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

 /*******************************************************************************
  * Copyright (c) 2004, 2006 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.ui.internal.themes;

 import java.util.Collection;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.ResourceBundle;

 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IExtensionRegistry;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.jface.resource.StringConverter;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.internal.WorkbenchPlugin;
 import org.eclipse.ui.internal.registry.IWorkbenchRegistryConstants;
 import org.eclipse.ui.internal.registry.RegistryReader;
 import org.eclipse.ui.themes.IColorFactory;

 /**
  * Registry reader for themes.
  *
  * @since 3.0
  */
 public class ThemeRegistryReader extends RegistryReader {

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

     private Collection categoryDefinitions = new HashSet();

     private Collection colorDefinitions = new HashSet();

     private Collection fontDefinitions = new HashSet();

     private ThemeDescriptor themeDescriptor = null;

     private ThemeRegistry themeRegistry;

     private Map dataMap = new HashMap();

     /**
      * ThemeRegistryReader constructor comment.
      */
     public ThemeRegistryReader() {
         super();
     }

     /**
      * Returns the category definitions.
      *
      * @return the category definitions
      */
     public Collection getCategoryDefinitions() {
         return categoryDefinitions;
     }

     /**
      * Returns the color definitions.
      *
      * @return the color definitions
      */
     public Collection getColorDefinitions() {
         return colorDefinitions;
     }

     /**
      * Returns the data map.
      *
      * @return the data map
      */
     public Map getData() {
         return dataMap;
     }

     /**
      * Returns the font definitions.
      *
      * @return the font definitions
      */
     public Collection getFontDefinitions() {
         return fontDefinitions;
     }

     /**
      * Read a category.
      *
      * @param element the element to read
      * @return the new category
      */
     private ThemeElementCategory readCategory(IConfigurationElement element) {
         String name = element.getAttribute(IWorkbenchRegistryConstants.ATT_LABEL);

         String id = element.getAttribute(IWorkbenchRegistryConstants.ATT_ID);
         String parentId = element.getAttribute(IWorkbenchRegistryConstants.ATT_PARENT_ID);

         String description = null;

         IConfigurationElement[] descriptions = element
                 .getChildren(IWorkbenchRegistryConstants.TAG_DESCRIPTION);

         if (descriptions.length > 0) {
 			description = descriptions[0].getValue();
 		}

         return new ThemeElementCategory(name, id, parentId, description,
                 element.getNamespace(), element);
     }

     /**
      * Read a color.
      *
      * @param element the element to read
      * @return the new color
      */
     private ColorDefinition readColor(IConfigurationElement element) {
         String name = element.getAttribute(IWorkbenchRegistryConstants.ATT_LABEL);

         String id = element.getAttribute(IWorkbenchRegistryConstants.ATT_ID);

         String defaultMapping = element.getAttribute(IWorkbenchRegistryConstants.ATT_DEFAULTS_TO);

         String value = getPlatformSpecificColorValue(element
                 .getChildren(IWorkbenchRegistryConstants.TAG_COLORVALUE));

         if (value == null) {
             value = getColorValue(element);
         }

         if ((value == null && defaultMapping == null)
                 || (value != null && defaultMapping != null)) {
             logError(element, RESOURCE_BUNDLE.getString("Colors.badDefault")); //$NON-NLS-1$
             return null;
         }

         String categoryId = element.getAttribute(IWorkbenchRegistryConstants.ATT_CATEGORY_ID);

         String description = null;
         boolean isEditable = true;
         String isEditableString = element.getAttribute(IWorkbenchRegistryConstants.ATT_IS_EDITABLE);
         if (isEditableString != null) {
             isEditable = Boolean.valueOf(isEditableString).booleanValue();
         }

         IConfigurationElement[] descriptions = element
                 .getChildren(IWorkbenchRegistryConstants.TAG_DESCRIPTION);

         if (descriptions.length > 0) {
 			description = descriptions[0].getValue();
 		}

         return new ColorDefinition(name, id, defaultMapping, value, categoryId,
                 isEditable, description, element.getDeclaringExtension()
                         .getNamespace());
     }

