[Win32] Improve StyledText caret scaling on DPI change

This commit replaces the win32-specific caret scaling with API-based
resizing to ensure proper repaint on DPI changes. Carets now update
location/size via resize() in their DPI change handlers, removing
platform dependencies. Additionally, StyledTexts set location, size and
visibility of their carets first before calling the DPI change handler
of Caret to make sure when Caret is repainted, the size, location and
visibility are properly set.

Author: amartya4256

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

@@ -10912,19 +10912,18 @@ void updateSelection(int startOffset, int replacedLength, int newLength) {
  * @noreference This method is not intended to be referenced by clients.
  */
 public static void updateAndRefreshCarets(StyledText styledText, Consumer<Caret> caretUpdater) {
-	Set<Caret> caretSet = new HashSet<>();
-	caretSet.add(styledText.getCaret());
+	styledText.updateCaretVisibility();
+	styledText.setCaretLocations();
+	Set<Caret> caretSet = new LinkedHashSet<>();
 	caretSet.add(styledText.defaultCaret);
+	caretSet.add(styledText.getCaret());
 	if (styledText.carets != null) {
 		for (Caret caret : styledText.carets) {
 			caretSet.add(caret);
 		}
 	}
 	caretSet.stream().filter(Objects::nonNull).forEach(caretUpdater);
 
-	styledText.updateCaretVisibility();
-	styledText.setCaretLocations();
-
 }
 
 }

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/internal/CommonWidgetsDPIChangeHandlers.java

@@ -51,11 +51,8 @@ private static void handleStyledTextDPIChange(Widget widget, int newZoom, float
 		if (!(widget instanceof StyledText styledText)) {
 			return;
 		}
-
-
 		StyledText.updateAndRefreshCarets(styledText, caretToRefresh -> {
 			DPIZoomChangeRegistry.applyChange(caretToRefresh, newZoom, scalingFactor);
-			Caret.win32_setHeight(caretToRefresh, styledText.getLineHeight());
 		});
 	}
 	private static void handleCComboDPIChange(Widget widget, int newZoom, float scalingFactor) {

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Caret.java

@@ -658,29 +658,6 @@ public void setVisible (boolean visible) {
 	}
 }
 
-/**
- * <b>IMPORTANT:</b> This method is not part of the public
- * API for Image. It is marked public only so that it
- * can be shared within the packages provided by SWT. It is not
- * available on all platforms, and should never be called from
- * application code.
- *
- * Sets the height o the caret in points.
- *
- * @param caret the caret to set the height of
- * @param height the height of caret to be set in points.
- *
- * @noreference This method is not intended to be referenced by clients.
- */
-public static void win32_setHeight(Caret caret, int height) {
-	caret.checkWidget();
-	if(caret.height != height) {
-		caret.height = height;
-		caret.resized = true;
-	}
-	if(caret.isVisible && caret.hasFocus()) caret.resize();
-}
-
 private static void handleDPIChange(Widget widget, int newZoom, float scalingFactor) {
 	if (!(widget instanceof Caret caret)) {
 		return;
@@ -694,6 +671,7 @@ private static void handleDPIChange(Widget widget, int newZoom, float scalingFac
 	if (caret.font != null) {
 		caret.setFont(caret.font);
 	}
+	if (caret.isVisible && caret.hasFocus ()) caret.resize();
 }
 }