Temporary commit: do the check in Composite instead of Control

Author: fedejeanne

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

@@ -1183,6 +1183,40 @@ void setResizeChildren (boolean resize) {
 	}
 }
 
+@Override
+public void setRedraw(boolean redraw) {
+	/*
+	 * Some embedded applications like webview2 (Edge), Excel, etc have a renderer
+	 * that will draw the whole application white when setting redraw to false and
+	 * will repaint it completely when setting it to true. This causes flickering,
+	 * which is why turning redraw off is not allowed in case this control has an
+	 * embedded application as a child.
+	 *
+	 * https://github.com/eclipse-platform/eclipse.platform.swt/issues/1122
+	 */
+	boolean isEmbedded = (style & SWT.EMBEDDED) != 0;
+	if (!redraw && (isEmbedded || hasEmbeddedChildren())) {
+		return;
+	}
+	super.setRedraw(redraw);
+}
+
+private boolean hasEmbeddedChildren() {
+	for (Control child : getChildren()) {
+		if (!child.isDisposed() && child.isVisible()) {
+
+			if ((child.style & SWT.EMBEDDED) != 0)
+				return true;
+
+			// if it's a composite, check its children too
+			if (child instanceof Composite comp && comp.hasEmbeddedChildren())
+				return true;
+		}
+	}
+
+	return false;
+}
+
 @Override
 boolean setTabGroupFocus () {
 	if (isTabItem ()) return setTabItemFocus ();

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

@@ -55,8 +55,6 @@ public abstract class Control extends Widget implements Drawable {
 		DPIZoomChangeRegistry.registerHandler(Control::handleDPIChange, Control.class);
 	}
 
-	private static Set<Control> embeddedControls = new HashSet<>();
-
 	/**
 	 * the handle to the OS resource
 	 * (Warning: This field is platform dependent)
@@ -713,9 +711,6 @@ void createWidget () {
 	if ((state & PARENT_BACKGROUND) != 0) {
 		setBackground ();
 	}
-	if((style & SWT.EMBEDDED) != 0) {
-		embeddedControls.add(this);
-	}
 }
 
 int defaultBackground () {
@@ -2499,9 +2494,6 @@ void releaseParent () {
 @Override
 void releaseWidget () {
 	super.releaseWidget ();
-	if((style & SWT.EMBEDDED) != 0) {
-		embeddedControls.remove(this);
-	}
 	if (toolTipText != null) {
 		setToolTipText (getShell (), null);
 	}
@@ -3614,23 +3606,6 @@ boolean setRadioSelection (boolean value) {
 	return false;
 }
 
-private boolean hasEmbeddedChildren() {
-	for (Control ec : embeddedControls) {
-		if (!ec.isDisposed() && ec.isVisible() && ec.isChildOf(this)) return true;
-	}
-	return false;
-}
-
-private boolean isChildOf(Control parent) {
-	Control c = this;
-	while (c != null) {
-		if (c == parent) return true;
-
-		c = c.getParent();
-	}
-	return false;
-}
-
 /**
  * If the argument is <code>false</code>, causes subsequent drawing
  * operations in the receiver to be ignored. No drawing of any kind
@@ -3656,21 +3631,6 @@ private boolean isChildOf(Control parent) {
  */
 public void setRedraw (boolean redraw) {
 	checkWidget ();
-
-	/*
-	 * Some embedded applications like webview2 (Edge), Excel, etc
-	 * have a renderer that will draw the whole application white
-	 * when setting redraw to false and will repaint it completely
-	 * when setting it to true. This causes flickering, which is why
-	 * turning redraw off is not allowed in case this control has an
-	 * embedded application as a child.
-	 *
-	 * https://github.com/eclipse-platform/eclipse.platform.swt/issues/1122
-	 */
-	if(!redraw && hasEmbeddedChildren()) {
-		return;
-	}
-
 	/*
 	 * Feature in Windows.  When WM_SETREDRAW is used to turn
 	 * off drawing in a widget, it clears the WS_VISIBLE bits