Bug 529617 - [CodeMining] Line number in vertical ruler can be not

synchronized with line header annotation

Change-Id: Idfb97cefe20d3fbdde0f8793f159d6c3cff2937b
Signed-off-by: angelozerr <angelo.zerr@gmail.com>
Also-By: Mickael Istria <mistria@redhat.com>

3 files changed, 175 insertions, 72 deletions

diff --git a/org.eclipse.jface.text/src/org/eclipse/jface/text/source/AnnotationRulerColumn.java b/org.eclipse.jface.text/src/org/eclipse/jface/text/source/AnnotationRulerColumn.java
index 2b4ca76392b..8f8b58c24d8 100644
--- a/org.eclipse.jface.text/src/org/eclipse/jface/text/source/AnnotationRulerColumn.java
+++ b/org.eclipse.jface.text/src/org/eclipse/jface/text/source/AnnotationRulerColumn.java
@@ -20,6 +20,7 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.function.Consumer;
 
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.custom.StyledText;
@@ -47,13 +48,10 @@ import org.eclipse.swt.widgets.Display;
 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.IRegion;
-import org.eclipse.jface.text.ITextListener;
 import org.eclipse.jface.text.ITextViewer;
 import org.eclipse.jface.text.ITextViewerExtension5;
-import org.eclipse.jface.text.IViewportListener;
 import org.eclipse.jface.text.JFaceTextUtil;
 import org.eclipse.jface.text.Position;
-import org.eclipse.jface.text.TextEvent;
 
 
 /**
@@ -70,24 +68,11 @@ public class AnnotationRulerColumn implements IVerticalRulerColumn, IVerticalRul
 	/**
 	 * Internal listener class.
 	 */
-	class InternalListener implements IViewportListener, IAnnotationModelListener, ITextListener {
-
-		@Override
-		public void viewportChanged(int verticalPosition) {
-			if (verticalPosition != fScrollPos)
-				redraw();
-		}
-
+	class AnnotationsListener implements IAnnotationModelListener {
 		@Override
 		public void modelChanged(IAnnotationModel model) {
 			postRedraw();
 		}
-
-		@Override
-		public void textChanged(TextEvent e) {
-			if (e.getViewerRedrawState())
-				postRedraw();
-		}
 	}
 
 	/**
@@ -139,7 +124,7 @@ public class AnnotationRulerColumn implements IVerticalRulerColumn, IVerticalRul
 	/** The buffer for double buffering */
 	private Image fBuffer;
 	/** The internal listener */
-	private InternalListener fInternalListener= new InternalListener();
+	private AnnotationsListener fAnnotationListener= new AnnotationsListener();
 	/** The width of this vertical ruler */
 	private int fWidth;
 	/** Switch for enabling/disabling the setModel method. */
@@ -192,6 +177,8 @@ public class AnnotationRulerColumn implements IVerticalRulerColumn, IVerticalRul
 	 */
 	private MouseListener fMouseListener;
 
+	private Consumer<StyledText> lineHeightChangeHandler= (t) -> postRedraw();
+
 	/**
 	 * Constructs this column with the given arguments.
 	 *
@@ -204,7 +191,7 @@ public class AnnotationRulerColumn implements IVerticalRulerColumn, IVerticalRul
 		this(width, annotationAccess);
 		fAllowSetModel= false;
 		fModel= model;
-		fModel.addAnnotationModelListener(fInternalListener);
+		fModel.addAnnotationModelListener(fAnnotationListener);
 	}
 
 	/**
@@ -230,7 +217,7 @@ public class AnnotationRulerColumn implements IVerticalRulerColumn, IVerticalRul
 		fWidth= width;
 		fAllowSetModel= false;
 		fModel= model;
-		fModel.addAnnotationModelListener(fInternalListener);
+		fModel.addAnnotationModelListener(fAnnotationListener);
 	}
 
