org.eclipse.ui.intro.quicklinks/src/org/eclipse/ui/intro/quicklinks/QuicklinksViewer.java - platform/eclipse.platform.ua - Git at Google

 /*******************************************************************************
  * Copyright (c) 2016 Manumitting Technologies Inc 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:
  *     Manumitting Technologies Inc - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.intro.quicklinks;

 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.io.UnsupportedEncodingException;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLEncoder;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Base64;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.function.Supplier;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;

 import org.eclipse.core.commands.CommandManager;
 import org.eclipse.core.commands.ParameterizedCommand;
 import org.eclipse.core.commands.SerializationException;
 import org.eclipse.core.commands.common.NotDefinedException;
 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.Platform;
 import org.eclipse.jface.resource.ImageDescriptor;
 import org.eclipse.jface.viewers.ArrayContentProvider;
 import org.eclipse.jface.viewers.TableViewer;
 import org.eclipse.osgi.util.NLS;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.graphics.ImageData;
 import org.eclipse.swt.graphics.ImageLoader;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.commands.ICommandImageService;
 import org.eclipse.ui.forms.widgets.FormToolkit;
 import org.eclipse.ui.forms.widgets.Section;
 import org.eclipse.ui.internal.intro.impl.model.AbstractIntroPartImplementation;
 import org.eclipse.ui.internal.intro.impl.model.IntroTheme;
 import org.eclipse.ui.internal.intro.impl.util.Log;
 import org.eclipse.ui.internal.menus.MenuHelper;
 import org.eclipse.ui.intro.config.IIntroContentProvider;
 import org.eclipse.ui.intro.config.IIntroContentProviderSite;
 import org.eclipse.ui.services.IServiceLocator;
 import org.osgi.framework.Bundle;
 import org.osgi.framework.FrameworkUtil;

 /**
  * An Intro content provider that populates a list of frequently-used commands
  * from an extension point. The appearance of these quicklinks is normally taken
  * from the command metadata, including the image icon, but can be tailored.
  * These tailorings can be made optional depending on the current theme.
  *
  * This implementation is still experimental and subject to change. Feedback
  * welcome as a <a href="http://eclip.se/9f">bug report on the Eclipse Bugzilla
  * against Platform/User Assistance</a>.
  */
 @SuppressWarnings("restriction")
 public class QuicklinksViewer implements IIntroContentProvider {

 	/** Represents the importance of an element */
 	enum Importance {
 		HIGH("high", 0), MEDIUM("medium", 1), LOW("low", 2); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$

 		String id;
 		int level;

 		Importance(String text, int importance) {
 			this.id = text;
 			this.level = importance;
 		}

 		public static Importance forId(String id) {
 			for (Importance i : values()) {
 				if (i.id.equals(id)) {
 					return i;
 				}
 			}
 			return LOW;
 		}
 	}

 	/** Model holding the relevant attributes of a Quicklink element */
 	class Quicklink implements Comparable<Quicklink> {
 		String commandSpec;
 		String url;
 		String label;
 		String description;
 		String iconUrl;
 		Importance importance = Importance.MEDIUM;
 		long rank;
 		String resolution;

 		public Quicklink() {
 		}

 		@Override
 		public int compareTo(Quicklink b) {
 			int impA = this.importance.level;
 			int impB = b.importance.level;
 			if (impA != impB) {
 				return impA - impB;
 			}
 			long diff = this.rank - b.rank;
 			if (diff > 0) {
 				return 1;
 			}
 			if (diff < 0) {
 				return -1;
 			}
 			return 0;
 		}
 	}

 	/**
 	 * Responsible for retrieving Quicklinks and applying any icon overrides
 	 */
 	class ModelReader implements Supplier<List<Quicklink>> {
 		private static final String QL_EXT_PT = "org.eclipse.ui.intro.quicklinks"; //$NON-NLS-1$
 		private static final String ELMT_COMMAND = "command"; //$NON-NLS-1$
 		private static final String ATT_ID = "id"; //$NON-NLS-1$
 		private static final String ELMT_URL = "url"; //$NON-NLS-1$
 		private static final String ATT_LOCATION = "location"; //$NON-NLS-1$

 		private static final String ELMT_OVERRIDE = "override"; //$NON-NLS-1$
 		private static final String ATT_COMMANDID = "command"; //$NON-NLS-1$
 		private static final String ATT_THEME = "theme"; //$NON-NLS-1$

 		private static final String ATT_LABEL = "label"; //$NON-NLS-1$
 		private static final String ATT_DESCRIPTION = "description"; //$NON-NLS-1$
 		private static final String ATT_ICON = "icon"; //$NON-NLS-1$
 		private static final String ATT_IMPORTANCE = "importance"; //$NON-NLS-1$
 		private static final String ATT_RESOLUTION = "resolution"; //$NON-NLS-1$

 		/** commandSpec/url &rarr; quicklink */
 		private Map<String, Quicklink> quicklinks = new LinkedHashMap<>();
 		/** bundle symbolic name &rarr; bundle id */
 		private Map<String, Long> bundleIds;
 		private Bundle[] bundles;

 		/**
 		 * Return the list of configured {@link Quicklink} that can be found.
 		 *
 		 * @return
 		 */
 		public List<Quicklink> get() {
 			IExtension extensions[] = getExtensions(QL_EXT_PT);

