[StickyScrolling] Use source viewer to calculate the sticky lines

Use the source viewer instead of the text widget to calculate the sticky lines. The source viewer is the standard instance for source code operations in JDT and other editors.

Preparation for #2398

Author: Christopher-Hermann

bundles/org.eclipse.ui.editors/src/org/eclipse/ui/internal/texteditor/stickyscroll/DefaultStickyLinesProvider.java

@@ -19,6 +19,9 @@
 
 import org.eclipse.swt.custom.StyledText;
 
+import org.eclipse.jface.text.ITextViewerExtension5;
+import org.eclipse.jface.text.source.ISourceViewer;
+
 /**
  * This class provides sticky lines for the given source code in the source viewer. The
  * implementation is completely based on indentation and therefore works by default for several
@@ -33,14 +36,16 @@ public class DefaultStickyLinesProvider implements IStickyLinesProvider {
 	private StickyLinesProperties fProperties;
 
 	@Override
-	public List<IStickyLine> getStickyLines(StyledText textWidget, int lineNumber, StickyLinesProperties properties) {
+	public List<IStickyLine> getStickyLines(ISourceViewer sourceViewer, int lineNumber, StickyLinesProperties properties) {
 		this.fProperties= properties;
 		LinkedList<IStickyLine> stickyLines= new LinkedList<>();
 
+		StyledText textWidget= sourceViewer.getTextWidget();
+		int textWidgetLineNumber= mapLineNumberToWidget(sourceViewer, lineNumber);
 		try {
-			int startIndetation= getStartIndentation(lineNumber, textWidget);
+			int startIndetation= getStartIndentation(textWidgetLineNumber, textWidget);
 
-			for (int i= lineNumber, previousIndetation= startIndetation; i >= 0; i--) {
+			for (int i= textWidgetLineNumber, previousIndetation= startIndetation; i >= 0; i--) {
 				String line= textWidget.getLine(i);
 				int indentation= getIndentation(line);
 
@@ -50,7 +55,7 @@ public List<IStickyLine> getStickyLines(StyledText textWidget, int lineNumber, S
 
 				if (indentation < previousIndetation) {
 					previousIndetation= indentation;
-					stickyLines.addFirst(new StickyLine(i, textWidget));
+					stickyLines.addFirst(new StickyLine(mapLineNumberToViewer(sourceViewer, i), textWidget));
 				}
 			}
 		} catch (IllegalArgumentException e) {
@@ -101,4 +106,18 @@ private int getIndentation(String line) {
 		return line.length() - line.stripLeading().length();
 	}
 
+	private int mapLineNumberToWidget(ISourceViewer sourceViewer, int line) {
+		if (sourceViewer instanceof ITextViewerExtension5 extension) {
+			return extension.modelLine2WidgetLine(line);
+		}
+		return line;
+	}
+
+	private int mapLineNumberToViewer(ISourceViewer sourceViewer, int line) {
+		if (sourceViewer instanceof ITextViewerExtension5 extension) {
+			return extension.widgetLine2ModelLine(line);
+		}
+		return line;
+	}
+
 }

bundles/org.eclipse.ui.editors/src/org/eclipse/ui/internal/texteditor/stickyscroll/IStickyLinesProvider.java

@@ -15,37 +15,35 @@
 
 import java.util.List;
 
-import org.eclipse.swt.custom.StyledText;
-
 import org.eclipse.jface.text.source.ISourceViewer;
 
 /**
- * A sticky lines provider calculates the sticky lines for a given text widget. The sticky lines
+ * A sticky lines provider calculates the sticky lines for a given source viewer. The sticky lines
  * will be displayed in the top area of the editor.
  * 
  * TODO move to public package and add since 3.19
  */
 public interface IStickyLinesProvider {
 
 	/**
-	 * Calculate the sticky lines for the source code of the given textWidget. Specific properties,
-	 * such as the <code>tabWidht</code> and the source viewer, can be retrieved from the
+	 * Calculate the sticky lines for the source code of the given sourceViewer. Specific
+	 * properties, such as the <code>tabWidht</code>, can be retrieved from the
 	 * <code>properties</code>.
 	 * 
-	 * @param textWidget The text widget containing the source code
+	 * @param sourceViewer The source viewer containing the source code and gives access to the text
+	 *            widget
 	 * @param lineNumber The line number to calculate the sticky lines for
 	 * @param properties Properties for additional information
 	 * @return The list of sticky lines to show
 	 */
-	public List<IStickyLine> getStickyLines(StyledText textWidget, int lineNumber, StickyLinesProperties properties);
+	public List<IStickyLine> getStickyLines(ISourceViewer sourceViewer, int lineNumber, StickyLinesProperties properties);
 
