r/org.eclipse.statet.r.ui/src/org/eclipse/statet/internal/r/ui/rhelp/RHelpUIServlet.java - statet/org.eclipse.statet-r - Git at Google

 /*=============================================================================#
  # Copyright (c) 2010, 2021 Stephan Wahlbrink and others.
  #
  # This program and the accompanying materials are made available under the
  # terms of the Eclipse Public License 2.0 which is available at
  # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
  # which is available at https://www.apache.org/licenses/LICENSE-2.0.
  #
  # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
  #
  # Contributors:
  #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
  #=============================================================================*/

 package org.eclipse.statet.internal.r.ui.rhelp;

 import java.io.PrintWriter;
 import java.nio.file.Path;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;

 import javax.servlet.ServletConfig;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;

 import org.eclipse.core.filesystem.EFS;
 import org.eclipse.core.filesystem.IFileStore;
 import org.eclipse.jface.preference.IPreferenceStore;
 import org.eclipse.jface.preference.JFacePreferences;
 import org.eclipse.jface.preference.PreferenceConverter;
 import org.eclipse.jface.resource.FontDescriptor;
 import org.eclipse.jface.resource.JFaceResources;
 import org.eclipse.jface.text.rules.IToken;
 import org.eclipse.jface.util.IPropertyChangeListener;
 import org.eclipse.jface.util.PropertyChangeEvent;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.graphics.FontData;
 import org.eclipse.swt.graphics.RGB;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.ui.IWorkbenchPage;
 import org.eclipse.ui.PartInitException;
 import org.eclipse.ui.editors.text.EditorsUI;
 import org.eclipse.ui.ide.IDE;
 import org.eclipse.ui.internal.editors.text.EditorsPlugin;

 import org.eclipse.statet.jcommons.lang.NonNullByDefault;
 import org.eclipse.statet.jcommons.lang.Nullable;

 import org.eclipse.statet.ecommons.preferences.PreferencesUtil;
 import org.eclipse.statet.ecommons.preferences.SettingsChangeNotifier;
 import org.eclipse.statet.ecommons.preferences.core.util.PreferenceUtils;
 import org.eclipse.statet.ecommons.ui.util.LayoutUtils;
 import org.eclipse.statet.ecommons.ui.util.UIAccess;

 import org.eclipse.statet.internal.r.ui.RIdentifierGroups;
 import org.eclipse.statet.internal.r.ui.RUIPlugin;
 import org.eclipse.statet.r.core.RCore;
 import org.eclipse.statet.r.ui.RUIPreferenceConstants;
 import org.eclipse.statet.rhelp.core.http.RHelpHttpServlet;
 import org.eclipse.statet.rhelp.core.http.jetty.JettyForwardHandler;
 import org.eclipse.statet.rhelp.core.http.jetty.JettyRHelpUtils;


 @NonNullByDefault
 public class RHelpUIServlet extends RHelpHttpServlet implements IPropertyChangeListener, SettingsChangeNotifier.ChangeListener {

 	private static final long serialVersionUID= 1L;


 	static final String STYLE_PARAM= "style"; //$NON-NLS-1$

 	static final String HOVER_STYLE= "hover"; //$NON-NLS-1$


 	private static final String[] DEFAULT_MATCH_COLORS= new String[] {
 		".SMATCH-A { background: #ceccf7; }\n",
 		".SMATCH-B { background: #ffffcf; }\n",
 		".SMATCH-C { background: aquamarine; }\n",
 		".SMATCH-D { background: palegreen; }\n",
 		".SMATCH-E { background: coral; }\n",
 		".SMATCH-F { background: wheat; }\n",
 		".SMATCH-G { background: khaki; }\n",
 		".SMATCH-H { background: lime; }\n",
 		".SMATCH-I { background: deepskyblue; }\n",
 		".SMATCH-J { background: plum; }\n",
 	};


 	private static void appendCssColor(final StringBuilder sb, final RGB color) {
 		sb.append('#');
 		String s= Integer.toHexString(color.red);
 		if (s.length() == 1) {
 			sb.append('0');
 		}
 		sb.append(s);
 		s= Integer.toHexString(color.green);
 		if (s.length() == 1) {
 			sb.append('0');
 		}
 		sb.append(s);
 		s= Integer.toHexString(color.blue);
 		if (s.length() == 1) {
 			sb.append('0');
 		}
 		sb.append(s);
 	}

