Michael Krkoska - initial API and implementation (bug 188333)
  *******************************************************************************/
 package org.eclipse.jface.viewers;

 import org.eclipse.swt.SWT;
 import org.eclipse.swt.custom.StyleRange;
 import org.eclipse.swt.graphics.Color;
 import org.eclipse.swt.graphics.GC;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.graphics.Rectangle;
 import org.eclipse.swt.graphics.TextLayout;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Event;
 import org.eclipse.swt.widgets.Widget;

 import org.eclipse.core.runtime.Assert;

 import org.eclipse.jface.viewers.StyledString.Styler;

 /**
  * A {@link StyledCellLabelProvider} supports styled labels by using owner
  * draw.
  * Besides the styles in labels, the label provider preserves native viewer behavior:
  * <ul>
  * <li>similar image and label positioning</li>
  * <li>native drawing of focus and selection</li>
  * </ul>
  * <p>
  * For providing the label's styles, create a subclass and overwrite
  * {@link StyledCellLabelProvider#update(ViewerCell)} to
  * return set all information needed to render a element. Use
  * {@link ViewerCell#setStyleRanges(StyleRange[])} to set style ranges
  * on the label.
  * </p>
  *
  * @since 3.4
  */
 public abstract class StyledCellLabelProvider extends OwnerDrawLabelProvider {


 	/**
 	 * Style constant for indicating that the styled colors are to be applied
 	 * even it the viewer's item is selected. Default is not to apply colors.
 	 */
 	public static final int COLORS_ON_SELECTION = 1 << 0;

 	/**
 	 * Style constant for indicating to draw the focus if requested by the owner
 	 * draw event. Default is to draw the focus.
 	 */
 	public static final int NO_FOCUS = 1 << 1;

 	/**
 	 * Private constant to indicate if owner draw is enabled for the
 	 * label provider's column.
 	 */
 	private static final int OWNER_DRAW_ENABLED = 1 << 4;

 	private int style;

 	// reused text layout
 	private TextLayout cachedTextLayout;

 	private ColumnViewer viewer;
 	private ViewerColumn column;

 	private Widget itemOfLastMeasure;
 	private int deltaOfLastMeasure;

 	/**
 	 * Creates a new StyledCellLabelProvider. By default, owner draw is enabled, focus is drawn and no
 	 * colors are painted on selected elements.
 	 */
 	public StyledCellLabelProvider() {
 		this(0);
 	}

 	/**
 	 * Creates a new StyledCellLabelProvider. By default, owner draw is enabled.
 	 *
 	 * @param style
 	 *            the style bits
 	 * @see StyledCellLabelProvider#COLORS_ON_SELECTION
 	 * @see StyledCellLabelProvider#NO_FOCUS
 	 */
 	public StyledCellLabelProvider(int style) {
 		this.style = style & (COLORS_ON_SELECTION | NO_FOCUS)
 							| OWNER_DRAW_ENABLED;
 	}

 	/**
 	 * Returns <code>true</code> is the owner draw rendering is enabled for this label provider.
 	 * By default owner draw rendering is enabled. If owner draw rendering is disabled, rending is
 	 * done by the viewer and no styled ranges (see {@link ViewerCell#getStyleRanges()})
 	 * are drawn.
 	 *
 	 * @return <code>true</code> is the rendering of styles is enabled.
 	 */
 	public boolean isOwnerDrawEnabled() {
 		return (this.style & OWNER_DRAW_ENABLED) != 0;
 	}

 	/**
 	 * Specifies whether owner draw rendering is enabled for this label
 	 * provider. By default owner draw rendering is enabled. If owner draw
 	 * rendering is disabled, rendering is done by the viewer and no styled
 	 * ranges (see {@link ViewerCell#getStyleRanges()}) are drawn.
 	 * It is the caller's responsibility to also call
 	 * {@link StructuredViewer#refresh()} or similar methods to update the
 	 * underlying widget.
 	 *
 	 * @param enabled
 	 *            specifies if owner draw rendering is enabled
 	 */
 	public void setOwnerDrawEnabled(boolean enabled) {
 		boolean isEnabled= isOwnerDrawEnabled();
 		if (isEnabled != enabled) {
 			if (enabled) {
 				this.style |= OWNER_DRAW_ENABLED;
 			} else {
 				this.style &= ~OWNER_DRAW_ENABLED;
 			}
 			if (this.viewer != null) {
 				setOwnerDrawEnabled(this.viewer, this.column, enabled);
 			}
 		}
 	}