 			// Process definitions from the product bundle first
 			Bundle productBundle = Platform.getProduct().getDefiningBundle();
 			if(productBundle != null) {
 				for (IExtension ext : extensions) {
 					if (productBundle.getSymbolicName().equals(ext.getNamespaceIdentifier())) {
 						for (IConfigurationElement ce : ext.getConfigurationElements()) {
 							processDefinition(ce);
 						}
 					}
 				}
 			}

 			for (IExtension ext : extensions) {
 				if (productBundle == null || !productBundle.getSymbolicName().equals(ext.getNamespaceIdentifier())) {
 					for (IConfigurationElement ce : ext.getConfigurationElements()) {
 						processDefinition(ce);
 					}
 				}
 			}

 			// Now process all command overrides
 			for (IExtension ext : extensions) {
 				for (IConfigurationElement ce : ext.getConfigurationElements()) {
 					if (!ELMT_OVERRIDE.equals(ce.getName())) {
 						continue;
 					}
 					String theme = ce.getAttribute(ATT_THEME);
 					String commandSpecPattern = ce.getAttribute(ATT_COMMANDID);
 					String icon = ce.getAttribute(ATT_ICON);
 					if (theme != null && icon != null && Objects.equals(theme, getCurrentThemeId())
 							&& commandSpecPattern != null) {
 						findMatchingQuicklinks(commandSpecPattern)
 								.forEach(ql -> ql.iconUrl = getImageURL(ce, ATT_ICON));
 					}
 				}
 			}
 			return new ArrayList<>(quicklinks.values());
 		}

 		private void processDefinition(IConfigurationElement ce) {
 			if (!ELMT_COMMAND.equals(ce.getName()) && !ELMT_URL.equals(ce.getName())) {
 				return;
 			}

 			String key = null;
 			Quicklink ql = new Quicklink();
 			if (ELMT_COMMAND.equals(ce.getName())) {
 				key = ce.getAttribute(ATT_ID);
 				if (key == null) {
 					Log.warning(NLS.bind("Skipping '{0}': missing {1}", ce.getName(), ATT_ID)); //$NON-NLS-1$
 					return;
 				}
 				ql.commandSpec = key;
 				ql.label = ce.getAttribute(ATT_LABEL);
 				ql.description = ce.getAttribute(ATT_DESCRIPTION);
 				ql.iconUrl = getImageURL(ce, ATT_ICON);
 			} else if (ELMT_URL.equals(ce.getName())) {
 				key = ce.getAttribute(ATT_LOCATION);
 				if (key == null) {
 					Log.warning(NLS.bind("Skipping '{0}': missing {1}", ELMT_URL, ATT_LOCATION)); //$NON-NLS-1$
 					return;
 				}
 				ql.url = key;
 				ql.label = ce.getAttribute(ATT_LABEL);
 				ql.description = ce.getAttribute(ATT_DESCRIPTION);
 				ql.iconUrl = getImageURL(ce, ATT_ICON);
 			}
 			ql.rank = getRank(ce.getContributor().getName());
 			if (ce.getAttribute(ATT_IMPORTANCE) != null) {
 				ql.importance = Importance.forId(ce.getAttribute(ATT_IMPORTANCE));
 			}
 			if (ce.getAttribute(ATT_RESOLUTION) != null) {
 				ql.resolution = ce.getAttribute(ATT_RESOLUTION);
 			}
 			// discard if already seen
 			quicklinks.putIfAbsent(key, ql);
 		}

 		/**
 		 * Find {@link Quicklink}s whose {@code commandSpec} matches the simple
 		 * wildcard pattern in {@code commandSpecPattern}
 		 *
 		 * @param commandSpecPattern
 		 *            a simple wildcard pattern supporting *, ?
 		 * @return the set of matching Quicklinks
 		 */
 		private Stream<Quicklink> findMatchingQuicklinks(String commandSpecPattern) {
 			// transform simple wildcards into regexp
 			String regexp = commandSpecPattern.replace(".", "\\.").replace("(", "\\(").replace(")", "\\)") //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ //$NON-NLS-5$ //$NON-NLS-6$
 					.replace("*", ".*"); //$NON-NLS-1$ //$NON-NLS-2$
 			final Pattern pattern = Pattern.compile(regexp);
 			return quicklinks.values().stream().filter(
 					ql -> ql.commandSpec != null && (commandSpecPattern.equals(ql.commandSpec)
 							|| pattern.matcher(ql.commandSpec).matches()));
 		}

 		private IExtension[] getExtensions(String extPtId) {
 			IExtensionRegistry registry = locator.getService(IExtensionRegistry.class);
 			IExtensionPoint extPt = registry.getExtensionPoint(extPtId);
 			return extPt == null ? new IExtension[0] : extPt.getExtensions();
 		}


 		private long getRank(String bundleSymbolicName) {
 			if (bundleIds == null) {
 				Bundle bundle = FrameworkUtil.getBundle(getClass());
 				bundleIds = new HashMap<>();
 				bundles = bundle.getBundleContext().getBundles();
 			}
 			return bundleIds.computeIfAbsent(bundleSymbolicName, bsn -> {
 				for (Bundle b : bundles) {
 					if (bsn.equals(b.getSymbolicName())
 							&& (b.getState() & (Bundle.INSTALLED | Bundle.UNINSTALLED)) == 0) {
 						return b.getBundleId();
 					}
 				}
 				return Long.MAX_VALUE;
 			});
 		}

