bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/colors/ColorsPreferencePage.java - platform/eclipse.platform.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2003 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Common Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/cpl-v10.html
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.internal.colors;

 import java.text.MessageFormat;
 import java.util.Arrays;
 import java.util.Comparator;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.ResourceBundle;

 import org.eclipse.jface.dialogs.Dialog;
 import org.eclipse.jface.preference.ColorSelector;
 import org.eclipse.jface.preference.PreferencePage;
 import org.eclipse.jface.resource.JFaceResources;
 import org.eclipse.jface.resource.StringConverter;
 import org.eclipse.jface.util.IPropertyChangeListener;
 import org.eclipse.jface.util.PropertyChangeEvent;
 import org.eclipse.jface.viewers.ArrayContentProvider;
 import org.eclipse.jface.viewers.ISelectionChangedListener;
 import org.eclipse.jface.viewers.IStructuredSelection;
 import org.eclipse.jface.viewers.LabelProvider;
 import org.eclipse.jface.viewers.ListViewer;
 import org.eclipse.jface.viewers.SelectionChangedEvent;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.events.SelectionAdapter;
 import org.eclipse.swt.events.SelectionEvent;
 import org.eclipse.swt.graphics.RGB;
 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.Control;
 import org.eclipse.swt.widgets.Label;
 import org.eclipse.swt.widgets.Text;
 import org.eclipse.ui.IWorkbench;
 import org.eclipse.ui.IWorkbenchPreferencePage;

 /**
  * Preference page for management of system colors defined in the
  * <code>org.eclipse.ui.colorDefinitions</code> extension point.
  *
  * @since 3.0
  */
 public class ColorsPreferencePage
 	extends PreferencePage
 	implements IWorkbenchPreferencePage {

 	/**
 	 * Comparator used in <code>ColorDefinition</code> [] searching.
 	 */
 	private static final Comparator COMPARATOR = new Comparator() {

 		/* (non-Javadoc)
 		 * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
 		 */
 		public int compare(Object arg0, Object arg1) {
 			String str0 = getCompareString(arg0);
 			String str1 = getCompareString(arg1);
 			return str0.compareTo(str1);
 		}

 		/**
 		 * @param object
 		 * @return <code>String</code> representation of the object.
 		 */
 		private String getCompareString(Object object) {
 			if (object instanceof String)
 				return (String) object;
 			else
 				return ((ColorDefinition) object).getId();
 		}
 	};

 	/**
 	 * The translation bundle in which to look up internationalized text.
 	 */
 	private final static ResourceBundle RESOURCE_BUNDLE =
 		ResourceBundle.getBundle(ColorsPreferencePage.class.getName());
 	private ListViewer colorList;

 	private ColorSelector colorSelector;
 	private Text commentText;
 	private Text descriptionText;
 	private Button resetButton;

 	/**
 	 * Map of defintion id->RGB objects that map to changes expressed in this
 	 * UI session.
 	 */
 	private Map valuesToSet = new HashMap(7);

 	/**
 	 * Create a new instance of the receiver.
 	 */
 	public ColorsPreferencePage() {
 	}

 	/**
 	 * Create the color selection control.
 	 *
 	 * @param parent the parent <code>Composite</code>.
 	 */
 	private void createColorControl(Composite parent) {

 		Composite composite = new Composite(parent, SWT.NONE);
 		GridLayout layout = new GridLayout(2, false);
 		layout.marginHeight = 0;
 		layout.marginWidth = 0;
 		composite.setLayout(layout);

 		Label label = new Label(composite, SWT.LEFT);
 		label.setText(RESOURCE_BUNDLE.getString("ColorsPreferencePage.value")); //$NON-NLS-1$
 		Dialog.applyDialogFont(label);
 		GridData data = new GridData(GridData.FILL_HORIZONTAL);
 		data.horizontalSpan = 2;
 		label.setLayoutData(data);

 		colorSelector = new ColorSelector(composite);
 		colorSelector.getButton().setLayoutData(new GridData());
 		colorSelector.setEnabled(false);

 		resetButton = new Button(composite, SWT.PUSH);
 		resetButton.setText(RESOURCE_BUNDLE.getString("ColorsPreferencePage.reset")); //$NON-NLS-1$
 		resetButton.setEnabled(false);
 	}

