bundles/org.eclipse.e4.ui.css.swt.theme/src/org/eclipse/e4/ui/css/swt/internal/theme/ThemeEngine.java - platform/eclipse.platform.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2010, 2017 Tom Schindl 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:
  *     Tom Schindl <tom.schindl@bestsolution.at> - initial API and implementation
  *     Brian de Alwis - added support for multiple CSS engines
  *     Lars Vogel <Lars.Vogel@gmail.com> - Bug 422702
  *     IBM Corporation - initial API and implementation
  *     Lucas Bullen (Red Hat Inc.) - [Bug 527806] Ship all themes for all OS & WS
  *******************************************************************************/
 package org.eclipse.e4.ui.css.swt.internal.theme;

 import java.io.BufferedOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.URL;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;

 import org.eclipse.core.runtime.Assert;
 import org.eclipse.core.runtime.FileLocator;
 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IExtension;
 import org.eclipse.core.runtime.IExtensionPoint;
 import org.eclipse.core.runtime.IExtensionRegistry;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.Path;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.core.runtime.RegistryFactory;
 import org.eclipse.core.runtime.preferences.IEclipsePreferences;
 import org.eclipse.core.runtime.preferences.InstanceScope;
 import org.eclipse.e4.ui.css.core.engine.CSSElementContext;
 import org.eclipse.e4.ui.css.core.engine.CSSEngine;
 import org.eclipse.e4.ui.css.core.util.impl.resources.FileResourcesLocatorImpl;
 import org.eclipse.e4.ui.css.core.util.impl.resources.OSGiResourceLocator;
 import org.eclipse.e4.ui.css.core.util.resources.IResourceLocator;
 import org.eclipse.e4.ui.css.swt.helpers.EclipsePreferencesHelper;
 import org.eclipse.e4.ui.css.swt.theme.ITheme;
 import org.eclipse.e4.ui.css.swt.theme.IThemeEngine;
 import org.eclipse.osgi.service.datalocation.Location;
 import org.eclipse.swt.widgets.Display;
 import org.osgi.framework.Bundle;
 import org.osgi.framework.BundleContext;
 import org.osgi.framework.FrameworkUtil;
 import org.osgi.framework.ServiceReference;
 import org.osgi.service.event.Event;
 import org.osgi.service.event.EventAdmin;
 import org.osgi.service.prefs.BackingStoreException;
 import org.w3c.css.sac.InputSource;
 import org.w3c.dom.Element;
 import org.w3c.dom.css.CSSStyleDeclaration;

 public class ThemeEngine implements IThemeEngine {
 	private List<Theme> themes = new ArrayList<>();
 	private Map<String, List<String>> themesToVarients = new HashMap<>();
 	private List<CSSEngine> cssEngines = new ArrayList<>();

 	// kept for theme notifications only
 	private Display display;

 	private ITheme currentTheme;

 	private List<String> globalStyles = new ArrayList<>();
 	private List<IResourceLocator> globalSourceLocators = new ArrayList<>();

 	private HashMap<String, List<String>> stylesheets = new HashMap<>();
 	private HashMap<String, List<String>> modifiedStylesheets = new HashMap<>();
 	private HashMap<String, List<IResourceLocator>> sourceLocators = new HashMap<>();

 	private static final String THEMEID_KEY = "themeid";

 	public static final String THEME_PLUGIN_ID = "org.eclipse.e4.ui.css.swt.theme";

 	public ThemeEngine(Display display) {
 		this.display = display;

 		IExtensionRegistry registry = RegistryFactory.getRegistry();
 		IExtensionPoint extPoint = registry
 				.getExtensionPoint("org.eclipse.e4.ui.css.swt.theme");

 		//load any modified style sheets
 		Location configLocation = org.eclipse.core.runtime.Platform.getConfigurationLocation();
 		String e4CSSPath = null;
 		try {
 			URL locationURL = new URL(configLocation.getDataArea(ThemeEngine.THEME_PLUGIN_ID).toString());
 			File locationFile = new File(locationURL.getFile());
 			e4CSSPath = locationFile.getPath();
 		} catch (IOException e1) {
 		}

 		IPath path = new Path(e4CSSPath + System.getProperty("file.separator"));
 		File modDir= new File(path.toFile().toURI());
 		if (!modDir.exists()) {
 			modDir.mkdirs();
 		}

 		//Check for old css files
 		File oldModDir= new File(
 				System.getProperty("user.home") + System.getProperty("file.separator") + ".e4css" + System.getProperty("file.separator")); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
 		if (oldModDir.exists()) {
 			File done = new File(oldModDir, ".processed");
 			if (!done.exists()) {
 				// copy over files into config area
 				try {
 					done.createNewFile();
 					File[] oldModifiedFiles = oldModDir.listFiles();
 					for (File oldModifiedFile : oldModifiedFiles) {
 						if (oldModifiedFile.getName().contains(".css")) {
 							copyFile(oldModifiedFile.getPath(), path
 									+ System.getProperty("file.separator")
 									+ oldModifiedFile.getName());
 						}
 					}
 				} catch (IOException e1) {
 				}
 			}
 		}


