org.eclipse.help.ui/src/org/eclipse/help/ui/internal/views/EngineResultSection.java - platform/eclipse.platform.ua - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2017 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
  * which accompanies this distribution, and is available at
  * https://www.eclipse.org/legal/epl-2.0/
  *
  * SPDX-License-Identifier: EPL-2.0
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.help.ui.internal.views;

 import java.net.URL;
 import java.util.ArrayList;

 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.help.IHelpResource;
 import org.eclipse.help.internal.base.BaseHelpSystem;
 import org.eclipse.help.internal.base.HelpBasePlugin;
 import org.eclipse.help.internal.search.SearchHit;
 import org.eclipse.help.search.ISearchEngineResult;
 import org.eclipse.help.search.ISearchEngineResult2;
 import org.eclipse.help.ui.internal.HelpUIPlugin;
 import org.eclipse.help.ui.internal.HelpUIResources;
 import org.eclipse.help.ui.internal.IHelpUIConstants;
 import org.eclipse.help.ui.internal.Messages;
 import org.eclipse.help.ui.internal.util.EscapeUtils;
 import org.eclipse.osgi.util.NLS;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.custom.BusyIndicator;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.graphics.ImageData;
 import org.eclipse.swt.layout.GridData;
 import org.eclipse.swt.layout.GridLayout;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
 import org.eclipse.swt.widgets.Label;
 import org.eclipse.swt.widgets.Menu;
 import org.eclipse.ui.ISharedImages;
 import org.eclipse.ui.IWorkbenchPage;
 import org.eclipse.ui.IWorkbenchWindow;
 import org.eclipse.ui.PartInitException;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.forms.IFormColors;
 import org.eclipse.ui.forms.events.ExpansionAdapter;
 import org.eclipse.ui.forms.events.ExpansionEvent;
 import org.eclipse.ui.forms.events.HyperlinkAdapter;
 import org.eclipse.ui.forms.events.HyperlinkEvent;
 import org.eclipse.ui.forms.events.IHyperlinkListener;
 import org.eclipse.ui.forms.widgets.FormText;
 import org.eclipse.ui.forms.widgets.FormToolkit;
 import org.eclipse.ui.forms.widgets.ImageHyperlink;
 import org.eclipse.ui.forms.widgets.Section;
 import org.eclipse.ui.forms.widgets.TableWrapData;
 import org.eclipse.ui.forms.widgets.TableWrapLayout;
 import org.osgi.framework.Bundle;

 public class EngineResultSection {

 	private static final String KEY_PREFIX_GRAYED = "grayed:"; //$NON-NLS-1$

 	private static final String CAT_HEADING_PREFIX = "catheading:"; //$NON-NLS-1$

 	private SearchResultsPart part;

 	private EngineDescriptor desc;

 	private IStatus errorStatus;

 	private ArrayList<ISearchEngineResult> hits;

 	private Section section;

 	private Composite container;

 	private FormText searchResults;

 	private ImageHyperlink prevLink;

 	private ImageHyperlink nextLink;

 	private boolean needsUpdating;

 	private FederatedSearchSorter sorter;

 	private int HITS_PER_PAGE = 10;

 	private static final String HREF_PROGRESS = "__progress__"; //$NON-NLS-1$

 	private static final String PROGRESS_VIEW = "org.eclipse.ui.views.ProgressView"; //$NON-NLS-1$

 	private int resultOffset = 0;

 	public EngineResultSection(SearchResultsPart part, EngineDescriptor desc) {
 		this.part = part;
 		this.desc = desc;
 		hits = new ArrayList<>();
 		sorter = new FederatedSearchSorter();
 	}

 	public boolean hasControl(Control control) {
 		return searchResults.equals(control);
 	}

 	public boolean matches(EngineDescriptor desc) {
 		return this.desc == desc;
 	}

 	public Control createControl(Composite parent, final FormToolkit toolkit) {
 		section = toolkit.createSection(parent, Section.SHORT_TITLE_BAR | Section.COMPACT | Section.TWISTIE
 				| Section.EXPANDED | Section.LEFT_TEXT_CLIENT_ALIGNMENT);
 		// section.marginHeight = 10;
 		container = toolkit.createComposite(section);
 		TableWrapLayout layout = new TableWrapLayout();
 		layout.topMargin = 0;
 		layout.bottomMargin = 0;
 		layout.leftMargin = 0;
 		layout.rightMargin = 0;
 		layout.verticalSpacing = 0;
 		container.setLayout(layout);
 		createFormText(container, toolkit);
 		searchResults.setLayoutData(new TableWrapData(TableWrapData.FILL_GRAB));
 		searchResults.setColor("summary", parent.getDisplay().getSystemColor(SWT.COLOR_WIDGET_DARK_SHADOW)); //$NON-NLS-1$
 		section.setClient(container);
 		updateSectionTitle(0);
 		section.addExpansionListener(new ExpansionAdapter() {

 			@Override
 			public void expansionStateChanging(ExpansionEvent e) {
 				if (needsUpdating)
 					asyncUpdateResults(true, false);
 			}
 		});
 		return section;
 	}

 	private void createFormText(Composite parent, FormToolkit toolkit) {
 		searchResults = toolkit.createFormText(parent, false);
 		searchResults.setColor(IFormColors.TITLE, toolkit.getColors().getColor(IFormColors.TITLE));
 		searchResults.marginHeight = 5;
 		String topicKey = IHelpUIConstants.IMAGE_FILE_F1TOPIC;
 		String searchKey = IHelpUIConstants.IMAGE_HELP_SEARCH;
 		searchResults.setImage(topicKey, HelpUIResources.getImage(topicKey));
 		searchResults.setImage(searchKey, HelpUIResources.getImage(searchKey));
 		searchResults.setColor("summary", parent.getDisplay().getSystemColor( //$NON-NLS-1$
 				SWT.COLOR_WIDGET_DARK_SHADOW));
 		searchResults.setImage(ISharedImages.IMG_TOOL_FORWARD, PlatformUI.getWorkbench().getSharedImages()
 				.getImage(ISharedImages.IMG_TOOL_FORWARD));
 		searchResults.setImage(ISharedImages.IMG_TOOL_BACK, PlatformUI.getWorkbench().getSharedImages()
 				.getImage(ISharedImages.IMG_TOOL_BACK));
 		searchResults.setImage(ISharedImages.IMG_OBJS_ERROR_TSK, PlatformUI.getWorkbench().getSharedImages()
 				.getImage(ISharedImages.IMG_OBJS_ERROR_TSK));
 		searchResults.setImage(desc.getId(), desc.getIconImage());
 		searchResults.setImage(KEY_PREFIX_GRAYED + desc.getId(), getGrayedImage(desc.getIconImage()));
 		searchResults.addHyperlinkListener(new IHyperlinkListener() {

