Move text and style calculation to StickyLine

Author: Christopher-Hermann

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

@@ -33,9 +33,9 @@ public class DefaultStickyLinesProvider implements IStickyLinesProvider {
 	private StickyLinesProperties fProperties;
 
 	@Override
-	public List<StickyLine> getStickyLines(StyledText textWidget, int lineNumber, StickyLinesProperties properties) {
+	public List<IStickyLine> getStickyLines(StyledText textWidget, int lineNumber, StickyLinesProperties properties) {
 		this.fProperties= properties;
-		LinkedList<StickyLine> stickyLines= new LinkedList<>();
+		LinkedList<IStickyLine> stickyLines= new LinkedList<>();
 
 		try {
 			int startIndetation= getStartIndentation(lineNumber, textWidget);
@@ -50,7 +50,7 @@ public List<StickyLine> getStickyLines(StyledText textWidget, int lineNumber, St
 
 				if (indentation < previousIndetation) {
 					previousIndetation= indentation;
-					stickyLines.addFirst(new StickyLine(line, i));
+					stickyLines.addFirst(new StickyLine(i, textWidget));
 				}
 			}
 		} catch (IllegalArgumentException e) {

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

@@ -0,0 +1,44 @@
+/*******************************************************************************
+ * Copyright (c) 2024 SAP SE.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     SAP SE - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.ui.internal.texteditor.stickyscroll;
+
+import org.eclipse.swt.custom.StyleRange;
+
+/**
+ * Representation of a sticky line.
+ */
+public interface IStickyLine {
+
+	/**
+	 * Returns the line number of the sticky line.
+	 * 
+	 * @return the line number of the sticky line
+	 */
+	int getLineNumber();
+
+	/**
+	 * Returns the text of the sticky line.
+	 * 
+	 * @return the text of the sticky line
+	 */
+	String getText();
+
+	/**
+	 * Returns the style ranges of the sticky line.
+	 * 
+	 * @return the style ranges of the sticky line
+	 */
+	StyleRange[] getStyleRanges();
+
+}

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

@@ -41,7 +41,7 @@ public interface IStickyLinesProvider {
 	 * @see ISourceViewer#getTextWidget()
 	 * @see StyledText#getTopIndex()
 	 */
-	public List<StickyLine> getStickyLines(StyledText textWidget, int lineNumber, StickyLinesProperties properties);
+	public List<IStickyLine> getStickyLines(StyledText textWidget, int lineNumber, StickyLinesProperties properties);
 
 	/**
 	 * Additional properties and access in order to calculate the sticky lines.

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

@@ -13,13 +13,47 @@
  *******************************************************************************/
 package org.eclipse.ui.internal.texteditor.stickyscroll;
 
+import org.eclipse.swt.custom.StyleRange;
+import org.eclipse.swt.custom.StyledText;
+
 /**
- * 
- * A record representing a sticky line containing the text to display, and line number. It serves as
- * an abstraction to represent sticky line for sticky scrolling.
- * 
- * @param text the text of the corresponding sticky line
- * @param lineNumber the specific line number of the sticky line
+ * Default implementation of {@link IStickyLine}. Information about the text and style ranges are
+ * calculated from the given text widget.
  */
-public record StickyLine(String text, int lineNumber) {
+public class StickyLine implements IStickyLine {
+
+	private int lineNumber;
+
+	private String text;
+
+	private StyledText textWidget;
+
+	public StickyLine(int lineNumber, StyledText textWidget) {
+		this.lineNumber= lineNumber;
+		this.textWidget= textWidget;
+	}
+
+	@Override
+	public int getLineNumber() {
+		return this.lineNumber;
+	}
+
+	@Override
+	public String getText() {
+		if (text == null) {
+			text= textWidget.getLine(lineNumber);
+		}
+		return text;
+	}
+
+	@Override
+	public StyleRange[] getStyleRanges() {
+		int offsetAtLine= textWidget.getOffsetAtLine(lineNumber);
+		StyleRange[] styleRanges= textWidget.getStyleRanges(offsetAtLine, getText().length());
+		for (StyleRange styleRange : styleRanges) {
+			styleRange.start= styleRange.start - offsetAtLine;
+		}
+		return styleRanges;
+	}
+
 }

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

@@ -14,8 +14,6 @@
 package org.eclipse.ui.internal.texteditor.stickyscroll;
 
 import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 import java.util.StringJoiner;
@@ -65,7 +63,7 @@
 /**
  * This class builds a control that is rendered on top of the given source viewer. The controls
  * shows the sticky lines that are set via {@link #setStickyLines(List)} on top of the source
- * viewer. The {@link StickyLine#lineNumber()} is linked to to corresponding line number in the
+ * viewer. The {@link StickyLine#getLineNumber()} is linked to to corresponding line number in the
  * given source viewer, with index starting at 0.
  * 
  * As part of its responsibilities, the class handles layout arrangement and styling of the sticky
@@ -87,7 +85,7 @@ public class StickyScrollingControl {
 
 	private static final String DISABLE_CSS= "org.eclipse.e4.ui.css.disabled"; //$NON-NLS-1$
 