 	/**
 	 * Returns the viewer on which this label provider is installed on or <code>null</code> if the
 	 * label provider is not installed.
 	 *
 	 * @return the viewer on which this label provider is installed on or <code>null</code> if the
 	 * label provider is not installed.
 	 */
 	protected final ColumnViewer getViewer() {
 		return this.viewer;
 	}

 	/**
 	 * Returns the column on which this label provider is installed on or <code>null</code> if the
 	 * label provider is not installed.
 	 *
 	 * @return the column on which this label provider is installed on or <code>null</code> if the
 	 * label provider is not installed.
 	 */
 	protected final ViewerColumn getColumn() {
 		return this.column;
 	}

 	/* (non-Javadoc)
 	 * @see org.eclipse.jface.viewers.OwnerDrawLabelProvider#initialize(org.eclipse.jface.viewers.ColumnViewer, org.eclipse.jface.viewers.ViewerColumn)
 	 */
 	public void initialize(ColumnViewer viewer, ViewerColumn column) {
 		Assert.isTrue(this.viewer == null && this.column == null, "Label provider instance already in use"); //$NON-NLS-1$

 		this.viewer= viewer;
 		this.column= column;
 		super.initialize(viewer, column, isOwnerDrawEnabled());
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.jface.viewers.BaseLabelProvider#dispose()
 	 */
 	public void dispose() {
 		if (this.cachedTextLayout != null) {
 			cachedTextLayout.dispose();
 			cachedTextLayout = null;
 		}

 		this.viewer= null;
 		this.column= null;

 		super.dispose();
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.jface.viewers.OwnerDrawLabelProvider#update(org.eclipse.jface.viewers.ViewerCell)
 	 */
 	public void update(ViewerCell cell) {
 		// clients must override and configure the cell and call super
 		super.update(cell); // calls 'repaint' to trigger the paint listener
 	}

 	private TextLayout getSharedTextLayout(Display display) {
 		if (cachedTextLayout == null) {
 			int orientation = viewer.getControl().getStyle() & (SWT.LEFT_TO_RIGHT | SWT.RIGHT_TO_LEFT);
 			cachedTextLayout = new TextLayout(display);
 			cachedTextLayout.setOrientation(orientation);
 		}
 		return cachedTextLayout;
 	}

 	private boolean useColors(Event event) {
 		return (event.detail & SWT.SELECTED) == 0
 				|| (this.style & COLORS_ON_SELECTION) != 0;
 	}

 	private boolean drawFocus(Event event) {
 		return (event.detail & SWT.FOCUSED) != 0
 				&& (this.style & NO_FOCUS) == 0;
 	}

 	/**
 	 * Prepares the given style range before it is applied to the label. This method makes sure that
 	 * no colors are drawn when the element is selected.
 	 * The current version of the {@link StyledCellLabelProvider} will also ignore all font settings on the
 	 * style range. Clients can override.
 	 *
 	 * @param styleRange
 	 *               the style range to prepare. the style range element must not be modified
 	 * @param applyColors
 	 *               specifies if colors should be applied.
 	 * @return
 	 *               returns the style range to use on the label
 	 */
 	protected StyleRange prepareStyleRange(StyleRange styleRange, boolean applyColors) {
 		// if no colors apply or font is set, create a clone and clear the
 		// colors and font
 		if (!applyColors && (styleRange.foreground != null || styleRange.background != null)) {
 			styleRange = (StyleRange) styleRange.clone();
 			if (!applyColors) {
 				styleRange.foreground = null;
 				styleRange.background = null;
 			}
 		}
 		return styleRange;
 	}

 	private ViewerCell getViewerCell(Event event, Object element) {
 		ViewerRow row= viewer.getViewerRowFromItem(event.item);
 		return new ViewerCell(row, event.index, element);
 	}