 			@Override
 			public void linkActivated(HyperlinkEvent e) {
 				Object href = e.getHref();
 				String shref = (String) href;
 				if (HREF_PROGRESS.equals(href)) {
 					showProgressView();
 				} else if (shref.startsWith("bmk:")) { //$NON-NLS-1$
 					doBookmark(e.getLabel(), shref);
 				} else if (shref.startsWith(CAT_HEADING_PREFIX)) {
 					part.doCategoryLink(shref.substring(CAT_HEADING_PREFIX.length()));
 				} else
 					part.doOpenLink(e.getHref());
 			}

 			@Override
 			public void linkEntered(HyperlinkEvent e) {
 				part.parent.handleLinkEntered(e);
 			}

 			@Override
 			public void linkExited(HyperlinkEvent e) {
 				part.parent.handleLinkExited(e);
 			}
 		});
 		initializeText();
 		part.parent.hookFormText(searchResults);
 		needsUpdating = true;
 	}

 	private void initializeText() {
 		Bundle bundle = Platform.getBundle("org.eclipse.ui.views"); //$NON-NLS-1$
 		if (bundle != null) {
 			StringBuilder buff = new StringBuilder();
 			buff.append("<form>"); //$NON-NLS-1$
 			buff.append("<p><a href=\""); //$NON-NLS-1$
 			buff.append(HREF_PROGRESS);
 			buff.append("\""); //$NON-NLS-1$
 			if (!Platform.getWS().equals(Platform.WS_GTK)) {
 				buff.append(" alt=\""); //$NON-NLS-1$
 				buff.append(Messages.EngineResultSection_progressTooltip);
 				buff.append("\""); //$NON-NLS-1$
 			}
 			buff.append(">"); //$NON-NLS-1$
 			buff.append(Messages.EngineResultSection_searchInProgress);
 			buff.append("</a></p></form>"); //$NON-NLS-1$
 			searchResults.setText(buff.toString(), true, false);
 		} else {
 			searchResults.setText(Messages.EngineResultSection_progress2, false, false);
 		}
 	}

 	private void showProgressView() {
 		IWorkbenchWindow window = PlatformUI.getWorkbench().getActiveWorkbenchWindow();
 		if (window != null) {
 			IWorkbenchPage page = window.getActivePage();
 			if (page != null) {
 				try {
 					page.showView(PROGRESS_VIEW);
 				} catch (PartInitException e) {
 					HelpUIPlugin.logError(Messages.EngineResultSection_progressError, e);
 				}
 			}
 		}
 	}

 	public synchronized void add(ISearchEngineResult match) {
 		hits.add(match);
 		asyncUpdateResults(false, false);
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.help.internal.search.federated.ISearchEngineResultCollector#add(org.eclipse.help.internal.search.federated.ISearchEngineResult[])
 	 */
 	public synchronized void add(ISearchEngineResult[] matches) {
 		for (int i = 0; i < matches.length; i++)
 			hits.add(matches[i]);
 		asyncUpdateResults(false, false);
 	}

 	public synchronized void error(IStatus status) {
 		errorStatus = status;
 		asyncUpdateResults(false, false);
 	}

 	public synchronized void completed() {
 		if (hits.size() == 0 && !searchResults.isDisposed())
 			asyncUpdateResults(false, false);
 	}

 	public synchronized void canceling() {
 		if (hits.size() == 0 && !searchResults.isDisposed()) {
 			StringBuilder buff = new StringBuilder();
 			buff.append("<form>"); //$NON-NLS-1$
 			buff.append("<p><span color=\"summary\">");//$NON-NLS-1$
 			buff.append(Messages.EngineResultSection_canceling);
 			buff.append("</span></p>"); //$NON-NLS-1$
 			buff.append("</form>"); //$NON-NLS-1$
 			searchResults.setText(buff.toString(), true, false);
 		}
 	}

 	private void asyncUpdateResults(boolean now, final boolean scrollToBeginning) {
 		Runnable runnable = () -> BusyIndicator.showWhile(PlatformUI.getWorkbench().getDisplay(), () -> {
 			if (section.isDisposed()) {
 				return;
 			}
 			updateResults(true);
 			if (scrollToBeginning) {
 				searchResults.setFocus();
 				FormToolkit.setControlVisible(section, true);
 				part.updateSeparatorVisibility();
 			}
 		});
 		if (section.isDisposed()) {
 			return;
 		}
 		if (now) {
 			PlatformUI.getWorkbench().getDisplay().syncExec(runnable);
 		} else {
 			PlatformUI.getWorkbench().getDisplay().asyncExec(runnable);
 		}
 	}

 	private ISearchEngineResult[] getResults() {
 		ArrayList<ISearchEngineResult> list = hits;
 		if (desc.getEngineTypeId().equals(IHelpUIConstants.INTERNAL_HELP_ID)) {
 			if (part.parent.isFilteredByRoles()) {
 				list = new ArrayList<>();
 				for (int i = 0; i < hits.size(); i++) {
 					ISearchEngineResult hit = hits.get(i);
 					if (HelpBasePlugin.getActivitySupport().isEnabled(hit.getHref()))
 						list.add(hit);
 				}
 			}
 		}
 		ISearchEngineResult[] results = list.toArray(new ISearchEngineResult[list.size()]);
 		if (part.getShowCategories())
 			sorter.sort(null, results);
 		return results;
 	}

