Bug 331629 - [disassembly] pageUp/pageDown scrolling jumps over unknown sections unexpectedly

In cooperation with Kirk Beitz

2 files changed, 76 insertions, 10 deletions

diff --git a/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/debug/internal/ui/disassembly/DisassemblyPart.java b/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/debug/internal/ui/disassembly/DisassemblyPart.java
index 800983c63c5..32d3d2b1cd0 100644
--- a/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/debug/internal/ui/disassembly/DisassemblyPart.java
+++ b/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/debug/internal/ui/disassembly/DisassemblyPart.java
@@ -616,7 +616,7 @@ public abstract class DisassemblyPart extends WorkbenchPart implements IDisassem
 		parent.setLayout(layout);
 		fVerticalRuler = createVerticalRuler();
 		int styles = SWT.V_SCROLL | SWT.H_SCROLL | SWT.MULTI | SWT.BORDER | SWT.FULL_SELECTION;
-		fViewer = new DisassemblyViewer(parent, fVerticalRuler, getOverviewRuler(), true, styles);
+		fViewer = new DisassemblyViewer(this, parent, fVerticalRuler, getOverviewRuler(), true, styles);
 		SourceViewerConfiguration sourceViewerConfig = new DisassemblyViewerConfiguration(this);
 		fViewer.addTextPresentationListener(this);
 		fViewer.configure(sourceViewerConfig);
@@ -1381,15 +1381,14 @@ public abstract class DisassemblyPart extends WorkbenchPart implements IDisassem
 		fBackend.gotoSymbol(symbol);
 	}
 
-	private void gotoPosition(Position pos, boolean select) {
+	private void gotoPosition(Position pos, boolean onTop) {
 		if (fViewer == null) {
 			return;
 		}
 		setFocusPosition(pos);
-		fViewer.setSelectedRange(pos.offset, select ? Math.max(pos.length-1, 0) : 0);
+		fViewer.setSelectedRange(pos.offset, 0);
 		int revealOffset = pos.offset;
-		boolean onTop = false;
-		if (/* !fUpdateBeforeFocus && */ pos.offset > 0) {
+		if (pos.offset > 0) {
 			try {
 				AddressRangePosition previousPos = fDocument.getModelPosition(pos.offset - 1);
 				if (previousPos instanceof LabelPosition) {
@@ -2936,4 +2935,54 @@ public abstract class DisassemblyPart extends WorkbenchPart implements IDisassem
 	private static boolean isGuiThread() {
 		return Display.getCurrent() != null;
 	}
+
+	boolean keyScroll(int keyCode) {
+		BigInteger topAddress = getTopAddress();
+		BigInteger bottomAddress = getBottomAddress();
+		BigInteger addressRange = bottomAddress.subtract(topAddress);
+		StyledText styledText = fViewer.getTextWidget();
+		Rectangle clientArea = styledText.getClientArea();
+		int lineRange;
+		if (SWT.PAGE_UP == keyCode || SWT.PAGE_DOWN == keyCode) {
+			lineRange = clientArea.height / styledText.getLineHeight();
+		} else {
+			lineRange = 1;
+		}
+		addressRange = addressRange.min(BigInteger.valueOf(lineRange * fDocument.getMeanSizeOfInstructions()));
+		BigInteger scrollToAddress;
+		switch (keyCode) {
+		case SWT.PAGE_UP:
+		case SWT.ARROW_UP:
+			scrollToAddress = topAddress.subtract(addressRange).max(fStartAddress);
+			break;
+		case SWT.PAGE_DOWN:
+			scrollToAddress = topAddress.add(addressRange).min(bottomAddress);
+			break;
+		case SWT.ARROW_DOWN:
+			scrollToAddress = bottomAddress.add(addressRange).min(bottomAddress);
+			break;
+		default:
+			assert false;	// invalid keycode passed
+			scrollToAddress = fFocusAddress;
+		}
+		AddressRangePosition pos = getPositionOfAddress(scrollToAddress);
+		if (pos != null && pos.fValid) {
+			if (SWT.ARROW_DOWN == keyCode && pos.fAddressOffset.compareTo(bottomAddress) <= 0
+				|| SWT.ARROW_UP == keyCode && pos.fAddressOffset.compareTo(topAddress) >= 0) {
+				return false;
+			}
+			gotoPosition(pos, SWT.ARROW_DOWN != keyCode);
+		} else {
+			gotoAddress(scrollToAddress);
+		}
+		return true;
+	}
+
+	private BigInteger getBottomAddress() {
+		BigInteger bottomAddress = getAddressOfLine(fViewer.getBottomIndex());
+		if (bottomAddress == null || bottomAddress.equals(PC_UNKNOWN)) {
+			bottomAddress = fEndAddress.subtract(BigInteger.ONE);
+		}
+		return bottomAddress;
+	}
 }
diff --git a/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/debug/internal/ui/disassembly/DisassemblyViewer.java b/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/debug/internal/ui/disassembly/DisassemblyViewer.java
index d5863dc5123..7d4a4e43006 100644
--- a/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/debug/internal/ui/disassembly/DisassemblyViewer.java
+++ b/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/debug/internal/ui/disassembly/DisassemblyViewer.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2010 Wind River Systems and others.
+ * Copyright (c) 2007, 2011 Wind River 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
@@ -24,12 +24,15 @@ import org.eclipse.jface.text.source.IOverviewRuler;
 import org.eclipse.jface.text.source.IVerticalRuler;
 import org.eclipse.jface.text.source.IVerticalRulerColumn;
 import org.eclipse.jface.text.source.SourceViewer;
+import org.eclipse.swt.SWT;
 import org.eclipse.swt.custom.StyledText;
+import org.eclipse.swt.custom.VerifyKeyListener;
 import org.eclipse.swt.dnd.Clipboard;
 import org.eclipse.swt.dnd.TextTransfer;
 import org.eclipse.swt.dnd.Transfer;
 import org.eclipse.swt.events.ControlEvent;
 import org.eclipse.swt.events.ControlListener;
+import org.eclipse.swt.events.VerifyEvent;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.graphics.Rectangle;
 import org.eclipse.swt.widgets.Composite;
@@ -52,13 +55,14 @@ public class DisassemblyViewer extends SourceViewer {
 		public void controlMoved(ControlEvent e) {
 		}
 	}
-	
+
 	private boolean fUserTriggeredScrolling;
 	private int fCachedLastTopPixel;
 	