 	/**
 	 * Additional properties and access in order to calculate the sticky lines.
 	 * 
 	 * @param tabWith The with of a tab
-	 * @param sourceViewer The sourceViewer to access additional information
 	 */
-	record StickyLinesProperties(int tabWith, ISourceViewer sourceViewer) {
+	record StickyLinesProperties(int tabWith) {
 	}
 
 }

bundles/org.eclipse.ui.editors/src/org/eclipse/ui/internal/texteditor/stickyscroll/StickyScrollingControl.java

@@ -206,7 +206,7 @@ private void updateStickyScrollingControls() {
 		for (int i= 0; i < getNumberStickyLines(); i++) {
 			IStickyLine stickyLine= stickyLines.get(i);
 			stickyLineTextJoiner.add(stickyLine.getText());
-			int lineNumber= getSourceViewerLineNumber(stickyLine.getLineNumber());
+			int lineNumber= stickyLine.getLineNumber();
 			stickyLineNumberJoiner.add(fillLineNumberWithLeadingSpaces(lineNumber + 1));
 		}
 
@@ -222,13 +222,6 @@ private void updateStickyScrollingControls() {
 		}
 	}
 
-	private int getSourceViewerLineNumber(int i) {
-		if (sourceViewer instanceof ITextViewerExtension5 extension) {
-			return extension.widgetLine2ModelLine(i);
-		}
-		return i;
-	}
-
 	private String fillLineNumberWithLeadingSpaces(int lineNumber) {
 		int lineCount= sourceViewer.getDocument().getNumberOfLines();
 		int lineNumberLength= String.valueOf(lineCount).length();
@@ -399,6 +392,8 @@ private int getNumberStickyLines() {
 	 * resized/moved.<br>
 	 */
 	private void addSourceViewerListeners() {
+		StyledText textWidget= sourceViewer.getTextWidget();
+
 		if (sourceViewer instanceof ITextViewerExtension4 extension) {
 			textPresentationListener= e -> {
 				Job.create("Update sticky lines styling", (ICoreRunnable) monitor -> { //$NON-NLS-1$
@@ -411,13 +406,12 @@ private void addSourceViewerListeners() {
 		}
 
 		caretListener= new StickyScollingCaretListener();
-		sourceViewer.getTextWidget().addCaretListener(caretListener);
-		sourceViewer.getTextWidget().addKeyListener(caretListener);
+		textWidget.addCaretListener(caretListener);
+		textWidget.addKeyListener(caretListener);
 
 		controlListener= new ControlListener() {
 			@Override
 			public void controlResized(ControlEvent e) {
-				StyledText textWidget= sourceViewer.getTextWidget();
 				limitVisibleStickyLinesToTextWidgetHeight(textWidget);
 				layoutStickyLines();
 				if (stickyScrollingHandler != null) {
@@ -430,7 +424,7 @@ public void controlMoved(ControlEvent e) {
 				layoutStickyLines();
 			}
 		};
-		sourceViewer.getTextWidget().addControlListener(controlListener);
+		textWidget.addControlListener(controlListener);
 	}
 
 	private void limitVisibleStickyLinesToTextWidgetHeight(StyledText textWidget) {

bundles/org.eclipse.ui.editors/src/org/eclipse/ui/internal/texteditor/stickyscroll/StickyScrollingHandler.java

@@ -25,7 +25,6 @@
 import java.util.LinkedList;
 import java.util.List;
 
-import org.eclipse.swt.custom.StyledText;
 import org.eclipse.swt.graphics.Color;
 import org.eclipse.swt.graphics.RGB;
 
@@ -140,7 +139,7 @@ private StickyScrollingControlSettings loadControlSettings(IPreferenceStore stor
 
 	private StickyLinesProperties loadStickyLinesProperties(IPreferenceStore store) {
 		int tabWidth= store.getInt(EDITOR_TAB_WIDTH);
-		return new StickyLinesProperties(tabWidth, sourceViewer);
+		return new StickyLinesProperties(tabWidth);
 	}
 
 	@Override
@@ -155,11 +154,10 @@ public void viewportChanged(int newVerticalOffset) {
 	private void calculateAndShowStickyLines() {
 		List<IStickyLine> stickyLines= Collections.emptyList();
 
