Make ApplicationWindow::activeFocusControl work with plain Window

[ChangeLog][Controls][ApplicationWindow] The attached activeFocusControl
property has been made functional with a plain QML Window to make the
functionality available when using QQuickWindow/View/Widget instead of
ApplicationWindow.

Task-number: QTBUG-61336
Change-Id: I46b91bca436d58c349c4f9ba8816245ab4ca33a4
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

1 files changed, 46 insertions, 30 deletions

diff --git a/src/quicktemplates2/qquickapplicationwindow.cpp b/src/quicktemplates2/qquickapplicationwindow.cpp
index 6dda6f5d..9311958e 100644
--- a/src/quicktemplates2/qquickapplicationwindow.cpp
+++ b/src/quicktemplates2/qquickapplicationwindow.cpp
@@ -306,28 +306,21 @@ void QQuickApplicationWindowPrivate::resolvePalette()
     setPalette_helper(resolvedPalette);
 }
 
-void QQuickApplicationWindowPrivate::_q_updateActiveFocus()
+static QQuickItem *findActiveFocusControl(QQuickWindow *window)
 {
-    Q_Q(QQuickApplicationWindow);
-    QQuickItem *item = q->activeFocusItem();
+    QQuickItem *item = window->activeFocusItem();
     while (item) {
-        QQuickControl *control = qobject_cast<QQuickControl *>(item);
-        if (control) {
-            setActiveFocusControl(control);
-            break;
-        }
-        QQuickTextField *textField = qobject_cast<QQuickTextField *>(item);
-        if (textField) {
-            setActiveFocusControl(textField);
-            break;
-        }
-        QQuickTextArea *textArea = qobject_cast<QQuickTextArea *>(item);
-        if (textArea) {
-            setActiveFocusControl(textArea);
-            break;
-        }
+        if (qobject_cast<QQuickControl *>(item) || qobject_cast<QQuickTextField *>(item) || qobject_cast<QQuickTextArea *>(item))
+            return item;
         item = item->parentItem();
     }
+    return item;
+}
+
+void QQuickApplicationWindowPrivate::_q_updateActiveFocus()
+{
+    Q_Q(QQuickApplicationWindow);
+    setActiveFocusControl(findActiveFocusControl(q));
 }
 
 void QQuickApplicationWindowPrivate::setActiveFocusControl(QQuickItem *control)
@@ -800,11 +793,17 @@ class QQuickApplicationWindowAttachedPrivate : public QObjectPrivate
     Q_DECLARE_PUBLIC(QQuickApplicationWindowAttached)
 
 public:
-    QQuickApplicationWindowAttachedPrivate() : window(nullptr) { }
+    QQuickApplicationWindowAttachedPrivate()
+        : window(nullptr),
+          activeFocusControl(nullptr)
+    {
+    }
 
     void windowChange(QQuickWindow *wnd);
+    void activeFocusChange();
 
     QQuickWindow *window;
+    QQuickItem *activeFocusControl;
 };
 
 void QQuickApplicationWindowAttachedPrivate::windowChange(QQuickWindow *wnd)
@@ -818,22 +817,28 @@ void QQuickApplicationWindowAttachedPrivate::windowChange(QQuickWindow *wnd)
         oldWindow = nullptr; // being deleted (QTBUG-52731)
 
     if (oldWindow) {
-        QObject::disconnect(oldWindow, &QQuickApplicationWindow::activeFocusControlChanged,
-                            q, &QQuickApplicationWindowAttached::activeFocusControlChanged);
+        disconnect(oldWindow, &QQuickApplicationWindow::activeFocusControlChanged,
+                   this, &QQuickApplicationWindowAttachedPrivate::activeFocusChange);
         QObject::disconnect(oldWindow, &QQuickApplicationWindow::headerChanged,
                             q, &QQuickApplicationWindowAttached::headerChanged);
         QObject::disconnect(oldWindow, &QQuickApplicationWindow::footerChanged,
                             q, &QQuickApplicationWindowAttached::footerChanged);
+    } else if (window) {
+        disconnect(window, &QQuickWindow::activeFocusItemChanged,
+                   this, &QQuickApplicationWindowAttachedPrivate::activeFocusChange);
     }
 
     QQuickApplicationWindow *newWindow = qobject_cast<QQuickApplicationWindow *>(wnd);
     if (newWindow) {
-        QObject::connect(newWindow, &QQuickApplicationWindow::activeFocusControlChanged,
-                         q, &QQuickApplicationWindowAttached::activeFocusControlChanged);
+        connect(newWindow, &QQuickApplicationWindow::activeFocusControlChanged,
+                this, &QQuickApplicationWindowAttachedPrivate::activeFocusChange);
         QObject::connect(newWindow, &QQuickApplicationWindow::headerChanged,
                          q, &QQuickApplicationWindowAttached::headerChanged);
         QObject::connect(newWindow, &QQuickApplicationWindow::footerChanged,
                          q, &QQuickApplicationWindowAttached::footerChanged);
+    } else if (wnd) {
+        connect(wnd, &QQuickWindow::activeFocusItemChanged,
+                this, &QQuickApplicationWindowAttachedPrivate::activeFocusChange);
     }
 
     window = wnd;
@@ -841,14 +846,28 @@ void QQuickApplicationWindowAttachedPrivate::windowChange(QQuickWindow *wnd)
     emit q->contentItemChanged();
     emit q->overlayChanged();
 
-    if ((oldWindow && oldWindow->activeFocusControl()) || (newWindow && newWindow->activeFocusControl()))
-        emit q->activeFocusControlChanged();
+    activeFocusChange();
     if ((oldWindow && oldWindow->header()) || (newWindow && newWindow->header()))
         emit q->headerChanged();
     if ((oldWindow && oldWindow->footer()) || (newWindow && newWindow->footer()))
         emit q->footerChanged();
 }
 
+void QQuickApplicationWindowAttachedPrivate::activeFocusChange()
+{
+    Q_Q(QQuickApplicationWindowAttached);
+    QQuickItem *control = nullptr;
+    if (QQuickApplicationWindow *appWindow = qobject_cast<QQuickApplicationWindow *>(window))
+        control = appWindow->activeFocusControl();
+    else if (window)
+        control = findActiveFocusControl(window);
+    if (activeFocusControl == control)
+        return;
+
+    activeFocusControl = control;
+    emit q->activeFocusControlChanged();
+}
+
 QQuickApplicationWindowAttached::QQuickApplicationWindowAttached(QObject *parent)
     : QObject(*(new QQuickApplicationWindowAttachedPrivate), parent)
 {
@@ -910,17 +929,14 @@ QQuickItem *QQuickApplicationWindowAttached::contentItem() const
 
     This attached property holds the control that currently has active focus, or \c null
     if there is no control with active focus. The property can be attached to any item.
-    The value is \c null if the item is not in an ApplicationWindow, or the window has
-    no active focus.
+    The value is \c null if the item is not in a window, or the window has no active focus.
 
     \sa Window::activeFocusItem, {Attached ApplicationWindow Properties}
 */
 QQuickItem *QQuickApplicationWindowAttached::activeFocusControl() const
 {
     Q_D(const QQuickApplicationWindowAttached);
-    if (QQuickApplicationWindow *window = qobject_cast<QQuickApplicationWindow *>(d->window))
-        return window->activeFocusControl();
-    return nullptr;
+    return d->activeFocusControl;
 }
 
 /*!