     /**
      * Gets the color value, either via the value attribute or from a color
      * factory.
      *
      * @param element the element to check
      * @return the color string
      */
     private String getColorValue(IConfigurationElement element) {
         if (element == null) {
 			return null;
 		}

         String value = element.getAttribute(IWorkbenchRegistryConstants.ATT_VALUE);
         if (value == null) {
             value = checkColorFactory(element);
         }
         return value;
     }

     /**
      * Check for platform specific color values.  This will return the
      * "best match" for the current platform.
      *
      * @param elements the elements to check
      * @return the platform specific color, if any
      */
     private String getPlatformSpecificColorValue(
             IConfigurationElement[] elements) {
         return getColorValue(getBestPlatformMatch(elements));
     }

     /**
      * Get the element that has os/ws attributes that best match the current
      * platform.
      *
      * @param elements the elements to check
      * @return the best match, if any
      */
     private IConfigurationElement getBestPlatformMatch(
             IConfigurationElement[] elements) {
         IConfigurationElement match = null;

         String osname = Platform.getOS();
         String wsname = Platform.getWS();

         for (int i = 0; i < elements.length; i++) {
             IConfigurationElement element = elements[i];
             String elementOs = element.getAttribute(IWorkbenchRegistryConstants.ATT_OS);
             String elementWs = element.getAttribute(IWorkbenchRegistryConstants.ATT_WS);

             if (osname.equalsIgnoreCase(elementOs)) {
                 if (wsname.equalsIgnoreCase(elementWs)) {
                     // best possible match.  Return
                     return element;
                 }
                 match = element;
             } else if (wsname.equalsIgnoreCase(elementWs)) {
                 match = element;
             }
         }

         return match;
     }

     /* (non-Javadoc)
      * @see org.eclipse.ui.internal.registry.RegistryReader#readElement(org.eclipse.core.runtime.IConfigurationElement)
      */
     public boolean readElement(IConfigurationElement element) {
         String elementName = element.getName();
         if (themeDescriptor == null && elementName.equals(IWorkbenchRegistryConstants.TAG_COLORDEFINITION)) {
             ColorDefinition definition = readColor(element);
             if (definition != null) {
                 if (!colorDefinitions.contains(definition)) {
 	                colorDefinitions.add(definition);
 	                themeRegistry.add(definition);
                 }
             }
             return true;
         } else if (themeDescriptor != null
                 && elementName.equals(IWorkbenchRegistryConstants.TAG_COLOROVERRIDE)) {
             ColorDefinition definition = readColor(element);
             if (definition != null) {
                 themeDescriptor.add(definition);
             }
             return true;
         } else if (themeDescriptor == null
                 && elementName.equals(IWorkbenchRegistryConstants.TAG_FONTDEFINITION)) {
             FontDefinition definition = readFont(element);
             if (definition != null) {
                 if (!fontDefinitions.contains(definition)) {
 	                fontDefinitions.add(definition);
 	                themeRegistry.add(definition);
                 }
             }
             return true;
         } else if (themeDescriptor != null
                 && elementName.equals(IWorkbenchRegistryConstants.TAG_FONTOVERRIDE)) {
             FontDefinition definition = readFont(element);
             if (definition != null) {
                 themeDescriptor.add(definition);
             }
             return true;
         } else if (themeDescriptor == null
                 && elementName.equals(IWorkbenchRegistryConstants.TAG_CATEGORYDEFINITION)) {
             ThemeElementCategory definition = readCategory(element);
             if (definition != null) {
                 if (!categoryDefinitions.contains(definition)) {
 	                categoryDefinitions.add(definition);
 	                themeRegistry.add(definition);
                 }
             }
             return true;
         } else if (element.getName().equals(IWorkbenchRegistryConstants.TAG_THEME)) {
             if (themeDescriptor != null) {
 				logError(element, RESOURCE_BUNDLE
                         .getString("Themes.badNesting")); //$NON-NLS-1$
 			} else {
                 themeDescriptor = readTheme(element);
                 if (themeDescriptor != null) {
                     readElementChildren(element);
                     themeDescriptor = null;
                 }
                 return true;
             }
         } else if (themeDescriptor != null
                 && elementName.equals(IWorkbenchRegistryConstants.TAG_DESCRIPTION)) {
             themeDescriptor.setDescription(element.getValue());
             return true;
         } else if (elementName.equals(IWorkbenchRegistryConstants.TAG_DATA)) {
             String name = element.getAttribute(IWorkbenchRegistryConstants.ATT_NAME);
             String value = element.getAttribute(IWorkbenchRegistryConstants.ATT_VALUE);
             if (name == null || value == null) {
                 logError(element, RESOURCE_BUNDLE.getString("Data.badData")); //$NON-NLS-1$
             } else {
                 if (themeDescriptor != null) {
                     themeDescriptor.setData(name, value);
                 } else {
                     themeRegistry.setData(name, value);
                     if (!dataMap.containsKey(name)) {
 						dataMap.put(name, value);
 					}
                 }
             }
             return true;
         } else if (elementName.equals(IWorkbenchRegistryConstants.TAG_CATEGORYPRESENTATIONBINDING)) {
             String categoryId = element.getAttribute(IWorkbenchRegistryConstants.ATT_CATEGORY_ID);
             String presentationId = element.getAttribute(IWorkbenchRegistryConstants.ATT_PRESENTATIONID);
             themeRegistry.addCategoryPresentationBinding(categoryId,
                     presentationId);
             return true;
         }

