/*******************************************************************************

 * Copyright (c) 2007 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.viewers;

import org.eclipse.core.runtime.Assert;

import org.eclipse.jface.window.Window;

import org.eclipse.swt.SWT;

import org.eclipse.swt.custom.StyleRange;

import org.eclipse.swt.graphics.Color;

import org.eclipse.swt.graphics.Font;

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.Item;

import org.eclipse.swt.widgets.TableItem;

import org.eclipse.swt.widgets.TreeItem;

/**

 * A {@link SimpleStyledCellLabelProvider} supports styled labels by using owner

 * draw by preserving 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 SimpleStyledCellLabelProvider#getLabelPresentationInfo(Object)} to

 * return all information needed to render a element.

 * </p>

 * <p>

 * The {@link SimpleStyledCellLabelProvider} will ignore all font settings on

 * {@link StyleRange}. Different fonts would make labels wider, and the native

 * selection drawing could not be reused.

 * </p>

 * 

 * <p>

 * To set up styled labels for your viewer's control, you must call

 * {@link OwnerDrawLabelProvider#setUpOwnerDraw(ColumnViewer)}.

 * </p>

 * 

 * <p><strong>NOTE:</strong> This API is experimental and may be deleted or

 * changed before 3.4 is released.</p>

 * 

 * @since 3.4

 */

public abstract class SimpleStyledCellLabelProvider extends

		OwnerDrawLabelProvider {

	/**

	 * Holds all information used to render a styled element.

	 */

	public static class LabelPresentationInfo {

		private final String text;

		private final Image image;

		private final StyleRange[] ranges;

		private final Font defaultFont;

		private final Color defaultForegroundColor;

		private final Color defaultBackgroundColor;

		/**

		 * Creates a {@link SimpleStyledCellLabelProvider.LabelPresentationInfo}.

		 * 

		 * @param text

		 *            the text of the current element

		 * @param ranges

		 *            the styled ranges for the element

		 * @param image

		 *            the image for the element or <code>null</code>

		 * @param defaultFont

		 *            the default font for the element or <code>null</code>

		 * @param defaultForegroundColor

		 *            the default foreground color for the element or

		 *            <code>null</code>

		 * @param defaultBackgroundColor

		 *            the default background color for the element or

		 *            <code>null</code>

		 */

		public LabelPresentationInfo(String text, StyleRange[] ranges,

				Image image, Font defaultFont, Color defaultForegroundColor,

				Color defaultBackgroundColor) {

			Assert.isNotNull(text);

			Assert.isNotNull(ranges);

			this.text = text;

			this.ranges = ranges;

			this.image = image;

			this.defaultFont = defaultFont;

			this.defaultForegroundColor = defaultForegroundColor;

			this.defaultBackgroundColor = defaultBackgroundColor;

		}

		/**

		 * Provides the text of the current element.

		 * 

		 * @return returns the text.

		 */

		public String getText() {

			return this.text;

		}

		/**

		 * Provides the styled ranges that can be applied to the text provided

		 * by {@link #getText()}. The {@link SimpleStyledCellLabelProvider}

		 * will ignore all font settings.

		 * 

		 * @return the styled ranges for the element

		 */

		public StyleRange[] getStyleRanges() {

			return this.ranges;

		}

		/**

		 * Provides the image of the current element.

		 * 

		 * @return returns the image.

		 */

		public Image getImage() {

			return this.image;

		}

		/**

		 * Provides a default background color of the current element, which is

		 * used for the part of the label where no background color is specified

		 * in the StyleRanges provided by {@link #getStyleRanges}.

		 * 

		 * @return the background color for the element, or <code>null</code>

		 *         to use the default background color

		 */

		public Color getDefaultBackground() {

			return this.defaultBackgroundColor;

		}

		/**

		 * Provides a default font of the current element.

		 * 

		 * @return the font for the element, or <code>null</code> to use the

		 *         default font

		 */

		public Font getDefaultFont() {

			return this.defaultFont;

		}

		/**

		 * Provides a default foreground color of the current element, which is

		 * used for the part of the label where no foreground color is specified

		 * in the StyleRanges provided by {@link #getStyleRanges}.