 	private static void appendELinkColors(final StringBuilder sb, final RGB foregroundColor) {
 		final RGB hyperlinkColor= JFaceResources.getColorRegistry().getRGB(JFacePreferences.HYPERLINK_COLOR);
 		sb.append("a { color: "); //$NON-NLS-1$
 				appendCssColor(sb, hyperlinkColor);
 				sb.append("; }\n");//$NON-NLS-1$
 		sb.append("a:hover, a:active, a:focus { color: "); //$NON-NLS-1$
 				appendCssColor(sb, JFaceResources.getColorRegistry().getRGB(JFacePreferences.ACTIVE_HYPERLINK_COLOR));
 				sb.append("; }\n"); //$NON-NLS-1$
 		sb.append("a:visited { color: "); //$NON-NLS-1$
 		appendCssColor(sb, new RGB(
 				(hyperlinkColor.red + ((hyperlinkColor.red <= 127) ? +64 : -64)),
 				(hyperlinkColor.green + foregroundColor.green) / 2,
 				(hyperlinkColor.blue + ((hyperlinkColor.blue > 32) ? -32 : +32) + foregroundColor.blue ) / 2 ));
 				sb.append("; }\n"); //$NON-NLS-1$
 	}

 	private static void appendMatchColors(final StringBuilder sb) {
 		int i= 0;
 		final RGB rgb= PreferenceConverter.getColor(
 				EditorsPlugin.getDefault().getPreferenceStore(),
 				"searchResultIndicationColor"); //$NON-NLS-1$
 		if (rgb != null) {
 			sb.append(".SMATCH-A { background: ");
 			appendCssColor(sb, rgb);
 			sb.append("; }\n"); //$NON-NLS-1$
 			i++;
 		}
 		while (i < DEFAULT_MATCH_COLORS.length) {
 			sb.append(DEFAULT_MATCH_COLORS[i++]);
 		}
 	}


 	public static class Browse extends RHelpUIServlet {

 		private static final long serialVersionUID= 1L;

 		@Override
 		protected void collectCss(final StringBuilder sb) {
 			final RGB foregroundColor= JFaceResources.getColorRegistry().getRGB("org.eclipse.statet.workbench.themes.DocViewColor"); //$NON-NLS-1$
 			final RGB docBackgroundColor= JFaceResources.getColorRegistry().getRGB("org.eclipse.statet.workbench.themes.DocViewBackgroundColor"); //$NON-NLS-1$
 			final RGB borderColor= Display.getCurrent().getSystemColor(SWT.COLOR_WIDGET_NORMAL_SHADOW).getRGB();

 			{	final FontDescriptor docFontDescr= JFaceResources.getFontDescriptor("org.eclipse.statet.workbench.themes.DocViewFont"); //$NON-NLS-1$
 				final FontData fontData= docFontDescr.getFontData()[0];

 				sb.append("body { font-family: '"); //$NON-NLS-1$
 						sb.append(fontData.getName());
 						sb.append("'; font-size:"); //$NON-NLS-1$
 						sb.append(fontData.getHeight());
 						sb.append("pt; color:"); //$NON-NLS-1$
 						appendCssColor(sb, foregroundColor);
 						sb.append("; background:"); //$NON-NLS-1$
 						appendCssColor(sb, docBackgroundColor);
 						sb.append("; }\n"); //$NON-NLS-1$
 			}

 			appendELinkColors(sb, foregroundColor);

 			sb.append("div.toc a, div.toc a:visited { color: "); //$NON-NLS-1$
 					appendCssColor(sb, foregroundColor);
 					sb.append("; }\n"); //$NON-NLS-1$

 			sb.append("@media screen {\n"); //$NON-NLS-1$

 			sb.append("body { margin: "); //$NON-NLS-1$
 					sb.append(LayoutUtils.defaultVSpacing());
 					sb.append("px "); //$NON-NLS-1$
 					sb.append(LayoutUtils.defaultHSpacing());
 					sb.append("px; }\n"); //$NON-NLS-1$

 			sb.append("div.toc { display: inline; float: right; border: 1px solid "); //$NON-NLS-1$
 					appendCssColor(sb, borderColor);
 					sb.append("; }\n"); //$NON-NLS-1$

 			sb.append("span.mnemonic, div.toc a.mnemonic { text-decoration: underline; }\n"); //$NON-NLS-1$
 			sb.append("hr { border: 0; height: 1px; background: " ); //$NON-NLS-1$
 					appendCssColor(sb, borderColor);
 					sb.append("; }\n"); //$NON-NLS-1$

 			sb.append("}\n" ); // @media //$NON-NLS-1$

 			appendMatchColors(sb);

 			super.collectCss(sb);
 		}

 	}

 	public static class Info extends RHelpUIServlet {

 		private static final long serialVersionUID= 1L;

 		@Override
 		protected void collectCss(final StringBuilder sb) {
 			final Display display= Display.getCurrent();
 			final RGB infoForegroundColor= display.getSystemColor(SWT.COLOR_INFO_FOREGROUND).getRGB();
 			final RGB infoBackgroundColor= display.getSystemColor(SWT.COLOR_INFO_BACKGROUND).getRGB();
 			final int vIndent= Math.max(1, LayoutUtils.defaultVSpacing() / 4);
 			final int hIndent= Math.max(3, LayoutUtils.defaultHSpacing() / 2);