 		File[] modifiedFiles = modDir.listFiles();
 		String currentOS = Platform.getOS();
 		String currentWS = Platform.getWS();
 		for (IExtension e : extPoint.getExtensions()) {
 			for (IConfigurationElement ce : e.getConfigurationElements()) {
 				if (ce.getName().equals("theme")) {
 					try {
 						String version = ce.getAttribute("os_version");
 						if (version == null) {
 							version ="";
 						}
 						String originalCSSFile;
 						String basestylesheeturi = originalCSSFile = ce
 								.getAttribute("basestylesheeturi");
 						if (!basestylesheeturi.startsWith("platform:/plugin/")) {
 							basestylesheeturi = "platform:/plugin/"
 									+ ce.getContributor().getName() + "/"
 									+ basestylesheeturi;
 						}
 						final String themeBaseId = ce.getAttribute("id") + version;
 						String themeId = themeBaseId;
 						String label = ce.getAttribute("label");
 						String os = ce.getAttribute("os");
 						String ws = ce.getAttribute("ws");
 						if ((os != null && !os.equals(currentOS)) || (ws != null && !ws.equals(currentWS))) {
 							if (!themesToVarients.containsKey(themeBaseId)) {
 								themesToVarients.put(themeBaseId, new ArrayList<>());
 							}
 							themeId = getVarientThemeId(themeBaseId, os, ws);
 							themesToVarients.get(themeBaseId).add(themeId);
 							label = getVarientThemeLabel(label, os, ws);
 						}
 						registerTheme(
 								themeId, label, basestylesheeturi,
 								version);

 						//check for modified files
 						if (modifiedFiles != null) {
 							int slash = originalCSSFile.lastIndexOf('/');
 							if (slash != -1) {
 								originalCSSFile = originalCSSFile.substring(slash + 1);
 								for (File modifiedFile : modifiedFiles) {
 									String modifiedFileName = modifiedFile.getName();
 									if (modifiedFileName.contains(".css") && modifiedFileName.equals(originalCSSFile)) {  //$NON-NLS-1$
 										//								modifiedStylesheets
 										ArrayList<String> styleSheets = new ArrayList<>();
 										styleSheets.add(modifiedFile.toURI().toString());
 										modifiedStylesheets.put(themeId, styleSheets);
 									}
 								}
 							}
 						}
 					} catch (IllegalArgumentException e1) {
 						ThemeEngineManager.logError(e1.getMessage(), e1);
 					}
 				}
 			}
 		}

 		for (IExtension e : extPoint.getExtensions()) {
 			for (IConfigurationElement ce : e.getConfigurationElements()) {
 				if (ce.getName().equals("stylesheet")) {
 					IConfigurationElement[] cces = ce.getChildren("themeid");
 					if (cces.length == 0) {
 						registerStylesheet("platform:/plugin/"
 								+ ce.getContributor().getName() + "/"
 								+ ce.getAttribute("uri"));

 						for (IConfigurationElement resourceEl : ce
 								.getChildren("osgiresourcelocator")) {
 							String uri = resourceEl.getAttribute("uri");
 							if (uri != null) {
 								registerResourceLocator(new OSGiResourceLocator(
 										uri));
 							}
 						}
 					} else {
 						List<String> themes = new ArrayList<>();
 						for (IConfigurationElement cce : cces) {
 							String refid = cce.getAttribute("refid");
 							List<String> varientOSList = themesToVarients.get(refid);
 							if (varientOSList != null) {
 								themes.addAll(varientOSList);
 							}
 							themes.add(refid);
 						}
 						registerStylesheet(
 								"platform:/plugin/" + ce.getContributor().getName() + "/" + ce.getAttribute("uri"),
 								themes.toArray(new String[themes.size()]));
 						for (IConfigurationElement resourceEl : ce
 								.getChildren("osgiresourcelocator")) {
 							String uri = resourceEl.getAttribute("uri");
 							if (uri != null) {
 								registerResourceLocator(new OSGiResourceLocator(
 										uri));
 							}
 						}
 					}
 				}
 			}
 		}

 		// register a default resolver for platform uri's
 		registerResourceLocator(new OSGiResourceLocator(
 				"platform:/plugin/org.eclipse.ui.themes/css/"));
 		// register a default resolver for file uri's
 		registerResourceLocator(new FileResourcesLocatorImpl());
 		// FIXME: perhaps ResourcesLocatorManager shouldn't have a default?
 		// registerResourceLocator(new HttpResourcesLocatorImpl());
 	}

 	private String getVarientThemeId(String id, String os, String ws) {
 		if (os != null) {
 			id += '_' + os;
 		}
 		if (ws != null) {
 			id += '-' + ws;
 		}
 		return id;
 	}

 	private String getVarientThemeLabel(String label, String os, String ws) {
 		String currentOS = Platform.getOS();
 		String currentWS = Platform.getWS();
 		if (os != null && !os.equals(currentOS)) {
 			String osName;
 			switch (os) {
 			case Platform.OS_AIX:		osName="AIX";break;
 			case Platform.OS_HPUX:		osName="HP/UX";break;
 			case Platform.OS_LINUX:		osName="Linux";break;
 			case Platform.OS_MACOSX:	osName="Mac OS X";break;
 			case Platform.OS_QNX:		osName="QNX";break;
 			case Platform.OS_SOLARIS:	osName="Solaris";break;
 			case Platform.OS_WIN32:		osName="Windows";break;
 			default:					osName=os;break;
 			}
 			label += " [" + osName;
 		}
 		if (ws != null && !ws.equals(currentWS)) {
 			String wsName;
 			switch (ws) {
 			case Platform.WS_CARBON:	wsName="Carbon";break;
 			case Platform.WS_COCOA:		wsName="Cocoa";break;
 			case Platform.WS_GTK:		wsName="GTK";break;
 			case Platform.WS_MOTIF:		wsName="Motif";break;
 			case Platform.WS_PHOTON:	wsName="Photon";break;
 			case Platform.WS_WPF:		wsName="WPF";break;
 			default:					wsName=ws;break;
 			}
 			label += " - " + wsName;
 		}
 		if (os != null && !os.equals(currentOS)) {
 			label += "]";
 		}
 		return label;
 	}