		 * 

		 * @return the foreground color for the element, or <code>null</code>

		 *         to use the default foreground color

		 */

		public Color getDefaultForeground() {

			return this.defaultForegroundColor;

		}

	}

	private static final String KEY_TEXT_LAYOUT = "styled_label_key_"; //$NON-NLS-1$

	/**

	 * 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 final int style;

	private TextLayout cachedTextLayout; // reused text layout for

											// 'cachedLabelInfo'

	private LabelPresentationInfo cachedLabelInfo;

	private boolean cachedWasWithColors;

	/**

	 * Creates a new StyledCellLabelProvider. The label provider does not apply

	 * colors on selection.

	 */

	public SimpleStyledCellLabelProvider() {

		this(0);

	}

	/**

	 * Creates a new StyledCellLabelProvider.

	 * 

	 * @param style

	 *            the style bits

	 * @see SimpleStyledCellLabelProvider#COLORS_ON_SELECTION

	 * @see SimpleStyledCellLabelProvider#NO_FOCUS

	 */

	public SimpleStyledCellLabelProvider(int style) {

		this.style = style;

	}

	/**

	 * Returns a {@link LabelPresentationInfo} instance containing the text,

	 * image and style information to use for displaying element.

	 * 

	 * @param element

	 *            the element to create a presentation info for

	 * @return the presentation info

	 */

	protected abstract LabelPresentationInfo getLabelPresentationInfo(

			Object element);

	/*

	 * (non-Javadoc)

	 * 

	 * @see org.eclipse.jface.viewers.BaseLabelProvider#dispose()

	 */

	public void dispose() {

		if (this.cachedTextLayout != null) {

			cachedTextLayout.dispose();

			cachedTextLayout = null;

		}

		cachedLabelInfo = null;

	}

	/*

	 * (non-Javadoc)

	 * 

	 * @see org.eclipse.jface.viewers.OwnerDrawLabelProvider#update(org.eclipse.jface.viewers.ViewerCell)

	 */

	public void update(ViewerCell cell) {

		LabelPresentationInfo info = getLabelPresentationInfo(cell.getElement());

		cell.getItem().setData(KEY_TEXT_LAYOUT + cell.getColumnIndex(), info); // store it in the item

														// to avoid

														// recomputation

		cell.setImage(info.getImage()); // seems to be necessary so that

										// item.getText/ImageBounds work

		cell.setText(info.getText());

		cell.setFont(info.getDefaultFont());

		super.update(cell);

	}

	private TextLayout getSharedTextLayout(Display display) {

		if (cachedTextLayout == null) {

			cachedTextLayout = new TextLayout(display);

			cachedTextLayout.setOrientation(Window.getDefaultOrientation());

		}

		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;

	}

	/**

	 * Returns a {@link LabelPresentationInfo} instance for the given event.

	 * 

	 * @param event

	 *            the measure or paint event for which a TextLayout is needed

	 * @param element

	 *            the model element

	 * @return a TextLayout instance

	 */

	private LabelPresentationInfo getLabelPresentationInfo(Event event,

			Object element) {

		// cache the label info in the data as owner draw labels are requested

		// in a high rate

		LabelPresentationInfo labelInfo = (LabelPresentationInfo) event.item

				.getData(KEY_TEXT_LAYOUT + event.index);

		if (labelInfo == null) {

			labelInfo = getLabelPresentationInfo(element);

			event.item.setData(KEY_TEXT_LAYOUT + event.index, labelInfo);

		}

		return labelInfo;

	}

	/**

	 * Returns a {@link TextLayout} instance for the given

	 * {@link LabelPresentationInfo}. The text layout instance is managed by

	 * the label provider. Caller of the method must not dispose the text

	 * layout.

	 * 

	 * @param diplay

	 *            the current display

	 * @param labelPresentation

	 *            the viewerLabel the label info

	 * 

	 * @param applyColors

	 *            if set, create colors in the result

	 * @param element

	 *            the model element

	 * @return a TextLayout instance

	 */

	private TextLayout getTextLayoutForInfo(Display display,

			LabelPresentationInfo labelPresentation, boolean applyColors) {

		// can use cache?

		if (cachedLabelInfo == labelPresentation

				&& applyColors == cachedWasWithColors) {

			return cachedTextLayout; // use cached layout

		}

		TextLayout sharedLayout = getSharedTextLayout(display);

		applyInfoToLayout(sharedLayout, labelPresentation, applyColors);

		cachedLabelInfo = labelPresentation;

		cachedWasWithColors = applyColors;

		return sharedLayout;

	}

	/**

	 * Fills the given text layout with the styles, text and font of the label

	 * info.