-	private List<StickyLine> stickyLines;
+	private List<IStickyLine> stickyLines;
 
 	private ISourceViewer sourceViewer;
 
@@ -135,7 +133,7 @@ public StickyScrollingControl(ISourceViewer sourceViewer, IVerticalRuler vertica
 	 * 
 	 * @param stickyLines The sticky lines to show
 	 */
-	public void setStickyLines(List<StickyLine> stickyLines) {
+	public void setStickyLines(List<IStickyLine> stickyLines) {
 		if (!stickyLines.equals(this.stickyLines)) {
 			this.stickyLines= stickyLines;
 			updateStickyScrollingControls();
@@ -206,9 +204,9 @@ private void updateStickyScrollingControls() {
 		StringJoiner stickyLineTextJoiner= new StringJoiner(System.lineSeparator());
 		StringJoiner stickyLineNumberJoiner= new StringJoiner(System.lineSeparator());
 		for (int i= 0; i < getNumberStickyLines(); i++) {
-			StickyLine stickyLine= stickyLines.get(i);
-			stickyLineTextJoiner.add(stickyLine.text());
-			int lineNumber= getSourceViewerLineNumber(stickyLine.lineNumber());
+			IStickyLine stickyLine= stickyLines.get(i);
+			stickyLineTextJoiner.add(stickyLine.getText());
+			int lineNumber= getSourceViewerLineNumber(stickyLine.getLineNumber());
 			stickyLineNumberJoiner.add(fillLineNumberWithLeadingSpaces(lineNumber + 1));
 		}
 
@@ -244,14 +242,19 @@ private void styleStickyLines() {
 			return;
 		}
 
-		List<StyleRange> stickyLinesStyleRanges= new ArrayList<>();
-		int stickyLineTextOffset= 0;
-		for (int i= 0; i < getNumberStickyLines(); i++) {
-			StickyLine stickyLine= stickyLines.get(i);
-			stickyLinesStyleRanges.addAll(getStickyLineStyleRanges(stickyLine, stickyLineTextOffset));
-			stickyLineTextOffset+= stickyLine.text().length() + System.lineSeparator().length();
+		int stickyLineOffset= 0;
+		for (IStickyLine stickyLine : stickyLines) {
+			StyleRange[] styleRanges= stickyLine.getStyleRanges();
+
+			if (styleRanges != null) {
+				for (StyleRange styleRange : styleRanges) {
+					styleRange.start+= stickyLineOffset;
+					stickyLineText.setStyleRange(styleRange);
+				}
+			}
+
+			stickyLineOffset+= stickyLine.getText().length() + System.lineSeparator().length();
 		}
-		stickyLineText.setStyleRanges(stickyLinesStyleRanges.toArray(StyleRange[]::new));
 
 		stickyLineNumber.setFont(textWidget.getFont());
 		stickyLineNumber.setStyleRange(new StyleRange(0, stickyLineNumber.getText().length(), settings.lineNumberColor(), null));
@@ -263,22 +266,6 @@ private void styleStickyLines() {
 		stickyLineText.setLeftMargin(textWidget.getLeftMargin());
 	}
 
-	private List<StyleRange> getStickyLineStyleRanges(StickyLine stickyLine, int stickyLineTextOffset) {
-		int lineNumber= stickyLine.lineNumber();
-		try {
-			StyledText textWidget= sourceViewer.getTextWidget();
-			int offsetAtLine= textWidget.getOffsetAtLine(lineNumber);
-			StyleRange[] styleRanges= textWidget.getStyleRanges(offsetAtLine, stickyLine.text().length());
-			for (StyleRange styleRange : styleRanges) {
-				styleRange.start= styleRange.start - offsetAtLine + stickyLineTextOffset;
-			}
-			return Arrays.asList(styleRanges);
-		} catch (IllegalArgumentException e) {
-			//Styling could not be copied, skip!
-			return Collections.emptyList();
-		}
-	}
-
 	private void layoutStickyLines() {
 		if (getNumberStickyLines() == 0) {
 			stickyLinesCanvas.setVisible(false);
@@ -365,12 +352,12 @@ private void calculateAndSetStickyLinesCanvasBounds() {
 
 	private void navigateToClickedLine(MouseEvent event) {
 		int clickedStickyLineIndex= stickyLineText.getLineIndex(event.y);
-		StickyLine clickedStickyLine= stickyLines.get(clickedStickyLineIndex);
+		IStickyLine clickedStickyLine= stickyLines.get(clickedStickyLineIndex);
 
 		try {
-			int offset= sourceViewer.getDocument().getLineOffset(clickedStickyLine.lineNumber());
+			int offset= sourceViewer.getDocument().getLineOffset(clickedStickyLine.getLineNumber());
 			sourceViewer.setSelectedRange(offset, 0);
-			ensureSourceViewerLineVisible(clickedStickyLine.lineNumber());
+			ensureSourceViewerLineVisible(clickedStickyLine.getLineNumber());
 		} catch (BadLocationException e) {
 			//Do not navigate
 		}