 			{	final FontDescriptor docFontDescr= JFaceResources.getDialogFontDescriptor();
 				final FontData fontData= docFontDescr.getFontData()[0];
 				sb.append("body { font-family: '"); //$NON-NLS-1$
 						sb.append(fontData.getName());
 						sb.append("'; font-size: "); //$NON-NLS-1$
 						sb.append(fontData.getHeight());
 						sb.append("pt; color: "); //$NON-NLS-1$
 						appendCssColor(sb, infoForegroundColor);
 						sb.append("; background: "); //$NON-NLS-1$
 						appendCssColor(sb, infoBackgroundColor);
 						sb.append("; margin: 0 "); //$NON-NLS-1$
 						sb.append(hIndent);
 						sb.append("px "); //$NON-NLS-1$
 						sb.append(vIndent);
 						sb.append("px; }\n"); //$NON-NLS-1$
 			}
 			appendELinkColors(sb, infoForegroundColor);

 			sb.append("h2, h3#description { display: none; }\n"); //$NON-NLS-1$
 			sb.append("h3 { font-size: 90%; margin-bottom: 0.4em; }\n"); //$NON-NLS-1$
 			sb.append("p, pre { margin-top: 0.4em; margin-bottom: 0.4em; }\n" ); //$NON-NLS-1$

 			sb.append("hr { visibility: hidden; }\n"); //$NON-NLS-1$

 			super.collectCss(sb);
 		}

 	}


 	private volatile @Nullable String cssStyle;

 	private RHelpRCodeScanner rCodeScanner;


 	@SuppressWarnings("null")
 	public RHelpUIServlet() {
 	}


 	@Override
 	public void init(final ServletConfig config) throws ServletException {
 		super.init(config);

 		init(RCore.getRHelpManager(),
 				JettyRHelpUtils.newResourceHandler(config.getServletContext()),
 				new JettyForwardHandler() );

 		this.rCodeScanner= new RHelpRCodeScanner(RUIPlugin.getInstance().getEditorPreferenceStore());

 		EditorsUI.getPreferenceStore().addPropertyChangeListener(this);
 		JFaceResources.getFontRegistry().addListener(this);
 		JFaceResources.getColorRegistry().addListener(this);
 		PreferencesUtil.getSettingsChangeNotifier().addChangeListener(this);
 		updateStyles();
 	}

 	@Override
 	public void propertyChange(final PropertyChangeEvent event) {
 		if (event.getProperty().equals("org.eclipse.statet.workbench.themes.DocViewFont") //$NON-NLS-1$
 				|| event.getProperty().equals("org.eclipse.statet.workbench.themes.DocViewBackgroundColor") //$NON-NLS-1$
 				|| event.getProperty().equals("org.eclipse.statet.workbench.themes.DocViewColor") //$NON-NLS-1$
 				|| event.getProperty().equals(JFaceResources.DIALOG_FONT)
 				|| event.getProperty().equals(JFacePreferences.HYPERLINK_COLOR)
 				|| event.getProperty().equals(JFacePreferences.ACTIVE_HYPERLINK_COLOR)
 				|| event.getProperty().equals("searchResultIndicationColor") ) { //$NON-NLS-1$
 			updateStyles();
 		}
 	}

 	@Override
 	public void settingsChanged(final Set<String> groupIds) {
 		if (groupIds.contains(RUIPreferenceConstants.R.TS_GROUP_ID)
 				|| groupIds.contains(RIdentifierGroups.GROUP_ID)) {
 			final Map<String, Object> options= new HashMap<>();
 			synchronized (this.rCodeScanner) {
 				this.rCodeScanner.handleSettingsChanged(groupIds, options);
 			}
 		}
 	}

 	@Override
 	public void destroy() {
 		super.destroy();

 		final IPreferenceStore preferenceStore= EditorsUI.getPreferenceStore();
 		if (preferenceStore != null) {
 			preferenceStore.removePropertyChangeListener(this);
 		}
 		JFaceResources.getFontRegistry().removeListener(this);
 		JFaceResources.getColorRegistry().removeListener(this);
 		PreferencesUtil.getSettingsChangeNotifier().removeChangeListener(this);
 	}


 	@Override
 	protected boolean getShowInternal() {
 		return PreferenceUtils.getInstancePrefs().getPreferenceValue(
 				RHelpPreferences.SHOW_INTERNAL_ENABLED_PREF );
 	}

 	@Override
 	protected boolean canOpenFile(final String ext) {
 		return true;
 	}