	 * 

	 * @param layout

	 *            the text layout to fill

	 * @param labelInfo

	 *            the viewer label

	 * @param applyColors

	 *            is set, colors will be used

	 */

	private void applyInfoToLayout(TextLayout layout,

			LabelPresentationInfo labelInfo, boolean applyColors) {

		layout.setText(""); // make sure no previous ranges are kept //$NON-NLS-1$

		layout.setText(labelInfo.getText());

		layout.setFont(labelInfo.getDefaultFont()); // set also if null to clear

													// previous usages

		StyleRange[] styleRanges = labelInfo.getStyleRanges();

		for (int i = 0; i < styleRanges.length; i++) {

			StyleRange curr = styleRanges[i];

			// if no colors apply or font is set, create a clone and clear the

			// colors and font

			if (curr.font != null || !applyColors

					&& (curr.foreground != null || curr.background != null)) {

				curr = (StyleRange) curr.clone();

				curr.font = null;

				if (!applyColors) {

					curr.foreground = null;

					curr.background = null;

				}

			}

			layout.setStyle(curr, curr.start, curr.start + curr.length - 1);

		}

	}

	/**

	 * 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) {

		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) {

		// use native measuring

	}

	/*

	 * (non-Javadoc)

	 * 

	 * @see org.eclipse.jface.viewers.OwnerDrawLabelProvider#paint(org.eclipse.swt.widgets.Event,

	 *      java.lang.Object)

	 */

	protected void paint(Event event, Object element) {

		LabelPresentationInfo labelInfo = getLabelPresentationInfo(event,

				element);

		boolean applyColors = useColors(event);

		GC gc = event.gc;

		Color oldForeground = gc.getForeground(); // remember colors to

													// restore the GC later

		Color oldBackground = gc.getBackground();

		if (applyColors) {

			Color foreground = labelInfo.getDefaultForeground();

			if (foreground != null) {

				gc.setForeground(foreground);

			}

			Color background = labelInfo.getDefaultBackground();

			if (background != null) {

				gc.setBackground(background);

			}

		}

		Image image = labelInfo.getImage();

		if (image != null) {

			Rectangle imageBounds = getImageBounds(event);

			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);

		}

		TextLayout textLayout = getTextLayoutForInfo(event.display, labelInfo,

				applyColors);

		Rectangle layoutBounds = textLayout.getBounds();

		Rectangle textBounds = getTextBounds(event);

		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 = getBounds(event);

			gc.drawFocus(focusBounds.x, focusBounds.y, focusBounds.width,

					focusBounds.height);

		}

		gc.setForeground(oldForeground);

		gc.setBackground(oldBackground);

	}

	private Rectangle getBounds(Event event) {

		Item item = (Item) event.item;

		if (item instanceof TreeItem) {

			return ((TreeItem) item).getBounds();

		} else if (item instanceof TableItem) {

			return ((TableItem) item).getBounds();

		}

		return null;

	}

	private Rectangle getImageBounds(Event event) {

		Item item = (Item) event.item;

		if (item instanceof TreeItem) {

			return ((TreeItem) item).getImageBounds(event.index);

		} else if (item instanceof TableItem) {

			return ((TableItem) item).getImageBounds(event.index);

		}

		return null;

	}

	private Rectangle getTextBounds(Event event) {

		Item item = (Item) event.item;

		if (item instanceof TreeItem) {

			return ((TreeItem) item).getTextBounds(event.index);

		} else if (item instanceof TableItem) {

			return ((TableItem) item).getTextBounds(event.index);

		}

		return null;