 	/**
 	 * Returns a copy of the given image but grayed and half transparent.
 	 * This gives the icon a grayed/disabled look.
 	 *
 	 * @param image the image to gray
 	 * @return the grayed image
 	 */
 	private Image getGrayedImage(Image image) {
 		// first gray the image
 		Image temp = new Image(image.getDevice(), image, SWT.IMAGE_GRAY);
 		// then add alpha to blend it 50/50 with the background
 		ImageData data = temp.getImageData();
 		ImageData maskData = data.getTransparencyMask();
 		if (maskData != null) {
 			for (int y=0;y<maskData.height;++y) {
 				for (int x=0;x<maskData.width;++x) {
 					if (maskData.getPixel(x, y) == 0) {
 						// masked; set to transparent
 						data.setAlpha(x, y, 0);
 					}
 					else {
 						// not masked; set to translucent
 						data.setAlpha(x, y, 128);
 					}
 				}
 			}
 			data.maskData = null;
 		}
 		Image grayed = new Image(image.getDevice(), data);
 		temp.dispose();
 		return grayed;
 	}

 	void updateResults(boolean reflow) {
 		ISearchEngineResult[] results = getResults();
 		updateSectionTitle(results.length);
 		StringBuilder buff = new StringBuilder();
 		buff.append("<form>"); //$NON-NLS-1$
 		IHelpResource oldCat = null;

 		for (int i = resultOffset; i < results.length; i++) {
 			if (i - resultOffset == HITS_PER_PAGE) {
 				break;
 			}
 			ISearchEngineResult hit = results[i];
 			IHelpResource cat = hit.getCategory();
 			if (part.getShowCategories() && cat != null
 					&& (oldCat == null || !oldCat.getLabel().equals(cat.getLabel()))) {
 				buff.append("<p>"); //$NON-NLS-1$
 				if (cat.getHref() != null) {
 					buff.append("<a bold=\"true\" href=\""); //$NON-NLS-1$
 					String absoluteHref = ""; //$NON-NLS-1$
 					if (cat.getHref().endsWith(".xml")) { //$NON-NLS-1$
 						absoluteHref = absoluteHref + CAT_HEADING_PREFIX;
 					}
 					absoluteHref = absoluteHref + hit.toAbsoluteHref(cat.getHref(), true);
 					buff.append(EscapeUtils.escapeSpecialChars(absoluteHref));
 					buff.append("\">"); //$NON-NLS-1$
 					buff.append(cat.getLabel());
 					buff.append("</a>"); //$NON-NLS-1$
 				} else {
 					buff.append("<b>"); //$NON-NLS-1$
 					buff.append(cat.getLabel());
 					buff.append("</b>"); //$NON-NLS-1$
 				}
 				buff.append("</p>"); //$NON-NLS-1$
 				oldCat = cat;
 			}
 			int indent = part.getShowCategories() && cat != null ? 26 : 21;
 			int bindent = part.getShowCategories() && cat != null ? 5 : 0;
 			buff.append("<li indent=\"" + indent + "\" bindent=\"" + bindent + "\" style=\"image\" value=\""); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
 			String imageId = desc.getId();
 			boolean isPotentialHit = (hit instanceof SearchHit && ((SearchHit)hit).isPotentialHit());
 			if (hit instanceof ISearchEngineResult2) {
 				URL iconURL = ((ISearchEngineResult2) hit).getIconURL();
 				if (iconURL != null) {
 					String id = null;
 					if (isPotentialHit) {
 						id = registerGrayedHitIcon(iconURL);
 					}
 					else {
 						id = registerHitIcon(iconURL);
 					}
 					if (id != null)
 						imageId = id;
 				}
 			}

 			if (isPotentialHit) {
 				imageId = KEY_PREFIX_GRAYED + imageId;
 			}

 			buff.append(imageId);
 			buff.append("\">"); //$NON-NLS-1$
 			buff.append("<a href=\""); //$NON-NLS-1$
 			String href=null;
 			if (hit instanceof ISearchEngineResult2) {
 				ISearchEngineResult2 hit2 = (ISearchEngineResult2)hit;
 				if (((ISearchEngineResult2)hit).canOpen()) {
 					href = "open:"+desc.getId()+"?id="+hit2.getId(); //$NON-NLS-1$ //$NON-NLS-2$
 				}
 			}
 			if (href==null) {
 				if (hit.getForceExternalWindow())
 					href = "nw:";//$NON-NLS-1$
 				href = EscapeUtils.escapeSpecialChars(hit.toAbsoluteHref(hit.getHref(), false));
 			}
 			buff.append(href);
 			buff.append("\""); //$NON-NLS-1$
 			if (hit.getCategory() != null && Platform.getWS() != Platform.WS_GTK) {
 				buff.append(" alt=\""); //$NON-NLS-1$
 				buff.append(hit.getCategory().getLabel());
 				buff.append("\""); //$NON-NLS-1$
 			}
 			buff.append(">"); //$NON-NLS-1$
 			String elabel = null;
 			if (isPotentialHit) {
 				// add "(potential hit)"
 				elabel = Messages.bind(Messages.SearchPart_potential_hit, hit.getLabel());
 			}
 			else {
 				elabel = hit.getLabel();
 			}

 			elabel = EscapeUtils.escapeSpecialChars(elabel);
 			buff.append(elabel);
 			buff.append("</a>"); //$NON-NLS-1$
 			if (part.getShowDescription()) {
 				String edesc = hit.getDescription();
 				if (edesc != null) {
 					edesc = EscapeUtils.escapeSpecialChars(edesc);
 					buff.append("<br/>"); //$NON-NLS-1$
 					buff.append(edesc);
 				}
 			}
 			buff.append("</li>"); //$NON-NLS-1$
 		}
 		if (errorStatus != null)
 			updateErrorStatus(buff);
 		updateNavigation(results.length);
 		buff.append("</form>"); //$NON-NLS-1$
 		searchResults.setText(buff.toString(), true, false);
 		section.layout();
 		if (reflow)
 			part.reflow();
 	}