 	/**
 	 * Create the <code>ListViewer</code> that will contain all color
 	 * definitions as defined in the extension point.
 	 *
 	 * @param parent the parent <code>Composite</code>.
 	 */
 	private void createColorList(Composite parent) {
 		Composite composite = new Composite(parent, SWT.NULL);
 		GridLayout layout = new GridLayout();
 		layout.marginWidth = 0;
 		layout.marginHeight = 0;
 		composite.setLayout(layout);
 		GridData data = new GridData(GridData.FILL_BOTH);
 		data.grabExcessHorizontalSpace = true;
 		composite.setLayoutData(data);

 		Label label = new Label(composite, SWT.LEFT);
 		label.setText(RESOURCE_BUNDLE.getString("ColorsPreferencePage.colors")); //$NON-NLS-1$
 		Dialog.applyDialogFont(label);

 		colorList =
 			new ListViewer(
 				composite,
 				SWT.SINGLE | SWT.H_SCROLL | SWT.V_SCROLL | SWT.BORDER);
 		colorList.setContentProvider(new ArrayContentProvider());
 		colorList.setInput(ColorDefinition.getDefinitions());
 		colorList.setLabelProvider(new LabelProvider() {
 			/* (non-Javadoc)
 			 * @see org.eclipse.jface.viewers.ILabelProvider#getText(java.lang.Object)
 			 */
 			public String getText(Object element) {
 				return ((ColorDefinition) element).getLabel();
 			}
 		});

 		colorList.getControl().setFont(JFaceResources.getViewerFont());
 		data =
 			new GridData(
 				GridData.VERTICAL_ALIGN_BEGINNING | GridData.FILL_BOTH);
 		data.grabExcessHorizontalSpace = true;
 		colorList.getControl().setLayoutData(data);
 	}

 	/**
 	 * Create the text box that will contain the current colors comment text
 	 * (if any).  This includes whether the color is set to its default value or
 	 * and what that might be in the case of a mapping.
 	 *
 	 * @param parent the parent <code>Composite</code>.
 	 */
 	private void createCommentControl(Composite parent) {
 		Composite composite = new Composite(parent, SWT.NONE);
 		GridLayout layout = new GridLayout();
 		layout.marginWidth = 0;
 		layout.marginHeight = 0;
 		composite.setLayout(layout);
 		GridData data = new GridData(GridData.FILL_BOTH);
 		composite.setLayoutData(data);

 		Label label = new Label(composite, SWT.LEFT);
 		label.setText(RESOURCE_BUNDLE.getString("ColorsPreferencePage.comment")); //$NON-NLS-1$
 		Dialog.applyDialogFont(label);

 		commentText =
 			new Text(composite, SWT.READ_ONLY | SWT.BORDER | SWT.WRAP);
 		commentText.setLayoutData(new GridData(GridData.FILL_BOTH));

 	}

 	/* (non-Javadoc)
 	 * @see org.eclipse.jface.preference.PreferencePage#createContents(org.eclipse.swt.widgets.Composite)
 	 */
 	protected Control createContents(Composite parent) {
 		Composite mainColumn = new Composite(parent, SWT.NONE);
 		GridLayout layout = new GridLayout();
 		layout.numColumns = 2;
 		layout.marginWidth = 0;
 		layout.marginHeight = 0;
 		mainColumn.setFont(parent.getFont());
 		mainColumn.setLayout(layout);

 		createColorList(mainColumn);
 		Composite controlColumn = new Composite(mainColumn, SWT.NONE);
 		controlColumn.setLayoutData(new GridData(GridData.FILL_BOTH));
 		layout = new GridLayout();
 		layout.marginHeight = 0;
 		layout.marginWidth = 0;
 		controlColumn.setLayout(layout);

 		createColorControl(controlColumn);
 		createCommentControl(controlColumn);

 		createDescriptionControl(mainColumn);

 		hookListeners();

 		return mainColumn;
 	}

 	/**
 	 * Create the text box that will contain the current colors description
 	 * text (if any).
 	 *
 	 * @param parent the parent <code>Composite</code>.
 	 */
 	private void createDescriptionControl(Composite parent) {
 		Composite composite = new Composite(parent, SWT.NONE);
 		GridLayout layout = new GridLayout();
 		layout.marginWidth = 0;
 		layout.marginHeight = 0;
 		composite.setLayout(layout);
 		GridData data = new GridData(GridData.FILL_BOTH);
 		data.horizontalSpan = 2;
 		composite.setLayoutData(data);