 	@Override
 	public synchronized ITheme registerTheme(String id, String label,
 			String basestylesheetURI) throws IllegalArgumentException {
 		return  registerTheme(id, label, basestylesheetURI, "");
 	}

 	public synchronized ITheme registerTheme(String id, String label,
 			String basestylesheetURI, String osVersion) throws IllegalArgumentException {
 		for (Theme t : themes) {
 			if (t.getId().equals(id)) {
 				throw new IllegalArgumentException("A theme with the id '" + id
 						+ "' is already registered");
 			}
 		}
 		Theme theme = new Theme(id, label);
 		if (osVersion != "") {
 			theme.setOsVersion(osVersion);
 		}
 		themes.add(theme);
 		registerStyle(id, basestylesheetURI);
 		return theme;
 	}

 	@Override
 	public synchronized void registerStylesheet(String uri, String... themes) {
 		Bundle bundle = FrameworkUtil.getBundle(ThemeEngine.class);
 		String osname = bundle.getBundleContext().getProperty("osgi.os");
 		String wsname = bundle.getBundleContext().getProperty("osgi.ws");

 		uri = uri.replaceAll("\\$os\\$", osname).replaceAll("\\$ws\\$", wsname);

 		if (themes.length == 0) {
 			globalStyles.add(uri);
 		} else {
 			for (String t : themes) {
 				registerStyle(t, uri);
 			}
 		}
 	}

 	@Override
 	public synchronized void registerResourceLocator(IResourceLocator locator,
 			String... themes) {
 		if (themes.length == 0) {
 			globalSourceLocators.add(locator);
 		} else {
 			for (String t : themes) {
 				List<IResourceLocator> list = sourceLocators.get(t);
 				if (list == null) {
 					list = new ArrayList<>();
 					sourceLocators.put(t, list);
 				}
 				list.add(locator);
 			}
 		}
 	}

 	private void registerStyle(String id, String stylesheet) {
 		List<String> s = stylesheets.get(id);
 		if (s == null) {
 			s = new ArrayList<>();
 			stylesheets.put(id, s);
 		}
 		s.add(stylesheet);
 	}

 	private List<String> getAllStyles(String id) {
 		// check for any modifications first
 		List<String> m = modifiedStylesheets.get(id);
 		if (m != null) {
 			m = new ArrayList<>(m);
 			m.addAll(globalStyles);
 			return m;
 		}

 		List<String> s = stylesheets.get(id);
 		if (s == null) {
 			s = Collections.emptyList();
 		}

 		s = new ArrayList<>(s);
 		s.addAll(globalStyles);
 		return s;

 	}

 	private List<IResourceLocator> getResourceLocators(String id) {
 		List<IResourceLocator> list = new ArrayList<>(
 				globalSourceLocators);
 		List<IResourceLocator> s = sourceLocators.get(id);
 		if (s != null) {
 			list.addAll(s);
 		}

 		return list;
 	}

 	@Override
 	public void setTheme(String themeId, boolean restore) {
 		String osVersion = System.getProperty("os.version");
 		if (osVersion != null) {
 			boolean found = false;
 			for (Theme t : themes) {
 				String osVersionList = t.getOsVersion();
 				if (osVersionList != null) {
 					String[] osVersions = osVersionList.split(","); //$NON-NLS-1$
 					for (String osVersionFromTheme : osVersions) {
 						if (osVersionFromTheme != null && osVersion.contains(osVersionFromTheme)) {
 							String themeVersion = themeId + osVersionList;
 							if (t.getId().equals(themeVersion)) {
 								setTheme(t, restore);
 								found = true;
 								break;
 							}
 						}
 					}
 				}
 			}
 			if (found) {
 				return;
 			}
 		}
 		//try generic
 		for (Theme t : themes) {
 			if (t.getId().equals(themeId)) {
 				setTheme(t, restore);
 				break;
 			}
 		}
 	}

 	@Override
 	public void setTheme(ITheme theme, boolean restore) {
 		setTheme(theme, restore, false);
 	}

 	public void setTheme(ITheme theme, boolean restore, boolean force) {
 		Assert.isNotNull(theme, "The theme must not be null");

 		if (this.currentTheme != theme || force) {
 			if (currentTheme != null) {
 				for (IResourceLocator l : getResourceLocators(currentTheme
 						.getId())) {
 					for (CSSEngine engine : cssEngines) {
 						engine.getResourcesLocatorManager()
 						.unregisterResourceLocator(l);
 					}
 				}
 			}

 			this.currentTheme = theme;
 			for (CSSEngine engine : cssEngines) {
 				engine.reset();
 			}

 			for (IResourceLocator l : getResourceLocators(theme.getId())) {
 				for (CSSEngine engine : cssEngines) {
 					engine.getResourcesLocatorManager()
 					.registerResourceLocator(l);
 				}
 			}
 			for (String stylesheet : getAllStyles(theme.getId())) {
 				URL url;
 				InputStream stream = null;
 				try {
 					url = FileLocator.resolve(new URL(stylesheet.toString()));
 					for (CSSEngine engine : cssEngines) {
 						try {
 							stream = url.openStream();
 							InputSource source = new InputSource();
 							source.setByteStream(stream);
 							source.setURI(url.toString());
 							engine.parseStyleSheet(source);
 						} catch (IOException e) {
 							ThemeEngineManager.logError(e.getMessage(), e);
 						} finally {
 							if (stream != null) {
 								try {
 									stream.close();
 								} catch (IOException e) {
 									ThemeEngineManager.logError(e.getMessage(), e);
 								}
 							}
 						}
 					}
 				} catch (IOException e) {
 					ThemeEngineManager.logError(e.getMessage(), e);
 				}
 			}
 		}