 		/**
 		 * @return URL to image, suitable for using in an external browser; may
 		 *         be a <code>data:</code> URL; may be null
 		 */
 		private String getImageURL(IConfigurationElement ce, String attr) {
 			String iconURL = MenuHelper.getIconURI(ce, attr);
 			if (iconURL != null) {
 				return asBrowserURL(iconURL);
 			}
 			return null;
 		}
 	}

 	/** Source: http://stackoverflow.com/a/417184 */
 	private static final int MAX_URL_LENGTH = 2083;

 	private IIntroContentProviderSite site;
 	private IServiceLocator locator;
 	private CommandManager manager;
 	private ICommandImageService images;
 	private Supplier<List<Quicklink>> model;

 	public void init(IIntroContentProviderSite site) {
 		this.site = site;
 		// IIntroContentProviderSite should provide services.
 		if (site instanceof IServiceLocator) {
 			this.locator = (IServiceLocator) site;
 		} else if (site instanceof AbstractIntroPartImplementation) {
 			this.locator = ((AbstractIntroPartImplementation) site).getIntroPart().getIntroSite();
 		} else {
 			this.locator = PlatformUI.getWorkbench();
 		}
 		manager = locator.getService(CommandManager.class);
 		images = locator.getService(ICommandImageService.class);

 		model = new ModelReader();
 	}

 	/**
 	 * Find the current Welcome/Intro identifier
 	 *
 	 * @return the current identifier or {@code null} if no theme
 	 */
 	protected String getCurrentThemeId() {
 		if (site instanceof AbstractIntroPartImplementation) {
 			IntroTheme theme = ((AbstractIntroPartImplementation) site).getModel().getTheme();
 			return theme.getId();
 		}
 		return null;
 	}

 	public void createContent(String id, PrintWriter out) {
 		// Content is already embedded within a <div id="...">
 		getQuicklinks().forEach(ql -> {
 			try {
 				// ah how lovely to embed HTML in code
 				String urlEncodedCommand = asEmbeddedURL(ql);
 				out.append("<a class='content-link'"); //$NON-NLS-1$
 				if (ql.commandSpec != null) {
 					out.append(" id='").append(asCSSId(ql.commandSpec)).append("' "); //$NON-NLS-1$ //$NON-NLS-2$
 				}
 				out.append(" href='"); //$NON-NLS-1$
 				out.append(urlEncodedCommand);
 				out.append("'>"); //$NON-NLS-1$
 				if (ql.iconUrl != null) {
 					out.append("<img class='background-image' src='").append(ql.iconUrl).append("'>"); //$NON-NLS-1$ //$NON-NLS-2$
 				}
 				out.append("\n<div class='link-extra-div'></div>\n"); // UNKNOWN //$NON-NLS-1$
 				out.append("<span class='link-label'>"); //$NON-NLS-1$
 				out.append(ql.label);
 				out.append("</span>"); //$NON-NLS-1$
 				if (ql.description != null) {
 					out.append("\n<p><span class='text'>"); //$NON-NLS-1$
 					out.append(ql.description);
 					out.append("</span></p>"); //$NON-NLS-1$
 				}
 				out.append("</a>"); //$NON-NLS-1$
 			} catch (UnsupportedEncodingException e) {
 				e.printStackTrace();
 			}
 		});
 	}

 	private String asEmbeddedURL(Quicklink ql) throws UnsupportedEncodingException {
 		if (ql.url != null) {
 			return ql.url;
 		}
 		String encoded = URLEncoder.encode(ql.commandSpec, "UTF-8"); //$NON-NLS-1$
 		if (ql.resolution != null) {
 			encoded += "&standby=" + ql.resolution; //$NON-NLS-1$
 		}
 		return "http://org.eclipse.ui.intro/execute?command=" + encoded; //$NON-NLS-1$
 	}

 	/**
 	 * Transform the Eclipse Command identifier (with dots) to a CSS-compatible
 	 * class
 	 */
 	private String asCSSId(String commandSpec) {
 		int indexOf = commandSpec.indexOf('(');
 		if (indexOf > 0) {
 			commandSpec = commandSpec.substring(0, indexOf);
 		}
 		return commandSpec.replace('.', '_');
 	}

 	/**
 	 * Rewrite or possible extract the icon at the given URL to a stable URL
 	 * that can be embedded in HTML and rendered in a browser. May create
 	 * temporary files that will be cleaned up on exit.
 	 *
 	 * @param iconURL
 	 * @return stable URL
 	 */
 	private String asBrowserURL(String iconURL) {
 		if (iconURL.startsWith("file:") || iconURL.startsWith("http:")) { //$NON-NLS-1$ //$NON-NLS-2$
 			return iconURL;
 		}
 		try {
 			URL original = new URL(iconURL);
 			URL toLocal = FileLocator.toFileURL(original);
 			if (!toLocal.sameFile(original)) {
 				return toLocal.toString();
 			}
 		} catch (IOException e1) {
 			/* ignore */
 		}