         return false;
     }

     /**
      * Read a font.
      *
      * @param element the element to read
      * @return the new font
      */
     private FontDefinition readFont(IConfigurationElement element) {
         String name = element.getAttribute(IWorkbenchRegistryConstants.ATT_LABEL);

         String id = element.getAttribute(IWorkbenchRegistryConstants.ATT_ID);

         String defaultMapping = element.getAttribute(IWorkbenchRegistryConstants.ATT_DEFAULTS_TO);

         String value = getPlatformSpecificFontValue(element
                 .getChildren(IWorkbenchRegistryConstants.TAG_FONTVALUE));
         if (value == null) {
             value = element.getAttribute(IWorkbenchRegistryConstants.ATT_VALUE);
         }

         if (value != null && defaultMapping != null) {
             logError(element, RESOURCE_BUNDLE.getString("Fonts.badDefault")); //$NON-NLS-1$
             return null;
         }

         String categoryId = element.getAttribute(IWorkbenchRegistryConstants.ATT_CATEGORY_ID);

         boolean isEditable = true;
         String isEditableString = element.getAttribute(IWorkbenchRegistryConstants.ATT_IS_EDITABLE);
         if (isEditableString != null) {
             isEditable = Boolean.valueOf(isEditableString).booleanValue();
         }

         String description = null;

         IConfigurationElement[] descriptions = element
                 .getChildren(IWorkbenchRegistryConstants.TAG_DESCRIPTION);

         if (descriptions.length > 0) {
 			description = descriptions[0].getValue();
 		}

         return new FontDefinition(name, id, defaultMapping, value, categoryId,
                 isEditable, description);
     }

     /**
      * Check for platform specific font values.  This will return the
      * "best match" for the current platform.
      *
      * @param elements the elements to check
      * @return the platform specific font, if any
      */
     private String getPlatformSpecificFontValue(IConfigurationElement[] elements) {
         return getFontValue(getBestPlatformMatch(elements));
     }

     /**
      * Gets the font valu from the value attribute.
      *
      * @param element the element to check
      * @return the font string
      */
     private String getFontValue(IConfigurationElement element) {
         if (element == null) {
 			return null;
 		}

         return element.getAttribute(IWorkbenchRegistryConstants.ATT_VALUE);
     }

     /**
      * Attempt to load the color value from the colorFactory attribute.
      *
      * @param element the element to load from
      * @return the value, or null if it could not be obtained
      */
     private String checkColorFactory(IConfigurationElement element) {
         String value = null;
         if (element.getAttribute(IWorkbenchRegistryConstants.ATT_COLORFACTORY) != null
                 || element.getChildren(IWorkbenchRegistryConstants.ATT_COLORFACTORY).length > 0) {
             try {
                 IColorFactory factory = (IColorFactory) element
                         .createExecutableExtension(IWorkbenchRegistryConstants.ATT_COLORFACTORY);
                 value = StringConverter.asString(factory.createColor());
             } catch (Exception e) {
                 WorkbenchPlugin.log(RESOURCE_BUNDLE
                         .getString("Colors.badFactory"), //$NON-NLS-1$
                         WorkbenchPlugin.getStatus(e));
             }
         }
         return value;
     }