	}

}

/*******************************************************************************

 * Copyright (c) 2007 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.snippets.viewers;

import java.io.File;

import java.text.MessageFormat;

import org.eclipse.jface.viewers.ColumnViewer;

import org.eclipse.jface.viewers.IBaseLabelProvider;

import org.eclipse.jface.viewers.ILabelProvider;

import org.eclipse.jface.viewers.ITreeContentProvider;

import org.eclipse.jface.viewers.LabelProvider;

import org.eclipse.jface.viewers.OwnerDrawLabelProvider;

import org.eclipse.jface.viewers.SimpleStyledCellLabelProvider;

import org.eclipse.jface.viewers.TableViewer;

import org.eclipse.jface.viewers.Viewer;

import org.eclipse.swt.SWT;

import org.eclipse.swt.custom.StyleRange;

import org.eclipse.swt.graphics.Color;

import org.eclipse.swt.graphics.Image;

import org.eclipse.swt.layout.GridData;

import org.eclipse.swt.layout.GridLayout;

import org.eclipse.swt.widgets.Button;

import org.eclipse.swt.widgets.Composite;

import org.eclipse.swt.widgets.Display;

import org.eclipse.swt.widgets.Event;

import org.eclipse.swt.widgets.Label;

import org.eclipse.swt.widgets.Listener;

import org.eclipse.swt.widgets.Shell;

/**

 * Using a {@link SimpleStyledCellLabelProvider} on table viewer. Compare the result with a native table viewer.

 */

public class Snippet101SimpleStyledCellLabelProvider {

	private static final int SHELL_WIDTH= 640;

	private static final Display DISPLAY= Display.getDefault();

	public static void main(String[] args) {

		Shell shell= new Shell(DISPLAY, SWT.CLOSE | SWT.RESIZE);

		shell.setSize(SHELL_WIDTH, 300);

		shell.setLayout(new GridLayout(1, false));

		Snippet101SimpleStyledCellLabelProvider example= new Snippet101SimpleStyledCellLabelProvider();

		example.createPartControl(shell);

		shell.open();

		while (!shell.isDisposed()) {

			if (!DISPLAY.readAndDispatch()) {

				DISPLAY.sleep();

			}

		}

		DISPLAY.dispose();

	}

	public Snippet101SimpleStyledCellLabelProvider() {

	}

	public void createPartControl(Composite parent) {

		Composite composite= new Composite(parent, SWT.NONE);

		composite.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true, 2, 1));

		composite.setLayout(new GridLayout(2, true));

		ExampleLabelProvider labelProvider= new ExampleLabelProvider();

		final ColumnViewer ownerDrawViewer= createViewer("Owner draw viewer:", composite, new DecoratingLabelProvider(labelProvider)); //$NON-NLS-1$

		OwnerDrawLabelProvider.setUpOwnerDraw(ownerDrawViewer);

		final ColumnViewer normalViewer= createViewer("Normal viewer:", composite, labelProvider); //$NON-NLS-1$

		Button button= new Button(parent, SWT.NONE);

		button.setText("Refresh Viewers"); //$NON-NLS-1$

		button.addListener(SWT.Modify, new Listener() {

			public void handleEvent(Event event) {

				ownerDrawViewer.refresh();

				normalViewer.refresh();

			}

		});

	}

	private ColumnViewer createViewer(String description, Composite parent, IBaseLabelProvider labelProviders) {

		Composite composite= new Composite(parent, SWT.NONE);

		composite.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true, 1, 1));

		composite.setLayout(new GridLayout(1, true));

		Label label= new Label(composite, SWT.NONE);

		label.setLayoutData(new GridData(SWT.BEGINNING, SWT.CENTER, false, false));

		label.setText(description);

		TableViewer tableViewer= new TableViewer(composite, SWT.MULTI | SWT.H_SCROLL | SWT.V_SCROLL);

		tableViewer.setContentProvider(new FileSystemContentProvider());

		tableViewer.setLabelProvider(labelProviders);

		GridData data= new GridData(GridData.FILL, GridData.FILL, true, true);

		tableViewer.getControl().setLayoutData(data);

		File[] roots = File.listRoots();

		File root = null;

		for (int i = 0; i < roots.length; i++) {

			String[] list = roots[i].list();

			if (list != null && list.length > 0) {

				root = roots[i];

				break;

			}

		}

		if (root == null) {

			throw new RuntimeException("couldn't get a non-empty root file");

		}

		tableViewer.setInput(root);

		return tableViewer;

	}

	/**

	 * Implements a {@link SimpleStyledCellLabelProvider} that wraps a normal label

	 * provider and adds some decorations in color

	 */

	private static class DecoratingLabelProvider extends SimpleStyledCellLabelProvider {

		private static final StyleRange[] NO_RANGES= new StyleRange[0];

		private final ILabelProvider fWrappedLabelProvider;

		public DecoratingLabelProvider(ILabelProvider labelProvider) {

			fWrappedLabelProvider= labelProvider;

