Bug 521382 - [generic editor] Default highlighter for generic editorI20171107-2000

Added extension point for highlight reconcilers, when one is added the
default is turned off

Change-Id: Ibbe8d3df69ba5d364c027bd8c8f07aa7b4e71902
Signed-off-by: Lucas Bullen <lbullen@redhat.com>

3 files changed, 254 insertions, 0 deletions

diff --git a/org.eclipse.ui.genericeditor.examples/plugin.xml b/org.eclipse.ui.genericeditor.examples/plugin.xml
index a4fd6f752d5..97238a81750 100644
--- a/org.eclipse.ui.genericeditor.examples/plugin.xml
+++ b/org.eclipse.ui.genericeditor.examples/plugin.xml
@@ -10,6 +10,7 @@
 <!-- Contributors:                                                          -->
 <!--     Sopot Cela & Mickael Istria (Red Hat Inc). -initial implementation -->
 <!--     Lucas Bullen (Red Hat Inc.) - Bug 508829 custom reconciler support -->
+<!--    							 - Bug 521382 default highlighter		-->
 <!-- ====================================================================== -->
 <plugin>
    <extension
@@ -76,4 +77,11 @@
             contentType="org.eclipse.ui.genericeditor.examples.dotproject">
       </autoEditStrategy>
    </extension>
+   <extension
+         point="org.eclipse.ui.genericeditor.highlightReconcilers">
+      <highlightReconciler
+            class="org.eclipse.ui.genericeditor.examples.dotproject.HighlightReconciler"
+            contentType="org.eclipse.ui.genericeditor.examples.dotproject">
+      </highlightReconciler>
+   </extension>
 </plugin>
diff --git a/org.eclipse.ui.genericeditor.examples/src/org/eclipse/ui/genericeditor/examples/dotproject/HighlightReconciler.java b/org.eclipse.ui.genericeditor.examples/src/org/eclipse/ui/genericeditor/examples/dotproject/HighlightReconciler.java
new file mode 100644
index 00000000000..dd520c273a6
--- /dev/null
+++ b/org.eclipse.ui.genericeditor.examples/src/org/eclipse/ui/genericeditor/examples/dotproject/HighlightReconciler.java
@@ -0,0 +1,37 @@
+/*******************************************************************************
+ * Copyright (c) 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:
+ * - Lucas Bullen (Red Hat Inc.)
+ *******************************************************************************/
+package org.eclipse.ui.genericeditor.examples.dotproject;
+
+import org.eclipse.jface.text.IDocument;
+import org.eclipse.jface.text.ITextViewer;
+import org.eclipse.jface.text.reconciler.Reconciler;
+
+public class HighlightReconciler extends Reconciler {
+
+	private HighlightStrategy fStrategy;
+
+	public HighlightReconciler() {
+        fStrategy = new HighlightStrategy();
+        this.setReconcilingStrategy(fStrategy, IDocument.DEFAULT_CONTENT_TYPE);
+    }
+
+	@Override
+	public void install(ITextViewer textViewer) {
+		super.install(textViewer);
+		fStrategy.install(textViewer);
+	}
+
+	@Override
+	public void uninstall() {
+		super.uninstall();
+		fStrategy.uninstall();
+	}
+}
\ No newline at end of file
diff --git a/org.eclipse.ui.genericeditor.examples/src/org/eclipse/ui/genericeditor/examples/dotproject/HighlightStrategy.java b/org.eclipse.ui.genericeditor.examples/src/org/eclipse/ui/genericeditor/examples/dotproject/HighlightStrategy.java
new file mode 100644
index 00000000000..58d1b9060a2
--- /dev/null
+++ b/org.eclipse.ui.genericeditor.examples/src/org/eclipse/ui/genericeditor/examples/dotproject/HighlightStrategy.java
@@ -0,0 +1,209 @@
+/*******************************************************************************
+ * Copyright (c) 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:
+ * - Lucas Bullen (Red Hat Inc.)