 	/**
 	 * Handle the erase event. The default implementation does nothing to ensure
 	 * keep native selection highlighting working.
 	 *
 	 * @param event
 	 *            the erase event
 	 * @param element
 	 *            the model object
 	 * @see SWT#EraseItem
 	 */
 	protected void erase(Event event, Object element) {
 		// use native erase
 		if (isOwnerDrawEnabled()) {
 			// info has been set by 'update': announce that we paint ourselves
 			event.detail &= ~SWT.FOREGROUND;
 		}
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.jface.viewers.OwnerDrawLabelProvider#measure(org.eclipse.swt.widgets.Event,
 	 *      java.lang.Object)
 	 */
 	protected void measure(Event event, Object element) {
 		if (!isOwnerDrawEnabled())
 			return;

 		ViewerCell cell= getViewerCell(event, element);
 		boolean applyColors = useColors(event); // returns false because of bug 228376

 		TextLayout layout = getSharedTextLayout(event.display);

 		int textWidthDelta = deltaOfLastMeasure = updateTextLayout(layout, cell, applyColors);
 		/* remove-begin if bug 228695 fixed */
 		itemOfLastMeasure = event.item;
 		/* remove-end if bug 228695 fixed */

 		event.width += textWidthDelta;
 	}

 	/**
 	 * @param layout
 	 * @param cell
 	 * @param applyColors
 	 * @return the text width delta (0 if the text layout contains no other font)
 	 */
 	private int updateTextLayout(TextLayout layout, ViewerCell cell,
 			boolean applyColors) {
 		layout.setText(""); //$NON-NLS-1$  //make sure all previous ranges are cleared (see bug 226090)

 		layout.setText(cell.getText());
 		layout.setFont(cell.getFont()); // set also if null to clear previous usages

 		int originalTextWidth = layout.getBounds().width; // text width without any styles
 		boolean containsOtherFont= false;

 		StyleRange[] styleRanges = cell.getStyleRanges();
 		if (styleRanges != null) { // user didn't fill styled ranges
 			for (int i = 0; i < styleRanges.length; i++) {
 				StyleRange curr = prepareStyleRange(styleRanges[i], applyColors);
 				layout.setStyle(curr, curr.start, curr.start + curr.length - 1);
 				if (curr.font != null) {
 					containsOtherFont= true;
 				}
 			}
 		}
 		int textWidthDelta = 0;
 		if (containsOtherFont) {
 			textWidthDelta = layout.getBounds().width - originalTextWidth;
 		}
 		return textWidthDelta;
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.jface.viewers.OwnerDrawLabelProvider#paint(org.eclipse.swt.widgets.Event,
 	 *      java.lang.Object)
 	 */
 	protected void paint(Event event, Object element) {
 		if (!isOwnerDrawEnabled())
 			return;

 		ViewerCell cell= getViewerCell(event, element);

 		boolean applyColors= useColors(event);

 		GC gc = event.gc;
 		// remember colors to restore the GC later
 		Color oldForeground = gc.getForeground();
 		Color oldBackground = gc.getBackground();

 		if (applyColors) {
 			Color foreground= cell.getForeground();
 			if (foreground != null) {
 				gc.setForeground(foreground);
 			}

 			Color background= cell.getBackground();
 			if (background != null) {
 				gc.setBackground(background);
 			}
 		}
 		Image image = cell.getImage();
 		if (image != null) {
 			Rectangle imageBounds = cell.getImageBounds();
 			if (imageBounds != null) {
 				Rectangle bounds = image.getBounds();

 				// center the image in the given space
 				int x = imageBounds.x
 						+ Math.max(0, (imageBounds.width - bounds.width) / 2);
 				int y = imageBounds.y
 						+ Math.max(0, (imageBounds.height - bounds.height) / 2);
 				gc.drawImage(image, x, y);
 			}
 		}

 		Rectangle textBounds = cell.getTextBounds();
 		if (textBounds != null) {
 			TextLayout textLayout= getSharedTextLayout(event.display);

 			/* remove-begin if bug 228695 fixed */
 			if (event.item != itemOfLastMeasure) {
 				// fLayout has not been configured in 'measure()'
 				deltaOfLastMeasure = updateTextLayout(textLayout, cell, applyColors);
 				itemOfLastMeasure = event.item;
 			}
 			/* remove-end if bug 228695 fixed */