 	@Override
 	protected void doOpenFile(final Path file) {
 		try {
 			final IFileStore fileStore= EFS.getLocalFileSystem().getStore(file.toUri());
 			UIAccess.getDisplay().asyncExec(new Runnable() {
 				@Override
 				public void run() {
 					final IWorkbenchPage page= UIAccess.getActiveWorkbenchPage(true);
 					try {
 						IDE.openEditorOnFileStore(page, fileStore);
 					}
 					catch (final PartInitException e) {}
 				}
 			});
 		}
 		catch (final Exception e) {}
 	}


 	private void updateStyles() {
 		final StringBuilder sb= new StringBuilder(1024);
 		UIAccess.getDisplay().syncExec(new Runnable() {
 			@Override
 			public void run() {
 				collectCss(sb);
 			}
 		});
 		sb.append(".header { display: none; }"); //$NON-NLS-1$
 		this.cssStyle= sb.toString();
 	}

 	protected void collectCss(final StringBuilder sb) {
 	}

 	@Override
 	protected void customizeCss(final PrintWriter writer) {
 //		updateStyles();
 		writer.print(this.cssStyle);
 	}

 	@Override
 	protected void customizePageHtmlHeader(final HttpServletRequest req, final PrintWriter writer) {
 		customizeHtmlHeader(req, writer, true);
 	}

 	@Override
 	protected void customizeIndexHtmlHeader(final HttpServletRequest req, final PrintWriter writer) {
 		customizeHtmlHeader(req, writer, false);
 	}

 	protected void customizeHtmlHeader(final HttpServletRequest req, final PrintWriter writer,
 			final boolean page) {
 		writer.println("<script type=\"text/javascript\">/* <![CDATA[ */"); //$NON-NLS-1$

 		writer.println("function keyNavHandler(event) {"); //$NON-NLS-1$
 		writer.println("if (!event) event= window.event;"); //$NON-NLS-1$
 		writer.println("if (event.which) { key= event.which } else if (event.keyCode) { key= event.keyCode };"); //$NON-NLS-1$
 		writer.println("if (!event.ctrlKey && !event.altKey) { var anchor= 0;"); //$NON-NLS-1$
 		if (page) {
 			writer.println("if (key == 68) anchor= \"#description\"; " + //$NON-NLS-1$
 					"else if (key == 85) anchor= \"#usage\"; " + //$NON-NLS-1$
 					"else if (key == 65) anchor= \"#arguments\"; " + //$NON-NLS-1$
 					"else if (key == 73) anchor= \"#details\"; " + //$NON-NLS-1$
 					"else if (key == 86) anchor= \"#value\"; " + //$NON-NLS-1$
 					"else if (key == 79) anchor= \"#authors\"; " + //$NON-NLS-1$
 					"else if (key == 82) anchor= \"#references\"; " + //$NON-NLS-1$
 					"else if (key == 69) anchor= \"#examples\"; " + //$NON-NLS-1$
 					"else if (key == 83) anchor= \"#seealso\";"); //$NON-NLS-1$
 		}
 		else {
 			writer.println("if (key >= 65 && key <= 90) anchor= \"#idx\"+String.fromCharCode(key+32);"); //$NON-NLS-1$
 		}
 		writer.println("if (anchor) { window.location.hash= anchor; event.cancelBubble= true; return false; }"); //$NON-NLS-1$
 		writer.println("} return true; }"); //$NON-NLS-1$
 		writer.println("document.onkeydown= keyNavHandler;"); //$NON-NLS-1$

 		writer.println("/* ]]> */</script>"); //$NON-NLS-1$

 		if (HOVER_STYLE.equals(req.getParameter(STYLE_PARAM))) {
 			writer.println("<style type=\"text/css\">body { overflow: hidden; }</style>"); //$NON-NLS-1$
 		}
 	}

 	@Override
 	protected void printRCode(final PrintWriter writer, final String html) {
 		synchronized (this.rCodeScanner) {
 			this.rCodeScanner.setHtml(html);
 			writer.write("<span style=\""); //$NON-NLS-1$
 			writer.write(this.rCodeScanner.getDefaultStyle());
 			writer.write("\">"); //$NON-NLS-1$