     /**
      * Read a theme.
      *
      * @param element the element to read
      * @return the new theme
      */
     protected ThemeDescriptor readTheme(IConfigurationElement element) {
         ThemeDescriptor desc = null;

         String id = element.getAttribute(ThemeDescriptor.ATT_ID);
         if (id == null) {
 			return null;
 		}
         //see if the theme has already been created in another extension
         desc = (ThemeDescriptor) themeRegistry.findTheme(id);
         //if not, create it
         if (desc == null) {
             desc = new ThemeDescriptor(id);
             themeRegistry.add(desc);
         }
         //set the name as applicable
         desc.extractName(element);

         return desc;
     }

     /**
      * Read the theme extensions within a registry.
      *
      * @param in the registry to read
      * @param out the registry to write to
      */
     public void readThemes(IExtensionRegistry in, ThemeRegistry out) {
         // this does not seem to really ever be throwing an the exception
         setRegistry(out);
         readRegistry(in, PlatformUI.PLUGIN_ID, IWorkbenchRegistryConstants.PL_THEMES);

         // support for old font definitions
         readRegistry(in, PlatformUI.PLUGIN_ID,
                 IWorkbenchRegistryConstants.PL_FONT_DEFINITIONS);
     }

     /**
      * Set the output registry.
      *
      * @param out the output registry
      */
     public void setRegistry(ThemeRegistry out) {
         themeRegistry = out;
     }
 }
	/*******************************************************************************
	* Copyright (c) 2004, 2006 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.ui.internal.themes;

	import java.util.Collection;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.Map;
	import java.util.ResourceBundle;

	import org.eclipse.core.runtime.IConfigurationElement;
	import org.eclipse.core.runtime.IExtensionRegistry;
	import org.eclipse.core.runtime.Platform;
	import org.eclipse.jface.resource.StringConverter;
	import org.eclipse.ui.PlatformUI;
	import org.eclipse.ui.internal.WorkbenchPlugin;
	import org.eclipse.ui.internal.registry.IWorkbenchRegistryConstants;
	import org.eclipse.ui.internal.registry.RegistryReader;
	import org.eclipse.ui.themes.IColorFactory;

	/**
	* Registry reader for themes.
	*
	* @since 3.0
	*/
	public class ThemeRegistryReader extends RegistryReader {

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

	private Collection categoryDefinitions = new HashSet();

	private Collection colorDefinitions = new HashSet();

	private Collection fontDefinitions = new HashSet();

	private ThemeDescriptor themeDescriptor = null;

	private ThemeRegistry themeRegistry;

	private Map dataMap = new HashMap();

	/**
	* ThemeRegistryReader constructor comment.
	*/
	public ThemeRegistryReader() {
	super();
	}

	/**
	* Returns the category definitions.
	*
	* @return the category definitions
	*/
	public Collection getCategoryDefinitions() {
	return categoryDefinitions;
	}

	/**
	* Returns the color definitions.
	*
	* @return the color definitions
	*/
	public Collection getColorDefinitions() {
	return colorDefinitions;
	}

	/**
	* Returns the data map.
	*
	* @return the data map
	*/
	public Map getData() {
	return dataMap;
	}

	/**
	* Returns the font definitions.
	*
	* @return the font definitions
	*/
	public Collection getFontDefinitions() {
	return fontDefinitions;
	}

	/**
	* Read a category.
	*
	* @param element the element to read
	* @return the new category
	*/
	private ThemeElementCategory readCategory(IConfigurationElement element) {
	String name = element.getAttribute(IWorkbenchRegistryConstants.ATT_LABEL);