-		StyledText textWidget= sourceViewer.getTextWidget();
-		int startLine= textWidget.getTopIndex();
+		int startLine= sourceViewer.getTopIndex();
 
 		if (startLine > 0) {
-			stickyLines= stickyLinesProvider.getStickyLines(textWidget, startLine, stickyLinesProperties);
+			stickyLines= stickyLinesProvider.getStickyLines(sourceViewer, sourceViewer.getTopIndex(), stickyLinesProperties);
 		}
 
 		if (stickyLines == null) {
@@ -179,11 +177,10 @@ private List<IStickyLine> adaptStickyLinesToVisibleArea(List<IStickyLine> sticky
 		LinkedList<IStickyLine> adaptedStickyLines= new LinkedList<>(stickyLines);
 
 		int firstVisibleLine= startLine + adaptedStickyLines.size();
-		StyledText textWidget= sourceViewer.getTextWidget();
-		int maximumLines= textWidget.getLineCount();
+		int numberOfLines= sourceViewer.getDocument().getNumberOfLines();
 
-		for (int i= startLine + 1; i <= firstVisibleLine && i < maximumLines; i++) {
-			List<IStickyLine> stickyLinesInLineI= stickyLinesProvider.getStickyLines(textWidget, i, stickyLinesProperties);
+		for (int i= startLine + 1; i <= firstVisibleLine && i < numberOfLines; i++) {
+			List<IStickyLine> stickyLinesInLineI= stickyLinesProvider.getStickyLines(sourceViewer, i, stickyLinesProperties);
 
 			if (stickyLinesInLineI.size() > adaptedStickyLines.size()) {
 				adaptedStickyLines= new LinkedList<>(stickyLinesInLineI);

tests/org.eclipse.ui.editors.tests/src/org/eclipse/ui/internal/texteditor/stickyscroll/DefaultStickyLinesProviderTest.java

@@ -25,9 +25,13 @@
 
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.custom.StyledText;
+import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Shell;
 
+import org.eclipse.jface.text.IRegion;
+import org.eclipse.jface.text.ITextViewerExtension5;
+import org.eclipse.jface.text.source.IVerticalRuler;
 import org.eclipse.jface.text.source.SourceViewer;
 
 import org.eclipse.ui.internal.texteditor.stickyscroll.IStickyLinesProvider.StickyLinesProperties;
@@ -46,12 +50,12 @@ public void setup() {
 		sourceViewer = new SourceViewer(shell, null, SWT.None);
 		stickyLinesProvider = new DefaultStickyLinesProvider();
 		textWidget = sourceViewer.getTextWidget();
-		stickyLinesProperties = new StickyLinesProperties(4, sourceViewer);
+		stickyLinesProperties = new StickyLinesProperties(4);
 	}
 
 	@Test
 	public void testEmptySourceCode() {
-		List<IStickyLine> stickyLines = stickyLinesProvider.getStickyLines(textWidget, 0, stickyLinesProperties);
+		List<IStickyLine> stickyLines = stickyLinesProvider.getStickyLines(sourceViewer, 0, stickyLinesProperties);
 
 		assertThat(stickyLines, is(empty()));
 	}
@@ -63,7 +67,7 @@ public void testSingleStickyLine() {
 				 line 2<""";
 		setText(text);
 
-		List<IStickyLine> stickyLines = stickyLinesProvider.getStickyLines(textWidget, 1, stickyLinesProperties);
+		List<IStickyLine> stickyLines = stickyLinesProvider.getStickyLines(sourceViewer, 1, stickyLinesProperties);
 
 		assertEquals(1, stickyLines.size());
 		assertEquals(0, stickyLines.get(0).getLineNumber());
@@ -78,7 +82,7 @@ public void testLineUnderStickyLine() {
 				  line 4""";
 		setText(text);
 
-		List<IStickyLine> stickyLines = stickyLinesProvider.getStickyLines(textWidget, 1, stickyLinesProperties);
+		List<IStickyLine> stickyLines = stickyLinesProvider.getStickyLines(sourceViewer, 1, stickyLinesProperties);
 
 		assertEquals(1, stickyLines.size());
 		assertEquals(0, stickyLines.get(0).getLineNumber());
@@ -93,7 +97,7 @@ public void testNewStickyRoot() {
 				 line 4<""";
 		setText(text);
 