 			IToken token;
 			int currentIdx= 0;
 			while (!(token= this.rCodeScanner.nextToken()).isEOF()) {
 				final String data= (String) token.getData();
 				if (data != null) {
 					final int tokenIdx= this.rCodeScanner.getTokenOffset();
 					if (tokenIdx > currentIdx) {
 						writer.write(html, currentIdx, tokenIdx-currentIdx);
 					}
 					writer.write("<span style=\""); //$NON-NLS-1$
 					writer.write(data);
 					writer.write("\">"); //$NON-NLS-1$
 					writer.write(html, tokenIdx, this.rCodeScanner.getTokenLength());
 					writer.write("</span>"); //$NON-NLS-1$
 					currentIdx= tokenIdx + this.rCodeScanner.getTokenLength();
 				}
 			}
 			writer.write(html, currentIdx, html.length()-currentIdx);

 			writer.write("</span>"); //$NON-NLS-1$
 		}
 	}

 }
	/*=============================================================================#
	# Copyright (c) 2010, 2021 Stephan Wahlbrink and others.
	#
	# This program and the accompanying materials are made available under the
	# terms of the Eclipse Public License 2.0 which is available at
	# https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
	# which is available at https://www.apache.org/licenses/LICENSE-2.0.
	#
	# SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
	#
	# Contributors:
	# Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
	#=============================================================================*/

	package org.eclipse.statet.internal.r.ui.rhelp;

	import java.io.PrintWriter;
	import java.nio.file.Path;
	import java.util.HashMap;
	import java.util.Map;
	import java.util.Set;

	import javax.servlet.ServletConfig;
	import javax.servlet.ServletException;
	import javax.servlet.http.HttpServletRequest;

	import org.eclipse.core.filesystem.EFS;
	import org.eclipse.core.filesystem.IFileStore;
	import org.eclipse.jface.preference.IPreferenceStore;
	import org.eclipse.jface.preference.JFacePreferences;
	import org.eclipse.jface.preference.PreferenceConverter;
	import org.eclipse.jface.resource.FontDescriptor;
	import org.eclipse.jface.resource.JFaceResources;
	import org.eclipse.jface.text.rules.IToken;
	import org.eclipse.jface.util.IPropertyChangeListener;
	import org.eclipse.jface.util.PropertyChangeEvent;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.graphics.FontData;
	import org.eclipse.swt.graphics.RGB;
	import org.eclipse.swt.widgets.Display;
	import org.eclipse.ui.IWorkbenchPage;
	import org.eclipse.ui.PartInitException;
	import org.eclipse.ui.editors.text.EditorsUI;
	import org.eclipse.ui.ide.IDE;
	import org.eclipse.ui.internal.editors.text.EditorsPlugin;

	import org.eclipse.statet.jcommons.lang.NonNullByDefault;
	import org.eclipse.statet.jcommons.lang.Nullable;

	import org.eclipse.statet.ecommons.preferences.PreferencesUtil;
	import org.eclipse.statet.ecommons.preferences.SettingsChangeNotifier;
	import org.eclipse.statet.ecommons.preferences.core.util.PreferenceUtils;
	import org.eclipse.statet.ecommons.ui.util.LayoutUtils;
	import org.eclipse.statet.ecommons.ui.util.UIAccess;

	import org.eclipse.statet.internal.r.ui.RIdentifierGroups;
	import org.eclipse.statet.internal.r.ui.RUIPlugin;
	import org.eclipse.statet.r.core.RCore;
	import org.eclipse.statet.r.ui.RUIPreferenceConstants;
	import org.eclipse.statet.rhelp.core.http.RHelpHttpServlet;
	import org.eclipse.statet.rhelp.core.http.jetty.JettyForwardHandler;
	import org.eclipse.statet.rhelp.core.http.jetty.JettyRHelpUtils;


	@NonNullByDefault
	public class RHelpUIServlet extends RHelpHttpServlet implements IPropertyChangeListener, SettingsChangeNotifier.ChangeListener {

	private static final long serialVersionUID= 1L;


	static final String STYLE_PARAM= "style"; //$NON-NLS-1$

	static final String HOVER_STYLE= "hover"; //$NON-NLS-1$


	private static final String[] DEFAULT_MATCH_COLORS= new String[] {
	".SMATCH-A { background: #ceccf7; }\n",
	".SMATCH-B { background: #ffffcf; }\n",
	".SMATCH-C { background: aquamarine; }\n",
	".SMATCH-D { background: palegreen; }\n",
	".SMATCH-E { background: coral; }\n",
	".SMATCH-F { background: wheat; }\n",
	".SMATCH-G { background: khaki; }\n",
	".SMATCH-H { background: lime; }\n",
	".SMATCH-I { background: deepskyblue; }\n",
	".SMATCH-J { background: plum; }\n",
	};


	private static void appendCssColor(final StringBuilder sb, final RGB color) {
	sb.append('#');
	String s= Integer.toHexString(color.red);
	if (s.length() == 1) {
	sb.append('0');
	}
	sb.append(s);
	s= Integer.toHexString(color.green);
	if (s.length() == 1) {
	sb.append('0');
	}
	sb.append(s);
	s= Integer.toHexString(color.blue);
	if (s.length() == 1) {
	sb.append('0');
	}
	sb.append(s);
	}