	String id = element.getAttribute(IWorkbenchRegistryConstants.ATT_ID);
	String parentId = element.getAttribute(IWorkbenchRegistryConstants.ATT_PARENT_ID);

	String description = null;

	IConfigurationElement[] descriptions = element
	.getChildren(IWorkbenchRegistryConstants.TAG_DESCRIPTION);

	if (descriptions.length > 0) {
	description = descriptions[0].getValue();
	}

	return new ThemeElementCategory(name, id, parentId, description,
	element.getNamespace(), element);
	}

	/**
	* Read a color.
	*
	* @param element the element to read
	* @return the new color
	*/
	private ColorDefinition readColor(IConfigurationElement element) {
	String name = element.getAttribute(IWorkbenchRegistryConstants.ATT_LABEL);

	String id = element.getAttribute(IWorkbenchRegistryConstants.ATT_ID);

	String defaultMapping = element.getAttribute(IWorkbenchRegistryConstants.ATT_DEFAULTS_TO);

	String value = getPlatformSpecificColorValue(element
	.getChildren(IWorkbenchRegistryConstants.TAG_COLORVALUE));

	if (value == null) {
	value = getColorValue(element);
	}

	if ((value == null && defaultMapping == null)
	\|\| (value != null && defaultMapping != null)) {
	logError(element, RESOURCE_BUNDLE.getString("Colors.badDefault")); //$NON-NLS-1$
	return null;
	}

	String categoryId = element.getAttribute(IWorkbenchRegistryConstants.ATT_CATEGORY_ID);

	String description = null;
	boolean isEditable = true;
	String isEditableString = element.getAttribute(IWorkbenchRegistryConstants.ATT_IS_EDITABLE);
	if (isEditableString != null) {
	isEditable = Boolean.valueOf(isEditableString).booleanValue();
	}

	IConfigurationElement[] descriptions = element
	.getChildren(IWorkbenchRegistryConstants.TAG_DESCRIPTION);

	if (descriptions.length > 0) {
	description = descriptions[0].getValue();
	}

	return new ColorDefinition(name, id, defaultMapping, value, categoryId,
	isEditable, description, element.getDeclaringExtension()
	.getNamespace());
	}

	/**
	* Gets the color value, either via the value attribute or from a color
	* factory.
	*
	* @param element the element to check
	* @return the color string
	*/
	private String getColorValue(IConfigurationElement element) {
	if (element == null) {
	return null;
	}

	String value = element.getAttribute(IWorkbenchRegistryConstants.ATT_VALUE);
	if (value == null) {
	value = checkColorFactory(element);
	}
	return value;
	}

	/**
	* Check for platform specific color values. This will return the
	* "best match" for the current platform.
	*
	* @param elements the elements to check
	* @return the platform specific color, if any
	*/
	private String getPlatformSpecificColorValue(
	IConfigurationElement[] elements) {
	return getColorValue(getBestPlatformMatch(elements));
	}

	/**
	* Get the element that has os/ws attributes that best match the current
	* platform.
	*
	* @param elements the elements to check
	* @return the best match, if any
	*/
	private IConfigurationElement getBestPlatformMatch(
	IConfigurationElement[] elements) {
	IConfigurationElement match = null;

	String osname = Platform.getOS();
	String wsname = Platform.getWS();

	for (int i = 0; i < elements.length; i++) {
	IConfigurationElement element = elements[i];
	String elementOs = element.getAttribute(IWorkbenchRegistryConstants.ATT_OS);
	String elementWs = element.getAttribute(IWorkbenchRegistryConstants.ATT_WS);

	if (osname.equalsIgnoreCase(elementOs)) {
	if (wsname.equalsIgnoreCase(elementWs)) {
	// best possible match. Return
	return element;
	}
	match = element;
	} else if (wsname.equalsIgnoreCase(elementWs)) {
	match = element;
	}
	}