 			/* remove-begin if bug 228376 fixed */
 			if (!applyColors) {
 				// need to remove colors for selected elements: measure doesn't provide that information, see bug 228376
 				StyleRange[] styleRanges= cell.getStyleRanges();
 				if (styleRanges != null) {
 					for (int i= 0; i < styleRanges.length; i++) {
 						StyleRange curr = prepareStyleRange(styleRanges[i], applyColors);
 						textLayout.setStyle(curr, curr.start, curr.start + curr.length - 1);
 					}
 				}
 			}
 			/* remove-end if bug 228376 fixed */

 			Rectangle layoutBounds = textLayout.getBounds();

 			int x = textBounds.x;
 			int y = textBounds.y
 					+ Math.max(0, (textBounds.height - layoutBounds.height) / 2);

 			textLayout.draw(gc, x, y);
 		}

 		if (drawFocus(event)) {
 			Rectangle focusBounds = cell.getViewerRow().getBounds();
 			gc.drawFocus(focusBounds.x, focusBounds.y, focusBounds.width + deltaOfLastMeasure,
 					focusBounds.height);
 		}

 		if (applyColors) {
 			gc.setForeground(oldForeground);
 			gc.setBackground(oldBackground);
 		}
 	}

 	/**
 	 * Applies decoration styles to the decorated string and adds the styles of the previously
 	 * undecorated string.
 	 * <p>
 	 * If the <code>decoratedString</code> contains the <code>styledString</code>, then the result
 	 * keeps the styles of the <code>styledString</code> and styles the decorations with the
 	 * <code>decorationStyler</code>. Otherwise, the decorated string is returned without any
 	 * styles.
 	 *
 	 * @param decoratedString the decorated string
 	 * @param decorationStyler the styler to use for the decoration or <code>null</code> for no
 	 *            styles
 	 * @param styledString the original styled string
 	 *
 	 * @return the styled decorated string (can be the given <code>styledString</code>)
 	 * @since 3.5
 	 */
 	public static StyledString styleDecoratedString(String decoratedString, Styler decorationStyler, StyledString styledString) {
 		String label= styledString.getString();
 		int originalStart= decoratedString.indexOf(label);
 		if (originalStart == -1) {
 			return new StyledString(decoratedString); // the decorator did something wild
 		}

 		if (decoratedString.length() == label.length())
 			return styledString;

 		if (originalStart > 0) {
 			StyledString newString= new StyledString(decoratedString.substring(0, originalStart), decorationStyler);
 			newString.append(styledString);
 			styledString= newString;
 		}
 		if (decoratedString.length() > originalStart + label.length()) { // decorator appended something
 			return styledString.append(decoratedString.substring(originalStart + label.length()), decorationStyler);
 		}
 		return styledString; // no change
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2007, 2009 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
	* Michael Krkoska - initial API and implementation (bug 188333)
	*******************************************************************************/
	package org.eclipse.jface.viewers;

	import org.eclipse.swt.SWT;
	import org.eclipse.swt.custom.StyleRange;
	import org.eclipse.swt.graphics.Color;
	import org.eclipse.swt.graphics.GC;
	import org.eclipse.swt.graphics.Image;
	import org.eclipse.swt.graphics.Rectangle;
	import org.eclipse.swt.graphics.TextLayout;
	import org.eclipse.swt.widgets.Display;
	import org.eclipse.swt.widgets.Event;
	import org.eclipse.swt.widgets.Widget;

	import org.eclipse.core.runtime.Assert;

	import org.eclipse.jface.viewers.StyledString.Styler;

	/**
	* A {@link StyledCellLabelProvider} supports styled labels by using owner
	* draw.
	* Besides the styles in labels, the label provider preserves native viewer behavior:
	* <ul>
	* <li>similar image and label positioning</li>
	* <li>native drawing of focus and selection</li>
	* </ul>
	* <p>
	* For providing the label's styles, create a subclass and overwrite
	* {@link StyledCellLabelProvider#update(ViewerCell)} to
	* return set all information needed to render a element. Use
	* {@link ViewerCell#setStyleRanges(StyleRange[])} to set style ranges
	* on the label.
	* </p>
	*
	* @since 3.4
	*/
	public abstract class StyledCellLabelProvider extends OwnerDrawLabelProvider {



	/**
	* Style constant for indicating that the styled colors are to be applied
	* even it the viewer's item is selected. Default is not to apply colors.
	*/
	public static final int COLORS_ON_SELECTION = 1 << 0;