 	/**
 	 * Registers the given icon URL for use with this section. Icons
 	 * must be registered before use and referenced by the returned
 	 * ID.
 	 *
 	 * @param iconURL the URL to the icon
 	 * @return the ID to use for referencing the icon
 	 */
 	private String registerHitIcon(URL iconURL) {
 		Image image = HelpUIResources.getImage(iconURL);
 		if (image != null) {
 			searchResults.setImage(iconURL.toString(), image);
 			return iconURL.toString();
 		}
 		return null;
 	}

 	/**
 	 * Same as registerHitIcon() but to register a grayed icon. You
 	 * can provide the same URL for both the regular and grayed icons,
 	 * but two different IDs will be returned.
 	 *
 	 * @param iconURL the URL to the icon
 	 * @return the ID to use for referencing the icon
 	 */
 	private String registerGrayedHitIcon(URL iconURL) {
 		Image image = HelpUIResources.getImage(iconURL);
 		if (image != null) {
 			searchResults.setImage(iconURL.toString(), image);
 			return KEY_PREFIX_GRAYED + iconURL.toString();
 		}
 		return null;
 	}

 	private void updateErrorStatus(StringBuilder buff) {
 		int indent = 21;
 		buff.append("<li indent=\"" + indent + "\" style=\"image\" value=\""); //$NON-NLS-1$ //$NON-NLS-2$
 		buff.append(ISharedImages.IMG_OBJS_ERROR_TSK);
 		buff.append("\">"); //$NON-NLS-1$
 		buff.append("<b>"); //$NON-NLS-1$
 		buff.append(EscapeUtils.escapeSpecialChars(errorStatus.getMessage()));
 		buff.append("</b>"); //$NON-NLS-1$
 		buff.append("<br/>"); //$NON-NLS-1$
 		Throwable t = errorStatus.getException();
 		if (t != null && t.getMessage() != null)
 			buff.append(EscapeUtils.escapeSpecialChars(t.getMessage()));
 		buff.append("</li>"); //$NON-NLS-1$
 	}

 	private void updateNavigation(int size) {
 		if (size > HITS_PER_PAGE) {
 			if (prevLink == null) {
 				FormToolkit toolkit = part.getToolkit();
 				Composite navContainer = toolkit.createComposite(container);
 				TableWrapData td = new TableWrapData(TableWrapData.FILL_GRAB);
 				navContainer.setLayoutData(td);
 				GridLayout glayout = new GridLayout();
 				glayout.numColumns = 2;
 				navContainer.setLayout(glayout);
 				GridData gd;
 				/*
 				 * Label sep = toolkit.createLabel(navContainer, null, SWT.SEPARATOR |
 				 * SWT.HORIZONTAL); GridData gd = new GridData(GridData.HORIZONTAL_ALIGN_FILL);
 				 * gd.horizontalSpan = 2; gd.widthHint = 2; sep.setLayoutData(gd);
 				 */
 				prevLink = toolkit.createImageHyperlink(navContainer, SWT.NULL);

 				prevLink.setText(NLS.bind(Messages.EngineResultSection_previous, "" + HITS_PER_PAGE)); //$NON-NLS-1$
 				prevLink.setImage(PlatformUI.getWorkbench().getSharedImages().getImage(
 						ISharedImages.IMG_TOOL_BACK));
 				prevLink.addHyperlinkListener(new HyperlinkAdapter() {

 					@Override
 					public void linkActivated(HyperlinkEvent e) {
 						resultOffset -= HITS_PER_PAGE;
 						asyncUpdateResults(false, true);
 					}
 				});
 				nextLink = toolkit.createImageHyperlink(navContainer, SWT.RIGHT);

 				nextLink.setImage(PlatformUI.getWorkbench().getSharedImages().getImage(
 						ISharedImages.IMG_TOOL_FORWARD));
 				gd = new GridData(GridData.HORIZONTAL_ALIGN_END);
 				gd.grabExcessHorizontalSpace = true;
 				nextLink.setLayoutData(gd);
 				nextLink.addHyperlinkListener(new HyperlinkAdapter() {

 					@Override
 					public void linkActivated(HyperlinkEvent e) {
 						resultOffset += HITS_PER_PAGE;
 						asyncUpdateResults(false, true);
 					}
 				});
 			}
 			prevLink.setVisible(resultOffset > 0);

 			int nextOffset = resultOffset + HITS_PER_PAGE;
 			int remainder = hits.size() - nextOffset;
 			remainder = Math.min(remainder, HITS_PER_PAGE);

 			nextLink.setText(NLS.bind(Messages.EngineResultSection_next, "" + remainder)); //$NON-NLS-1$
 			nextLink.setVisible(hits.size() > resultOffset + HITS_PER_PAGE);
 		} else {
 			if (prevLink != null) {
 				prevLink.getParent().setMenu(null);
 				prevLink.getParent().dispose();
 				prevLink = null;
 				nextLink = null;
 			}
 		}
 	}

 	private void updateSectionTitle(int size) {
 		if (errorStatus != null) {
 			Label label = part.getToolkit().createLabel(section, null);
 			label.setImage(PlatformUI.getWorkbench().getSharedImages().getImage(
 					ISharedImages.IMG_OBJS_ERROR_TSK));
 			section.setTextClient(label);
 			section.setText(Messages.EngineResultSection_sectionTitle_error);
 		} else {
 			section.setTextClient(null);
 		}
 		if (size == 1)
 			section.setText(NLS.bind(Messages.EngineResultSection_sectionTitle_hit, desc.getLabel(), "" //$NON-NLS-1$
 					+ hits.size()));
 		else if (size <= HITS_PER_PAGE)
 			section.setText(NLS.bind(Messages.EngineResultSection_sectionTitle_hits, desc.getLabel(),
 					"" + hits.size())); //$NON-NLS-1$
 		else {
 			int from = (resultOffset + 1);
 			int to = (resultOffset + HITS_PER_PAGE);
 			to = Math.min(to, size);
 			section.setText(NLS.bind(Messages.EngineResultSection_sectionTitle_hitsRange, new String[] {
 					desc.getLabel(), "" + from, "" + to, "" + size })); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
 		}
 	}

 	private void doBookmark(final String label, String href) {
 		final String fhref = href.substring(4);
 		BusyIndicator.showWhile(container.getDisplay(),
 				() -> BaseHelpSystem.getBookmarkManager().addBookmark(fhref, label));
 	}

 	public void dispose() {
 		part.parent.unhookFormText(searchResults);
 		if (!section.isDisposed()) {
 			recursiveSetMenu(section, null);
 			section.dispose();
 		}
 	}

 	private void recursiveSetMenu(Control control, Menu menu) {
 		control.setMenu(menu);
 		if (control instanceof Composite) {
 			Composite parent = (Composite) control;
 			Control[] children = parent.getChildren();
 			for (int i = 0; i < children.length; i++) {
 				recursiveSetMenu(children[i], menu);
 			}
 		}
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2017 IBM Corporation and others.
	*
	* This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License 2.0
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/legal/epl-2.0/
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.help.ui.internal.views;

	import java.net.URL;
	import java.util.ArrayList;