	return match;
	}

	/* (non-Javadoc)
	* @see org.eclipse.ui.internal.registry.RegistryReader#readElement(org.eclipse.core.runtime.IConfigurationElement)
	*/
	public boolean readElement(IConfigurationElement element) {
	String elementName = element.getName();
	if (themeDescriptor == null && elementName.equals(IWorkbenchRegistryConstants.TAG_COLORDEFINITION)) {
	ColorDefinition definition = readColor(element);
	if (definition != null) {
	if (!colorDefinitions.contains(definition)) {
	colorDefinitions.add(definition);
	themeRegistry.add(definition);
	}
	}
	return true;
	} else if (themeDescriptor != null
	&& elementName.equals(IWorkbenchRegistryConstants.TAG_COLOROVERRIDE)) {
	ColorDefinition definition = readColor(element);
	if (definition != null) {
	themeDescriptor.add(definition);
	}
	return true;
	} else if (themeDescriptor == null
	&& elementName.equals(IWorkbenchRegistryConstants.TAG_FONTDEFINITION)) {
	FontDefinition definition = readFont(element);
	if (definition != null) {
	if (!fontDefinitions.contains(definition)) {
	fontDefinitions.add(definition);
	themeRegistry.add(definition);
	}
	}
	return true;
	} else if (themeDescriptor != null
	&& elementName.equals(IWorkbenchRegistryConstants.TAG_FONTOVERRIDE)) {
	FontDefinition definition = readFont(element);
	if (definition != null) {
	themeDescriptor.add(definition);
	}
	return true;
	} else if (themeDescriptor == null
	&& elementName.equals(IWorkbenchRegistryConstants.TAG_CATEGORYDEFINITION)) {
	ThemeElementCategory definition = readCategory(element);
	if (definition != null) {
	if (!categoryDefinitions.contains(definition)) {
	categoryDefinitions.add(definition);
	themeRegistry.add(definition);
	}
	}
	return true;
	} else if (element.getName().equals(IWorkbenchRegistryConstants.TAG_THEME)) {
	if (themeDescriptor != null) {
	logError(element, RESOURCE_BUNDLE
	.getString("Themes.badNesting")); //$NON-NLS-1$
	} else {
	themeDescriptor = readTheme(element);
	if (themeDescriptor != null) {
	readElementChildren(element);
	themeDescriptor = null;
	}
	return true;
	}
	} else if (themeDescriptor != null
	&& elementName.equals(IWorkbenchRegistryConstants.TAG_DESCRIPTION)) {
	themeDescriptor.setDescription(element.getValue());
	return true;
	} else if (elementName.equals(IWorkbenchRegistryConstants.TAG_DATA)) {
	String name = element.getAttribute(IWorkbenchRegistryConstants.ATT_NAME);
	String value = element.getAttribute(IWorkbenchRegistryConstants.ATT_VALUE);
	if (name == null \|\| value == null) {
	logError(element, RESOURCE_BUNDLE.getString("Data.badData")); //$NON-NLS-1$
	} else {
	if (themeDescriptor != null) {
	themeDescriptor.setData(name, value);
	} else {
	themeRegistry.setData(name, value);
	if (!dataMap.containsKey(name)) {
	dataMap.put(name, value);
	}
	}
	}
	return true;
	} else if (elementName.equals(IWorkbenchRegistryConstants.TAG_CATEGORYPRESENTATIONBINDING)) {
	String categoryId = element.getAttribute(IWorkbenchRegistryConstants.ATT_CATEGORY_ID);
	String presentationId = element.getAttribute(IWorkbenchRegistryConstants.ATT_PRESENTATIONID);
	themeRegistry.addCategoryPresentationBinding(categoryId,
	presentationId);
	return true;
	}

	return false;
	}

	/**
	* Read a font.
	*
	* @param element the element to read
	* @return the new font
	*/
	private FontDefinition readFont(IConfigurationElement element) {
	String name = element.getAttribute(IWorkbenchRegistryConstants.ATT_LABEL);

	String id = element.getAttribute(IWorkbenchRegistryConstants.ATT_ID);

	String defaultMapping = element.getAttribute(IWorkbenchRegistryConstants.ATT_DEFAULTS_TO);

