Fix dirty indicator pixel offset, add theme-switching snippet, fix test EOF

- Remove spurious y+1/-1 offset in drawDirtyIndicator; the oval is
  already centered from closeRect bounds, unlike the X drawing which
  needs the nudge due to its Math.max(1,...) coordinate logic
- Extend Snippet393 with a dark/light theme toggle button to demonstrate
  that the dirty bullet color adapts to the tab foreground color
- Add missing newline at end of Test_org_eclipse_swt_custom_CTabItem.java

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: vogella

bundles/org.eclipse.swt/Eclipse SWT Custom Widgets/common/org/eclipse/swt/custom/CTabFolderRenderer.java

@@ -938,7 +938,6 @@ private void drawDirtyIndicator(GC gc, Rectangle closeRect) {
 		int diameter = 8;
 		int x = closeRect.x + (closeRect.width - diameter) / 2;
 		int y = closeRect.y + (closeRect.height - diameter) / 2;
-		y += parent.onBottom ? -1 : 1;
 		Color originalBackground = gc.getBackground();
 		gc.setBackground(gc.getForeground());
 		gc.fillOval(x, y, diameter, diameter);

examples/org.eclipse.swt.snippets/src/org/eclipse/swt/snippets/Snippet393.java

@@ -11,13 +11,15 @@
 package org.eclipse.swt.snippets;
 
 /*
- * CTabFolder example: dirty indicator using bullet dot on close button
+ * CTabFolder example: dirty indicator using bullet dot on close button,
+ * with runtime dark/light theme switching to show color adaptation.
  *
  * For a list of all SWT example snippets see
  * http://www.eclipse.org/swt/snippets/
  */
 import org.eclipse.swt.*;
 import org.eclipse.swt.custom.*;
+import org.eclipse.swt.graphics.*;
 import org.eclipse.swt.layout.*;
 import org.eclipse.swt.widgets.*;
 
@@ -55,6 +57,45 @@ public static void main(String[] args) {
 			}
 		});
 
+		boolean[] isDark = {false};
+		Button toggleThemeButton = new Button(shell, SWT.PUSH);
+		toggleThemeButton.setText("Switch to Dark Theme");
+		toggleThemeButton.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false));
+		toggleThemeButton.addListener(SWT.Selection, e -> {
+			isDark[0] = !isDark[0];
+			if (isDark[0]) {
+				Color tabBg = new Color(display, 43, 43, 43);
+				Color selBg = new Color(display, 60, 63, 65);
+				Color contentBg = new Color(display, 30, 30, 30);
+				Color fg = new Color(display, 187, 187, 187);
+				folder.setBackground(tabBg);
+				folder.setForeground(fg);
+				folder.setSelectionBackground(selBg);
+				folder.setSelectionForeground(fg);
+				for (int i = 0; i < folder.getItemCount(); i++) {
+					Control ctrl = folder.getItem(i).getControl();
+					if (ctrl != null) {
+						ctrl.setBackground(contentBg);
+						ctrl.setForeground(fg);
+					}
+				}
+				toggleThemeButton.setText("Switch to Light Theme");
+			} else {
+				folder.setBackground(null);
+				folder.setForeground(null);
+				folder.setSelectionBackground((Color) null);
+				folder.setSelectionForeground(null);
+				for (int i = 0; i < folder.getItemCount(); i++) {
+					Control ctrl = folder.getItem(i).getControl();
+					if (ctrl != null) {
+						ctrl.setBackground(null);
+						ctrl.setForeground(null);
+					}
+				}
+				toggleThemeButton.setText("Switch to Dark Theme");
+			}
+		});
+
 		shell.setSize(400, 300);
 		shell.open();
 		while (!shell.isDisposed()) {

tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_custom_CTabItem.java

@@ -96,4 +96,4 @@ public void test_dirtyIndicatorCloseStyle() {
 	cTabFolder.setDirtyIndicatorCloseStyle(false);
 	assertFalse(cTabFolder.getDirtyIndicatorCloseStyle());
 }
-}
+}