+ *******************************************************************************/
+package org.eclipse.ui.genericeditor.examples.dotproject;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.preferences.IEclipsePreferences;
+import org.eclipse.core.runtime.preferences.IEclipsePreferences.IPreferenceChangeListener;
+import org.eclipse.core.runtime.preferences.IEclipsePreferences.PreferenceChangeEvent;
+import org.eclipse.core.runtime.preferences.InstanceScope;
+import org.eclipse.jface.text.IDocument;
+import org.eclipse.jface.text.IRegion;
+import org.eclipse.jface.text.ISynchronizable;
+import org.eclipse.jface.text.ITextViewer;
+import org.eclipse.jface.text.ITextViewerExtension5;
+import org.eclipse.jface.text.Position;
+import org.eclipse.jface.text.reconciler.DirtyRegion;
+import org.eclipse.jface.text.reconciler.IReconcilingStrategy;
+import org.eclipse.jface.text.reconciler.IReconcilingStrategyExtension;
+import org.eclipse.jface.text.source.Annotation;
+import org.eclipse.jface.text.source.IAnnotationModel;
+import org.eclipse.jface.text.source.IAnnotationModelExtension;
+import org.eclipse.jface.text.source.ISourceViewer;
+import org.eclipse.swt.custom.CaretEvent;
+import org.eclipse.swt.custom.CaretListener;
+
+/**
+*
+* This Reconciler Strategy is an example for how to override the default highlight strategy.
+* It will highlight closing and opening tag names that match the current word the user is on.
+*
+*/
+public class HighlightStrategy implements IReconcilingStrategy, IReconcilingStrategyExtension, CaretListener, IPreferenceChangeListener {
+
+	private static final String ANNOTATION_TYPE = "org.eclipse.ui.genericeditor.text"; //$NON-NLS-1$
+	public static final String TOGGLE_HIGHLIGHT_PREFERENCE = "org.eclipse.ui.genericeditor.togglehighlight"; //$NON-NLS-1$
+	public static final String GENERIC_EDITOR_BUNDLE_ID = "org.eclipse.ui.genericeditor"; //$NON-NLS-1$
+
+	private boolean enabled;
+	private ISourceViewer sourceViewer;
+	private IDocument document;
+
+	private static final String TAG_NAME_REGEX = "<\\/?\\s*([a-zA-Z]+)"; //$NON-NLS-1$
+	private static final Pattern TAG_NAME_PATTERN = Pattern.compile(TAG_NAME_REGEX);
+
+	private Annotation[] fOccurrenceAnnotations = null;
+
+	private void applyHighlights(int offset) {
+		if (sourceViewer == null || !enabled) {
+			return;
+		}
+		String text = document.get();
+		offset = ((ITextViewerExtension5)sourceViewer).widgetOffset2ModelOffset(offset);
+
+		int wordStartOffset = Math.max(text.lastIndexOf('/',offset),text.lastIndexOf('<',offset))+1;
+		int wordEndOffset = findEndingOffset(text, offset);
+		if(wordEndOffset <= wordStartOffset || wordEndOffset == -1 || wordStartOffset == -1)
+			return;
+		String word = text.substring(wordStartOffset, wordEndOffset);
+		if(word.indexOf('>') != -1 || word.indexOf('<') != -1) {
+			removeOccurrenceAnnotations();
+			return;
+		}
+
+		Matcher m = TAG_NAME_PATTERN.matcher(text);
+		Map<Annotation, Position> annotationMap = new HashMap<>();
+		while(m.find()) {
+			if(m.group(1).equals(word)) {
+				annotationMap.put(new Annotation(ANNOTATION_TYPE, false, null),
+						new Position(m.start(1), m.end(1) - m.start(1)));
+			}
+		}
+
+		if(annotationMap.size() < 2) {
+			removeOccurrenceAnnotations();
+			return;
+		}
+
+		IAnnotationModel annotationModel = sourceViewer.getAnnotationModel();
+		synchronized (getLockObject(annotationModel)) {
+			if (annotationModel instanceof IAnnotationModelExtension) {