 		// extract content
 		try {
 			return asDataURL(ImageDescriptor.createFromURL(new URL(iconURL)));
 		} catch (MalformedURLException e) {
 			// should probably log this
 			return iconURL;
 		}
 	}

 	/**
 	 * Write out the image as a data: URL if possible or to the file-system.
 	 *
 	 * @param descriptor
 	 * @return URL with the resulting image
 	 */
 	private String asDataURL(ImageDescriptor descriptor) {
 		if (descriptor == null) {
 			return null;
 		}
 		ImageData data = descriptor.getImageData();
 		if (data == null) {
 			return null;
 		}
 		ImageLoader loader = new ImageLoader();
 		loader.data = new ImageData[] { data };

 		ByteArrayOutputStream output = new ByteArrayOutputStream();
 		loader.save(output, SWT.IMAGE_PNG);
 		if (output.size() * 4 / 3 < MAX_URL_LENGTH) {
 			// You'd think there was a more efficient way to do this...
 			return "data:image/png;base64," + Base64.getEncoder().encodeToString(output.toByteArray()); //$NON-NLS-1$
 		}
 		try {
 			File tempFile = File.createTempFile("qlink", "png"); //$NON-NLS-1$ //$NON-NLS-2$
 			FileOutputStream fos = new FileOutputStream(tempFile);
 			fos.write(output.toByteArray());
 			fos.close();
 			tempFile.deleteOnExit();
 			return tempFile.toURI().toString();
 		} catch (IOException e) {
 			e.printStackTrace();
 			return null;
 		}
 	}

 	public void createContent(String id, Composite parent, FormToolkit toolkit) {
 		Section section = toolkit.createSection(parent, Section.EXPANDED);
 		TableViewer tableViewer = new TableViewer(toolkit.createTable(section, SWT.FULL_SELECTION));
 		tableViewer.setLabelProvider(new URLLabelProvider() {
 			@Override
 			public String getText(Object element) {
 				if (element instanceof Quicklink) {
 					return ((Quicklink) element).label;
 				}
 				return super.getText(element);
 			}

 			@Override
 			public Image getImage(Object element) {
 				if (element instanceof Quicklink) {
 					return super.getImage(((Quicklink) element).iconUrl);
 				}
 				return super.getImage(element);
 			}
 		});
 		tableViewer.setContentProvider(new ArrayContentProvider());
 		tableViewer.setInput(getQuicklinks().toArray());
 	}

 	private List<Quicklink> getQuicklinks() {
 		List<Quicklink> links = model.get();
 		if (links.isEmpty()) {
 			links = generateDefaultQuicklinks();
 		}
 		return links.stream().filter(this::populateQuicklink).sorted(Quicklink::compareTo)
 				.collect(Collectors.toList());
 	}

 	/**
 	 * Attempt to populate common fields given other information. For commands,
 	 * we look up information in the ICommandService and ICommandImageService.
 	 * Return false if this quicklink cannot be found and should not be shown.
 	 *
 	 * @return true if should be included
 	 */
 	private boolean populateQuicklink(Quicklink ql) {
 		if (ql.commandSpec == null) {
 			// non-commmands are fine
 			return true;
 		}
 		try {
 			ParameterizedCommand pc = manager.deserialize(ql.commandSpec);
 			if (!pc.getCommand().isDefined()) {
 				// not an error: just not found
 				return false;
 			}
 			if (ql.label == null) {
 				ql.label = pc.getCommand().getName();
 			}
 			if (ql.description == null) {
 				ql.description = pc.getCommand().getDescription();
 			}
 			if (ql.iconUrl == null && images != null) {
 				ImageDescriptor descriptor = images.getImageDescriptor(pc.getId());
 				if (descriptor != null) {
 					String iconUrl = MenuHelper.getImageUrl(descriptor);
 					ql.iconUrl = iconUrl != null ? asBrowserURL(iconUrl) : asDataURL(descriptor);
 				}
 			}
 			return true;
 		} catch (NotDefinedException | SerializationException e) {
 			// exclude commands that don't exist or are mis-fashioned
 			return false;
 		}
 	}

 	/** Simplify creating a quicklink for a command */
 	private Quicklink forCommand(String commandSpec) {
 		Quicklink ql = new Quicklink();
 		ql.commandSpec = commandSpec;
 		return ql;
 	}

 	/** Simplify creating a quicklink for a command */
 	private Quicklink forCommand(String commandSpec, Importance importance) {
 		Quicklink ql = new Quicklink();
 		ql.commandSpec = commandSpec;
 		ql.importance = importance;
 		return ql;
 	}