 		Label label = new Label(composite, SWT.LEFT);
 		label.setText(RESOURCE_BUNDLE.getString("ColorsPreferencePage.description")); //$NON-NLS-1$
 		Dialog.applyDialogFont(label);

 		descriptionText =
 			new Text(composite, SWT.READ_ONLY | SWT.BORDER | SWT.WRAP);
 		data = new GridData(GridData.FILL_BOTH);
 		descriptionText.setLayoutData(data);
 	}

 	/**
 	 * Hook all control listeners.
 	 */
 	private void hookListeners() {
 		colorSelector.addListener(new IPropertyChangeListener() {

 			/* (non-Javadoc)
 			 * @see org.eclipse.jface.util.IPropertyChangeListener#propertyChange(org.eclipse.jface.util.PropertyChangeEvent)
 			 */
 			public void propertyChange(PropertyChangeEvent event) {
 				ColorDefinition definition =
 					(ColorDefinition) ((IStructuredSelection) colorList
 						.getSelection())
 						.getFirstElement();

 				RGB newRGB = (RGB) event.getNewValue();
 				if (definition != null && newRGB != null) {
 					valuesToSet.put(definition.getId(), newRGB);
 				}

 				updateControls(definition);
 			}
 		});

 		colorList.addSelectionChangedListener(new ISelectionChangedListener() {

 			/* (non-Javadoc)
 			 * @see org.eclipse.jface.viewers.ISelectionChangedListener#selectionChanged(org.eclipse.jface.viewers.SelectionChangedEvent)
 			 */
 			public void selectionChanged(SelectionChangedEvent event) {
 				if (event.getSelection().isEmpty()) {
 					updateControls(null);
 				} else {
 					updateControls(
 						(ColorDefinition) ((IStructuredSelection) event
 							.getSelection())
 							.getFirstElement());
 				}
 			}
 		});

 		resetButton.addSelectionListener(new SelectionAdapter() {

 			/* (non-Javadoc)
 			 * @see org.eclipse.swt.events.SelectionListener#widgetSelected(org.eclipse.swt.events.SelectionEvent)
 			 */
 			public void widgetSelected(SelectionEvent e) {
 				ColorDefinition definition =
 					(ColorDefinition) ((IStructuredSelection) colorList
 						.getSelection())
 						.getFirstElement();
 				if (resetColor(definition))
 					updateControls(definition);
 			}
 		});
 	}

 	/* (non-Javadoc)
 	 * @see org.eclipse.ui.IWorkbenchPreferencePage#init(org.eclipse.ui.IWorkbench)
 	 */
 	public void init(IWorkbench workbench) {
 		setPreferenceStore(workbench.getPreferenceStore());
 	}

 	/**
 	 * Answers whether the definition is currently set to the default value.
 	 *
 	 * @param definition the <code>ColorDefinition</code> to check.
 	 * @return Return whether the definition is currently mapped to the default
 	 * 		value, either in the preference store or in the local change record
 	 * 		of this preference page.
 	 */
 	private boolean isDefault(ColorDefinition definition) {
 		String id = definition.getId();
 		if (valuesToSet.containsKey(id)) {
 			if (valuesToSet
 				.get(id)
 				.equals(
 					StringConverter.asRGB(
 						getPreferenceStore().getDefaultString(id),
 						null)))
 				return true;

 			return false;
 		}

 		if (getPreferenceStore().isDefault(id))
 			return true;

 		return false;
 	}

 	/* (non-Javadoc)
 	 * @see org.eclipse.jface.preference.PreferencePage#performDefaults()
 	 */
 	protected void performDefaults() {
 		ColorDefinition[] definitions = ColorDefinition.getDefinitions();
 		for (int i = 0; i < definitions.length; i++) {
 			resetColor(definitions[i]);
 		}

 		updateControls(
 			(ColorDefinition) ((IStructuredSelection) colorList.getSelection())
 				.getFirstElement());
 	}