+				((IAnnotationModelExtension) annotationModel).replaceAnnotations(fOccurrenceAnnotations, annotationMap);
+			} else {
+				removeOccurrenceAnnotations();
+				Iterator<Entry<Annotation, Position>> iter = annotationMap.entrySet().iterator();
+				while (iter.hasNext()) {
+					Entry<Annotation, Position> mapEntry = iter.next();
+					annotationModel.addAnnotation(mapEntry.getKey(), mapEntry.getValue());
+				}
+			}
+			fOccurrenceAnnotations = annotationMap.keySet().toArray(new Annotation[annotationMap.keySet().size()]);
+		}
+	}
+
+	private static int findEndingOffset(String text, int offset) {
+		String substring = text.substring(offset);
+		String[] split = substring.split("[^a-zA-Z0-9]+");//$NON-NLS-1$
+		if(split.length == 0) {
+			return -1;
+		}
+		return offset + split[0].length();
+	}
+
+	public void install(ITextViewer viewer) {
+		if (!(viewer instanceof ISourceViewer)) {
+			return;
+		}
+		IEclipsePreferences preferences = InstanceScope.INSTANCE.getNode(GENERIC_EDITOR_BUNDLE_ID);
+		preferences.addPreferenceChangeListener(this);
+		this.enabled = preferences.getBoolean(TOGGLE_HIGHLIGHT_PREFERENCE, true);
+		this.sourceViewer = (ISourceViewer) viewer;
+		this.sourceViewer.getTextWidget().addCaretListener(this);
+	}
+
+	public void uninstall() {
+		if (sourceViewer != null) {
+			sourceViewer.getTextWidget().removeCaretListener(this);
+		}
+		IEclipsePreferences preferences = InstanceScope.INSTANCE.getNode(GENERIC_EDITOR_BUNDLE_ID);
+		preferences.removePreferenceChangeListener(this);
+	}
+
+	@Override
+	public void preferenceChange(PreferenceChangeEvent event) {
+		if (event.getKey().equals(TOGGLE_HIGHLIGHT_PREFERENCE)) {
+			this.enabled = Boolean.parseBoolean(event.getNewValue().toString());
+			if (enabled) {
+				initialReconcile();
+			} else {
+				removeOccurrenceAnnotations();
+			}
+		}
+	}
+
+	@Override
+	public void caretMoved(CaretEvent event) {
+		applyHighlights(event.caretOffset);
+	}
+
+	@Override
+	public void initialReconcile() {
+		if (sourceViewer != null) {
+			sourceViewer.getTextWidget().getDisplay().asyncExec(() -> {
+				if (sourceViewer != null) {
+					applyHighlights(sourceViewer.getTextWidget().getCaretOffset());
+				}
+			});
+		}
+	}
+
+	void removeOccurrenceAnnotations() {
+		IAnnotationModel annotationModel = sourceViewer.getAnnotationModel();
+		if (annotationModel == null || fOccurrenceAnnotations == null)
+			return;
+
+		synchronized (getLockObject(annotationModel)) {
+			if (annotationModel instanceof IAnnotationModelExtension) {
+				((IAnnotationModelExtension) annotationModel).replaceAnnotations(fOccurrenceAnnotations, null);
+			} else {
+				for (Annotation fOccurrenceAnnotation : fOccurrenceAnnotations)
+					annotationModel.removeAnnotation(fOccurrenceAnnotation);
+			}
+			fOccurrenceAnnotations = null;
+		}
+	}
+
+	private static Object getLockObject(IAnnotationModel annotationModel) {
+		if (annotationModel instanceof ISynchronizable) {
+			Object lock = ((ISynchronizable) annotationModel).getLockObject();
+			if (lock != null)
+				return lock;
+		}
+		return annotationModel;
+	}
+
+	@Override
+	public void setDocument(IDocument document) {
+		this.document = document;
+	}
+
+	@Override
+	public void reconcile(DirtyRegion dirtyRegion, IRegion subRegion) {
+		// Do nothing
+	}
+
+	@Override
+	public void reconcile(IRegion partition) {
+		// Do nothing
+	}
+
+	@Override
+	public void setProgressMonitor(IProgressMonitor monitor) {
+		// Not used
+	}
+}