 	/**
 	 * Return the default commands to be shown if there is no other content
 	 * available
 	 */
 	private List<Quicklink> generateDefaultQuicklinks() {
 		return Arrays.asList(forCommand("org.eclipse.oomph.setup.ui.questionnaire", Importance.HIGH), //$NON-NLS-1$
 				forCommand("org.eclipse.ui.cheatsheets.openCheatSheet"), //$NON-NLS-1$
 				forCommand("org.eclipse.ui.newWizard"), //$NON-NLS-1$
 				forCommand("org.eclipse.ui.file.import"), //$NON-NLS-1$
 				forCommand("org.eclipse.epp.mpc.ui.command.showMarketplaceWizard"), //$NON-NLS-1$
 				forCommand("org.eclipse.ui.edit.text.openLocalFile", Importance.LOW)); //$NON-NLS-1$
 	}

 	public void dispose() {
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2016 Manumitting Technologies Inc 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:
	* Manumitting Technologies Inc - initial API and implementation
	*******************************************************************************/
	package org.eclipse.ui.intro.quicklinks;

	import java.io.ByteArrayOutputStream;
	import java.io.File;
	import java.io.FileOutputStream;
	import java.io.IOException;
	import java.io.PrintWriter;
	import java.io.UnsupportedEncodingException;
	import java.net.MalformedURLException;
	import java.net.URL;
	import java.net.URLEncoder;
	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.Base64;
	import java.util.HashMap;
	import java.util.LinkedHashMap;
	import java.util.List;
	import java.util.Map;
	import java.util.Objects;
	import java.util.function.Supplier;
	import java.util.regex.Pattern;
	import java.util.stream.Collectors;
	import java.util.stream.Stream;

	import org.eclipse.core.commands.CommandManager;
	import org.eclipse.core.commands.ParameterizedCommand;
	import org.eclipse.core.commands.SerializationException;
	import org.eclipse.core.commands.common.NotDefinedException;
	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.Platform;
	import org.eclipse.jface.resource.ImageDescriptor;
	import org.eclipse.jface.viewers.ArrayContentProvider;
	import org.eclipse.jface.viewers.TableViewer;
	import org.eclipse.osgi.util.NLS;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.graphics.Image;
	import org.eclipse.swt.graphics.ImageData;
	import org.eclipse.swt.graphics.ImageLoader;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.ui.PlatformUI;
	import org.eclipse.ui.commands.ICommandImageService;
	import org.eclipse.ui.forms.widgets.FormToolkit;
	import org.eclipse.ui.forms.widgets.Section;
	import org.eclipse.ui.internal.intro.impl.model.AbstractIntroPartImplementation;
	import org.eclipse.ui.internal.intro.impl.model.IntroTheme;
	import org.eclipse.ui.internal.intro.impl.util.Log;
	import org.eclipse.ui.internal.menus.MenuHelper;
	import org.eclipse.ui.intro.config.IIntroContentProvider;
	import org.eclipse.ui.intro.config.IIntroContentProviderSite;
	import org.eclipse.ui.services.IServiceLocator;
	import org.osgi.framework.Bundle;
	import org.osgi.framework.FrameworkUtil;

	/**
	* An Intro content provider that populates a list of frequently-used commands
	* from an extension point. The appearance of these quicklinks is normally taken
	* from the command metadata, including the image icon, but can be tailored.
	* These tailorings can be made optional depending on the current theme.
	*
	* This implementation is still experimental and subject to change. Feedback
	* welcome as a <a href="http://eclip.se/9f">bug report on the Eclipse Bugzilla
	* against Platform/User Assistance</a>.
	*/
	@SuppressWarnings("restriction")
	public class QuicklinksViewer implements IIntroContentProvider {

	/** Represents the importance of an element */
	enum Importance {
	HIGH("high", 0), MEDIUM("medium", 1), LOW("low", 2); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$

	String id;
	int level;

	Importance(String text, int importance) {
	this.id = text;
	this.level = importance;
	}

	public static Importance forId(String id) {
	for (Importance i : values()) {
	if (i.id.equals(id)) {
	return i;
	}
	}
	return LOW;
	}
	}

	/** Model holding the relevant attributes of a Quicklink element */
	class Quicklink implements Comparable<Quicklink> {
	String commandSpec;
	String url;
	String label;
	String description;
	String iconUrl;
	Importance importance = Importance.MEDIUM;
	long rank;
	String resolution;

	public Quicklink() {
	}

	@Override
	public int compareTo(Quicklink b) {
	int impA = this.importance.level;
	int impB = b.importance.level;
	if (impA != impB) {
	return impA - impB;
	}
	long diff = this.rank - b.rank;
	if (diff > 0) {
	return 1;
	}
	if (diff < 0) {
	return -1;
	}
	return 0;
	}
	}

	/**
	* Responsible for retrieving Quicklinks and applying any icon overrides
	*/
	class ModelReader implements Supplier<List<Quicklink>> {
	private static final String QL_EXT_PT = "org.eclipse.ui.intro.quicklinks"; //$NON-NLS-1$
	private static final String ELMT_COMMAND = "command"; //$NON-NLS-1$
	private static final String ATT_ID = "id"; //$NON-NLS-1$
	private static final String ELMT_URL = "url"; //$NON-NLS-1$
	private static final String ATT_LOCATION = "location"; //$NON-NLS-1$

	private static final String ELMT_OVERRIDE = "override"; //$NON-NLS-1$
	private static final String ATT_COMMANDID = "command"; //$NON-NLS-1$
	private static final String ATT_THEME = "theme"; //$NON-NLS-1$

	private static final String ATT_LABEL = "label"; //$NON-NLS-1$
	private static final String ATT_DESCRIPTION = "description"; //$NON-NLS-1$
	private static final String ATT_ICON = "icon"; //$NON-NLS-1$
	private static final String ATT_IMPORTANCE = "importance"; //$NON-NLS-1$
	private static final String ATT_RESOLUTION = "resolution"; //$NON-NLS-1$