	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.Platform;
	import org.eclipse.help.IHelpResource;
	import org.eclipse.help.internal.base.BaseHelpSystem;
	import org.eclipse.help.internal.base.HelpBasePlugin;
	import org.eclipse.help.internal.search.SearchHit;
	import org.eclipse.help.search.ISearchEngineResult;
	import org.eclipse.help.search.ISearchEngineResult2;
	import org.eclipse.help.ui.internal.HelpUIPlugin;
	import org.eclipse.help.ui.internal.HelpUIResources;
	import org.eclipse.help.ui.internal.IHelpUIConstants;
	import org.eclipse.help.ui.internal.Messages;
	import org.eclipse.help.ui.internal.util.EscapeUtils;
	import org.eclipse.osgi.util.NLS;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.custom.BusyIndicator;
	import org.eclipse.swt.graphics.Image;
	import org.eclipse.swt.graphics.ImageData;
	import org.eclipse.swt.layout.GridData;
	import org.eclipse.swt.layout.GridLayout;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Control;
	import org.eclipse.swt.widgets.Label;
	import org.eclipse.swt.widgets.Menu;
	import org.eclipse.ui.ISharedImages;
	import org.eclipse.ui.IWorkbenchPage;
	import org.eclipse.ui.IWorkbenchWindow;
	import org.eclipse.ui.PartInitException;
	import org.eclipse.ui.PlatformUI;
	import org.eclipse.ui.forms.IFormColors;
	import org.eclipse.ui.forms.events.ExpansionAdapter;
	import org.eclipse.ui.forms.events.ExpansionEvent;
	import org.eclipse.ui.forms.events.HyperlinkAdapter;
	import org.eclipse.ui.forms.events.HyperlinkEvent;
	import org.eclipse.ui.forms.events.IHyperlinkListener;
	import org.eclipse.ui.forms.widgets.FormText;
	import org.eclipse.ui.forms.widgets.FormToolkit;
	import org.eclipse.ui.forms.widgets.ImageHyperlink;
	import org.eclipse.ui.forms.widgets.Section;
	import org.eclipse.ui.forms.widgets.TableWrapData;
	import org.eclipse.ui.forms.widgets.TableWrapLayout;
	import org.osgi.framework.Bundle;

	public class EngineResultSection {

	private static final String KEY_PREFIX_GRAYED = "grayed:"; //$NON-NLS-1$

	private static final String CAT_HEADING_PREFIX = "catheading:"; //$NON-NLS-1$

	private SearchResultsPart part;

	private EngineDescriptor desc;

	private IStatus errorStatus;

	private ArrayList<ISearchEngineResult> hits;

	private Section section;

	private Composite container;

	private FormText searchResults;

	private ImageHyperlink prevLink;

	private ImageHyperlink nextLink;

	private boolean needsUpdating;

	private FederatedSearchSorter sorter;

	private int HITS_PER_PAGE = 10;

	private static final String HREF_PROGRESS = "__progress__"; //$NON-NLS-1$

	private static final String PROGRESS_VIEW = "org.eclipse.ui.views.ProgressView"; //$NON-NLS-1$

	private int resultOffset = 0;

	public EngineResultSection(SearchResultsPart part, EngineDescriptor desc) {
	this.part = part;
	this.desc = desc;
	hits = new ArrayList<>();
	sorter = new FederatedSearchSorter();
	}

	public boolean hasControl(Control control) {
	return searchResults.equals(control);
	}

	public boolean matches(EngineDescriptor desc) {
	return this.desc == desc;
	}

	public Control createControl(Composite parent, final FormToolkit toolkit) {
	section = toolkit.createSection(parent, Section.SHORT_TITLE_BAR \| Section.COMPACT \| Section.TWISTIE
	\| Section.EXPANDED \| Section.LEFT_TEXT_CLIENT_ALIGNMENT);
	// section.marginHeight = 10;
	container = toolkit.createComposite(section);
	TableWrapLayout layout = new TableWrapLayout();
	layout.topMargin = 0;
	layout.bottomMargin = 0;
	layout.leftMargin = 0;
	layout.rightMargin = 0;
	layout.verticalSpacing = 0;
	container.setLayout(layout);
	createFormText(container, toolkit);
	searchResults.setLayoutData(new TableWrapData(TableWrapData.FILL_GRAB));
	searchResults.setColor("summary", parent.getDisplay().getSystemColor(SWT.COLOR_WIDGET_DARK_SHADOW)); //$NON-NLS-1$
	section.setClient(container);
	updateSectionTitle(0);
	section.addExpansionListener(new ExpansionAdapter() {

