API changes for detecting active Window

interface/src/Application.cpp

@@ -868,6 +868,22 @@ bool setupEssentials(int& argc, char** argv, const QCommandLineParser& parser, b
     DependencyManager::set<SceneScriptingInterface>();
 #if !defined(DISABLE_QML)
     DependencyManager::set<OffscreenUi>();
+    {
+        auto window = DependencyManager::get<OffscreenUi>()->getWindow();
+        auto desktopScriptingInterface = DependencyManager::get<DesktopScriptingInterface>();
+        QObject::connect(window, &QQuickWindow::focusObjectChanged, [desktopScriptingInterface](QObject *object) {
+            if (object) {
+                if (object->objectName() == QString("desktop")) {
+                    emit desktopScriptingInterface->uiFocusChanged(false);
+                    return;
+                }
+                // Signal with empty object name happens in addition to regular named ones and is not necessary here
+                if (!object->objectName().isEmpty()) {
+                    emit desktopScriptingInterface->uiFocusChanged(true);
+                }
+            }
+        });
+    }
 #endif
     DependencyManager::set<Midi>();
     DependencyManager::set<PathUtils>();

interface/src/scripting/DesktopScriptingInterface.h

@@ -104,6 +104,15 @@ public:
     int getWidth();
     int getHeight();
 
+signals:
+
+    /*@jsdoc
+     * Triggered when keyboard focus changes to another overlay UI window.
+     * @param {boolean} isActive - <code>true</code> if the keyboard focus is on overlay UI window, <code>false</code> if not.
+     * @function Desktop.uiFocusChanged
+     * @returns {Signal}
+     */
+    void uiFocusChanged(bool isActive);
 
 private:
     static int flagAlwaysOnTop() { return AlwaysOnTop; }

interface/src/ui/LoginDialog.cpp

@@ -33,6 +33,7 @@
 #include "Application.h"
 #include "scripting/HMDScriptingInterface.h"
 #include "Constants.h"
+#include "scripting/DesktopScriptingInterface.h"
 
 HIFI_QML_DEF(LoginDialog)
 
@@ -67,6 +68,7 @@ void LoginDialog::showWithSelection() {
     auto hmd = DependencyManager::get<HMDScriptingInterface>();
 
     if (!qApp->isHMDMode()) {
+        emit DependencyManager::get<DesktopScriptingInterface>()->uiFocusChanged(true);
         if (qApp->getLoginDialogPoppedUp()) {
             LoginDialog::show();
             return;