	/** commandSpec/url → quicklink */
	private Map<String, Quicklink> quicklinks = new LinkedHashMap<>();
	/** bundle symbolic name → bundle id */
	private Map<String, Long> bundleIds;
	private Bundle[] bundles;

	/**
	* Return the list of configured {@link Quicklink} that can be found.
	*
	* @return
	*/
	public List<Quicklink> get() {
	IExtension extensions[] = getExtensions(QL_EXT_PT);

	// Process definitions from the product bundle first
	Bundle productBundle = Platform.getProduct().getDefiningBundle();
	if(productBundle != null) {
	for (IExtension ext : extensions) {
	if (productBundle.getSymbolicName().equals(ext.getNamespaceIdentifier())) {
	for (IConfigurationElement ce : ext.getConfigurationElements()) {
	processDefinition(ce);
	}
	}
	}
	}

	for (IExtension ext : extensions) {
	if (productBundle == null \|\| !productBundle.getSymbolicName().equals(ext.getNamespaceIdentifier())) {
	for (IConfigurationElement ce : ext.getConfigurationElements()) {
	processDefinition(ce);
	}
	}
	}

	// Now process all command overrides
	for (IExtension ext : extensions) {
	for (IConfigurationElement ce : ext.getConfigurationElements()) {
	if (!ELMT_OVERRIDE.equals(ce.getName())) {
	continue;
	}
	String theme = ce.getAttribute(ATT_THEME);
	String commandSpecPattern = ce.getAttribute(ATT_COMMANDID);
	String icon = ce.getAttribute(ATT_ICON);
	if (theme != null && icon != null && Objects.equals(theme, getCurrentThemeId())
	&& commandSpecPattern != null) {
	findMatchingQuicklinks(commandSpecPattern)
	.forEach(ql -> ql.iconUrl = getImageURL(ce, ATT_ICON));
	}
	}
	}
	return new ArrayList<>(quicklinks.values());
	}

	private void processDefinition(IConfigurationElement ce) {
	if (!ELMT_COMMAND.equals(ce.getName()) && !ELMT_URL.equals(ce.getName())) {
	return;
	}

	String key = null;
	Quicklink ql = new Quicklink();
	if (ELMT_COMMAND.equals(ce.getName())) {
	key = ce.getAttribute(ATT_ID);
	if (key == null) {
	Log.warning(NLS.bind("Skipping '{0}': missing {1}", ce.getName(), ATT_ID)); //$NON-NLS-1$
	return;
	}
	ql.commandSpec = key;
	ql.label = ce.getAttribute(ATT_LABEL);
	ql.description = ce.getAttribute(ATT_DESCRIPTION);
	ql.iconUrl = getImageURL(ce, ATT_ICON);
	} else if (ELMT_URL.equals(ce.getName())) {
	key = ce.getAttribute(ATT_LOCATION);
	if (key == null) {
	Log.warning(NLS.bind("Skipping '{0}': missing {1}", ELMT_URL, ATT_LOCATION)); //$NON-NLS-1$
	return;
	}
	ql.url = key;
	ql.label = ce.getAttribute(ATT_LABEL);
	ql.description = ce.getAttribute(ATT_DESCRIPTION);
	ql.iconUrl = getImageURL(ce, ATT_ICON);
	}
	ql.rank = getRank(ce.getContributor().getName());
	if (ce.getAttribute(ATT_IMPORTANCE) != null) {
	ql.importance = Importance.forId(ce.getAttribute(ATT_IMPORTANCE));
	}
	if (ce.getAttribute(ATT_RESOLUTION) != null) {
	ql.resolution = ce.getAttribute(ATT_RESOLUTION);
	}
	// discard if already seen
	quicklinks.putIfAbsent(key, ql);
	}

	/**
	* Find {@link Quicklink}s whose {@code commandSpec} matches the simple
	* wildcard pattern in {@code commandSpecPattern}
	*
	* @param commandSpecPattern
	* a simple wildcard pattern supporting *, ?
	* @return the set of matching Quicklinks
	*/
	private Stream<Quicklink> findMatchingQuicklinks(String commandSpecPattern) {
	// transform simple wildcards into regexp
	String regexp = commandSpecPattern.replace(".", "\\.").replace("(", "\\(").replace(")", "\\)") //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ //$NON-NLS-5$ //$NON-NLS-6$
	.replace("", "."); //$NON-NLS-1$ //$NON-NLS-2$
	final Pattern pattern = Pattern.compile(regexp);
	return quicklinks.values().stream().filter(
	ql -> ql.commandSpec != null && (commandSpecPattern.equals(ql.commandSpec)
	\|\| pattern.matcher(ql.commandSpec).matches()));
	}

	private IExtension[] getExtensions(String extPtId) {
	IExtensionRegistry registry = locator.getService(IExtensionRegistry.class);
	IExtensionPoint extPt = registry.getExtensionPoint(extPtId);
	return extPt == null ? new IExtension[0] : extPt.getExtensions();
	}


	private long getRank(String bundleSymbolicName) {
	if (bundleIds == null) {
	Bundle bundle = FrameworkUtil.getBundle(getClass());
	bundleIds = new HashMap<>();
	bundles = bundle.getBundleContext().getBundles();
	}
	return bundleIds.computeIfAbsent(bundleSymbolicName, bsn -> {
	for (Bundle b : bundles) {
	if (bsn.equals(b.getSymbolicName())
	&& (b.getState() & (Bundle.INSTALLED \| Bundle.UNINSTALLED)) == 0) {
	return b.getBundleId();
	}
	}
	return Long.MAX_VALUE;
	});
	}