 	/* (non-Javadoc)
 	 * @see org.eclipse.jface.preference.IPreferencePage#performOk()
 	 */
 	public boolean performOk() {
 		for (Iterator i = valuesToSet.keySet().iterator(); i.hasNext();) {
 			String id = (String) i.next();
 			RGB rgb = (RGB) valuesToSet.get(id);
 			String rgbString = StringConverter.asString(rgb);
 			String storeString = getPreferenceStore().getString(id);

 			if (!rgbString.equals(storeString)) {
 				JFaceResources.getColorRegistry().put(id, rgb);
 				getPreferenceStore().setValue(id, rgbString);
 			}
 		}

 		valuesToSet.clear();
 		return true;
 	}

 	/**
 	 * Resets the supplied definition to its default value.
 	 *
 	 * @param definition the <code>ColorDefinition</code> to reset.
 	 * @return whether any change was made.
 	 */
 	private boolean resetColor(ColorDefinition definition) {
 		if (!isDefault(definition)) {
 			RGB newRGB =
 				StringConverter.asRGB(
 					getPreferenceStore().getDefaultString(definition.getId()),
 					null);

 			if (newRGB != null) {
 				valuesToSet.put(definition.getId(), newRGB);
 				return true;
 			}
 		}
 		return false;
 	}

 	/**
 	 * Update the color controls based on the supplied definition.
 	 *
 	 * @param definition The currently selected <code>ColorDefinition</code>.
 	 */
 	private void updateControls(ColorDefinition definition) {
 		if (definition != null) {

 			RGB updatedRGB = (RGB) valuesToSet.get(definition.getId());
 			if (updatedRGB == null)
 				updatedRGB =
 					JFaceResources.getColorRegistry().getRGB(
 						definition.getId());

 			colorSelector.setColorValue(updatedRGB);
 		}
 		if (definition != null) {
 			resetButton.setEnabled(true);
 			colorSelector.setEnabled(true);
 			if (isDefault(definition)) {
 				if (definition.getDefaultsTo() != null) {
 					int idx =
 						Arrays.binarySearch(
 							ColorDefinition.getDefinitions(),
 							definition.getDefaultsTo(),
 							COMPARATOR);

 					if (idx >= 0) {
 						commentText.setText(MessageFormat.format(RESOURCE_BUNDLE.getString("ColorsPreferencePage.currentlyMappedTo"), //$NON-NLS-1$
 						new Object[] {
 							ColorDefinition
 								.getDefinitions()[idx]
 								.getLabel()}));
 					} else
 						commentText.setText(""); //$NON-NLS-1$
 				} else
 					commentText.setText(RESOURCE_BUNDLE.getString("ColorsPreferencePage.currentlyDefault")); //$NON-NLS-1$
 			} else
 				commentText.setText(RESOURCE_BUNDLE.getString("ColorsPreferencePage.customValue")); //$NON-NLS-1$

 			String description = definition.getDescription();
 			descriptionText.setText(description == null ? "" : description); //$NON-NLS-1$
 		} else {
 			resetButton.setEnabled(false);
 			colorSelector.setEnabled(false);
 			commentText.setText(""); //$NON-NLS-1$
 			descriptionText.setText(""); //$NON-NLS-1$
 		}
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2003 IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Common Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/cpl-v10.html
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.ui.internal.colors;

	import java.text.MessageFormat;
	import java.util.Arrays;
	import java.util.Comparator;
	import java.util.HashMap;
	import java.util.Iterator;
	import java.util.Map;
	import java.util.ResourceBundle;

	import org.eclipse.jface.dialogs.Dialog;
	import org.eclipse.jface.preference.ColorSelector;
	import org.eclipse.jface.preference.PreferencePage;
	import org.eclipse.jface.resource.JFaceResources;
	import org.eclipse.jface.resource.StringConverter;
	import org.eclipse.jface.util.IPropertyChangeListener;
	import org.eclipse.jface.util.PropertyChangeEvent;
	import org.eclipse.jface.viewers.ArrayContentProvider;
	import org.eclipse.jface.viewers.ISelectionChangedListener;
	import org.eclipse.jface.viewers.IStructuredSelection;
	import org.eclipse.jface.viewers.LabelProvider;
	import org.eclipse.jface.viewers.ListViewer;
	import org.eclipse.jface.viewers.SelectionChangedEvent;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.events.SelectionAdapter;
	import org.eclipse.swt.events.SelectionEvent;
	import org.eclipse.swt.graphics.RGB;
	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.Control;
	import org.eclipse.swt.widgets.Label;
	import org.eclipse.swt.widgets.Text;
	import org.eclipse.ui.IWorkbench;
	import org.eclipse.ui.IWorkbenchPreferencePage;

	/**
	* Preference page for management of system colors defined in the
	* <code>org.eclipse.ui.colorDefinitions</code> extension point.
	*
	* @since 3.0
	*/
	public class ColorsPreferencePage
	extends PreferencePage
	implements IWorkbenchPreferencePage {