 		if (restore) {
 			IEclipsePreferences pref = getPreferences();
 			EclipsePreferencesHelper.setPreviousThemeId(pref.get(THEMEID_KEY, null));
 			EclipsePreferencesHelper.setCurrentThemeId(theme.getId());

 			pref.put(THEMEID_KEY, theme.getId());
 			try {
 				pref.flush();
 			} catch (BackingStoreException e) {
 				ThemeEngineManager.logError(e.getMessage(), e);
 			}
 		}
 		sendThemeChangeEvent(restore);

 		for (CSSEngine engine : cssEngines) {
 			engine.reapply();
 		}
 	}

 	/**
 	 * Broadcast theme-change event using OSGi Event Admin.
 	 */
 	private void sendThemeChangeEvent(boolean restore) {
 		EventAdmin eventAdmin = getEventAdmin();
 		if (eventAdmin == null) {
 			return;
 		}
 		Map<String, Object> data = new HashMap<>();
 		data.put(IThemeEngine.Events.THEME_ENGINE, this);
 		data.put(IThemeEngine.Events.THEME, currentTheme);
 		data.put(IThemeEngine.Events.DEVICE, display);
 		data.put(IThemeEngine.Events.RESTORE, restore);
 		Event event = new Event(IThemeEngine.Events.THEME_CHANGED, data);
 		eventAdmin.sendEvent(event); // synchronous
 	}

 	public List<IResourceLocator> getCurrentResourceLocators() {
 		if(currentTheme == null) { return Collections.emptyList(); }
 		return getResourceLocators(currentTheme.getId());
 	}

 	private EventAdmin getEventAdmin() {
 		Bundle bundle = FrameworkUtil.getBundle(this.getClass());
 		if (bundle == null) {
 			return null;
 		}
 		BundleContext context = bundle.getBundleContext();
 		ServiceReference<EventAdmin> eventAdminRef = context
 				.getServiceReference(EventAdmin.class);
 		return context.getService(eventAdminRef);
 	}

 	@Override
 	public synchronized List<ITheme> getThemes() {
 		return Collections.unmodifiableList(new ArrayList<ITheme>(themes));
 	}

 	@Override
 	public void applyStyles(Object widget, boolean applyStylesToChildNodes) {
 		for (CSSEngine engine : cssEngines) {
 			Object element = engine.getElement(widget);
 			if (element != null) {
 				engine.applyStyles(element, applyStylesToChildNodes);
 			}
 		}
 	}

 	private String getPreferenceThemeId() {
 		return getPreferences().get(THEMEID_KEY, null);
 	}

 	private IEclipsePreferences getPreferences() {
 		return InstanceScope.INSTANCE.getNode(
 				FrameworkUtil.getBundle(
 						ThemeEngine.class).getSymbolicName());
 	}

 	void copyFile(String from, String to) throws IOException {
 		FileInputStream fStream = null;
 		BufferedOutputStream outputStream = null;
 		try {
 			fStream = new FileInputStream(from);
 			outputStream = new BufferedOutputStream(new FileOutputStream(to));
 			byte[] buffer = new byte[4096];
 			int c;
 			while ((c = fStream.read(buffer)) != -1) {
 				outputStream.write(buffer, 0, c);
 			}

 		} finally {
 			if (fStream != null) {
 				fStream.close();
 			}
 			if (outputStream != null) {
 				outputStream.close();
 			}
 		}
 	}

 	@Override
 	public void restore(String alternateTheme) {
 		String prefThemeId = getPreferenceThemeId();
 		boolean flag = true;
 		if (prefThemeId != null) {
 			for (ITheme t : getThemes()) {
 				if (prefThemeId.equals(t.getId())) {
 					setTheme(t, false);
 					flag = false;
 					break;
 				}
 			}
 		}

 		if (alternateTheme != null && flag) {
 			setTheme(alternateTheme, false);
 		}
 	}

 	@Override
 	public ITheme getActiveTheme() {
 		return currentTheme;
 	}

 	@Override
 	public CSSStyleDeclaration getStyle(Object widget) {
 		for (CSSEngine engine : cssEngines) {
 			CSSElementContext context = engine.getCSSElementContext(widget);
 			if (context != null) {
 				Element e = context.getElement();
 				if (e != null) {
 					return engine.getViewCSS().getComputedStyle(e, null);
 				}
 			}
 		}
 		return null;
 	}

 	public List<String> getStylesheets(ITheme selection) {
 		List<String> ss  = stylesheets.get(selection.getId());
 		return ss == null ? new ArrayList<>() : ss;
 	}

 	public void themeModified(ITheme theme, List<String> paths) {
 		modifiedStylesheets.put(theme.getId(), paths);
 		setTheme(theme, false, true);
 	}

 	public void resetCurrentTheme() {
 		if (currentTheme != null) {
 			setTheme(currentTheme, false, true);
 		}
 	}

 	public List<String> getModifiedStylesheets(ITheme selection) {
 		List<String> ss  = modifiedStylesheets.get(selection.getId());
 		return ss == null ? new ArrayList<>() : ss;
 	}

 	public void resetModifiedStylesheets(ITheme selection) {
 		modifiedStylesheets.remove(selection.getId());
 	}