	/**
	* Style constant for indicating to draw the focus if requested by the owner
	* draw event. Default is to draw the focus.
	*/
	public static final int NO_FOCUS = 1 << 1;

	/**
	* Private constant to indicate if owner draw is enabled for the
	* label provider's column.
	*/
	private static final int OWNER_DRAW_ENABLED = 1 << 4;

	private int style;

	// reused text layout
	private TextLayout cachedTextLayout;

	private ColumnViewer viewer;
	private ViewerColumn column;

	private Widget itemOfLastMeasure;
	private int deltaOfLastMeasure;

	/**
	* Creates a new StyledCellLabelProvider. By default, owner draw is enabled, focus is drawn and no
	* colors are painted on selected elements.
	*/
	public StyledCellLabelProvider() {
	this(0);
	}

	/**
	* Creates a new StyledCellLabelProvider. By default, owner draw is enabled.
	*
	* @param style
	* the style bits
	* @see StyledCellLabelProvider#COLORS_ON_SELECTION
	* @see StyledCellLabelProvider#NO_FOCUS
	*/
	public StyledCellLabelProvider(int style) {
	this.style = style & (COLORS_ON_SELECTION \| NO_FOCUS)
	\| OWNER_DRAW_ENABLED;
	}

	/**
	* Returns <code>true</code> is the owner draw rendering is enabled for this label provider.
	* By default owner draw rendering is enabled. If owner draw rendering is disabled, rending is
	* done by the viewer and no styled ranges (see {@link ViewerCell#getStyleRanges()})
	* are drawn.
	*
	* @return <code>true</code> is the rendering of styles is enabled.
	*/
	public boolean isOwnerDrawEnabled() {
	return (this.style & OWNER_DRAW_ENABLED) != 0;
	}

	/**
	* Specifies whether owner draw rendering is enabled for this label
	* provider. By default owner draw rendering is enabled. If owner draw
	* rendering is disabled, rendering is done by the viewer and no styled
	* ranges (see {@link ViewerCell#getStyleRanges()}) are drawn.
	* It is the caller's responsibility to also call
	* {@link StructuredViewer#refresh()} or similar methods to update the
	* underlying widget.
	*
	* @param enabled
	* specifies if owner draw rendering is enabled
	*/
	public void setOwnerDrawEnabled(boolean enabled) {
	boolean isEnabled= isOwnerDrawEnabled();
	if (isEnabled != enabled) {
	if (enabled) {
	this.style \|= OWNER_DRAW_ENABLED;
	} else {
	this.style &= ~OWNER_DRAW_ENABLED;
	}
	if (this.viewer != null) {
	setOwnerDrawEnabled(this.viewer, this.column, enabled);
	}
	}
	}

	/**
	* Returns the viewer on which this label provider is installed on or <code>null</code> if the
	* label provider is not installed.
	*
	* @return the viewer on which this label provider is installed on or <code>null</code> if the
	* label provider is not installed.
	*/
	protected final ColumnViewer getViewer() {
	return this.viewer;
	}

	/**
	* Returns the column on which this label provider is installed on or <code>null</code> if the
	* label provider is not installed.
	*
	* @return the column on which this label provider is installed on or <code>null</code> if the
	* label provider is not installed.
	*/
	protected final ViewerColumn getColumn() {
	return this.column;
	}

	/* (non-Javadoc)
	* @see org.eclipse.jface.viewers.OwnerDrawLabelProvider#initialize(org.eclipse.jface.viewers.ColumnViewer, org.eclipse.jface.viewers.ViewerColumn)
	*/
	public void initialize(ColumnViewer viewer, ViewerColumn column) {
	Assert.isTrue(this.viewer == null && this.column == null, "Label provider instance already in use"); //$NON-NLS-1$

	this.viewer= viewer;
	this.column= column;
	super.initialize(viewer, column, isOwnerDrawEnabled());
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.jface.viewers.BaseLabelProvider#dispose()
	*/
	public void dispose() {
	if (this.cachedTextLayout != null) {
	cachedTextLayout.dispose();
	cachedTextLayout = null;
	}

	this.viewer= null;
	this.column= null;

	super.dispose();
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.jface.viewers.OwnerDrawLabelProvider#update(org.eclipse.jface.viewers.ViewerCell)
	*/
	public void update(ViewerCell cell) {
	// clients must override and configure the cell and call super
	super.update(cell); // calls 'repaint' to trigger the paint listener
	}