 	/**
@@ -337,8 +324,7 @@ public class AnnotationRulerColumn implements IVerticalRulerColumn, IVerticalRul
 		});
 
 		if (fCachedTextViewer != null) {
-			fCachedTextViewer.addViewportListener(fInternalListener);
-			fCachedTextViewer.addTextListener(fInternalListener);
+			VisibleLinesTracker.track(fCachedTextViewer, lineHeightChangeHandler);
 			// on word wrap toggle a "resized" ControlEvent is fired: suggest a redraw of the ruler
 			fCachedTextWidget.addControlListener(new ControlAdapter() {
 				@Override
@@ -506,12 +492,11 @@ public class AnnotationRulerColumn implements IVerticalRulerColumn, IVerticalRul
 	private void handleDispose() {
 
 		if (fCachedTextViewer != null) {
-			fCachedTextViewer.removeViewportListener(fInternalListener);
-			fCachedTextViewer.removeTextListener(fInternalListener);
+			VisibleLinesTracker.untrack(fCachedTextViewer, lineHeightChangeHandler);
 		}
 
 		if (fModel != null)
-			fModel.removeAnnotationModelListener(fInternalListener);
+			fModel.removeAnnotationModelListener(fAnnotationListener);
 
 		if (fBuffer != null) {
 			fBuffer.dispose();
@@ -521,6 +506,7 @@ public class AnnotationRulerColumn implements IVerticalRulerColumn, IVerticalRul
 		fConfiguredAnnotationTypes.clear();
 		fAllowedAnnotationTypes.clear();
 		fAnnotationAccessExtension= null;
+
 	}
 
 	/**
@@ -867,12 +853,12 @@ public class AnnotationRulerColumn implements IVerticalRulerColumn, IVerticalRul
 		if (fAllowSetModel && model != fModel) {
 
 			if (fModel != null)
-				fModel.removeAnnotationModelListener(fInternalListener);
+				fModel.removeAnnotationModelListener(fAnnotationListener);
 
 			fModel= model;
 
 			if (fModel != null)
-				fModel.addAnnotationModelListener(fInternalListener);
+				fModel.addAnnotationModelListener(fAnnotationListener);
 
 			postRedraw();
 		}
diff --git a/org.eclipse.jface.text/src/org/eclipse/jface/text/source/LineNumberRulerColumn.java b/org.eclipse.jface.text/src/org/eclipse/jface/text/source/LineNumberRulerColumn.java
index 96c48b2dc1a..b1e24aaa5b9 100644
--- a/org.eclipse.jface.text/src/org/eclipse/jface/text/source/LineNumberRulerColumn.java
+++ b/org.eclipse.jface.text/src/org/eclipse/jface/text/source/LineNumberRulerColumn.java
@@ -17,6 +17,7 @@ package org.eclipse.jface.text.source;
 
 import java.lang.ref.WeakReference;
 import java.util.Arrays;
+import java.util.function.Consumer;
 
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.custom.StyledText;
@@ -51,13 +52,10 @@ import org.eclipse.jface.util.Util;
 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.IRegion;
-import org.eclipse.jface.text.ITextListener;
 import org.eclipse.jface.text.ITextViewer;
 import org.eclipse.jface.text.ITextViewerExtension;
 import org.eclipse.jface.text.ITextViewerExtension5;
-import org.eclipse.jface.text.IViewportListener;
 import org.eclipse.jface.text.JFaceTextUtil;
-import org.eclipse.jface.text.TextEvent;
 
 
 /**
@@ -79,41 +77,6 @@ public class LineNumberRulerColumn implements IVerticalRulerColumn {
 			&& !"false".equals(System.getProperty("LineNumberRulerColumn.retina.workaround")) //$NON-NLS-1$ //$NON-NLS-2$
 			&& internalSupportsZoomedPaint();
 
-	/**
-	 * Internal listener class.
-	 */
-	class InternalListener implements IViewportListener, ITextListener {
-
-		/**
-		 * @since 3.1
-		 */
-		private boolean fCachedRedrawState= true;
-
-		@Override
-		public void viewportChanged(int verticalPosition) {
-			if (fCachedRedrawState && verticalPosition != fScrollPos)
-				redraw();
-		}
-
-		@Override
-		public void textChanged(TextEvent event) {
-
-			fCachedRedrawState= event.getViewerRedrawState();
-			if (!fCachedRedrawState)
-				return;
-
-			if (updateNumberOfDigits()) {
-				computeIndentations();
-				layout(event.getViewerRedrawState());
-				return;
-			}
-
-			boolean viewerCompletelyShown= isViewerCompletelyShown();
-			if (viewerCompletelyShown || fSensitiveToTextChanges || event.getDocumentEvent() == null)
-				postRedraw();
-			fSensitiveToTextChanges= viewerCompletelyShown;
-		}
-	}
 