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

@@ -153,7 +153,7 @@ public void viewportChanged(int newVerticalOffset) {
 	}
 
 	private void calculateAndShowStickyLines() {
-		List<StickyLine> stickyLines= Collections.emptyList();
+		List<IStickyLine> stickyLines= Collections.emptyList();
 
 		StyledText textWidget= sourceViewer.getTextWidget();
 		int startLine= textWidget.getTopIndex();
@@ -171,19 +171,19 @@ private void calculateAndShowStickyLines() {
 		stickyScrollingControl.setStickyLines(stickyLines);
 	}
 
-	private List<StickyLine> adaptStickyLinesToVisibleArea(List<StickyLine> stickyLines, int startLine) {
+	private List<IStickyLine> adaptStickyLinesToVisibleArea(List<IStickyLine> stickyLines, int startLine) {
 		if (stickyLines.isEmpty()) {
 			return stickyLines;
 		}
 
-		LinkedList<StickyLine> adaptedStickyLines= new LinkedList<>(stickyLines);
+		LinkedList<IStickyLine> adaptedStickyLines= new LinkedList<>(stickyLines);
 
 		int firstVisibleLine= startLine + adaptedStickyLines.size();
 		StyledText textWidget= sourceViewer.getTextWidget();
 		int maximumLines= textWidget.getLineCount();
 
 		for (int i= startLine + 1; i <= firstVisibleLine && i < maximumLines; i++) {
-			List<StickyLine> stickyLinesInLineI= stickyLinesProvider.getStickyLines(textWidget, i, stickyLinesProperties);
+			List<IStickyLine> stickyLinesInLineI= stickyLinesProvider.getStickyLines(textWidget, i, stickyLinesProperties);
 
 			if (stickyLinesInLineI.size() > adaptedStickyLines.size()) {
 				adaptedStickyLines= new LinkedList<>(stickyLinesInLineI);

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

@@ -0,0 +1,86 @@
+/*******************************************************************************
+ * Copyright (c) 2024 SAP SE.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     SAP SE - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.ui.internal.texteditor.stickyscroll;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.custom.StyleRange;
+import org.eclipse.swt.custom.StyledText;
+import org.eclipse.swt.graphics.Color;
+import org.eclipse.swt.widgets.Shell;
+
+public class StickyLineTest {
+
+	private Shell shell;
+	private StyledText textWidget;
+	private Color color;
+
+	@Before
+	public void setUp() {
+		shell = new Shell();
+		textWidget = new StyledText(shell, SWT.NONE);
+		color = new Color(0, 0, 0);
+	}
+
+	@After
+	public void tearDown() {
+		shell.dispose();
+		color.dispose();
+	}
+
+	@Test
+	public void testGetLineNumber() {
+		StickyLine stickyLine = new StickyLine(1, textWidget);
+
+		assertEquals(1, stickyLine.getLineNumber());
+	}
+
+	@Test
+	public void testGetText() {
+		textWidget.setText("line1\nline2\nline3");
+		StickyLine stickyLine = new StickyLine(1, textWidget);
+
+		assertEquals("line2", stickyLine.getText());
+	}
+
+	@Test
+	public void testGetStyleRanges() {
+		textWidget.setText("line1\nline2\nline3");
+
+		// line1
+		textWidget.setStyleRange(new StyleRange(2, 1, color, null));
+
+		// line2
+		textWidget.setStyleRange(new StyleRange(6, 1, color, null));
+		textWidget.setStyleRange(new StyleRange(8, 2, color, null));
+
+		// line3
+		textWidget.setStyleRange(new StyleRange(15, 1, color, null));
+
+		StickyLine stickyLine = new StickyLine(1, textWidget);
+		StyleRange[] styleRanges = stickyLine.getStyleRanges();
+
+		assertEquals(2, styleRanges.length);
+		assertEquals(0, styleRanges[0].start);
+		assertEquals(1, styleRanges[0].length);
+		assertEquals(2, styleRanges[1].start);
+		assertEquals(2, styleRanges[1].length);
+	}
+
+}