 	@Override
 	public void addCSSEngine(CSSEngine cssEngine) {
 		cssEngines.add(cssEngine);
 		resetCurrentTheme();
 	}

 	public Collection<CSSEngine> getCSSEngines() {
 		return cssEngines;
 	}

 	@Override
 	public void removeCSSEngine(CSSEngine cssEngine) {
 		cssEngines.remove(cssEngine);
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2010, 2017 Tom Schindl 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:
	* Tom Schindl <tom.schindl@bestsolution.at> - initial API and implementation
	* Brian de Alwis - added support for multiple CSS engines
	* Lars Vogel <Lars.Vogel@gmail.com> - Bug 422702
	* IBM Corporation - initial API and implementation
	* Lucas Bullen (Red Hat Inc.) - [Bug 527806] Ship all themes for all OS & WS
	*******************************************************************************/
	package org.eclipse.e4.ui.css.swt.internal.theme;

	import java.io.BufferedOutputStream;
	import java.io.File;
	import java.io.FileInputStream;
	import java.io.FileOutputStream;
	import java.io.IOException;
	import java.io.InputStream;
	import java.net.URL;
	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.List;
	import java.util.Map;

	import org.eclipse.core.runtime.Assert;
	import org.eclipse.core.runtime.FileLocator;
	import org.eclipse.core.runtime.IConfigurationElement;
	import org.eclipse.core.runtime.IExtension;
	import org.eclipse.core.runtime.IExtensionPoint;
	import org.eclipse.core.runtime.IExtensionRegistry;
	import org.eclipse.core.runtime.IPath;
	import org.eclipse.core.runtime.Path;
	import org.eclipse.core.runtime.Platform;
	import org.eclipse.core.runtime.RegistryFactory;
	import org.eclipse.core.runtime.preferences.IEclipsePreferences;
	import org.eclipse.core.runtime.preferences.InstanceScope;
	import org.eclipse.e4.ui.css.core.engine.CSSElementContext;
	import org.eclipse.e4.ui.css.core.engine.CSSEngine;
	import org.eclipse.e4.ui.css.core.util.impl.resources.FileResourcesLocatorImpl;
	import org.eclipse.e4.ui.css.core.util.impl.resources.OSGiResourceLocator;
	import org.eclipse.e4.ui.css.core.util.resources.IResourceLocator;
	import org.eclipse.e4.ui.css.swt.helpers.EclipsePreferencesHelper;
	import org.eclipse.e4.ui.css.swt.theme.ITheme;
	import org.eclipse.e4.ui.css.swt.theme.IThemeEngine;
	import org.eclipse.osgi.service.datalocation.Location;
	import org.eclipse.swt.widgets.Display;
	import org.osgi.framework.Bundle;
	import org.osgi.framework.BundleContext;
	import org.osgi.framework.FrameworkUtil;
	import org.osgi.framework.ServiceReference;
	import org.osgi.service.event.Event;
	import org.osgi.service.event.EventAdmin;
	import org.osgi.service.prefs.BackingStoreException;
	import org.w3c.css.sac.InputSource;
	import org.w3c.dom.Element;
	import org.w3c.dom.css.CSSStyleDeclaration;

	public class ThemeEngine implements IThemeEngine {
	private List<Theme> themes = new ArrayList<>();
	private Map<String, List<String>> themesToVarients = new HashMap<>();
	private List<CSSEngine> cssEngines = new ArrayList<>();

	// kept for theme notifications only
	private Display display;

	private ITheme currentTheme;

	private List<String> globalStyles = new ArrayList<>();
	private List<IResourceLocator> globalSourceLocators = new ArrayList<>();

	private HashMap<String, List<String>> stylesheets = new HashMap<>();
	private HashMap<String, List<String>> modifiedStylesheets = new HashMap<>();
	private HashMap<String, List<IResourceLocator>> sourceLocators = new HashMap<>();

	private static final String THEMEID_KEY = "themeid";

	public static final String THEME_PLUGIN_ID = "org.eclipse.e4.ui.css.swt.theme";

	public ThemeEngine(Display display) {
	this.display = display;

	IExtensionRegistry registry = RegistryFactory.getRegistry();
	IExtensionPoint extPoint = registry
	.getExtensionPoint("org.eclipse.e4.ui.css.swt.theme");

	//load any modified style sheets
	Location configLocation = org.eclipse.core.runtime.Platform.getConfigurationLocation();
	String e4CSSPath = null;
	try {
	URL locationURL = new URL(configLocation.getDataArea(ThemeEngine.THEME_PLUGIN_ID).toString());
	File locationFile = new File(locationURL.getFile());
	e4CSSPath = locationFile.getPath();
	} catch (IOException e1) {
	}

	IPath path = new Path(e4CSSPath + System.getProperty("file.separator"));
	File modDir= new File(path.toFile().toURI());
	if (!modDir.exists()) {
	modDir.mkdirs();
	}

	//Check for old css files
	File oldModDir= new File(
	System.getProperty("user.home") + System.getProperty("file.separator") + ".e4css" + System.getProperty("file.separator")); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
	if (oldModDir.exists()) {
	File done = new File(oldModDir, ".processed");
	if (!done.exists()) {
	// copy over files into config area
	try {
	done.createNewFile();
	File[] oldModifiedFiles = oldModDir.listFiles();
	for (File oldModifiedFile : oldModifiedFiles) {
	if (oldModifiedFile.getName().contains(".css")) {
	copyFile(oldModifiedFile.getPath(), path
	+ System.getProperty("file.separator")
	+ oldModifiedFile.getName());
	}
	}
	} catch (IOException e1) {
	}
	}
	}