		}

		protected LabelPresentationInfo getLabelPresentationInfo(Object element) {

			String text= fWrappedLabelProvider.getText(element);

			Image image= fWrappedLabelProvider.getImage(element);

			StyleRange[] ranges= NO_RANGES;

			if (element instanceof File) {

				File file= (File) element;

				if (file.isFile()) {

					String decoration= MessageFormat.format(" ({0} bytes)", new Object[] { new Long(file.length()) }); //$NON-NLS-1$

					int decorationStart= text.length();

					int decorationLength= decoration.length();

					text+= decoration;

					Color decorationColor= Display.getDefault().getSystemColor(SWT.COLOR_DARK_BLUE);

					StyleRange styleRange= new StyleRange(decorationStart, decorationLength, decorationColor, null);

					ranges= new StyleRange[] { styleRange };

				}

			}

			return new LabelPresentationInfo(text, ranges, image, null, null, null);

		}

		public void dispose() {

			super.dispose();

			fWrappedLabelProvider.dispose();

		}

	}

	/**

	 * A simple label provider

	 */

	private static class ExampleLabelProvider extends LabelProvider {

		private static int IMAGE_SIZE= 16;

		private static final Image IMAGE1= new Image(DISPLAY, DISPLAY.getSystemImage(SWT.ICON_WARNING).getImageData().scaledTo(IMAGE_SIZE, IMAGE_SIZE));

		private static final Image IMAGE2= new Image(DISPLAY, DISPLAY.getSystemImage(SWT.ICON_ERROR).getImageData().scaledTo(IMAGE_SIZE, IMAGE_SIZE));

		public Image getImage(Object element) {

			if (element instanceof File) {

				File file= (File) element;

				if (file.isDirectory()) {

					return IMAGE1;

				} else {

					return IMAGE2;

				}

			}

			return null;

		}

		public String getText(Object element) {

			if (element instanceof File) {

				File file= (File) element;

				return file.getName();

			}

			return "null"; //$NON-NLS-1$

		}

	}

	private static class FileSystemContentProvider implements ITreeContentProvider {

		public Object[] getChildren(Object element) {

			if (element instanceof File) {

				File file= (File) element;

				if (file.isDirectory()) {

					File[] listFiles= file.listFiles();

					if (listFiles != null) {

						return listFiles;

					}

				}

			}

			return new Object[0];

		}

		public Object getParent(Object element) {

			if (element instanceof File) {

				File file= (File) element;

				return file.getParentFile();

			}

			return null;

		}

		public boolean hasChildren(Object element) {

			return getChildren(element).length > 0;

		}

		public Object[] getElements(Object inputElement) {

			return getChildren(inputElement);

		}

		public void dispose() {

		}

		public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {

		}

	}

}

/*******************************************************************************

 * Copyright (c) 2007 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.snippets.viewers;

import java.io.File;

import java.text.MessageFormat;

import java.util.Date;

import org.eclipse.jface.viewers.CellLabelProvider;

import org.eclipse.jface.viewers.ColumnLabelProvider;

import org.eclipse.jface.viewers.ColumnViewer;

import org.eclipse.jface.viewers.IBaseLabelProvider;

import org.eclipse.jface.viewers.ILabelProvider;

import org.eclipse.jface.viewers.ITreeContentProvider;

import org.eclipse.jface.viewers.OwnerDrawLabelProvider;

import org.eclipse.jface.viewers.SimpleStyledCellLabelProvider;

import org.eclipse.jface.viewers.TreeViewer;

import org.eclipse.jface.viewers.TreeViewerColumn;

import org.eclipse.jface.viewers.Viewer;

import org.eclipse.swt.SWT;

import org.eclipse.swt.custom.StyleRange;

import org.eclipse.swt.graphics.Color;

import org.eclipse.swt.graphics.Image;

import org.eclipse.swt.layout.GridData;

import org.eclipse.swt.layout.GridLayout;

import org.eclipse.swt.widgets.Button;

import org.eclipse.swt.widgets.Composite;

import org.eclipse.swt.widgets.Display;

import org.eclipse.swt.widgets.Event;

import org.eclipse.swt.widgets.Label;

import org.eclipse.swt.widgets.Listener;

import org.eclipse.swt.widgets.Shell;

/**

 * Using a {@link SimpleStyledCellLabelProvider} on tree viewer. Compare the result with a native tree viewer.