	/**
	* @return URL to image, suitable for using in an external browser; may
	* be a <code>data:</code> URL; may be null
	*/
	private String getImageURL(IConfigurationElement ce, String attr) {
	String iconURL = MenuHelper.getIconURI(ce, attr);
	if (iconURL != null) {
	return asBrowserURL(iconURL);
	}
	return null;
	}
	}

	/** Source: http://stackoverflow.com/a/417184 */
	private static final int MAX_URL_LENGTH = 2083;

	private IIntroContentProviderSite site;
	private IServiceLocator locator;
	private CommandManager manager;
	private ICommandImageService images;
	private Supplier<List<Quicklink>> model;

	public void init(IIntroContentProviderSite site) {
	this.site = site;
	// IIntroContentProviderSite should provide services.
	if (site instanceof IServiceLocator) {
	this.locator = (IServiceLocator) site;
	} else if (site instanceof AbstractIntroPartImplementation) {
	this.locator = ((AbstractIntroPartImplementation) site).getIntroPart().getIntroSite();
	} else {
	this.locator = PlatformUI.getWorkbench();
	}
	manager = locator.getService(CommandManager.class);
	images = locator.getService(ICommandImageService.class);

	model = new ModelReader();
	}

	/**
	* Find the current Welcome/Intro identifier
	*
	* @return the current identifier or {@code null} if no theme
	*/
	protected String getCurrentThemeId() {
	if (site instanceof AbstractIntroPartImplementation) {
	IntroTheme theme = ((AbstractIntroPartImplementation) site).getModel().getTheme();
	return theme.getId();
	}
	return null;
	}

	public void createContent(String id, PrintWriter out) {
	// Content is already embedded within a <div id="...">
	getQuicklinks().forEach(ql -> {
	try {
	// ah how lovely to embed HTML in code
	String urlEncodedCommand = asEmbeddedURL(ql);
	out.append("<a class='content-link'"); //$NON-NLS-1$
	if (ql.commandSpec != null) {
	out.append(" id='").append(asCSSId(ql.commandSpec)).append("' "); //$NON-NLS-1$ //$NON-NLS-2$
	}
	out.append(" href='"); //$NON-NLS-1$
	out.append(urlEncodedCommand);
	out.append("'>"); //$NON-NLS-1$
	if (ql.iconUrl != null) {
	out.append("<img class='background-image' src='").append(ql.iconUrl).append("'>"); //$NON-NLS-1$ //$NON-NLS-2$
	}
	out.append("\n<div class='link-extra-div'></div>\n"); // UNKNOWN //$NON-NLS-1$
	out.append("<span class='link-label'>"); //$NON-NLS-1$
	out.append(ql.label);
	out.append("</span>"); //$NON-NLS-1$
	if (ql.description != null) {
	out.append("\n<p><span class='text'>"); //$NON-NLS-1$
	out.append(ql.description);
	out.append("</span></p>"); //$NON-NLS-1$
	}
	out.append("</a>"); //$NON-NLS-1$
	} catch (UnsupportedEncodingException e) {
	e.printStackTrace();
	}
	});
	}

	private String asEmbeddedURL(Quicklink ql) throws UnsupportedEncodingException {
	if (ql.url != null) {
	return ql.url;
	}
	String encoded = URLEncoder.encode(ql.commandSpec, "UTF-8"); //$NON-NLS-1$
	if (ql.resolution != null) {
	encoded += "&standby=" + ql.resolution; //$NON-NLS-1$
	}
	return "http://org.eclipse.ui.intro/execute?command=" + encoded; //$NON-NLS-1$
	}

	/**
	* Transform the Eclipse Command identifier (with dots) to a CSS-compatible
	* class
	*/
	private String asCSSId(String commandSpec) {
	int indexOf = commandSpec.indexOf('(');
	if (indexOf > 0) {
	commandSpec = commandSpec.substring(0, indexOf);
	}
	return commandSpec.replace('.', '_');
	}

	/**
	* Rewrite or possible extract the icon at the given URL to a stable URL
	* that can be embedded in HTML and rendered in a browser. May create
	* temporary files that will be cleaned up on exit.
	*
	* @param iconURL
	* @return stable URL
	*/
	private String asBrowserURL(String iconURL) {
	if (iconURL.startsWith("file:") \|\| iconURL.startsWith("http:")) { //$NON-NLS-1$ //$NON-NLS-2$
	return iconURL;
	}
	try {
	URL original = new URL(iconURL);
	URL toLocal = FileLocator.toFileURL(original);
	if (!toLocal.sameFile(original)) {
	return toLocal.toString();
	}
	} catch (IOException e1) {
	/* ignore */
	}