	private static void appendELinkColors(final StringBuilder sb, final RGB foregroundColor) {
	final RGB hyperlinkColor= JFaceResources.getColorRegistry().getRGB(JFacePreferences.HYPERLINK_COLOR);
	sb.append("a { color: "); //$NON-NLS-1$
	appendCssColor(sb, hyperlinkColor);
	sb.append("; }\n");//$NON-NLS-1$
	sb.append("a:hover, a:active, a:focus { color: "); //$NON-NLS-1$
	appendCssColor(sb, JFaceResources.getColorRegistry().getRGB(JFacePreferences.ACTIVE_HYPERLINK_COLOR));
	sb.append("; }\n"); //$NON-NLS-1$
	sb.append("a:visited { color: "); //$NON-NLS-1$
	appendCssColor(sb, new RGB(
	(hyperlinkColor.red + ((hyperlinkColor.red <= 127) ? +64 : -64)),
	(hyperlinkColor.green + foregroundColor.green) / 2,
	(hyperlinkColor.blue + ((hyperlinkColor.blue > 32) ? -32 : +32) + foregroundColor.blue ) / 2 ));
	sb.append("; }\n"); //$NON-NLS-1$
	}

	private static void appendMatchColors(final StringBuilder sb) {
	int i= 0;
	final RGB rgb= PreferenceConverter.getColor(
	EditorsPlugin.getDefault().getPreferenceStore(),
	"searchResultIndicationColor"); //$NON-NLS-1$
	if (rgb != null) {
	sb.append(".SMATCH-A { background: ");
	appendCssColor(sb, rgb);
	sb.append("; }\n"); //$NON-NLS-1$
	i++;
	}
	while (i < DEFAULT_MATCH_COLORS.length) {
	sb.append(DEFAULT_MATCH_COLORS[i++]);
	}
	}


	public static class Browse extends RHelpUIServlet {

	private static final long serialVersionUID= 1L;

	@Override
	protected void collectCss(final StringBuilder sb) {
	final RGB foregroundColor= JFaceResources.getColorRegistry().getRGB("org.eclipse.statet.workbench.themes.DocViewColor"); //$NON-NLS-1$
	final RGB docBackgroundColor= JFaceResources.getColorRegistry().getRGB("org.eclipse.statet.workbench.themes.DocViewBackgroundColor"); //$NON-NLS-1$
	final RGB borderColor= Display.getCurrent().getSystemColor(SWT.COLOR_WIDGET_NORMAL_SHADOW).getRGB();

	{ final FontDescriptor docFontDescr= JFaceResources.getFontDescriptor("org.eclipse.statet.workbench.themes.DocViewFont"); //$NON-NLS-1$
	final FontData fontData= docFontDescr.getFontData()[0];

	sb.append("body { font-family: '"); //$NON-NLS-1$
	sb.append(fontData.getName());
	sb.append("'; font-size:"); //$NON-NLS-1$
	sb.append(fontData.getHeight());
	sb.append("pt; color:"); //$NON-NLS-1$
	appendCssColor(sb, foregroundColor);
	sb.append("; background:"); //$NON-NLS-1$
	appendCssColor(sb, docBackgroundColor);
	sb.append("; }\n"); //$NON-NLS-1$
	}

	appendELinkColors(sb, foregroundColor);

	sb.append("div.toc a, div.toc a:visited { color: "); //$NON-NLS-1$
	appendCssColor(sb, foregroundColor);
	sb.append("; }\n"); //$NON-NLS-1$

	sb.append("@media screen {\n"); //$NON-NLS-1$

	sb.append("body { margin: "); //$NON-NLS-1$
	sb.append(LayoutUtils.defaultVSpacing());
	sb.append("px "); //$NON-NLS-1$
	sb.append(LayoutUtils.defaultHSpacing());
	sb.append("px; }\n"); //$NON-NLS-1$

	sb.append("div.toc { display: inline; float: right; border: 1px solid "); //$NON-NLS-1$
	appendCssColor(sb, borderColor);
	sb.append("; }\n"); //$NON-NLS-1$

	sb.append("span.mnemonic, div.toc a.mnemonic { text-decoration: underline; }\n"); //$NON-NLS-1$
	sb.append("hr { border: 0; height: 1px; background: " ); //$NON-NLS-1$
	appendCssColor(sb, borderColor);
	sb.append("; }\n"); //$NON-NLS-1$

	sb.append("}\n" ); // @media //$NON-NLS-1$

	appendMatchColors(sb);

	super.collectCss(sb);
	}

	}

	public static class Info extends RHelpUIServlet {

	private static final long serialVersionUID= 1L;