 */

public class Snippet100SimpleStyledCellLabelProvider {

	private static final int SHELL_WIDTH= 640;

	private static final Display DISPLAY= Display.getDefault();

	public static void main(String[] args) {

		Shell shell= new Shell(DISPLAY, SWT.CLOSE | SWT.RESIZE);

		shell.setSize(SHELL_WIDTH, 300);

		shell.setLayout(new GridLayout(1, false));

		Snippet100SimpleStyledCellLabelProvider example= new Snippet100SimpleStyledCellLabelProvider();

		example.createPartControl(shell);

		shell.open();

		while (!shell.isDisposed()) {

			if (!DISPLAY.readAndDispatch()) {

				DISPLAY.sleep();

			}

		}

		DISPLAY.dispose();

	}

	public Snippet100SimpleStyledCellLabelProvider() {

	}

	public void createPartControl(Composite parent) {

		Composite composite= new Composite(parent, SWT.NONE);

		composite.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true, 2, 1));

		composite.setLayout(new GridLayout(2, true));

		ExampleLabelProvider labelProvider= new ExampleLabelProvider();

		ModifiedDateLabelProvider dateLabelProvider= new ModifiedDateLabelProvider();

		final ColumnViewer ownerDrawViewer= createViewer("Owner draw viewer:", composite, new DecoratingLabelProvider(labelProvider), new DecoratingDateLabelProvider(dateLabelProvider)); //$NON-NLS-1$

		OwnerDrawLabelProvider.setUpOwnerDraw(ownerDrawViewer);

		final ColumnViewer normalViewer= createViewer("Normal viewer:", composite, labelProvider, dateLabelProvider); //$NON-NLS-1$

		Button button= new Button(parent, SWT.NONE);

		button.setText("Refresh Viewers"); //$NON-NLS-1$

		button.addListener(SWT.Modify, new Listener() {

			public void handleEvent(Event event) {

				ownerDrawViewer.refresh();

				normalViewer.refresh();

			}

		});

	}

	private ColumnViewer createViewer(String description, Composite parent, CellLabelProvider labelProvider1, CellLabelProvider labelProvider2) {

		Composite composite= new Composite(parent, SWT.NONE);

		composite.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true, 1, 1));

		composite.setLayout(new GridLayout(1, true));

		Label label= new Label(composite, SWT.NONE);

		label.setLayoutData(new GridData(SWT.BEGINNING, SWT.CENTER, false, false));

		label.setText(description);

		TreeViewer treeViewer= new TreeViewer(composite, SWT.MULTI | SWT.H_SCROLL | SWT.V_SCROLL);

		treeViewer.getTree().setHeaderVisible(true);

		treeViewer.setContentProvider(new FileSystemContentProvider());

		TreeViewerColumn tvc1 = new TreeViewerColumn(treeViewer, SWT.NONE);

		tvc1.getColumn().setText("Name");

		tvc1.getColumn().setWidth(200);

		tvc1.setLabelProvider(labelProvider1);

		TreeViewerColumn tvc2 = new TreeViewerColumn(treeViewer, SWT.NONE);

		tvc2.getColumn().setText("Date Modified");

		tvc2.getColumn().setWidth(200);

		tvc2.setLabelProvider(labelProvider2);

		GridData data= new GridData(GridData.FILL, GridData.FILL, true, true);

		treeViewer.getControl().setLayoutData(data);

		File[] roots = File.listRoots();

		File root = null;

		for (int i = 0; i < roots.length; i++) {

			String[] list = roots[i].list();

			if (list != null && list.length > 0) {

				root = roots[i];

				break;

			}

		}

		if (root == null) {

			throw new RuntimeException("couldn't get a non-empty root file");

		}

		treeViewer.setInput(root);

		return treeViewer;

	}

	/**

	 * Implements a {@link SimpleStyledCellLabelProvider} that wraps a normal label

	 * provider and adds some decorations in color

	 */

	private static class DecoratingLabelProvider extends SimpleStyledCellLabelProvider {

		private static final StyleRange[] NO_RANGES= new StyleRange[0];

		private final ILabelProvider fWrappedLabelProvider;

		public DecoratingLabelProvider(ILabelProvider labelProvider) {

			fWrappedLabelProvider= labelProvider;

