Add processing of mouse movements in Edge browserHover

This contribution captures mouse movements in the edge browser and sends
according mouse move, enter and exit events to its listener.

contributes to
#1540

Author: amartya4256

bundles/org.eclipse.swt/Eclipse SWT Browser/win32/org/eclipse/swt/browser/Edge.java

@@ -78,6 +78,9 @@ public WebViewEnvironment(ICoreWebView2Environment environment) {
 	private boolean ignoreFocus;
 	private String lastCustomText;
 
+	record CursorPosition(Point location, boolean isInsideBrowser) {};
+	private CursorPosition previousCursorPosition = new CursorPosition(new Point(0, 0), false);
+
 	static {
 		NativeClearSessions = () -> {
 			ICoreWebView2CookieManager manager = getCookieManager();
@@ -654,6 +657,7 @@ void setupBrowser(int hr, long pv) {
 	browser.addListener(SWT.FocusIn, this::browserFocusIn);
 	browser.addListener(SWT.Resize, this::browserResize);
 	browser.addListener(SWT.Move, this::browserMove);
+	scheduleMouseMovementHandling();
 
 	containingEnvironment.instances().add(this);
 	// Sometimes when the shell of the browser is opened before the browser is
@@ -709,6 +713,52 @@ void browserResize(Event event) {
 	controller.put_IsVisible(true);
 }
 
+private void scheduleMouseMovementHandling() {
+	browser.getDisplay().timerExec(100, () -> {
+		if (browser.isDisposed()) {
+			return;
+		}
+		if (browser.isVisible() && hasDisplayFocus()) {
+			handleMouseMovement();
+		}
+		scheduleMouseMovementHandling();
+	});
+}
+
+private void handleMouseMovement() {
+	final Point currentCursorLocation = browser.getDisplay().getCursorLocation();
+	Point cursorLocationInControlCoordinate = browser.toControl(currentCursorLocation);
+	boolean isCursorInsideBrowser = browser.getBounds().contains(cursorLocationInControlCoordinate);
+	boolean hasCursorLocationChanged = !currentCursorLocation.equals(previousCursorPosition.location);
+
+	boolean mousePassedBrowserBorder = previousCursorPosition.isInsideBrowser != isCursorInsideBrowser;
+	boolean mouseMovedInsideBrowser = isCursorInsideBrowser && hasCursorLocationChanged;
+	if (mousePassedBrowserBorder) {
+		if (isCursorInsideBrowser) {
+			sendMouseEvent(cursorLocationInControlCoordinate, SWT.MouseEnter);
+		} else {
+			sendMouseEvent(cursorLocationInControlCoordinate, SWT.MouseExit);
+		}
+	} else if (mouseMovedInsideBrowser) {
+		sendMouseEvent(cursorLocationInControlCoordinate, SWT.MouseMove);
+	}
+	previousCursorPosition = new CursorPosition(currentCursorLocation, isCursorInsideBrowser);
+}
+
+private void sendMouseEvent(Point cursorLocationInControlCoordinate, int mouseEvent) {
+	Event newEvent = new Event();
+	newEvent.widget = browser;
+	Point position = cursorLocationInControlCoordinate;
+	newEvent.x = position.x;
+	newEvent.y = position.y;
+	newEvent.type = mouseEvent;
+	browser.notifyListeners(newEvent.type, newEvent);
+}
+
+private boolean hasDisplayFocus() {
+	return browser.getDisplay().getFocusControl() != null;
+}
+
 @Override
 public Object evaluate(String script) throws SWTException {
 	// Feature in WebView2. ExecuteScript works regardless of IsScriptEnabled setting.