	String value = getPlatformSpecificFontValue(element
	.getChildren(IWorkbenchRegistryConstants.TAG_FONTVALUE));
	if (value == null) {
	value = element.getAttribute(IWorkbenchRegistryConstants.ATT_VALUE);
	}

	if (value != null && defaultMapping != null) {
	logError(element, RESOURCE_BUNDLE.getString("Fonts.badDefault")); //$NON-NLS-1$
	return null;
	}

	String categoryId = element.getAttribute(IWorkbenchRegistryConstants.ATT_CATEGORY_ID);

	boolean isEditable = true;
	String isEditableString = element.getAttribute(IWorkbenchRegistryConstants.ATT_IS_EDITABLE);
	if (isEditableString != null) {
	isEditable = Boolean.valueOf(isEditableString).booleanValue();
	}

	String description = null;

	IConfigurationElement[] descriptions = element
	.getChildren(IWorkbenchRegistryConstants.TAG_DESCRIPTION);

	if (descriptions.length > 0) {
	description = descriptions[0].getValue();
	}

	return new FontDefinition(name, id, defaultMapping, value, categoryId,
	isEditable, description);
	}

	/**
	* Check for platform specific font values. This will return the
	* "best match" for the current platform.
	*
	* @param elements the elements to check
	* @return the platform specific font, if any
	*/
	private String getPlatformSpecificFontValue(IConfigurationElement[] elements) {
	return getFontValue(getBestPlatformMatch(elements));
	}

	/**
	* Gets the font valu from the value attribute.
	*
	* @param element the element to check
	* @return the font string
	*/
	private String getFontValue(IConfigurationElement element) {
	if (element == null) {
	return null;
	}

	return element.getAttribute(IWorkbenchRegistryConstants.ATT_VALUE);
	}

	/**
	* Attempt to load the color value from the colorFactory attribute.
	*
	* @param element the element to load from
	* @return the value, or null if it could not be obtained
	*/
	private String checkColorFactory(IConfigurationElement element) {
	String value = null;
	if (element.getAttribute(IWorkbenchRegistryConstants.ATT_COLORFACTORY) != null
	\|\| element.getChildren(IWorkbenchRegistryConstants.ATT_COLORFACTORY).length > 0) {
	try {
	IColorFactory factory = (IColorFactory) element
	.createExecutableExtension(IWorkbenchRegistryConstants.ATT_COLORFACTORY);
	value = StringConverter.asString(factory.createColor());
	} catch (Exception e) {
	WorkbenchPlugin.log(RESOURCE_BUNDLE
	.getString("Colors.badFactory"), //$NON-NLS-1$
	WorkbenchPlugin.getStatus(e));
	}
	}
	return value;
	}

	/**
	* Read a theme.
	*
	* @param element the element to read
	* @return the new theme
	*/
	protected ThemeDescriptor readTheme(IConfigurationElement element) {
	ThemeDescriptor desc = null;

	String id = element.getAttribute(ThemeDescriptor.ATT_ID);
	if (id == null) {
	return null;
	}
	//see if the theme has already been created in another extension
	desc = (ThemeDescriptor) themeRegistry.findTheme(id);
	//if not, create it
	if (desc == null) {
	desc = new ThemeDescriptor(id);
	themeRegistry.add(desc);
	}
	//set the name as applicable
	desc.extractName(element);

	return desc;
	}

	/**
	* Read the theme extensions within a registry.
	*
	* @param in the registry to read
	* @param out the registry to write to
	*/
	public void readThemes(IExtensionRegistry in, ThemeRegistry out) {
	// this does not seem to really ever be throwing an the exception
	setRegistry(out);
	readRegistry(in, PlatformUI.PLUGIN_ID, IWorkbenchRegistryConstants.PL_THEMES);

	// support for old font definitions
	readRegistry(in, PlatformUI.PLUGIN_ID,
	IWorkbenchRegistryConstants.PL_FONT_DEFINITIONS);
	}

	/**
	* Set the output registry.
	*
	* @param out the output registry
	*/
	public void setRegistry(ThemeRegistry out) {
	themeRegistry = out;
	}
	}