Edge: Ignore multiple gotFocus events if we were the one who caused them

Follow-up on #1849 / #1848.

Author: sratz

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

@@ -87,7 +87,7 @@ public WebViewEnvironment(ICoreWebView2Environment environment) {
 	HashMap<Long, LocationEvent> navigations = new HashMap<>();
 	/** Maps BrowserFunction index to the script ID from AddScriptToExecuteOnDocumentCreated. */
 	private final Map<Integer, String> functionScriptIds = new HashMap<>();
-	private boolean ignoreGotFocus;
+	private int ignoreGotFocus;
 	private boolean ignoreFocusIn;
 	private String lastCustomText;
 
@@ -898,7 +898,15 @@ void browserFocusIn(Event event) {
 	// We need to ignore that next event, as in the meantime the user might
 	// have moved focus to some other control and reacting on that event
 	// would bring us back to the Browser.
-	ignoreGotFocus = true;
+	// https://github.com/eclipse-platform/eclipse.platform.swt/pull/1849#issuecomment-4753007036
+	// There can be multiple focus-in events within the same event loop iteration,
+	// e.g.,
+	// other.setFocus();
+	// browser.setFocus();
+	// other.setFocus();
+	// browser.setFocus();
+	// We need to apply the ignore handling to all of them, so a counter is used.
+	ignoreGotFocus++;
 
 	controller.MoveFocus(COM.COREWEBVIEW2_MOVE_FOCUS_REASON_PROGRAMMATIC);
 }
@@ -1506,8 +1514,8 @@ private void asyncExec(Runnable r) {
 }
 
 int handleGotFocus(long pView, long pArg) {
-	if (ignoreGotFocus) {
-		ignoreGotFocus = false;
+	if (ignoreGotFocus > 0) {
+		ignoreGotFocus--;
 		return COM.S_OK;
 	}
 	// https://github.com/eclipse-platform/eclipse.platform.swt/issues/1139

tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_browser_Browser.java

@@ -3095,6 +3095,36 @@ public void test_TimerRegression_Issue2806() {
 
 }
 
+/**
+ * https://github.com/eclipse-platform/eclipse.platform.swt/issues/1848
+ * https://github.com/eclipse-platform/eclipse.platform.swt/pull/1849
+ *
+ * Send two focus events to the browser within the same event loop iteration.
+ * Edge uses
+ * controller.MoveFocus(COM.COREWEBVIEW2_MOVE_FOCUS_REASON_PROGRAMMATIC); //
+ * which triggers then asynchronoulsy. BOTH WebView2 events must then be handled
+ * (ignored) internally and not cause another call to browserFocusIn(). So we
+ * expect a total of 2 SWT events (not 3).
+ */
+@Test
+public void test_EdgeAsyncFocusHandling() {
+	assumeTrue(isEdge, "This test is intended for Edge only");
+
+	shell.open();
+	Text otherControl = new Text(shell, SWT.NONE);
+	processUiEvents();
+	List<Event> focusInEvents = new ArrayList<>();
+	browser.addListener(SWT.FocusIn, focusInEvents::add);
+
+	otherControl.setFocus();
+	browser.setFocus();
+	otherControl.setFocus();
+	browser.setFocus();
+	processUiEvents();
+
+	assertEquals(2, focusInEvents.size());
+}
+
 /* custom */
 /**
  * Wait for passTest to return true. Timeout otherwise.