	/**
	* Comparator used in <code>ColorDefinition</code> [] searching.
	*/
	private static final Comparator COMPARATOR = new Comparator() {

	/* (non-Javadoc)
	* @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
	*/
	public int compare(Object arg0, Object arg1) {
	String str0 = getCompareString(arg0);
	String str1 = getCompareString(arg1);
	return str0.compareTo(str1);
	}

	/**
	* @param object
	* @return <code>String</code> representation of the object.
	*/
	private String getCompareString(Object object) {
	if (object instanceof String)
	return (String) object;
	else
	return ((ColorDefinition) object).getId();
	}
	};

	/**
	* The translation bundle in which to look up internationalized text.
	*/
	private final static ResourceBundle RESOURCE_BUNDLE =
	ResourceBundle.getBundle(ColorsPreferencePage.class.getName());
	private ListViewer colorList;

	private ColorSelector colorSelector;
	private Text commentText;
	private Text descriptionText;
	private Button resetButton;

	/**
	* Map of defintion id->RGB objects that map to changes expressed in this
	* UI session.
	*/
	private Map valuesToSet = new HashMap(7);

	/**
	* Create a new instance of the receiver.
	*/
	public ColorsPreferencePage() {
	}

	/**
	* Create the color selection control.
	*
	* @param parent the parent <code>Composite</code>.
	*/
	private void createColorControl(Composite parent) {

	Composite composite = new Composite(parent, SWT.NONE);
	GridLayout layout = new GridLayout(2, false);
	layout.marginHeight = 0;
	layout.marginWidth = 0;
	composite.setLayout(layout);

	Label label = new Label(composite, SWT.LEFT);
	label.setText(RESOURCE_BUNDLE.getString("ColorsPreferencePage.value")); //$NON-NLS-1$
	Dialog.applyDialogFont(label);
	GridData data = new GridData(GridData.FILL_HORIZONTAL);
	data.horizontalSpan = 2;
	label.setLayoutData(data);

	colorSelector = new ColorSelector(composite);
	colorSelector.getButton().setLayoutData(new GridData());
	colorSelector.setEnabled(false);

	resetButton = new Button(composite, SWT.PUSH);
	resetButton.setText(RESOURCE_BUNDLE.getString("ColorsPreferencePage.reset")); //$NON-NLS-1$
	resetButton.setEnabled(false);
	}

	/**
	* Create the <code>ListViewer</code> that will contain all color
	* definitions as defined in the extension point.
	*
	* @param parent the parent <code>Composite</code>.
	*/
	private void createColorList(Composite parent) {
	Composite composite = new Composite(parent, SWT.NULL);
	GridLayout layout = new GridLayout();
	layout.marginWidth = 0;
	layout.marginHeight = 0;
	composite.setLayout(layout);
	GridData data = new GridData(GridData.FILL_BOTH);
	data.grabExcessHorizontalSpace = true;
	composite.setLayoutData(data);

	Label label = new Label(composite, SWT.LEFT);
	label.setText(RESOURCE_BUNDLE.getString("ColorsPreferencePage.colors")); //$NON-NLS-1$
	Dialog.applyDialogFont(label);

	colorList =
	new ListViewer(
	composite,
	SWT.SINGLE \| SWT.H_SCROLL \| SWT.V_SCROLL \| SWT.BORDER);
	colorList.setContentProvider(new ArrayContentProvider());
	colorList.setInput(ColorDefinition.getDefinitions());
	colorList.setLabelProvider(new LabelProvider() {
	/* (non-Javadoc)
	* @see org.eclipse.jface.viewers.ILabelProvider#getText(java.lang.Object)
	*/
	public String getText(Object element) {
	return ((ColorDefinition) element).getLabel();
	}
	});

	colorList.getControl().setFont(JFaceResources.getViewerFont());
	data =
	new GridData(
	GridData.VERTICAL_ALIGN_BEGINNING \| GridData.FILL_BOTH);
	data.grabExcessHorizontalSpace = true;
	colorList.getControl().setLayoutData(data);
	}

	/**
	* Create the text box that will contain the current colors comment text
	* (if any). This includes whether the color is set to its default value or
	* and what that might be in the case of a mapping.
	*
	* @param parent the parent <code>Composite</code>.
	*/
	private void createCommentControl(Composite parent) {
	Composite composite = new Composite(parent, SWT.NONE);
	GridLayout layout = new GridLayout();
	layout.marginWidth = 0;
	layout.marginHeight = 0;
	composite.setLayout(layout);
	GridData data = new GridData(GridData.FILL_BOTH);
	composite.setLayoutData(data);