		}

		protected LabelPresentationInfo getLabelPresentationInfo(Object element) {

			String text= fWrappedLabelProvider.getText(element);

			Image image= fWrappedLabelProvider.getImage(element);

			StyleRange[] ranges= NO_RANGES;

			if (element instanceof File) {

				File file= (File) element;

				if (file.isFile()) {

					String decoration= MessageFormat.format(" ({0} bytes)", new Object[] { new Long(file.length()) }); //$NON-NLS-1$

					int decorationStart= text.length();

					int decorationLength= decoration.length();

					text+= decoration;

					Color decorationColor= Display.getDefault().getSystemColor(SWT.COLOR_DARK_BLUE);

					StyleRange styleRange= new StyleRange(decorationStart, decorationLength, decorationColor, null);

					ranges= new StyleRange[] { styleRange };

				}

			}

			return new LabelPresentationInfo(text, ranges, image, null, null, null);

		}

		public void dispose() {

			super.dispose();

			fWrappedLabelProvider.dispose();

		}

	}

	private static class DecoratingDateLabelProvider extends SimpleStyledCellLabelProvider {

		private static final String[] DAYS = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};

		private static final StyleRange[] NO_RANGES= new StyleRange[0];

		private final ILabelProvider fWrappedLabelProvider;

		public DecoratingDateLabelProvider(ILabelProvider labelProvider) {

			fWrappedLabelProvider= labelProvider;

		}

		protected LabelPresentationInfo getLabelPresentationInfo(Object element) {

			String text= fWrappedLabelProvider.getText(element);

			Image image= fWrappedLabelProvider.getImage(element);

			StyleRange[] ranges= NO_RANGES;

			if (element instanceof File) {

				File file= (File) element;

				String decoration= " " + DAYS[new Date(file.lastModified()).getDay()]; 

				int decorationStart= text.length();

				int decorationLength= decoration.length();

				text+= decoration;

				Color decorationColor= Display.getDefault().getSystemColor(SWT.COLOR_GRAY);

				StyleRange styleRange= new StyleRange(decorationStart, decorationLength, decorationColor, null);

				ranges= new StyleRange[] { styleRange };

			}

			return new LabelPresentationInfo(text, ranges, image, null, null, null);

		}

		public void dispose() {

			super.dispose();

			fWrappedLabelProvider.dispose();

		}

	}

	/**

	 * A simple label provider

	 */

	private static class ExampleLabelProvider extends ColumnLabelProvider {

		private static int IMAGE_SIZE= 16;

		private static final Image IMAGE1= new Image(DISPLAY, DISPLAY.getSystemImage(SWT.ICON_WARNING).getImageData().scaledTo(IMAGE_SIZE, IMAGE_SIZE));

		private static final Image IMAGE2= new Image(DISPLAY, DISPLAY.getSystemImage(SWT.ICON_ERROR).getImageData().scaledTo(IMAGE_SIZE, IMAGE_SIZE));

		public Image getImage(Object element) {

			if (element instanceof File) {

				File file= (File) element;

				if (file.isDirectory()) {

					return IMAGE1;

				} else {

					return IMAGE2;

				}

			}

			return null;

		}

		public String getText(Object element) {

			if (element instanceof File) {

				File file= (File) element;

				return file.getName();

			}

			return "null"; //$NON-NLS-1$

		}

	}

	private static class ModifiedDateLabelProvider extends ColumnLabelProvider {

		public String getText(Object element) {

			if (element instanceof File) {

				File file= (File) element;

				return new Date(file.lastModified()).toLocaleString();

			}

			return "-"; //$NON-NLS-1$

		}

	}

	private static class FileSystemContentProvider implements ITreeContentProvider {

		public Object[] getChildren(Object element) {

			if (element instanceof File) {

				File file= (File) element;

				if (file.isDirectory()) {

					File[] listFiles= file.listFiles();

					if (listFiles != null) {

						return listFiles;

					}

				}

			}

			return new Object[0];

		}

		public Object getParent(Object element) {

			if (element instanceof File) {

				File file= (File) element;

				return file.getParentFile();

			}

			return null;

		}

		public boolean hasChildren(Object element) {

			return getChildren(element).length > 0;

		}

		public Object[] getElements(Object inputElement) {

			return getChildren(inputElement);

		}

		public void dispose() {

		}

		public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {

		}

	}

}