 	// extra resize listener to workaround bug 171018
 	// https://bugs.eclipse.org/bugs/show_bug.cgi?id=171018
 	private ResizeListener fResizeListener;
+	private DisassemblyPart fPart;
 
 	/**
 	 * Create a new DisassemblyViewer.
@@ -68,8 +72,9 @@ public class DisassemblyViewer extends SourceViewer {
 	 * @param showsAnnotationOverview
 	 * @param styles
 	 */
-	public DisassemblyViewer(Composite parent, IVerticalRuler ruler, IOverviewRuler overviewRuler, boolean showsAnnotationOverview, int styles) {
+	public DisassemblyViewer(DisassemblyPart part, Composite parent, IVerticalRuler ruler, IOverviewRuler overviewRuler, boolean showsAnnotationOverview, int styles) {
 		super(parent, ruler, overviewRuler, showsAnnotationOverview, styles);
+		fPart = part;
 		// always readonly
 		setEditable(false);
 	}
@@ -80,8 +85,20 @@ public class DisassemblyViewer extends SourceViewer {
 	@Override
 	protected void createControl(Composite parent, int styles) {
 		super.createControl(parent, styles);
+		StyledText textWidget = getTextWidget();
 		// see https://bugs.eclipse.org/bugs/show_bug.cgi?id=171018
-		getTextWidget().addControlListener(fResizeListener= new ResizeListener());
+		textWidget.addControlListener(fResizeListener= new ResizeListener());
+		textWidget.addVerifyKeyListener(new VerifyKeyListener() {
+			public void verifyKey(VerifyEvent event) {
+				switch (event.keyCode) {
+				case SWT.PAGE_UP:
+				case SWT.PAGE_DOWN:
+				case SWT.ARROW_UP:
+				case SWT.ARROW_DOWN:
+					event.doit = !fPart.keyScroll(event.keyCode);
+				}
+			}
+		});
 	}
 
 	/*
@@ -231,7 +248,7 @@ public class DisassemblyViewer extends SourceViewer {
 				if (!onTop && focusLine >= top && focusLine <= bottom - bottomBuffer) {
 					// do not scroll at all as it is already visible
 				} else {
-					if (focusLine > bottom - bottomBuffer && focusLine <= bottom) {
+					if (!onTop && focusLine > bottom - bottomBuffer && focusLine <= bottom) {
 						// focusLine is already in bottom bufferZone
 						// scroll to top of bottom bufferzone - for smooth down-scrolling
 						int scrollDelta = focusLine - (bottom - bottomBuffer);