	Label label = new Label(composite, SWT.LEFT);
	label.setText(RESOURCE_BUNDLE.getString("ColorsPreferencePage.comment")); //$NON-NLS-1$
	Dialog.applyDialogFont(label);

	commentText =
	new Text(composite, SWT.READ_ONLY \| SWT.BORDER \| SWT.WRAP);
	commentText.setLayoutData(new GridData(GridData.FILL_BOTH));

	}

	/* (non-Javadoc)
	* @see org.eclipse.jface.preference.PreferencePage#createContents(org.eclipse.swt.widgets.Composite)
	*/
	protected Control createContents(Composite parent) {
	Composite mainColumn = new Composite(parent, SWT.NONE);
	GridLayout layout = new GridLayout();
	layout.numColumns = 2;
	layout.marginWidth = 0;
	layout.marginHeight = 0;
	mainColumn.setFont(parent.getFont());
	mainColumn.setLayout(layout);

	createColorList(mainColumn);
	Composite controlColumn = new Composite(mainColumn, SWT.NONE);
	controlColumn.setLayoutData(new GridData(GridData.FILL_BOTH));
	layout = new GridLayout();
	layout.marginHeight = 0;
	layout.marginWidth = 0;
	controlColumn.setLayout(layout);

	createColorControl(controlColumn);
	createCommentControl(controlColumn);

	createDescriptionControl(mainColumn);

	hookListeners();

	return mainColumn;
	}

	/**
	* Create the text box that will contain the current colors description
	* text (if any).
	*
	* @param parent the parent <code>Composite</code>.
	*/
	private void createDescriptionControl(Composite parent) {
	Composite composite = new Composite(parent, SWT.NONE);
	GridLayout layout = new GridLayout();
	layout.marginWidth = 0;
	layout.marginHeight = 0;
	composite.setLayout(layout);
	GridData data = new GridData(GridData.FILL_BOTH);
	data.horizontalSpan = 2;
	composite.setLayoutData(data);

	Label label = new Label(composite, SWT.LEFT);
	label.setText(RESOURCE_BUNDLE.getString("ColorsPreferencePage.description")); //$NON-NLS-1$
	Dialog.applyDialogFont(label);

	descriptionText =
	new Text(composite, SWT.READ_ONLY \| SWT.BORDER \| SWT.WRAP);
	data = new GridData(GridData.FILL_BOTH);
	descriptionText.setLayoutData(data);
	}

	/**
	* Hook all control listeners.
	*/
	private void hookListeners() {
	colorSelector.addListener(new IPropertyChangeListener() {

	/* (non-Javadoc)
	* @see org.eclipse.jface.util.IPropertyChangeListener#propertyChange(org.eclipse.jface.util.PropertyChangeEvent)
	*/
	public void propertyChange(PropertyChangeEvent event) {
	ColorDefinition definition =
	(ColorDefinition) ((IStructuredSelection) colorList
	.getSelection())
	.getFirstElement();

	RGB newRGB = (RGB) event.getNewValue();
	if (definition != null && newRGB != null) {
	valuesToSet.put(definition.getId(), newRGB);
	}

	updateControls(definition);
	}
	});

	colorList.addSelectionChangedListener(new ISelectionChangedListener() {

	/* (non-Javadoc)
	* @see org.eclipse.jface.viewers.ISelectionChangedListener#selectionChanged(org.eclipse.jface.viewers.SelectionChangedEvent)
	*/
	public void selectionChanged(SelectionChangedEvent event) {
	if (event.getSelection().isEmpty()) {
	updateControls(null);
	} else {
	updateControls(
	(ColorDefinition) ((IStructuredSelection) event
	.getSelection())
	.getFirstElement());
	}
	}
	});

	resetButton.addSelectionListener(new SelectionAdapter() {

	/* (non-Javadoc)
	* @see org.eclipse.swt.events.SelectionListener#widgetSelected(org.eclipse.swt.events.SelectionEvent)
	*/
	public void widgetSelected(SelectionEvent e) {
	ColorDefinition definition =
	(ColorDefinition) ((IStructuredSelection) colorList
	.getSelection())
	.getFirstElement();
	if (resetColor(definition))
	updateControls(definition);
	}
	});
	}

