1 files changed, 133 insertions, 0 deletions
diff --git a/org.eclipse.ui.genericeditor/src/org/eclipse/ui/internal/genericeditor/hover/TextHoverRegistry.java b/org.eclipse.ui.genericeditor/src/org/eclipse/ui/internal/genericeditor/hover/TextHoverRegistry.java
new file mode 100644
index 00000000000..f68bbf74deb
--- /dev/null
+++ b/org.eclipse.ui.genericeditor/src/org/eclipse/ui/internal/genericeditor/hover/TextHoverRegistry.java
@@ -0,0 +1,133 @@
+/*******************************************************************************
+ * Copyright (c) 2016-2017 Red Hat 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:
+ * - Mickael Istria (Red Hat Inc.)
+ *******************************************************************************/
+package org.eclipse.ui.internal.genericeditor.hover;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.SortedSet;
+import java.util.TreeSet;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+import org.eclipse.core.runtime.IConfigurationElement;
+import org.eclipse.core.runtime.IRegistryChangeEvent;
+import org.eclipse.core.runtime.IRegistryChangeListener;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Platform;
+import org.eclipse.core.runtime.Status;
+import org.eclipse.core.runtime.content.IContentType;
+import org.eclipse.jface.preference.IPreferenceStore;
+import org.eclipse.jface.text.ITextHover;
+import org.eclipse.jface.text.source.ISourceViewer;
+import org.eclipse.ui.internal.genericeditor.GenericContentTypeRelatedExtension;
+import org.eclipse.ui.internal.genericeditor.GenericEditorPlugin;
+
+/**
+ * Text hover registry that manages the detectors
+ * contributed by the <code>org.eclipse.ui.workbench.texteditor.hoverProvider</code> extension point for
+ * targets contributed by the <code>org.eclipse.ui.workbench.texteditor.hyperlinkDetectorTargets</code> extension point.
+ *
+ * @since 1.0
+ */
+public final class TextHoverRegistry {
+
+	private static final String EXTENSION_POINT_ID = GenericEditorPlugin.BUNDLE_ID + ".hoverProviders"; //$NON-NLS-1$
+
+	private SortedSet<TextHoverExtension> extensions;
+	private boolean outOfSync = true;
+
+	static class TextHoverExtension extends GenericContentTypeRelatedExtension<ITextHover> {
+		private static final String ID_ATTRIBUTE = "id"; //$NON-NLS-1$
+		private static final String IS_BEFORE_ATTRIBUTE = "isBefore"; //$NON-NLS-1$
+		private static final String IS_AFTER_ATTRIBUTE = "isAfter"; //$NON-NLS-1$
+
+		private String id;
+		private String isBefore;
+		private String isAfter;
+
+		public TextHoverExtension(IConfigurationElement extension) throws Exception {
+			super(extension);
+			this.id = extension.getAttribute(ID_ATTRIBUTE);
+			this.isBefore = extension.getAttribute(IS_BEFORE_ATTRIBUTE);
+			this.isAfter = extension.getAttribute(IS_AFTER_ATTRIBUTE);
+		}
+
+		public String getId() {
+			if (this.id != null) {
+				return this.id;
+			}
+			return this.extension.getContributor().getName() + '@' + toString();
+		}
+
+		public String getIsAfter() {
+			return this.isAfter;
+		}
+
+		public String getIsBefore() {
+			return this.isBefore;
+		}
+
+		IConfigurationElement getConfigurationElement() {
+			return this.extension;
+		}
+	}
+
+	public TextHoverRegistry(IPreferenceStore preferenceStore) {
+		Platform.getExtensionRegistry().addRegistryChangeListener(new IRegistryChangeListener() {
+			@Override
+			public void registryChanged(IRegistryChangeEvent event) {
+				outOfSync = true;
+			}
+		}, EXTENSION_POINT_ID);
+	}
+
+	public List<ITextHover> getAvailableHovers(ISourceViewer sourceViewer, Set<IContentType> contentTypes) {
+		if (this.outOfSync) {
+			sync();
+		}
+		return this.extensions.stream()
+				.filter(ext -> contentTypes.contains(ext.targetContentType))
+				// don't sort in the stream as the initial structure is already sorted by isAfter/isBefore
+				.map(GenericContentTypeRelatedExtension<ITextHover>::createDelegate)
+				.collect(Collectors.toList());
+	}
+
+	private void sync() {
+		Set<IConfigurationElement> toRemoveExtensions = new HashSet<>();
+		Map<IConfigurationElement, TextHoverExtension> ext = new HashMap<>();
+		if (this.extensions != null) {
+			ext = this.extensions.stream().collect(Collectors.toMap(TextHoverExtension::getConfigurationElement, Function.identity()));
+			toRemoveExtensions = ext.keySet();
+		}
+		for (IConfigurationElement extension : Platform.getExtensionRegistry().getConfigurationElementsFor(EXTENSION_POINT_ID)) {
+			toRemoveExtensions.remove(extension);
+			if (!ext.containsKey(extension)) {
+				try {
+					ext.put(extension, new TextHoverExtension(extension));
+				} catch (Exception ex) {
+					GenericEditorPlugin.getDefault().getLog().log(new Status(IStatus.ERROR, GenericEditorPlugin.BUNDLE_ID, ex.getMessage(), ex));
+				}
+			}
+		}
+		for (IConfigurationElement toRemove : toRemoveExtensions) {
+			ext.remove(toRemove);
+		}
+
+		OrderedExtensionComparator comparator = new OrderedExtensionComparator(ext.values());
+		this.extensions = new TreeSet<>(comparator);
+		this.extensions.addAll(ext.values());
+		this.outOfSync = false;
+	}
+
+}