	File[] modifiedFiles = modDir.listFiles();
	String currentOS = Platform.getOS();
	String currentWS = Platform.getWS();
	for (IExtension e : extPoint.getExtensions()) {
	for (IConfigurationElement ce : e.getConfigurationElements()) {
	if (ce.getName().equals("theme")) {
	try {
	String version = ce.getAttribute("os_version");
	if (version == null) {
	version ="";
	}
	String originalCSSFile;
	String basestylesheeturi = originalCSSFile = ce
	.getAttribute("basestylesheeturi");
	if (!basestylesheeturi.startsWith("platform:/plugin/")) {
	basestylesheeturi = "platform:/plugin/"
	+ ce.getContributor().getName() + "/"
	+ basestylesheeturi;
	}
	final String themeBaseId = ce.getAttribute("id") + version;
	String themeId = themeBaseId;
	String label = ce.getAttribute("label");
	String os = ce.getAttribute("os");
	String ws = ce.getAttribute("ws");
	if ((os != null && !os.equals(currentOS)) \|\| (ws != null && !ws.equals(currentWS))) {
	if (!themesToVarients.containsKey(themeBaseId)) {
	themesToVarients.put(themeBaseId, new ArrayList<>());
	}
	themeId = getVarientThemeId(themeBaseId, os, ws);
	themesToVarients.get(themeBaseId).add(themeId);
	label = getVarientThemeLabel(label, os, ws);
	}
	registerTheme(
	themeId, label, basestylesheeturi,
	version);

	//check for modified files
	if (modifiedFiles != null) {
	int slash = originalCSSFile.lastIndexOf('/');
	if (slash != -1) {
	originalCSSFile = originalCSSFile.substring(slash + 1);
	for (File modifiedFile : modifiedFiles) {
	String modifiedFileName = modifiedFile.getName();
	if (modifiedFileName.contains(".css") && modifiedFileName.equals(originalCSSFile)) { //$NON-NLS-1$
	// modifiedStylesheets
	ArrayList<String> styleSheets = new ArrayList<>();
	styleSheets.add(modifiedFile.toURI().toString());
	modifiedStylesheets.put(themeId, styleSheets);
	}
	}
	}
	}
	} catch (IllegalArgumentException e1) {
	ThemeEngineManager.logError(e1.getMessage(), e1);
	}
	}
	}
	}

	for (IExtension e : extPoint.getExtensions()) {
	for (IConfigurationElement ce : e.getConfigurationElements()) {
	if (ce.getName().equals("stylesheet")) {
	IConfigurationElement[] cces = ce.getChildren("themeid");
	if (cces.length == 0) {
	registerStylesheet("platform:/plugin/"
	+ ce.getContributor().getName() + "/"
	+ ce.getAttribute("uri"));

	for (IConfigurationElement resourceEl : ce
	.getChildren("osgiresourcelocator")) {
	String uri = resourceEl.getAttribute("uri");
	if (uri != null) {
	registerResourceLocator(new OSGiResourceLocator(
	uri));
	}
	}
	} else {
	List<String> themes = new ArrayList<>();
	for (IConfigurationElement cce : cces) {
	String refid = cce.getAttribute("refid");
	List<String> varientOSList = themesToVarients.get(refid);
	if (varientOSList != null) {
	themes.addAll(varientOSList);
	}
	themes.add(refid);
	}
	registerStylesheet(
	"platform:/plugin/" + ce.getContributor().getName() + "/" + ce.getAttribute("uri"),
	themes.toArray(new String[themes.size()]));
	for (IConfigurationElement resourceEl : ce
	.getChildren("osgiresourcelocator")) {
	String uri = resourceEl.getAttribute("uri");
	if (uri != null) {
	registerResourceLocator(new OSGiResourceLocator(
	uri));
	}
	}
	}
	}
	}
	}

	// register a default resolver for platform uri's
	registerResourceLocator(new OSGiResourceLocator(
	"platform:/plugin/org.eclipse.ui.themes/css/"));
	// register a default resolver for file uri's
	registerResourceLocator(new FileResourcesLocatorImpl());
	// FIXME: perhaps ResourcesLocatorManager shouldn't have a default?
	// registerResourceLocator(new HttpResourcesLocatorImpl());
	}

	private String getVarientThemeId(String id, String os, String ws) {
	if (os != null) {
	id += '_' + os;
	}
	if (ws != null) {
	id += '-' + ws;
	}
	return id;
	}

	private String getVarientThemeLabel(String label, String os, String ws) {
	String currentOS = Platform.getOS();
	String currentWS = Platform.getWS();
	if (os != null && !os.equals(currentOS)) {
	String osName;
	switch (os) {
	case Platform.OS_AIX: osName="AIX";break;
	case Platform.OS_HPUX: osName="HP/UX";break;
	case Platform.OS_LINUX: osName="Linux";break;
	case Platform.OS_MACOSX: osName="Mac OS X";break;
	case Platform.OS_QNX: osName="QNX";break;
	case Platform.OS_SOLARIS: osName="Solaris";break;
	case Platform.OS_WIN32: osName="Windows";break;
	default: osName=os;break;
	}
	label += " [" + osName;
	}
	if (ws != null && !ws.equals(currentWS)) {
	String wsName;
	switch (ws) {
	case Platform.WS_CARBON: wsName="Carbon";break;
	case Platform.WS_COCOA: wsName="Cocoa";break;
	case Platform.WS_GTK: wsName="GTK";break;
	case Platform.WS_MOTIF: wsName="Motif";break;
	case Platform.WS_PHOTON: wsName="Photon";break;
	case Platform.WS_WPF: wsName="WPF";break;
	default: wsName=ws;break;
	}
	label += " - " + wsName;
	}
	if (os != null && !os.equals(currentOS)) {
	label += "]";
	}
	return label;
	}

