Bug 550620, 197958 - Fix style range override in TextConsoleViewer

Current implementation of override works most of the time since the
usual combinations of existing style ranges and link range are quite
limited.

New implementation yields correct results for any combination.

This also supersedes fix of Bug 111256.

Change-Id: Idcc94f4be0d7ca815e854a2d2a271a32494a2412
Signed-off-by: Paul Pazderski <paul-eclipse@ppazderski.de>

4 files changed, 87 insertions, 48 deletions

diff --git a/org.eclipse.ui.console/META-INF/MANIFEST.MF b/org.eclipse.ui.console/META-INF/MANIFEST.MF
index 2e5be95a9..e84c1e558 100644
--- a/org.eclipse.ui.console/META-INF/MANIFEST.MF
+++ b/org.eclipse.ui.console/META-INF/MANIFEST.MF
@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %pluginName
 Bundle-SymbolicName: org.eclipse.ui.console; singleton:=true
-Bundle-Version: 3.8.600.qualifier
+Bundle-Version: 3.8.700.qualifier
 Bundle-Activator: org.eclipse.ui.console.ConsolePlugin
 Bundle-Vendor: %providerName
 Bundle-Localization: plugin
diff --git a/org.eclipse.ui.console/pom.xml b/org.eclipse.ui.console/pom.xml
index 164593c55..7b76a4f3d 100644
--- a/org.eclipse.ui.console/pom.xml
+++ b/org.eclipse.ui.console/pom.xml
@@ -18,6 +18,6 @@
   </parent>
   <groupId>org.eclipse.ui</groupId>
   <artifactId>org.eclipse.ui.console</artifactId>
-  <version>3.8.600-SNAPSHOT</version>
+  <version>3.8.700-SNAPSHOT</version>
   <packaging>eclipse-plugin</packaging>
 </project>
diff --git a/org.eclipse.ui.console/src/org/eclipse/ui/console/TextConsole.java b/org.eclipse.ui.console/src/org/eclipse/ui/console/TextConsole.java
index e847c23fa..e0cf26783 100644
--- a/org.eclipse.ui.console/src/org/eclipse/ui/console/TextConsole.java
+++ b/org.eclipse.ui.console/src/org/eclipse/ui/console/TextConsole.java
@@ -376,10 +376,10 @@ public abstract class TextConsole extends AbstractConsole {
 	}
 
 	/**
-	 * Returns the hyperlink at the given offset of <code>null</code> if none.
+	 * Returns the hyperlink at the given offset or <code>null</code> if none.
 	 *
 	 * @param offset offset for which a hyperlink is requested
-	 * @return the hyperlink at the given offset of <code>null</code> if none
+	 * @return the hyperlink at the given offset or <code>null</code> if none
 	 */
 	public IHyperlink getHyperlink(int offset) {
 		try {
@@ -399,7 +399,8 @@ public abstract class TextConsole extends AbstractConsole {
 	/**
 	 * Binary search for the position at a given offset.
 	 *
-	 * @param offset the offset whose position should be found
+	 * @param offset    the offset whose position should be found
+	 * @param positions the positions list to search in
 	 * @return the position containing the offset, or <code>null</code>
 	 */
 	private Position findPosition(int offset, Position[] positions) {
diff --git a/org.eclipse.ui.console/src/org/eclipse/ui/console/TextConsoleViewer.java b/org.eclipse.ui.console/src/org/eclipse/ui/console/TextConsoleViewer.java
index 6a94c00bb..c5ffa14bd 100644
--- a/org.eclipse.ui.console/src/org/eclipse/ui/console/TextConsoleViewer.java
+++ b/org.eclipse.ui.console/src/org/eclipse/ui/console/TextConsoleViewer.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2018 IBM Corporation and others.
+ * Copyright (c) 2000, 2019 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -10,6 +10,7 @@
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
+ *     Paul Pazderski  - Bug 550620: reimplementation of style override (to fix existing and future problems with link styling)
  *******************************************************************************/
 
 package org.eclipse.ui.console;
@@ -377,11 +378,9 @@ public class TextConsoleViewer extends SourceViewer implements LineStyleListener
 			int offset = event.lineOffset;
 			int length = event.lineText.length();
 
-			StyleRange[] partitionerStyles = ((IConsoleDocumentPartitioner) document.getDocumentPartitioner()).getStyleRanges(event.lineOffset, event.lineText.length());
+			StyleRange[] partitionerStyles = ((IConsoleDocumentPartitioner) document.getDocumentPartitioner()).getStyleRanges(offset, length);
 			if (partitionerStyles != null) {
 				Collections.addAll(ranges, partitionerStyles);
-			} else {
-				ranges.add(new StyleRange(offset, length, null, null));
 			}
 
 			try {
@@ -393,7 +392,7 @@ public class TextConsoleViewer extends SourceViewer implements LineStyleListener
 						Position position = overlap[i];
 						StyleRange linkRange = new StyleRange(position.offset, position.length, color, null);
 						linkRange.underline = true;
-						override(ranges, linkRange);
+						overrideStyleRange(ranges, linkRange);
 					}
 				}
 			} catch (BadPositionCategoryException e) {
@@ -405,52 +404,92 @@ public class TextConsoleViewer extends SourceViewer implements LineStyleListener
 		}
 	}
 
