Fix "Show line numbers" settings is not correctly handled

When changing the "Show line numbers" setting for the editor, the sticky scrolling control should also react on the setting and hide the line numbers.

Fixes eclipse-platform#2269

Author: Christopher-Hermann

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

@@ -150,6 +150,8 @@ public void applySettings(StickyScrollingControlSettings newSettings) {
 		bottomSeparator.setBackground(settings.stickyLinesSeparatorColor());
 
 		updateStickyScrollingControls();
+		styleStickyLines();
+		layoutStickyLines();
 	}
 
 	public void dispose() {
@@ -298,15 +300,12 @@ private void layoutLineNumbers() {
 			return;
 		}
 
+		LineNumberColumn lineNumberColumn= getLineNumberColumn(verticalRuler);
 		if (!settings.showLineNumbers()) {
 			stickyLineNumber.setRightMargin(verticalRuler.getWidth());
 			((GridData) stickyLineNumber.getLayoutData()).widthHint= 0;
 			stickyLineNumber.setLeftMargin(0);
-			return;
-		}
-
-		LineNumberColumn lineNumberColumn= getLineNumberColumn(verticalRuler);
-		if (lineNumberColumn == null) {
+		} else if (lineNumberColumn == null) {
 			((GridData) stickyLineNumber.getLayoutData()).widthHint= verticalRuler.getWidth();
 			GC gc= new GC(stickyLinesCanvas);
 			gc.setFont(sourceViewer.getTextWidget().getFont());

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

@@ -17,6 +17,8 @@
 import static org.hamcrest.Matchers.greaterThan;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
 
 import java.util.List;
 
@@ -41,7 +43,7 @@
 import org.eclipse.swt.widgets.Shell;
 
 import org.eclipse.jface.text.Document;
-import org.eclipse.jface.text.source.CompositeRuler;
+import org.eclipse.jface.text.source.IVerticalRuler;
 import org.eclipse.jface.text.source.SourceViewer;
 
 public class StickyScrollingControlTest {
@@ -53,14 +55,14 @@ public class StickyScrollingControlTest {
 	private Color backgroundColor;
 	private Color separatorColor;
 	private StickyScrollingControl stickyScrollingControl;
-	private CompositeRuler ruler;
+	private IVerticalRuler ruler;
 
 	@Before
 	public void setup() {
 		shell = new Shell(Display.getDefault());
 		shell.setSize(200, 200);
 		shell.setLayout(new FillLayout());
-		ruler = new CompositeRuler();
+		ruler = mock(IVerticalRuler.class);
 		sourceViewer = new SourceViewer(shell, ruler, SWT.V_SCROLL | SWT.H_SCROLL);
 		sourceViewer.setDocument(new Document());
 		sourceViewer.getTextWidget().setBounds(0, 0, 200, 200);
@@ -153,6 +155,23 @@ public void testWithoutVerticalRuler() {
 		assertFalse(stickyLineNumber.isVisible());
 	}
 
+	@Test
+	public void testWithoutLineNumber() {
+		when(ruler.getWidth()).thenReturn(20);
+		List<StickyLine> stickyLines = List.of(new StickyLine("line 10", 9), new StickyLine("line 20", 19));
+		stickyScrollingControl.setStickyLines(stickyLines);
+
+		StyledText stickyLineNumber = getStickyLineNumber();
+		assertThat(stickyLineNumber.getLeftMargin(), greaterThan(0));
+
+		StickyScrollingControlSettings settings = new StickyScrollingControlSettings(5, lineNumberColor, hoverColor,
+				backgroundColor, separatorColor, false);
+		stickyScrollingControl.applySettings(settings);
+
+		stickyLineNumber = getStickyLineNumber();
+		assertEquals(0, stickyLineNumber.getLeftMargin());
+	}
+
 	@Test
 	public void testStyling() {
 		Font font = new Font(shell.getDisplay(), new FontData("Arial", 12, SWT.BOLD));