-		List<IStickyLine> stickyLines = stickyLinesProvider.getStickyLines(textWidget, 3, stickyLinesProperties);
+		List<IStickyLine> stickyLines = stickyLinesProvider.getStickyLines(sourceViewer, 3, stickyLinesProperties);
 
 		assertEquals(1, stickyLines.size());
 		assertEquals(2, stickyLines.get(0).getLineNumber());
@@ -109,7 +113,7 @@ public void testIgnoreEmptyLines() {
 				  line 3<""";
 		setText(text);
 
-		List<IStickyLine> stickyLines = stickyLinesProvider.getStickyLines(textWidget, 4, stickyLinesProperties);
+		List<IStickyLine> stickyLines = stickyLinesProvider.getStickyLines(sourceViewer, 4, stickyLinesProperties);
 
 		assertEquals(2, stickyLines.size());
 		assertEquals(0, stickyLines.get(0).getLineNumber());
@@ -118,14 +122,14 @@ public void testIgnoreEmptyLines() {
 
 	@Test
 	public void testLinesWithTabs() {
-		stickyLinesProperties = new StickyLinesProperties(2, sourceViewer);
+		stickyLinesProperties = new StickyLinesProperties(2);
 		String text = """
 				line 1
 				\tline 2
 				\t\tline 3<""";
 		setText(text);
 
-		List<IStickyLine> stickyLines = stickyLinesProvider.getStickyLines(textWidget, 2, stickyLinesProperties);
+		List<IStickyLine> stickyLines = stickyLinesProvider.getStickyLines(sourceViewer, 2, stickyLinesProperties);
 
 		assertEquals(2, stickyLines.size());
 		assertEquals(0, stickyLines.get(0).getLineNumber());
@@ -143,7 +147,7 @@ public void testStartAtEmptyLineWithNext() {
 		textWidget.setText(text);
 		textWidget.setTopIndex(3);
 
-		List<IStickyLine> stickyLines = stickyLinesProvider.getStickyLines(textWidget, 3, stickyLinesProperties);
+		List<IStickyLine> stickyLines = stickyLinesProvider.getStickyLines(sourceViewer, 3, stickyLinesProperties);
 
 		assertEquals(2, stickyLines.size());
 		assertEquals(0, stickyLines.get(0).getLineNumber());
@@ -160,13 +164,31 @@ public void testStartAtEmptyLineWithPrevious() {
 				line 4""";
 		setText(text);
 
-		List<IStickyLine> stickyLines = stickyLinesProvider.getStickyLines(textWidget, 3, stickyLinesProperties);
+		List<IStickyLine> stickyLines = stickyLinesProvider.getStickyLines(sourceViewer, 3, stickyLinesProperties);
 
 		assertEquals(2, stickyLines.size());
 		assertEquals(0, stickyLines.get(0).getLineNumber());
 		assertEquals(1, stickyLines.get(1).getLineNumber());
 	}
 
+	@Test
+	public void testStickyLineWithSourceViewerLineMapping() {
+		sourceViewer = new SourceViewerWithLineMapping(shell, null, SWT.None);
+		textWidget = sourceViewer.getTextWidget();
+
+		String text = """
+				line 1
+				 line 2<""";
+		setText(text);
+
+		// Source viewer line 43 that is mapped to line 1 in the text widget
+		List<IStickyLine> stickyLines = stickyLinesProvider.getStickyLines(sourceViewer, 1 + 42, stickyLinesProperties);
+
+		assertEquals(1, stickyLines.size());
+		// Source viewer line 42 that is mapped to line 0 in the text widget
+		assertEquals(0 + 42, stickyLines.get(0).getLineNumber());
+	}
+
 	/**
 	 * Set the text into the text widget and set the top index to the line
 	 * containing the <.
@@ -175,4 +197,32 @@ private void setText(String text) {
 		textWidget.setText(text);
 	}
 
+	private class SourceViewerWithLineMapping extends SourceViewer implements ITextViewerExtension5 {
+
+		public SourceViewerWithLineMapping(Composite parent, IVerticalRuler ruler, int styles) {
+			super(parent, ruler, styles);
+		}
+
+		@Override
+		public IRegion[] getCoveredModelRanges(IRegion modelRange) {
+			return null;
+		}
+
+		@Override
+		public boolean exposeModelRange(IRegion modelRange) {
+			return false;
+		}
+
+		@Override
+		public int widgetLine2ModelLine(int widgetLine) {
+			return widgetLine + 42;
+		}
+
+		@Override
+		public int modelLine2WidgetLine(int widgetLine) {
+			return widgetLine - 42;
+		}
+
+	}
+
 }