Clean styled text renderer.

Author: angelozerr

eclipse/codelens/org.eclipse.codelens/src/org/eclipse/swt/custom/patch/StyledTextPatcher.java

@@ -1,3 +1,13 @@
+/**
+ *  Copyright (c) 2015-2017 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 <[email protected]> - initial API and implementation
+ */
 package org.eclipse.swt.custom.patch;
 
 import java.lang.reflect.Field;

eclipse/codelens/org.eclipse.codelens/src/org/eclipse/swt/custom/patch/StyledTextRenderer.java

@@ -1,12 +1,29 @@
+/**
+ *  Copyright (c) 2015-2017 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 <[email protected]> - initial API and implementation
+ */
 package org.eclipse.swt.custom.patch;
 
+import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 
 import org.eclipse.swt.custom.StyledText;
 import org.eclipse.swt.custom.patch.internal.StyledTextRendererEmulator;
 import org.eclipse.swt.custom.provisional.ILineSpacingProvider;
 import org.eclipse.swt.graphics.TextLayout;
 
+/**
+ * Class which should replace the private class
+ * {@link org.eclipse.swt.custom.StyledTextRenderer} to support line spacing for
+ * a given line.
+ *
+ */
 public class StyledTextRenderer extends StyledTextRendererEmulator {
 
 	private ILineSpacingProvider lineSpacingProvider;
@@ -24,27 +41,35 @@ public void setLineSpacingProvider(ILineSpacingProvider lineSpacingProvider) {
 	@Override
 	protected TextLayout getTextLayout(int lineIndex, int orientation, int width, int lineSpacing, Object obj,
 			Method proceed, Object[] args) throws Exception {
+		// Compute line spacing for the given line index.
 		int newSpacing = lineSpacing;
-		TextLayout layout = super.getTextLayout(lineIndex, orientation, width, lineSpacing, obj, proceed, args);
 		if (lineSpacingProvider != null) {
 			Integer spacing = lineSpacingProvider.getLineSpacing(lineIndex);
 			if (spacing != null) {
 				newSpacing = spacing;
 			}
 		}
+		TextLayout layout = super.getTextLayout(lineIndex, orientation, width, lineSpacing, obj, proceed, args);
 		if (layout.getSpacing() != newSpacing) {
-			// Update spacing
+			// Update line spacing
 			layout.setSpacing(newSpacing);
+			// System.err.println("spacing changed [" + lineIndex + "] to " +
+			// newSpacing);
 
 			// invalidate text layout.
 			// call styledText.setVariableLineHeight();
-			Method m1 = styledText.getClass().getDeclaredMethod("setVariableLineHeight");
-			m1.setAccessible(true);
-			m1.invoke(styledText);
+			setVariableLineHeight();
 
 			// recreate text layout.
 			layout = super.getTextLayout(lineIndex, orientation, width, newSpacing, obj, proceed, args);
 		}
 		return layout;
 	}
+
+	private void setVariableLineHeight()
+			throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
+		Method m1 = styledText.getClass().getDeclaredMethod("setVariableLineHeight");
+		m1.setAccessible(true);
+		m1.invoke(styledText);
+	}
 }

eclipse/codelens/org.eclipse.codelens/src/org/eclipse/swt/custom/patch/internal/StyledTextRendererEmulator.java

@@ -1,12 +1,23 @@
+/**
+ *  Copyright (c) 2015-2017 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 <[email protected]> - initial API and implementation
+ */
 package org.eclipse.swt.custom.patch.internal;
 
 import java.lang.reflect.Method;
-
-import org.eclipse.swt.custom.StyledText;
 import org.eclipse.swt.graphics.TextLayout;
-
 import javassist.util.proxy.MethodHandler;
 
+/**
+ * Javassist method handler to override getTextLayout of StyledTextRenderer.
+ *
+ */
 public class StyledTextRendererEmulator implements MethodHandler {
 
 	@Override
@@ -26,7 +37,7 @@ protected TextLayout getTextLayout(int lineIndex, int orientation, int width, in
 		args[0] = lineIndex;
 		args[1] = orientation;
 		args[2] = width;
-		args[3] = lineSpacing;		
+		args[3] = lineSpacing;
 		return (TextLayout) proceed.invoke(obj, args);
 	}