	// extract content
	try {
	return asDataURL(ImageDescriptor.createFromURL(new URL(iconURL)));
	} catch (MalformedURLException e) {
	// should probably log this
	return iconURL;
	}
	}

	/**
	* Write out the image as a data: URL if possible or to the file-system.
	*
	* @param descriptor
	* @return URL with the resulting image
	*/
	private String asDataURL(ImageDescriptor descriptor) {
	if (descriptor == null) {
	return null;
	}
	ImageData data = descriptor.getImageData();
	if (data == null) {
	return null;
	}
	ImageLoader loader = new ImageLoader();
	loader.data = new ImageData[] { data };

	ByteArrayOutputStream output = new ByteArrayOutputStream();
	loader.save(output, SWT.IMAGE_PNG);
	if (output.size() * 4 / 3 < MAX_URL_LENGTH) {
	// You'd think there was a more efficient way to do this...
	return "data:image/png;base64," + Base64.getEncoder().encodeToString(output.toByteArray()); //$NON-NLS-1$
	}
	try {
	File tempFile = File.createTempFile("qlink", "png"); //$NON-NLS-1$ //$NON-NLS-2$
	FileOutputStream fos = new FileOutputStream(tempFile);
	fos.write(output.toByteArray());
	fos.close();
	tempFile.deleteOnExit();
	return tempFile.toURI().toString();
	} catch (IOException e) {
	e.printStackTrace();
	return null;
	}
	}

	public void createContent(String id, Composite parent, FormToolkit toolkit) {
	Section section = toolkit.createSection(parent, Section.EXPANDED);
	TableViewer tableViewer = new TableViewer(toolkit.createTable(section, SWT.FULL_SELECTION));
	tableViewer.setLabelProvider(new URLLabelProvider() {
	@Override
	public String getText(Object element) {
	if (element instanceof Quicklink) {
	return ((Quicklink) element).label;
	}
	return super.getText(element);
	}

	@Override
	public Image getImage(Object element) {
	if (element instanceof Quicklink) {
	return super.getImage(((Quicklink) element).iconUrl);
	}
	return super.getImage(element);
	}
	});
	tableViewer.setContentProvider(new ArrayContentProvider());
	tableViewer.setInput(getQuicklinks().toArray());
	}

	private List<Quicklink> getQuicklinks() {
	List<Quicklink> links = model.get();
	if (links.isEmpty()) {
	links = generateDefaultQuicklinks();
	}
	return links.stream().filter(this::populateQuicklink).sorted(Quicklink::compareTo)
	.collect(Collectors.toList());
	}

	/**
	* Attempt to populate common fields given other information. For commands,
	* we look up information in the ICommandService and ICommandImageService.
	* Return false if this quicklink cannot be found and should not be shown.
	*
	* @return true if should be included
	*/
	private boolean populateQuicklink(Quicklink ql) {
	if (ql.commandSpec == null) {
	// non-commmands are fine
	return true;
	}
	try {
	ParameterizedCommand pc = manager.deserialize(ql.commandSpec);
	if (!pc.getCommand().isDefined()) {
	// not an error: just not found
	return false;
	}
	if (ql.label == null) {
	ql.label = pc.getCommand().getName();
	}
	if (ql.description == null) {
	ql.description = pc.getCommand().getDescription();
	}
	if (ql.iconUrl == null && images != null) {
	ImageDescriptor descriptor = images.getImageDescriptor(pc.getId());
	if (descriptor != null) {
	String iconUrl = MenuHelper.getImageUrl(descriptor);
	ql.iconUrl = iconUrl != null ? asBrowserURL(iconUrl) : asDataURL(descriptor);
	}
	}
	return true;
	} catch (NotDefinedException \| SerializationException e) {
	// exclude commands that don't exist or are mis-fashioned
	return false;
	}
	}

	/** Simplify creating a quicklink for a command */
	private Quicklink forCommand(String commandSpec) {
	Quicklink ql = new Quicklink();
	ql.commandSpec = commandSpec;
	return ql;
	}

	/** Simplify creating a quicklink for a command */
	private Quicklink forCommand(String commandSpec, Importance importance) {
	Quicklink ql = new Quicklink();
	ql.commandSpec = commandSpec;
	ql.importance = importance;
	return ql;
	}

	/**
	* Return the default commands to be shown if there is no other content
	* available
	*/
	private List<Quicklink> generateDefaultQuicklinks() {
	return Arrays.asList(forCommand("org.eclipse.oomph.setup.ui.questionnaire", Importance.HIGH), //$NON-NLS-1$
	forCommand("org.eclipse.ui.cheatsheets.openCheatSheet"), //$NON-NLS-1$
	forCommand("org.eclipse.ui.newWizard"), //$NON-NLS-1$
	forCommand("org.eclipse.ui.file.import"), //$NON-NLS-1$
	forCommand("org.eclipse.epp.mpc.ui.command.showMarketplaceWizard"), //$NON-NLS-1$
	forCommand("org.eclipse.ui.edit.text.openLocalFile", Importance.LOW)); //$NON-NLS-1$
	}

	public void dispose() {
	}
	}