	@Override
	public synchronized ITheme registerTheme(String id, String label,
	String basestylesheetURI) throws IllegalArgumentException {
	return registerTheme(id, label, basestylesheetURI, "");
	}

	public synchronized ITheme registerTheme(String id, String label,
	String basestylesheetURI, String osVersion) throws IllegalArgumentException {
	for (Theme t : themes) {
	if (t.getId().equals(id)) {
	throw new IllegalArgumentException("A theme with the id '" + id
	+ "' is already registered");
	}
	}
	Theme theme = new Theme(id, label);
	if (osVersion != "") {
	theme.setOsVersion(osVersion);
	}
	themes.add(theme);
	registerStyle(id, basestylesheetURI);
	return theme;
	}

	@Override
	public synchronized void registerStylesheet(String uri, String... themes) {
	Bundle bundle = FrameworkUtil.getBundle(ThemeEngine.class);
	String osname = bundle.getBundleContext().getProperty("osgi.os");
	String wsname = bundle.getBundleContext().getProperty("osgi.ws");

	uri = uri.replaceAll("\\$os\\$", osname).replaceAll("\\$ws\\$", wsname);

	if (themes.length == 0) {
	globalStyles.add(uri);
	} else {
	for (String t : themes) {
	registerStyle(t, uri);
	}
	}
	}

	@Override
	public synchronized void registerResourceLocator(IResourceLocator locator,
	String... themes) {
	if (themes.length == 0) {
	globalSourceLocators.add(locator);
	} else {
	for (String t : themes) {
	List<IResourceLocator> list = sourceLocators.get(t);
	if (list == null) {
	list = new ArrayList<>();
	sourceLocators.put(t, list);
	}
	list.add(locator);
	}
	}
	}

	private void registerStyle(String id, String stylesheet) {
	List<String> s = stylesheets.get(id);
	if (s == null) {
	s = new ArrayList<>();
	stylesheets.put(id, s);
	}
	s.add(stylesheet);
	}

	private List<String> getAllStyles(String id) {
	// check for any modifications first
	List<String> m = modifiedStylesheets.get(id);
	if (m != null) {
	m = new ArrayList<>(m);
	m.addAll(globalStyles);
	return m;
	}

	List<String> s = stylesheets.get(id);
	if (s == null) {
	s = Collections.emptyList();
	}

	s = new ArrayList<>(s);
	s.addAll(globalStyles);
	return s;

	}

	private List<IResourceLocator> getResourceLocators(String id) {
	List<IResourceLocator> list = new ArrayList<>(
	globalSourceLocators);
	List<IResourceLocator> s = sourceLocators.get(id);
	if (s != null) {
	list.addAll(s);
	}

	return list;
	}

	@Override
	public void setTheme(String themeId, boolean restore) {
	String osVersion = System.getProperty("os.version");
	if (osVersion != null) {
	boolean found = false;
	for (Theme t : themes) {
	String osVersionList = t.getOsVersion();
	if (osVersionList != null) {
	String[] osVersions = osVersionList.split(","); //$NON-NLS-1$
	for (String osVersionFromTheme : osVersions) {
	if (osVersionFromTheme != null && osVersion.contains(osVersionFromTheme)) {
	String themeVersion = themeId + osVersionList;
	if (t.getId().equals(themeVersion)) {
	setTheme(t, restore);
	found = true;
	break;
	}
	}
	}
	}
	}
	if (found) {
	return;
	}
	}
	//try generic
	for (Theme t : themes) {
	if (t.getId().equals(themeId)) {
	setTheme(t, restore);
	break;
	}
	}
	}

	@Override
	public void setTheme(ITheme theme, boolean restore) {
	setTheme(theme, restore, false);
	}

	public void setTheme(ITheme theme, boolean restore, boolean force) {
	Assert.isNotNull(theme, "The theme must not be null");

	if (this.currentTheme != theme \|\| force) {
	if (currentTheme != null) {
	for (IResourceLocator l : getResourceLocators(currentTheme
	.getId())) {
	for (CSSEngine engine : cssEngines) {
	engine.getResourcesLocatorManager()
	.unregisterResourceLocator(l);
	}
	}
	}

	this.currentTheme = theme;
	for (CSSEngine engine : cssEngines) {
	engine.reset();
	}

	for (IResourceLocator l : getResourceLocators(theme.getId())) {
	for (CSSEngine engine : cssEngines) {
	engine.getResourcesLocatorManager()
	.registerResourceLocator(l);
	}
	}
	for (String stylesheet : getAllStyles(theme.getId())) {
	URL url;
	InputStream stream = null;
	try {
	url = FileLocator.resolve(new URL(stylesheet.toString()));
	for (CSSEngine engine : cssEngines) {
	try {
	stream = url.openStream();
	InputSource source = new InputSource();
	source.setByteStream(stream);
	source.setURI(url.toString());
	engine.parseStyleSheet(source);
	} catch (IOException e) {
	ThemeEngineManager.logError(e.getMessage(), e);
	} finally {
	if (stream != null) {
	try {
	stream.close();
	} catch (IOException e) {
	ThemeEngineManager.logError(e.getMessage(), e);
	}
	}
	}
	}
	} catch (IOException e) {
	ThemeEngineManager.logError(e.getMessage(), e);
	}
	}
	}