 	/**
 	 * Handles all the mouse interaction in this line number ruler column.
@@ -398,8 +361,6 @@ public class LineNumberRulerColumn implements IVerticalRulerColumn {
 	private int fScrollPos;
 	/** The drawable for double buffering */
 	private Image fBuffer;
-	/** The internal listener */
-	private InternalListener fInternalListener= new InternalListener();
 	/** The font of this column */
 	private Font fFont;
 	/** The indentation cache */
@@ -447,6 +408,12 @@ public class LineNumberRulerColumn implements IVerticalRulerColumn {
 	private WeakReference<Font> fLastFont;
 	private Font fLastZoomedFont;
 
+	/**
+	 * Redraw the ruler handler called when a line height change.
+	 *
+	 * @since 3.13
+	 */
+	private Consumer<StyledText> lineHeightChangeHandler= (t) -> postRedraw();
 
 	/**
 	 * Constructs a new vertical ruler column.
@@ -620,6 +587,10 @@ public class LineNumberRulerColumn implements IVerticalRulerColumn {
 			}
 		});
 
+		// track when StyledText is redrawn to check if some line height changed. In this case, the ruler must be redrawn
+		// to draw line number with well height.
+		VisibleLinesTracker.track(fCachedTextViewer, lineHeightChangeHandler);
+
 		fCanvas= new Canvas(parentControl, SWT.NO_FOCUS ) {
  			@Override
 			public void addMouseListener(MouseListener listener) {
@@ -660,9 +631,7 @@ public class LineNumberRulerColumn implements IVerticalRulerColumn {
 		fCanvas.addMouseWheelListener(fMouseHandler);
 
 		if (fCachedTextViewer != null) {
-
-			fCachedTextViewer.addViewportListener(fInternalListener);
-			fCachedTextViewer.addTextListener(fInternalListener);
+			VisibleLinesTracker.track(fCachedTextViewer, lineHeightChangeHandler);
 
 			if (fFont == null) {
 				if (fCachedTextWidget != null && !fCachedTextWidget.isDisposed())
@@ -684,8 +653,7 @@ public class LineNumberRulerColumn implements IVerticalRulerColumn {
 	protected void handleDispose() {
 
 		if (fCachedTextViewer != null) {
-			fCachedTextViewer.removeViewportListener(fInternalListener);
-			fCachedTextViewer.removeTextListener(fInternalListener);
+			VisibleLinesTracker.untrack(fCachedTextViewer, lineHeightChangeHandler);
 		}
 
