bug 395976: NPE in BuildConsoleViewer when widget is already disposed

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/buildconsole/BuildConsoleViewer.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2002, 2010 QNX Software Systems and others.
+ * Copyright (c) 2002, 2012 QNX Software Systems 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
@@ -48,21 +48,9 @@ public class BuildConsoleViewer extends TextViewer
 	 * Internal document listener.
 	 */
 	class InternalDocumentListener implements IDocumentListener {
-
-		/*
-		 * (non-Javadoc)
-		 *
-		 * @see org.eclipse.jface.text.IDocumentListener#documentAboutToBeChanged(org.eclipse.jface.text.DocumentEvent)
-		 */
 		@Override
 		public void documentAboutToBeChanged(DocumentEvent e) {
 		}
-
-		/*
-		 * (non-Javadoc)
-		 *
-		 * @see org.eclipse.jface.text.IDocumentListener#documentChanged(org.eclipse.jface.text.DocumentEvent)
-		 */
 		@Override
 		public void documentChanged(DocumentEvent e) {
 			revealEndOfDocument();
@@ -97,6 +85,7 @@ public class BuildConsoleViewer extends TextViewer
 	public BuildConsoleViewer(Composite parent) {
 		super(parent, getSWTStyles());
 		StyledText styledText = getTextWidget();
+		if (styledText != null) {
 			styledText.addLineStyleListener(this);
 			styledText.addLineBackgroundListener(this);
 			styledText.addMouseTrackListener(this);
@@ -105,6 +94,7 @@ public class BuildConsoleViewer extends TextViewer
 			styledText.setEditable(false);
 			styledText.setWordWrap(true);
 		}
+	}
 
 	/**
 	 * Returns the SWT style flags used when instantiating this viewer
@@ -119,12 +109,13 @@ public class BuildConsoleViewer extends TextViewer
 	 */
 	protected void revealEndOfDocument() {
 		if (isAutoScroll()) {
+			StyledText widget = getTextWidget();
+			if (widget != null) {
 				IDocument doc = getDocument();
 				int lines = doc.getNumberOfLines();
 				try {
 					// lines are 0-based
 					int lineStartOffset = doc.getLineOffset(lines - 1);
-				StyledText widget = getTextWidget();
 					if (lineStartOffset > 0) {
 						widget.setCaretOffset(lineStartOffset);
 						widget.showSelection();
@@ -137,12 +128,8 @@ public class BuildConsoleViewer extends TextViewer
 				}
 			}
 		}
+	}
 
-	/*
-	 * (non-Javadoc)
-	 *
-	 * @see org.eclipse.jface.text.ITextViewer#setDocument(org.eclipse.jface.text.IDocument)
-	 */
 	@Override
 	public void setDocument(IDocument doc) {
 		IDocument oldDoc = getDocument();
@@ -165,11 +152,6 @@ public class BuildConsoleViewer extends TextViewer
 		}
 	}
 
-	/*
-	 * (non-Javadoc)
-	 *
-	 * @see org.eclipse.swt.custom.LineStyleListener#lineGetStyle(org.eclipse.swt.custom.LineStyleEvent)
-	 */
 	@Override
 	public void lineGetStyle(LineStyleEvent event) {
 		IDocument document = getDocument();
@@ -202,6 +184,8 @@ public class BuildConsoleViewer extends TextViewer
 	}
 
 	public void selectPartition(BuildConsolePartitioner partitioner, BuildConsolePartition p) {
+		StyledText st = getTextWidget();
+		if (st != null) {
 			try {
 				int start = partitioner.getDocument().getLineOfOffset(p.getOffset());
 				int end = partitioner.getDocument().getLineOfOffset(p.getOffset()+p.getLength()-1);
@@ -218,22 +202,28 @@ public class BuildConsoleViewer extends TextViewer
 				}
 	
 				// Select line
-			StyledText st = getTextWidget();
 				st.redrawRange(0, partitioner.getDocument().getLength(), true);
 	
 			} catch (BadLocationException e) {
 				CUIPlugin.log(e);
 			}
 		}
+	}
 
 	@Override
 	public void mouseEnter(MouseEvent e) {
-		getTextWidget().addMouseListener(this);
+		StyledText widget = getTextWidget();
+		if (widget != null) {
+			widget.addMouseListener(this);
+		}
 	}
 
 	@Override
 	public void mouseExit(MouseEvent e) {
-		getTextWidget().removeMouseListener(this);
+		StyledText widget = getTextWidget();
+		if (widget != null) {
+			widget.removeMouseListener(this);
+		}
 	}
 
 	@Override
@@ -242,14 +232,17 @@ public class BuildConsoleViewer extends TextViewer
 
 	@Override
 	public void mouseDoubleClick(MouseEvent e) {
+		StyledText widget = getTextWidget();
+		if (widget != null) {
 			int offset = -1;
 			try {
 				Point p = new Point(e.x, e.y);
-			offset = getTextWidget().getOffsetAtLocation(p);
+				offset = widget.getOffsetAtLocation(p);
 				BuildConsole.getCurrentPage().moveToError(offset);
 			} catch (IllegalArgumentException ex) {
 			}
 		}
+	}
 
 	@Override
 	public void mouseDown(MouseEvent e) {