	if (restore) {
	IEclipsePreferences pref = getPreferences();
	EclipsePreferencesHelper.setPreviousThemeId(pref.get(THEMEID_KEY, null));
	EclipsePreferencesHelper.setCurrentThemeId(theme.getId());

	pref.put(THEMEID_KEY, theme.getId());
	try {
	pref.flush();
	} catch (BackingStoreException e) {
	ThemeEngineManager.logError(e.getMessage(), e);
	}
	}
	sendThemeChangeEvent(restore);

	for (CSSEngine engine : cssEngines) {
	engine.reapply();
	}
	}

	/**
	* Broadcast theme-change event using OSGi Event Admin.
	*/
	private void sendThemeChangeEvent(boolean restore) {
	EventAdmin eventAdmin = getEventAdmin();
	if (eventAdmin == null) {
	return;
	}
	Map<String, Object> data = new HashMap<>();
	data.put(IThemeEngine.Events.THEME_ENGINE, this);
	data.put(IThemeEngine.Events.THEME, currentTheme);
	data.put(IThemeEngine.Events.DEVICE, display);
	data.put(IThemeEngine.Events.RESTORE, restore);
	Event event = new Event(IThemeEngine.Events.THEME_CHANGED, data);
	eventAdmin.sendEvent(event); // synchronous
	}

	public List<IResourceLocator> getCurrentResourceLocators() {
	if(currentTheme == null) { return Collections.emptyList(); }
	return getResourceLocators(currentTheme.getId());
	}

	private EventAdmin getEventAdmin() {
	Bundle bundle = FrameworkUtil.getBundle(this.getClass());
	if (bundle == null) {
	return null;
	}
	BundleContext context = bundle.getBundleContext();
	ServiceReference<EventAdmin> eventAdminRef = context
	.getServiceReference(EventAdmin.class);
	return context.getService(eventAdminRef);
	}

	@Override
	public synchronized List<ITheme> getThemes() {
	return Collections.unmodifiableList(new ArrayList<ITheme>(themes));
	}

	@Override
	public void applyStyles(Object widget, boolean applyStylesToChildNodes) {
	for (CSSEngine engine : cssEngines) {
	Object element = engine.getElement(widget);
	if (element != null) {
	engine.applyStyles(element, applyStylesToChildNodes);
	}
	}
	}

	private String getPreferenceThemeId() {
	return getPreferences().get(THEMEID_KEY, null);
	}

	private IEclipsePreferences getPreferences() {
	return InstanceScope.INSTANCE.getNode(
	FrameworkUtil.getBundle(
	ThemeEngine.class).getSymbolicName());
	}

	void copyFile(String from, String to) throws IOException {
	FileInputStream fStream = null;
	BufferedOutputStream outputStream = null;
	try {
	fStream = new FileInputStream(from);
	outputStream = new BufferedOutputStream(new FileOutputStream(to));
	byte[] buffer = new byte[4096];
	int c;
	while ((c = fStream.read(buffer)) != -1) {
	outputStream.write(buffer, 0, c);
	}

	} finally {
	if (fStream != null) {
	fStream.close();
	}
	if (outputStream != null) {
	outputStream.close();
	}
	}
	}

	@Override
	public void restore(String alternateTheme) {
	String prefThemeId = getPreferenceThemeId();
	boolean flag = true;
	if (prefThemeId != null) {
	for (ITheme t : getThemes()) {
	if (prefThemeId.equals(t.getId())) {
	setTheme(t, false);
	flag = false;
	break;
	}
	}
	}

	if (alternateTheme != null && flag) {
	setTheme(alternateTheme, false);
	}
	}

	@Override
	public ITheme getActiveTheme() {
	return currentTheme;
	}

	@Override
	public CSSStyleDeclaration getStyle(Object widget) {
	for (CSSEngine engine : cssEngines) {
	CSSElementContext context = engine.getCSSElementContext(widget);
	if (context != null) {
	Element e = context.getElement();
	if (e != null) {
	return engine.getViewCSS().getComputedStyle(e, null);
	}
	}
	}
	return null;
	}

	public List<String> getStylesheets(ITheme selection) {
	List<String> ss = stylesheets.get(selection.getId());
	return ss == null ? new ArrayList<>() : ss;
	}

	public void themeModified(ITheme theme, List<String> paths) {
	modifiedStylesheets.put(theme.getId(), paths);
	setTheme(theme, false, true);
	}

	public void resetCurrentTheme() {
	if (currentTheme != null) {
	setTheme(currentTheme, false, true);
	}
	}

	public List<String> getModifiedStylesheets(ITheme selection) {
	List<String> ss = modifiedStylesheets.get(selection.getId());
	return ss == null ? new ArrayList<>() : ss;
	}

	public void resetModifiedStylesheets(ITheme selection) {
	modifiedStylesheets.remove(selection.getId());
	}

	@Override
	public void addCSSEngine(CSSEngine cssEngine) {
	cssEngines.add(cssEngine);
	resetCurrentTheme();
	}

	public Collection<CSSEngine> getCSSEngines() {
	return cssEngines;
	}

	@Override
	public void removeCSSEngine(CSSEngine cssEngine) {
	cssEngines.remove(cssEngine);
	}
	}