From 77a5a81942d7a629a770aeaf4d5131fb9974b29d Mon Sep 17 00:00:00 2001
From: Amartya Parijat <amartya.parijat@yatta.de>
Date: Tue, 22 Oct 2024 16:43:39 +0200
Subject: [PATCH] Add processing of mouse movements in Edge browser

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

contributes to
https://github.com/eclipse-platform/eclipse.platform.swt/issues/1540
---
 .../win32/org/eclipse/swt/browser/Edge.java   | 50 +++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/bundles/org.eclipse.swt/Eclipse SWT Browser/win32/org/eclipse/swt/browser/Edge.java b/bundles/org.eclipse.swt/Eclipse SWT Browser/win32/org/eclipse/swt/browser/Edge.java
index 33a4a30884e..beeff7d7d95 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT Browser/win32/org/eclipse/swt/browser/Edge.java	
+++ b/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;
 
+	private static 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.