 		if (fBuffer != null) {
diff --git a/org.eclipse.jface.text/src/org/eclipse/jface/text/source/VisibleLinesTracker.java b/org.eclipse.jface.text/src/org/eclipse/jface/text/source/VisibleLinesTracker.java
new file mode 100644
index 00000000000..14d966f8eef
--- /dev/null
+++ b/org.eclipse.jface.text/src/org/eclipse/jface/text/source/VisibleLinesTracker.java
@@ -0,0 +1,149 @@
+/**
+ *  Copyright (c) 2018 Angelo ZERR.
+ *  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:
+ *  Angelo Zerr <angelo.zerr@gmail.com> - Bug 527720 - [CodeMining] Line number in vertical ruler can be not synchronized with line header annotation
+ */
+package org.eclipse.jface.text.source;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.function.Consumer;
+
+import org.eclipse.swt.custom.StyledText;
+import org.eclipse.swt.events.PaintEvent;
+import org.eclipse.swt.events.PaintListener;
+
+import org.eclipse.jface.text.ITextViewer;
+import org.eclipse.jface.text.JFaceTextUtil;
+
+/**
+ * Class to track line height change of visible lines of a given {@link StyledText}.
+ *
+ */
+class VisibleLinesTracker implements PaintListener {
+
+	private static final String DATA_KEY= VisibleLinesTracker.class.getName();
+
+	/**
+	 * The viewer to track.
+	 */
+	private final ITextViewer viewer;
+
+	/**
+	 * The previous bottom line index.
+	 */
+	private int oldBottom= -1;
+
+	/**
+	 * The previous bottom line pixel.
+	 */
+	private int oldBottomPixel;
+
+	/**
+	 *
+	 * List of handler to call when a visible line height change.
+	 */
+	private final Collection<Consumer<StyledText>> handlers;
+
+	/**
+	 * Constructor to track line height change of visible lines of the {@link StyledText} of the
+	 * given viewer.
+	 *
+	 * @param viewer the viewer to track
+	 */
+	private VisibleLinesTracker(ITextViewer viewer) {
+		this.viewer= viewer;
+		this.handlers= new ArrayList<>();
+	}
+
+	@Override
+	public void paintControl(PaintEvent e) {
+		StyledText textWidget= viewer.getTextWidget();
+		// track if bottom line index or bottom line pixel changed.
+		if (oldBottom == -1) {
+			oldBottom= JFaceTextUtil.getPartialBottomIndex(viewer);
+			oldBottomPixel= JFaceTextUtil.getLinePixel(textWidget, oldBottom);
+			return;
+		}
+		int newBottom= JFaceTextUtil.getPartialBottomIndex(viewer);
+		if (newBottom != oldBottom) {
+			oldBottom= newBottom;
+			oldBottomPixel= JFaceTextUtil.getLinePixel(textWidget, oldBottom);
+			handlers.forEach(handler -> handler.accept(textWidget));
+			return;
+		}
+		int newBottomPixel= JFaceTextUtil.getLinePixel(textWidget, newBottom);
+		if (newBottomPixel != oldBottomPixel) {
+			oldBottomPixel= newBottomPixel;
+			handlers.forEach(handler -> handler.accept(textWidget));
+			return;
+		}
+	}
+
+	/**
+	 * Track the line height change of the {@link StyledText} of the given handler an call the given
+	 * handler.
+	 *
+	 * @param viewer the viewer to track
+	 * @param handler the handler to call when line height change.
+	 */
+	static void track(ITextViewer viewer, Consumer<StyledText> handler) {
+		StyledText textWidget= viewer != null ? viewer.getTextWidget() : null;
+		if (textWidget == null) {
+			return;
+		}
+		VisibleLinesTracker tracker= (VisibleLinesTracker) textWidget.getData(DATA_KEY);
+		if (tracker == null) {
+			tracker= new VisibleLinesTracker(viewer);
+			textWidget.setData(DATA_KEY, tracker);
+		}
+		tracker.addHandler(handler);
+	}
+
+	/**
+	 * Untrack the line height change of the {@link StyledText} of the given handler an call the
+	 * given handler.
+	 *
+	 * @param viewer the viewer to track
+	 * @param handler the handler to call when line height change.
+	 */
+	static void untrack(ITextViewer viewer, Consumer<StyledText> handler) {
+		StyledText textWidget= viewer != null ? viewer.getTextWidget() : null;
+		if (textWidget == null) {
+			return;
+		}
+		VisibleLinesTracker tracker= (VisibleLinesTracker) textWidget.getData(DATA_KEY);
+		if (tracker != null) {
+			tracker.removeHandler(handler);
+		}
+	}
+
+	/**
+	 * Add the given handler.
+	 *
+	 * @param handler the handler to call when a visible line height change.
+	 */
+	private void addHandler(Consumer<StyledText> handler) {
+		if (handlers.isEmpty()) {
+			viewer.getTextWidget().addPaintListener(this);
+		}
+		handlers.add(handler);
+	}
+
+	/**
+	 * Remove the given handler.
+	 *
+	 * @param handler the handler to call when a visible line height change.
+	 */
+	private void removeHandler(Consumer<StyledText> handler) {
+		handlers.remove(handler);
+		if (handlers.isEmpty()) {
+			viewer.getTextWidget().removePaintListener(this);
+		}
+	}
+}