	@Override
	protected void collectCss(final StringBuilder sb) {
	final Display display= Display.getCurrent();
	final RGB infoForegroundColor= display.getSystemColor(SWT.COLOR_INFO_FOREGROUND).getRGB();
	final RGB infoBackgroundColor= display.getSystemColor(SWT.COLOR_INFO_BACKGROUND).getRGB();
	final int vIndent= Math.max(1, LayoutUtils.defaultVSpacing() / 4);
	final int hIndent= Math.max(3, LayoutUtils.defaultHSpacing() / 2);

	{ final FontDescriptor docFontDescr= JFaceResources.getDialogFontDescriptor();
	final FontData fontData= docFontDescr.getFontData()[0];
	sb.append("body { font-family: '"); //$NON-NLS-1$
	sb.append(fontData.getName());
	sb.append("'; font-size: "); //$NON-NLS-1$
	sb.append(fontData.getHeight());
	sb.append("pt; color: "); //$NON-NLS-1$
	appendCssColor(sb, infoForegroundColor);
	sb.append("; background: "); //$NON-NLS-1$
	appendCssColor(sb, infoBackgroundColor);
	sb.append("; margin: 0 "); //$NON-NLS-1$
	sb.append(hIndent);
	sb.append("px "); //$NON-NLS-1$
	sb.append(vIndent);
	sb.append("px; }\n"); //$NON-NLS-1$
	}
	appendELinkColors(sb, infoForegroundColor);

	sb.append("h2, h3#description { display: none; }\n"); //$NON-NLS-1$
	sb.append("h3 { font-size: 90%; margin-bottom: 0.4em; }\n"); //$NON-NLS-1$
	sb.append("p, pre { margin-top: 0.4em; margin-bottom: 0.4em; }\n" ); //$NON-NLS-1$

	sb.append("hr { visibility: hidden; }\n"); //$NON-NLS-1$

	super.collectCss(sb);
	}

	}


	private volatile @Nullable String cssStyle;

	private RHelpRCodeScanner rCodeScanner;


	@SuppressWarnings("null")
	public RHelpUIServlet() {
	}


	@Override
	public void init(final ServletConfig config) throws ServletException {
	super.init(config);

	init(RCore.getRHelpManager(),
	JettyRHelpUtils.newResourceHandler(config.getServletContext()),
	new JettyForwardHandler() );

	this.rCodeScanner= new RHelpRCodeScanner(RUIPlugin.getInstance().getEditorPreferenceStore());

	EditorsUI.getPreferenceStore().addPropertyChangeListener(this);
	JFaceResources.getFontRegistry().addListener(this);
	JFaceResources.getColorRegistry().addListener(this);
	PreferencesUtil.getSettingsChangeNotifier().addChangeListener(this);
	updateStyles();
	}

	@Override
	public void propertyChange(final PropertyChangeEvent event) {
	if (event.getProperty().equals("org.eclipse.statet.workbench.themes.DocViewFont") //$NON-NLS-1$
	\|\| event.getProperty().equals("org.eclipse.statet.workbench.themes.DocViewBackgroundColor") //$NON-NLS-1$
	\|\| event.getProperty().equals("org.eclipse.statet.workbench.themes.DocViewColor") //$NON-NLS-1$
	\|\| event.getProperty().equals(JFaceResources.DIALOG_FONT)
	\|\| event.getProperty().equals(JFacePreferences.HYPERLINK_COLOR)
	\|\| event.getProperty().equals(JFacePreferences.ACTIVE_HYPERLINK_COLOR)
	\|\| event.getProperty().equals("searchResultIndicationColor") ) { //$NON-NLS-1$
	updateStyles();
	}
	}

	@Override
	public void settingsChanged(final Set<String> groupIds) {
	if (groupIds.contains(RUIPreferenceConstants.R.TS_GROUP_ID)
	\|\| groupIds.contains(RIdentifierGroups.GROUP_ID)) {
	final Map<String, Object> options= new HashMap<>();
	synchronized (this.rCodeScanner) {
	this.rCodeScanner.handleSettingsChanged(groupIds, options);
	}
	}
	}

	@Override
	public void destroy() {
	super.destroy();

	final IPreferenceStore preferenceStore= EditorsUI.getPreferenceStore();
	if (preferenceStore != null) {
	preferenceStore.removePropertyChangeListener(this);
	}
	JFaceResources.getFontRegistry().removeListener(this);
	JFaceResources.getColorRegistry().removeListener(this);
	PreferencesUtil.getSettingsChangeNotifier().removeChangeListener(this);
	}


	@Override
	protected boolean getShowInternal() {
	return PreferenceUtils.getInstancePrefs().getPreferenceValue(
	RHelpPreferences.SHOW_INTERNAL_ENABLED_PREF );
	}