	private TextLayout getSharedTextLayout(Display display) {
	if (cachedTextLayout == null) {
	int orientation = viewer.getControl().getStyle() & (SWT.LEFT_TO_RIGHT \| SWT.RIGHT_TO_LEFT);
	cachedTextLayout = new TextLayout(display);
	cachedTextLayout.setOrientation(orientation);
	}
	return cachedTextLayout;
	}

	private boolean useColors(Event event) {
	return (event.detail & SWT.SELECTED) == 0
	\|\| (this.style & COLORS_ON_SELECTION) != 0;
	}

	private boolean drawFocus(Event event) {
	return (event.detail & SWT.FOCUSED) != 0
	&& (this.style & NO_FOCUS) == 0;
	}

	/**
	* Prepares the given style range before it is applied to the label. This method makes sure that
	* no colors are drawn when the element is selected.
	* The current version of the {@link StyledCellLabelProvider} will also ignore all font settings on the
	* style range. Clients can override.
	*
	* @param styleRange
	* the style range to prepare. the style range element must not be modified
	* @param applyColors
	* specifies if colors should be applied.
	* @return
	* returns the style range to use on the label
	*/
	protected StyleRange prepareStyleRange(StyleRange styleRange, boolean applyColors) {
	// if no colors apply or font is set, create a clone and clear the
	// colors and font
	if (!applyColors && (styleRange.foreground != null \|\| styleRange.background != null)) {
	styleRange = (StyleRange) styleRange.clone();
	if (!applyColors) {
	styleRange.foreground = null;
	styleRange.background = null;
	}
	}
	return styleRange;
	}

	private ViewerCell getViewerCell(Event event, Object element) {
	ViewerRow row= viewer.getViewerRowFromItem(event.item);
	return new ViewerCell(row, event.index, element);
	}

	/**
	* Handle the erase event. The default implementation does nothing to ensure
	* keep native selection highlighting working.
	*
	* @param event
	* the erase event
	* @param element
	* the model object
	* @see SWT#EraseItem
	*/
	protected void erase(Event event, Object element) {
	// use native erase
	if (isOwnerDrawEnabled()) {
	// info has been set by 'update': announce that we paint ourselves
	event.detail &= ~SWT.FOREGROUND;
	}
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.jface.viewers.OwnerDrawLabelProvider#measure(org.eclipse.swt.widgets.Event,
	* java.lang.Object)
	*/
	protected void measure(Event event, Object element) {
	if (!isOwnerDrawEnabled())
	return;

	ViewerCell cell= getViewerCell(event, element);
	boolean applyColors = useColors(event); // returns false because of bug 228376

	TextLayout layout = getSharedTextLayout(event.display);

	int textWidthDelta = deltaOfLastMeasure = updateTextLayout(layout, cell, applyColors);
	/* remove-begin if bug 228695 fixed */
	itemOfLastMeasure = event.item;
	/* remove-end if bug 228695 fixed */

	event.width += textWidthDelta;
	}

	/**
	* @param layout
	* @param cell
	* @param applyColors
	* @return the text width delta (0 if the text layout contains no other font)
	*/
	private int updateTextLayout(TextLayout layout, ViewerCell cell,
	boolean applyColors) {
	layout.setText(""); //$NON-NLS-1$ //make sure all previous ranges are cleared (see bug 226090)

	layout.setText(cell.getText());
	layout.setFont(cell.getFont()); // set also if null to clear previous usages

	int originalTextWidth = layout.getBounds().width; // text width without any styles
	boolean containsOtherFont= false;

	StyleRange[] styleRanges = cell.getStyleRanges();
	if (styleRanges != null) { // user didn't fill styled ranges
	for (int i = 0; i < styleRanges.length; i++) {
	StyleRange curr = prepareStyleRange(styleRanges[i], applyColors);
	layout.setStyle(curr, curr.start, curr.start + curr.length - 1);
	if (curr.font != null) {
	containsOtherFont= true;
	}
	}
	}
	int textWidthDelta = 0;
	if (containsOtherFont) {
	textWidthDelta = layout.getBounds().width - originalTextWidth;
	}
	return textWidthDelta;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.jface.viewers.OwnerDrawLabelProvider#paint(org.eclipse.swt.widgets.Event,
	* java.lang.Object)
	*/
	protected void paint(Event event, Object element) {
	if (!isOwnerDrawEnabled())
	return;

