Edge: Send out LocationEvents for #fragment navigation

Resolves #1581.

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

@@ -949,13 +949,52 @@ int handleSourceChanged(long pView, long pArgs) {
 	// to an empty string. Navigations with NavigateToString set the Source
 	// to about:blank. Initial Source is about:blank. If Source value
 	// is the same between navigations, SourceChanged isn't fired.
-	// Calling LocationListener#changed() was moved to
-	// handleNavigationCompleted() to have consistent/symmetric
+	// Since we do not use NavigateToString (but always use a dummy file)
+	// we always see a proper (file:// URI).
+	// The main location events are fired from
+	// handleNavigationStarting() / handleNavigationCompleted()
+	// to get consistent/symmetric
 	// LocationListener.changing() -> LocationListener.changed() behavior.
-	// TODO: #fragment navigation inside a page does not result in
-	// NavigationStarted / NavigationCompleted events from WebView2.
-	// so for now we cannot send consistent changing() + changed() events
-	// for those scenarios.
+	// For #fragment navigation within a page, no NavigationStarted/NavigationCompleted
+	// events are send from WebView2.
+	// Instead, SourceChanged is fired.
+	// We therefore also handle this event specifically for in-same-document scenario.
+	// Since SourceChanged cannot be blocked, we only send out
+	// LocationListener#changed() events, no changing() events.
+	int[] isNewDocument = new int[1];
+	ICoreWebView2SourceChangedEventArgs args = new ICoreWebView2SourceChangedEventArgs(pArgs);
+	args.get_IsNewDocument(isNewDocument);
+	if (isNewDocument[0] == 0) {
+		// #fragment navigation inside the same document
+		long[] ppsz = new long[1];
+		int hr = webViewProvider.getWebView(true).get_Source(ppsz);
+		if (hr != COM.S_OK) return hr;
+		String url = wstrToString(ppsz[0], true);
+		int fragmentIndex = url.indexOf('#');
+		String urlWithoutFragment = fragmentIndex == -1 ? url : url.substring(0,fragmentIndex);
+		String location;
+		if (isLocationForCustomText(urlWithoutFragment)) {
+			if (fragmentIndex != -1) {
+				location = ABOUT_BLANK.toString() + url.substring(fragmentIndex);
+			} else {
+				location = ABOUT_BLANK.toString();
+			}
+		} else {
+			location = url;
+		}
+		browser.getDisplay().asyncExec(() -> {
+			if (browser.isDisposed()) return;
+			LocationEvent event = new LocationEvent(browser);
+			event.display = browser.getDisplay();
+			event.widget = browser;
+			event.location = location;
+			event.top = true;
+			for (LocationListener listener : locationListeners) {
+				listener.changed(event);
+				if (browser.isDisposed()) return;
+			}
+		});
+	}
 	return COM.S_OK;
 }