	@Override
	public void expansionStateChanging(ExpansionEvent e) {
	if (needsUpdating)
	asyncUpdateResults(true, false);
	}
	});
	return section;
	}

	private void createFormText(Composite parent, FormToolkit toolkit) {
	searchResults = toolkit.createFormText(parent, false);
	searchResults.setColor(IFormColors.TITLE, toolkit.getColors().getColor(IFormColors.TITLE));
	searchResults.marginHeight = 5;
	String topicKey = IHelpUIConstants.IMAGE_FILE_F1TOPIC;
	String searchKey = IHelpUIConstants.IMAGE_HELP_SEARCH;
	searchResults.setImage(topicKey, HelpUIResources.getImage(topicKey));
	searchResults.setImage(searchKey, HelpUIResources.getImage(searchKey));
	searchResults.setColor("summary", parent.getDisplay().getSystemColor( //$NON-NLS-1$
	SWT.COLOR_WIDGET_DARK_SHADOW));
	searchResults.setImage(ISharedImages.IMG_TOOL_FORWARD, PlatformUI.getWorkbench().getSharedImages()
	.getImage(ISharedImages.IMG_TOOL_FORWARD));
	searchResults.setImage(ISharedImages.IMG_TOOL_BACK, PlatformUI.getWorkbench().getSharedImages()
	.getImage(ISharedImages.IMG_TOOL_BACK));
	searchResults.setImage(ISharedImages.IMG_OBJS_ERROR_TSK, PlatformUI.getWorkbench().getSharedImages()
	.getImage(ISharedImages.IMG_OBJS_ERROR_TSK));
	searchResults.setImage(desc.getId(), desc.getIconImage());
	searchResults.setImage(KEY_PREFIX_GRAYED + desc.getId(), getGrayedImage(desc.getIconImage()));
	searchResults.addHyperlinkListener(new IHyperlinkListener() {

	@Override
	public void linkActivated(HyperlinkEvent e) {
	Object href = e.getHref();
	String shref = (String) href;
	if (HREF_PROGRESS.equals(href)) {
	showProgressView();
	} else if (shref.startsWith("bmk:")) { //$NON-NLS-1$
	doBookmark(e.getLabel(), shref);
	} else if (shref.startsWith(CAT_HEADING_PREFIX)) {
	part.doCategoryLink(shref.substring(CAT_HEADING_PREFIX.length()));
	} else
	part.doOpenLink(e.getHref());
	}

	@Override
	public void linkEntered(HyperlinkEvent e) {
	part.parent.handleLinkEntered(e);
	}

	@Override
	public void linkExited(HyperlinkEvent e) {
	part.parent.handleLinkExited(e);
	}
	});
	initializeText();
	part.parent.hookFormText(searchResults);
	needsUpdating = true;
	}

	private void initializeText() {
	Bundle bundle = Platform.getBundle("org.eclipse.ui.views"); //$NON-NLS-1$
	if (bundle != null) {
	StringBuilder buff = new StringBuilder();
	buff.append("<form>"); //$NON-NLS-1$
	buff.append("<p><a href=\""); //$NON-NLS-1$
	buff.append(HREF_PROGRESS);
	buff.append("\""); //$NON-NLS-1$
	if (!Platform.getWS().equals(Platform.WS_GTK)) {
	buff.append(" alt=\""); //$NON-NLS-1$
	buff.append(Messages.EngineResultSection_progressTooltip);
	buff.append("\""); //$NON-NLS-1$
	}
	buff.append(">"); //$NON-NLS-1$
	buff.append(Messages.EngineResultSection_searchInProgress);
	buff.append("</a></p></form>"); //$NON-NLS-1$
	searchResults.setText(buff.toString(), true, false);
	} else {
	searchResults.setText(Messages.EngineResultSection_progress2, false, false);
	}
	}

	private void showProgressView() {
	IWorkbenchWindow window = PlatformUI.getWorkbench().getActiveWorkbenchWindow();
	if (window != null) {
	IWorkbenchPage page = window.getActivePage();
	if (page != null) {
	try {
	page.showView(PROGRESS_VIEW);
	} catch (PartInitException e) {
	HelpUIPlugin.logError(Messages.EngineResultSection_progressError, e);
	}
	}
	}
	}

	public synchronized void add(ISearchEngineResult match) {
	hits.add(match);
	asyncUpdateResults(false, false);
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.help.internal.search.federated.ISearchEngineResultCollector#add(org.eclipse.help.internal.search.federated.ISearchEngineResult[])
	*/
	public synchronized void add(ISearchEngineResult[] matches) {
	for (int i = 0; i < matches.length; i++)
	hits.add(matches[i]);
	asyncUpdateResults(false, false);
	}

	public synchronized void error(IStatus status) {
	errorStatus = status;
	asyncUpdateResults(false, false);
	}

	public synchronized void completed() {
	if (hits.size() == 0 && !searchResults.isDisposed())
	asyncUpdateResults(false, false);
	}

	public synchronized void canceling() {
	if (hits.size() == 0 && !searchResults.isDisposed()) {
	StringBuilder buff = new StringBuilder();
	buff.append("<form>"); //$NON-NLS-1$
	buff.append("<p><span color=\"summary\">");//$NON-NLS-1$
	buff.append(Messages.EngineResultSection_canceling);
	buff.append("</span></p>"); //$NON-NLS-1$
	buff.append("</form>"); //$NON-NLS-1$
	searchResults.setText(buff.toString(), true, false);
	}
	}

	private void asyncUpdateResults(boolean now, final boolean scrollToBeginning) {
	Runnable runnable = () -> BusyIndicator.showWhile(PlatformUI.getWorkbench().getDisplay(), () -> {
	if (section.isDisposed()) {
	return;
	}
	updateResults(true);
	if (scrollToBeginning) {
	searchResults.setFocus();
	FormToolkit.setControlVisible(section, true);
	part.updateSeparatorVisibility();
	}
	});
	if (section.isDisposed()) {
	return;
	}
	if (now) {
	PlatformUI.getWorkbench().getDisplay().syncExec(runnable);
	} else {
	PlatformUI.getWorkbench().getDisplay().asyncExec(runnable);
	}
	}

	private ISearchEngineResult[] getResults() {
	ArrayList<ISearchEngineResult> list = hits;
	if (desc.getEngineTypeId().equals(IHelpUIConstants.INTERNAL_HELP_ID)) {
	if (part.parent.isFilteredByRoles()) {
	list = new ArrayList<>();
	for (int i = 0; i < hits.size(); i++) {
	ISearchEngineResult hit = hits.get(i);
	if (HelpBasePlugin.getActivitySupport().isEnabled(hit.getHref()))
	list.add(hit);
	}
	}
	}
	ISearchEngineResult[] results = list.toArray(new ISearchEngineResult[list.size()]);
	if (part.getShowCategories())
	sorter.sort(null, results);
	return results;
	}