	ViewerCell cell= getViewerCell(event, element);

	boolean applyColors= useColors(event);

	GC gc = event.gc;
	// remember colors to restore the GC later
	Color oldForeground = gc.getForeground();
	Color oldBackground = gc.getBackground();

	if (applyColors) {
	Color foreground= cell.getForeground();
	if (foreground != null) {
	gc.setForeground(foreground);
	}

	Color background= cell.getBackground();
	if (background != null) {
	gc.setBackground(background);
	}
	}
	Image image = cell.getImage();
	if (image != null) {
	Rectangle imageBounds = cell.getImageBounds();
	if (imageBounds != null) {
	Rectangle bounds = image.getBounds();

	// center the image in the given space
	int x = imageBounds.x
	+ Math.max(0, (imageBounds.width - bounds.width) / 2);
	int y = imageBounds.y
	+ Math.max(0, (imageBounds.height - bounds.height) / 2);
	gc.drawImage(image, x, y);
	}
	}

	Rectangle textBounds = cell.getTextBounds();
	if (textBounds != null) {
	TextLayout textLayout= getSharedTextLayout(event.display);

	/* remove-begin if bug 228695 fixed */
	if (event.item != itemOfLastMeasure) {
	// fLayout has not been configured in 'measure()'
	deltaOfLastMeasure = updateTextLayout(textLayout, cell, applyColors);
	itemOfLastMeasure = event.item;
	}
	/* remove-end if bug 228695 fixed */

	/* remove-begin if bug 228376 fixed */
	if (!applyColors) {
	// need to remove colors for selected elements: measure doesn't provide that information, see bug 228376
	StyleRange[] styleRanges= cell.getStyleRanges();
	if (styleRanges != null) {
	for (int i= 0; i < styleRanges.length; i++) {
	StyleRange curr = prepareStyleRange(styleRanges[i], applyColors);
	textLayout.setStyle(curr, curr.start, curr.start + curr.length - 1);
	}
	}
	}
	/* remove-end if bug 228376 fixed */

	Rectangle layoutBounds = textLayout.getBounds();

	int x = textBounds.x;
	int y = textBounds.y
	+ Math.max(0, (textBounds.height - layoutBounds.height) / 2);

	textLayout.draw(gc, x, y);
	}

	if (drawFocus(event)) {
	Rectangle focusBounds = cell.getViewerRow().getBounds();
	gc.drawFocus(focusBounds.x, focusBounds.y, focusBounds.width + deltaOfLastMeasure,
	focusBounds.height);
	}

	if (applyColors) {
	gc.setForeground(oldForeground);
	gc.setBackground(oldBackground);
	}
	}

	/**
	* Applies decoration styles to the decorated string and adds the styles of the previously
	* undecorated string.
	* <p>
	* If the <code>decoratedString</code> contains the <code>styledString</code>, then the result
	* keeps the styles of the <code>styledString</code> and styles the decorations with the
	* <code>decorationStyler</code>. Otherwise, the decorated string is returned without any
	* styles.
	*
	* @param decoratedString the decorated string
	* @param decorationStyler the styler to use for the decoration or <code>null</code> for no
	* styles
	* @param styledString the original styled string
	*
	* @return the styled decorated string (can be the given <code>styledString</code>)
	* @since 3.5
	*/
	public static StyledString styleDecoratedString(String decoratedString, Styler decorationStyler, StyledString styledString) {
	String label= styledString.getString();
	int originalStart= decoratedString.indexOf(label);
	if (originalStart == -1) {
	return new StyledString(decoratedString); // the decorator did something wild
	}

	if (decoratedString.length() == label.length())
	return styledString;

	if (originalStart > 0) {
	StyledString newString= new StyledString(decoratedString.substring(0, originalStart), decorationStyler);
	newString.append(styledString);
	styledString= newString;
	}
	if (decoratedString.length() > originalStart + label.length()) { // decorator appended something
	return styledString.append(decoratedString.substring(originalStart + label.length()), decorationStyler);
	}
	return styledString; // no change
	}

	}