	/* (non-Javadoc)
	* @see org.eclipse.ui.IWorkbenchPreferencePage#init(org.eclipse.ui.IWorkbench)
	*/
	public void init(IWorkbench workbench) {
	setPreferenceStore(workbench.getPreferenceStore());
	}

	/**
	* Answers whether the definition is currently set to the default value.
	*
	* @param definition the <code>ColorDefinition</code> to check.
	* @return Return whether the definition is currently mapped to the default
	* value, either in the preference store or in the local change record
	* of this preference page.
	*/
	private boolean isDefault(ColorDefinition definition) {
	String id = definition.getId();
	if (valuesToSet.containsKey(id)) {
	if (valuesToSet
	.get(id)
	.equals(
	StringConverter.asRGB(
	getPreferenceStore().getDefaultString(id),
	null)))
	return true;

	return false;
	}

	if (getPreferenceStore().isDefault(id))
	return true;

	return false;
	}

	/* (non-Javadoc)
	* @see org.eclipse.jface.preference.PreferencePage#performDefaults()
	*/
	protected void performDefaults() {
	ColorDefinition[] definitions = ColorDefinition.getDefinitions();
	for (int i = 0; i < definitions.length; i++) {
	resetColor(definitions[i]);
	}

	updateControls(
	(ColorDefinition) ((IStructuredSelection) colorList.getSelection())
	.getFirstElement());
	}

	/* (non-Javadoc)
	* @see org.eclipse.jface.preference.IPreferencePage#performOk()
	*/
	public boolean performOk() {
	for (Iterator i = valuesToSet.keySet().iterator(); i.hasNext();) {
	String id = (String) i.next();
	RGB rgb = (RGB) valuesToSet.get(id);
	String rgbString = StringConverter.asString(rgb);
	String storeString = getPreferenceStore().getString(id);

	if (!rgbString.equals(storeString)) {
	JFaceResources.getColorRegistry().put(id, rgb);
	getPreferenceStore().setValue(id, rgbString);
	}
	}

	valuesToSet.clear();
	return true;
	}

	/**
	* Resets the supplied definition to its default value.
	*
	* @param definition the <code>ColorDefinition</code> to reset.
	* @return whether any change was made.
	*/
	private boolean resetColor(ColorDefinition definition) {
	if (!isDefault(definition)) {
	RGB newRGB =
	StringConverter.asRGB(
	getPreferenceStore().getDefaultString(definition.getId()),
	null);

	if (newRGB != null) {
	valuesToSet.put(definition.getId(), newRGB);
	return true;
	}
	}
	return false;
	}

	/**
	* Update the color controls based on the supplied definition.
	*
	* @param definition The currently selected <code>ColorDefinition</code>.
	*/
	private void updateControls(ColorDefinition definition) {
	if (definition != null) {

	RGB updatedRGB = (RGB) valuesToSet.get(definition.getId());
	if (updatedRGB == null)
	updatedRGB =
	JFaceResources.getColorRegistry().getRGB(
	definition.getId());

	colorSelector.setColorValue(updatedRGB);
	}
	if (definition != null) {
	resetButton.setEnabled(true);
	colorSelector.setEnabled(true);
	if (isDefault(definition)) {
	if (definition.getDefaultsTo() != null) {
	int idx =
	Arrays.binarySearch(
	ColorDefinition.getDefinitions(),
	definition.getDefaultsTo(),
	COMPARATOR);

	if (idx >= 0) {
	commentText.setText(MessageFormat.format(RESOURCE_BUNDLE.getString("ColorsPreferencePage.currentlyMappedTo"), //$NON-NLS-1$
	new Object[] {
	ColorDefinition
	.getDefinitions()[idx]
	.getLabel()}));
	} else
	commentText.setText(""); //$NON-NLS-1$
	} else
	commentText.setText(RESOURCE_BUNDLE.getString("ColorsPreferencePage.currentlyDefault")); //$NON-NLS-1$
	} else
	commentText.setText(RESOURCE_BUNDLE.getString("ColorsPreferencePage.customValue")); //$NON-NLS-1$

	String description = definition.getDescription();
	descriptionText.setText(description == null ? "" : description); //$NON-NLS-1$
	} else {
	resetButton.setEnabled(false);
	colorSelector.setEnabled(false);
	commentText.setText(""); //$NON-NLS-1$
	descriptionText.setText(""); //$NON-NLS-1$
	}
	}
	}