	@Override
	protected boolean canOpenFile(final String ext) {
	return true;
	}

	@Override
	protected void doOpenFile(final Path file) {
	try {
	final IFileStore fileStore= EFS.getLocalFileSystem().getStore(file.toUri());
	UIAccess.getDisplay().asyncExec(new Runnable() {
	@Override
	public void run() {
	final IWorkbenchPage page= UIAccess.getActiveWorkbenchPage(true);
	try {
	IDE.openEditorOnFileStore(page, fileStore);
	}
	catch (final PartInitException e) {}
	}
	});
	}
	catch (final Exception e) {}
	}


	private void updateStyles() {
	final StringBuilder sb= new StringBuilder(1024);
	UIAccess.getDisplay().syncExec(new Runnable() {
	@Override
	public void run() {
	collectCss(sb);
	}
	});
	sb.append(".header { display: none; }"); //$NON-NLS-1$
	this.cssStyle= sb.toString();
	}

	protected void collectCss(final StringBuilder sb) {
	}

	@Override
	protected void customizeCss(final PrintWriter writer) {
	// updateStyles();
	writer.print(this.cssStyle);
	}

	@Override
	protected void customizePageHtmlHeader(final HttpServletRequest req, final PrintWriter writer) {
	customizeHtmlHeader(req, writer, true);
	}

	@Override
	protected void customizeIndexHtmlHeader(final HttpServletRequest req, final PrintWriter writer) {
	customizeHtmlHeader(req, writer, false);
	}

	protected void customizeHtmlHeader(final HttpServletRequest req, final PrintWriter writer,
	final boolean page) {
	writer.println("<script type=\"text/javascript\">/* <![CDATA[ */"); //$NON-NLS-1$

	writer.println("function keyNavHandler(event) {"); //$NON-NLS-1$
	writer.println("if (!event) event= window.event;"); //$NON-NLS-1$
	writer.println("if (event.which) { key= event.which } else if (event.keyCode) { key= event.keyCode };"); //$NON-NLS-1$
	writer.println("if (!event.ctrlKey && !event.altKey) { var anchor= 0;"); //$NON-NLS-1$
	if (page) {
	writer.println("if (key == 68) anchor= \"#description\"; " + //$NON-NLS-1$
	"else if (key == 85) anchor= \"#usage\"; " + //$NON-NLS-1$
	"else if (key == 65) anchor= \"#arguments\"; " + //$NON-NLS-1$
	"else if (key == 73) anchor= \"#details\"; " + //$NON-NLS-1$
	"else if (key == 86) anchor= \"#value\"; " + //$NON-NLS-1$
	"else if (key == 79) anchor= \"#authors\"; " + //$NON-NLS-1$
	"else if (key == 82) anchor= \"#references\"; " + //$NON-NLS-1$
	"else if (key == 69) anchor= \"#examples\"; " + //$NON-NLS-1$
	"else if (key == 83) anchor= \"#seealso\";"); //$NON-NLS-1$
	}
	else {
	writer.println("if (key >= 65 && key <= 90) anchor= \"#idx\"+String.fromCharCode(key+32);"); //$NON-NLS-1$
	}
	writer.println("if (anchor) { window.location.hash= anchor; event.cancelBubble= true; return false; }"); //$NON-NLS-1$
	writer.println("} return true; }"); //$NON-NLS-1$
	writer.println("document.onkeydown= keyNavHandler;"); //$NON-NLS-1$

	writer.println("/* ]]> */</script>"); //$NON-NLS-1$

	if (HOVER_STYLE.equals(req.getParameter(STYLE_PARAM))) {
	writer.println("<style type=\"text/css\">body { overflow: hidden; }</style>"); //$NON-NLS-1$
	}
	}

	@Override
	protected void printRCode(final PrintWriter writer, final String html) {
	synchronized (this.rCodeScanner) {
	this.rCodeScanner.setHtml(html);
	writer.write("<span style=\""); //$NON-NLS-1$
	writer.write(this.rCodeScanner.getDefaultStyle());
	writer.write("\">"); //$NON-NLS-1$

	IToken token;
	int currentIdx= 0;
	while (!(token= this.rCodeScanner.nextToken()).isEOF()) {
	final String data= (String) token.getData();
	if (data != null) {
	final int tokenIdx= this.rCodeScanner.getTokenOffset();
	if (tokenIdx > currentIdx) {
	writer.write(html, currentIdx, tokenIdx-currentIdx);
	}
	writer.write("<span style=\""); //$NON-NLS-1$
	writer.write(data);
	writer.write("\">"); //$NON-NLS-1$
	writer.write(html, tokenIdx, this.rCodeScanner.getTokenLength());
	writer.write("</span>"); //$NON-NLS-1$
	currentIdx= tokenIdx + this.rCodeScanner.getTokenLength();
	}
	}
	writer.write(html, currentIdx, html.length()-currentIdx);

	writer.write("</span>"); //$NON-NLS-1$
	}
	}

	}