	/**
	* Returns a copy of the given image but grayed and half transparent.
	* This gives the icon a grayed/disabled look.
	*
	* @param image the image to gray
	* @return the grayed image
	*/
	private Image getGrayedImage(Image image) {
	// first gray the image
	Image temp = new Image(image.getDevice(), image, SWT.IMAGE_GRAY);
	// then add alpha to blend it 50/50 with the background
	ImageData data = temp.getImageData();
	ImageData maskData = data.getTransparencyMask();
	if (maskData != null) {
	for (int y=0;y<maskData.height;++y) {
	for (int x=0;x<maskData.width;++x) {
	if (maskData.getPixel(x, y) == 0) {
	// masked; set to transparent
	data.setAlpha(x, y, 0);
	}
	else {
	// not masked; set to translucent
	data.setAlpha(x, y, 128);
	}
	}
	}
	data.maskData = null;
	}
	Image grayed = new Image(image.getDevice(), data);
	temp.dispose();
	return grayed;
	}

	void updateResults(boolean reflow) {
	ISearchEngineResult[] results = getResults();
	updateSectionTitle(results.length);
	StringBuilder buff = new StringBuilder();
	buff.append("<form>"); //$NON-NLS-1$
	IHelpResource oldCat = null;

	for (int i = resultOffset; i < results.length; i++) {
	if (i - resultOffset == HITS_PER_PAGE) {
	break;
	}
	ISearchEngineResult hit = results[i];
	IHelpResource cat = hit.getCategory();
	if (part.getShowCategories() && cat != null
	&& (oldCat == null \|\| !oldCat.getLabel().equals(cat.getLabel()))) {
	buff.append("<p>"); //$NON-NLS-1$
	if (cat.getHref() != null) {
	buff.append("<a bold=\"true\" href=\""); //$NON-NLS-1$
	String absoluteHref = ""; //$NON-NLS-1$
	if (cat.getHref().endsWith(".xml")) { //$NON-NLS-1$
	absoluteHref = absoluteHref + CAT_HEADING_PREFIX;
	}
	absoluteHref = absoluteHref + hit.toAbsoluteHref(cat.getHref(), true);
	buff.append(EscapeUtils.escapeSpecialChars(absoluteHref));
	buff.append("\">"); //$NON-NLS-1$
	buff.append(cat.getLabel());
	buff.append("</a>"); //$NON-NLS-1$
	} else {
	buff.append("<b>"); //$NON-NLS-1$
	buff.append(cat.getLabel());
	buff.append("</b>"); //$NON-NLS-1$
	}
	buff.append("</p>"); //$NON-NLS-1$
	oldCat = cat;
	}
	int indent = part.getShowCategories() && cat != null ? 26 : 21;
	int bindent = part.getShowCategories() && cat != null ? 5 : 0;
	buff.append("<li indent=\"" + indent + "\" bindent=\"" + bindent + "\" style=\"image\" value=\""); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
	String imageId = desc.getId();
	boolean isPotentialHit = (hit instanceof SearchHit && ((SearchHit)hit).isPotentialHit());
	if (hit instanceof ISearchEngineResult2) {
	URL iconURL = ((ISearchEngineResult2) hit).getIconURL();
	if (iconURL != null) {
	String id = null;
	if (isPotentialHit) {
	id = registerGrayedHitIcon(iconURL);
	}
	else {
	id = registerHitIcon(iconURL);
	}
	if (id != null)
	imageId = id;
	}
	}

	if (isPotentialHit) {
	imageId = KEY_PREFIX_GRAYED + imageId;
	}

	buff.append(imageId);
	buff.append("\">"); //$NON-NLS-1$
	buff.append("<a href=\""); //$NON-NLS-1$
	String href=null;
	if (hit instanceof ISearchEngineResult2) {
	ISearchEngineResult2 hit2 = (ISearchEngineResult2)hit;
	if (((ISearchEngineResult2)hit).canOpen()) {
	href = "open:"+desc.getId()+"?id="+hit2.getId(); //$NON-NLS-1$ //$NON-NLS-2$
	}
	}
	if (href==null) {
	if (hit.getForceExternalWindow())
	href = "nw:";//$NON-NLS-1$
	href = EscapeUtils.escapeSpecialChars(hit.toAbsoluteHref(hit.getHref(), false));
	}
	buff.append(href);
	buff.append("\""); //$NON-NLS-1$
	if (hit.getCategory() != null && Platform.getWS() != Platform.WS_GTK) {
	buff.append(" alt=\""); //$NON-NLS-1$
	buff.append(hit.getCategory().getLabel());
	buff.append("\""); //$NON-NLS-1$
	}
	buff.append(">"); //$NON-NLS-1$
	String elabel = null;
	if (isPotentialHit) {
	// add "(potential hit)"
	elabel = Messages.bind(Messages.SearchPart_potential_hit, hit.getLabel());
	}
	else {
	elabel = hit.getLabel();
	}

	elabel = EscapeUtils.escapeSpecialChars(elabel);
	buff.append(elabel);
	buff.append("</a>"); //$NON-NLS-1$
	if (part.getShowDescription()) {
	String edesc = hit.getDescription();
	if (edesc != null) {
	edesc = EscapeUtils.escapeSpecialChars(edesc);
	buff.append("<br/>"); //$NON-NLS-1$
	buff.append(edesc);
	}
	}
	buff.append("</li>"); //$NON-NLS-1$
	}
	if (errorStatus != null)
	updateErrorStatus(buff);
	updateNavigation(results.length);
	buff.append("</form>"); //$NON-NLS-1$
	searchResults.setText(buff.toString(), true, false);
	section.layout();
	if (reflow)
	part.reflow();
	}

	/**
	* Registers the given icon URL for use with this section. Icons
	* must be registered before use and referenced by the returned
	* ID.
	*
	* @param iconURL the URL to the icon
	* @return the ID to use for referencing the icon
	*/
	private String registerHitIcon(URL iconURL) {
	Image image = HelpUIResources.getImage(iconURL);
	if (image != null) {
	searchResults.setImage(iconURL.toString(), image);
	return iconURL.toString();
	}
	return null;
	}