-	private void override(List<StyleRange> ranges, StyleRange newRange) {
-		if (ranges.isEmpty()) {
-			ranges.add(newRange);
-			return;
-		}
-
-		int start = newRange.start;
-		int end = start + newRange.length;
-		for (int i = 0; i < ranges.size(); i++) {
-			StyleRange existingRange = ranges.get(i);
-			int rEnd = existingRange.start + existingRange.length;
-			if (end <= existingRange.start || start >= rEnd) {
-				continue;
-			}
-
-			if (start < existingRange.start && end > existingRange.start) {
-				start = existingRange.start;
+	/**
+	 * Apply new style range to list of existing style ranges. If the new style
+	 * range overlaps with any of the existing style ranges the new style overrides
+	 * the existing one in the affected range by splitting/adjusting the existing
+	 * ones.
+	 *
+	 * @param ranges   list of existing style ranges (will contain the new style
+	 *                 range when finished)
+	 * @param newRange new style range which should be combined with the existing
+	 *                 ranges
+	 */
+	private static void overrideStyleRange(List<StyleRange> ranges, StyleRange newRange) {
+		final int overrideStart = newRange.start;
+		final int overrideEnd = overrideStart + newRange.length;
+		int insertIndex = ranges.size();
+		for (int i = ranges.size() - 1; i >= 0; i--) {
+			final StyleRange existingRange = ranges.get(i);
+			final int existingStart = existingRange.start;
+			final int existingEnd = existingStart + existingRange.length;
+
+			// Find first position to insert where offset of new range is smaller then all
+			// offsets before. This way the list is still sorted by offset after insert if
+			// it was sorted before and it will not fail if list was not sorted.
+			if (overrideStart <= existingStart) {
+				insertIndex = i;
 			}
 
-			if (start >= existingRange.start && end <= rEnd) {
-				existingRange.length = start - existingRange.start;
-				ranges.add(++i, newRange);
-				if (end != rEnd) {
-					ranges.add(++i, new StyleRange(end, rEnd - end - 1, existingRange.foreground, existingRange.background));
+			// adjust the existing range if required
+			if (overrideStart <= existingStart) { // new range starts before or with existing
+				if (overrideEnd < existingStart) {
+					// new range lies before existing range. No overlapping.
+					// new range: ++++_________
+					// existing : ________=====
+					// . result : ++++____=====
+					// nothing to do
+				} else if (overrideEnd < existingEnd) {
+					// new range overlaps start of existing.
+					// new range: ++++++++_____
+					// existing : _____========
+					// . result : ++++++++=====
+					final int overlap = overrideEnd - existingStart;
+					existingRange.start += overlap;
+					existingRange.length -= overlap;
+				} else {
+					// new range completely overlaps existing.
+					// new range: ___++++++++++
+					// existing : ___======____
+					// . result : ___++++++++++
+					ranges.remove(i);
+				}
+			} else { // new range starts inside or after existing
+				if (existingEnd < overrideStart) {
+					// new range lies after existing range. No overlapping.
+					// new range: _________++++
+					// existing : =====________
+					// . result : =====____++++
+					// nothing to do
+				} else if (overrideEnd >= existingEnd) {
+					// new range overlaps end of existing.
+					// new range: _____++++++++
+					// existing : ========_____
+					// . result : =====++++++++
+					existingRange.length -= existingEnd - overrideStart;
+				} else {
+					// new range lies inside existing range but not overrides all of it
+					// (and does not touch first or last offset of existing)
+					// new range: ____+++++____
+					// existing : =============
+					// . result : ====+++++====
+					final StyleRange clonedRange = (StyleRange) existingRange.clone();
+					existingRange.length = overrideStart - existingStart;
+					clonedRange.start = overrideEnd;
+					clonedRange.length = existingEnd - overrideEnd;
+					ranges.add(i + 1, clonedRange);
 				}
-				return;
-			} else if (start >= existingRange.start && start < rEnd) {
-				existingRange.length = start - existingRange.start;
-				ranges.add(++i, newRange);
-			} else if (end >= rEnd) {
-				ranges.remove(i);
-			} else {
-				ranges.add(++i, new StyleRange(end + 1, rEnd - end + 1, existingRange.foreground, existingRange.background));
 			}
 		}
+		ranges.add(insertIndex, newRange);
 	}
 
 	/**
 	 * Binary search for the positions overlapping the given range
 	 *
-	 * @param offset
-	 *            the offset of the range
-	 * @param length
-	 *            the length of the range
-	 * @param positions
-	 *            the positions to search
+	 * @param offset    the offset of the range
+	 * @param length    the length of the range
+	 * @param positions the positions to search
 	 * @return the positions overlapping the given range, or <code>null</code>
 	 */
 	private Position[] findPosition(int offset, int length, Position[] positions) {
@@ -635,8 +674,7 @@ public class TextConsoleViewer extends SourceViewer implements LineStyleListener
 	 * Returns the hyperlink at the specified offset, or <code>null</code> if
 	 * none.
 	 *
-	 * @param offset
-	 *            offset at which a hyperlink has been requested
+	 * @param offset offset at which a hyperlink has been requested
 	 * @return hyperlink at the specified offset, or <code>null</code> if none
 	 */
 	public IHyperlink getHyperlink(int offset) {