	/**
	* Same as registerHitIcon() but to register a grayed icon. You
	* can provide the same URL for both the regular and grayed icons,
	* but two different IDs will be returned.
	*
	* @param iconURL the URL to the icon
	* @return the ID to use for referencing the icon
	*/
	private String registerGrayedHitIcon(URL iconURL) {
	Image image = HelpUIResources.getImage(iconURL);
	if (image != null) {
	searchResults.setImage(iconURL.toString(), image);
	return KEY_PREFIX_GRAYED + iconURL.toString();
	}
	return null;
	}

	private void updateErrorStatus(StringBuilder buff) {
	int indent = 21;
	buff.append("<li indent=\"" + indent + "\" style=\"image\" value=\""); //$NON-NLS-1$ //$NON-NLS-2$
	buff.append(ISharedImages.IMG_OBJS_ERROR_TSK);
	buff.append("\">"); //$NON-NLS-1$
	buff.append("<b>"); //$NON-NLS-1$
	buff.append(EscapeUtils.escapeSpecialChars(errorStatus.getMessage()));
	buff.append("</b>"); //$NON-NLS-1$
	buff.append("<br/>"); //$NON-NLS-1$
	Throwable t = errorStatus.getException();
	if (t != null && t.getMessage() != null)
	buff.append(EscapeUtils.escapeSpecialChars(t.getMessage()));
	buff.append("</li>"); //$NON-NLS-1$
	}

	private void updateNavigation(int size) {
	if (size > HITS_PER_PAGE) {
	if (prevLink == null) {
	FormToolkit toolkit = part.getToolkit();
	Composite navContainer = toolkit.createComposite(container);
	TableWrapData td = new TableWrapData(TableWrapData.FILL_GRAB);
	navContainer.setLayoutData(td);
	GridLayout glayout = new GridLayout();
	glayout.numColumns = 2;
	navContainer.setLayout(glayout);
	GridData gd;
	/*
	* Label sep = toolkit.createLabel(navContainer, null, SWT.SEPARATOR \|
	* SWT.HORIZONTAL); GridData gd = new GridData(GridData.HORIZONTAL_ALIGN_FILL);
	* gd.horizontalSpan = 2; gd.widthHint = 2; sep.setLayoutData(gd);
	*/
	prevLink = toolkit.createImageHyperlink(navContainer, SWT.NULL);

	prevLink.setText(NLS.bind(Messages.EngineResultSection_previous, "" + HITS_PER_PAGE)); //$NON-NLS-1$
	prevLink.setImage(PlatformUI.getWorkbench().getSharedImages().getImage(
	ISharedImages.IMG_TOOL_BACK));
	prevLink.addHyperlinkListener(new HyperlinkAdapter() {

	@Override
	public void linkActivated(HyperlinkEvent e) {
	resultOffset -= HITS_PER_PAGE;
	asyncUpdateResults(false, true);
	}
	});
	nextLink = toolkit.createImageHyperlink(navContainer, SWT.RIGHT);

	nextLink.setImage(PlatformUI.getWorkbench().getSharedImages().getImage(
	ISharedImages.IMG_TOOL_FORWARD));
	gd = new GridData(GridData.HORIZONTAL_ALIGN_END);
	gd.grabExcessHorizontalSpace = true;
	nextLink.setLayoutData(gd);
	nextLink.addHyperlinkListener(new HyperlinkAdapter() {

	@Override
	public void linkActivated(HyperlinkEvent e) {
	resultOffset += HITS_PER_PAGE;
	asyncUpdateResults(false, true);
	}
	});
	}
	prevLink.setVisible(resultOffset > 0);

	int nextOffset = resultOffset + HITS_PER_PAGE;
	int remainder = hits.size() - nextOffset;
	remainder = Math.min(remainder, HITS_PER_PAGE);

	nextLink.setText(NLS.bind(Messages.EngineResultSection_next, "" + remainder)); //$NON-NLS-1$
	nextLink.setVisible(hits.size() > resultOffset + HITS_PER_PAGE);
	} else {
	if (prevLink != null) {
	prevLink.getParent().setMenu(null);
	prevLink.getParent().dispose();
	prevLink = null;
	nextLink = null;
	}
	}
	}

	private void updateSectionTitle(int size) {
	if (errorStatus != null) {
	Label label = part.getToolkit().createLabel(section, null);
	label.setImage(PlatformUI.getWorkbench().getSharedImages().getImage(
	ISharedImages.IMG_OBJS_ERROR_TSK));
	section.setTextClient(label);
	section.setText(Messages.EngineResultSection_sectionTitle_error);
	} else {
	section.setTextClient(null);
	}
	if (size == 1)
	section.setText(NLS.bind(Messages.EngineResultSection_sectionTitle_hit, desc.getLabel(), "" //$NON-NLS-1$
	+ hits.size()));
	else if (size <= HITS_PER_PAGE)
	section.setText(NLS.bind(Messages.EngineResultSection_sectionTitle_hits, desc.getLabel(),
	"" + hits.size())); //$NON-NLS-1$
	else {
	int from = (resultOffset + 1);
	int to = (resultOffset + HITS_PER_PAGE);
	to = Math.min(to, size);
	section.setText(NLS.bind(Messages.EngineResultSection_sectionTitle_hitsRange, new String[] {
	desc.getLabel(), "" + from, "" + to, "" + size })); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
	}
	}

	private void doBookmark(final String label, String href) {
	final String fhref = href.substring(4);
	BusyIndicator.showWhile(container.getDisplay(),
	() -> BaseHelpSystem.getBookmarkManager().addBookmark(fhref, label));
	}

	public void dispose() {
	part.parent.unhookFormText(searchResults);
	if (!section.isDisposed()) {
	recursiveSetMenu(section, null);
	section.dispose();
	}
	}

	private void recursiveSetMenu(Control control, Menu menu) {
	control.setMenu(menu);
	if (control instanceof Composite) {
	Composite parent = (Composite) control;
	Control[] children = parent.getChildren();
	for (int i = 0; i < children.length; i++) {
	recursiveSetMenu(children[i], menu);
	}
	}
	}
	}