Split up close handling in QWidget into a pre and post step

If we are the one initiating the close (from Qt Widget land), we want
to mark the widget as closing as early as possible.

Clarified the role of close_helper by renaming it to handleClose.

Change-Id: Iae250a0ae1583d743c59e99fcb99fdf18d2a1882
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

src/widgets/dialogs/qdialog.cpp

@@ -155,7 +155,7 @@ void QDialogPrivate::hide(int resultCode)
     q->setResult(resultCode);
     q->hide();
 
-    close_helper(QWidgetPrivate::CloseNoEvent);
+    handleClose(QWidgetPrivate::CloseNoEvent);
     resetModalitySetByOpen();
 }
 

src/widgets/kernel/qwidget.cpp

@@ -1005,7 +1005,7 @@ void QWidgetPrivate::init(QWidget *parentWidget, Qt::WindowFlags f)
     data.window_modality = Qt::NonModal;
 
     data.sizehint_forced = 0;
-    data.is_closing = 0;
+    data.is_closing = false;
     data.in_show = 0;
     data.in_set_window_state = 0;
     data.in_destructor = false;
@@ -1466,7 +1466,7 @@ QWidget::~QWidget()
 
     if (isWindow() && isVisible() && internalWinId()) {
         QT_TRY {
-            d->close_helper(QWidgetPrivate::CloseNoEvent);
+            d->handleClose(QWidgetPrivate::CloseNoEvent);
         } QT_CATCH(...) {
             // if we're out of memory, at least hide the window.
             QT_TRY {
@@ -8385,13 +8385,12 @@ void QWidgetPrivate::hideChildren(bool spontaneous)
 
     The function is also called by the QWidget destructor, with \a mode set to CloseNoEvent.
 */
-bool QWidgetPrivate::close_helper(CloseMode mode)
+bool QWidgetPrivate::handleClose(CloseMode mode)
 {
-    if (data.is_closing)
-        return true;
-
     Q_Q(QWidget);
-    data.is_closing = 1;
+
+    // We might not have initiated the close, so update the state now that we know
+    data.is_closing = true;
 
     QPointer<QWidget> that = q;
     QPointer<QWidget> parentWidget = (q->parentWidget() && !QObjectPrivate::get(q->parentWidget())->wasDeleted) ? q->parentWidget() : nullptr;
@@ -8404,7 +8403,7 @@ bool QWidgetPrivate::close_helper(CloseMode mode)
         else
             QCoreApplication::sendEvent(q, &e);
         if (!that.isNull() && !e.isAccepted()) {
-            data.is_closing = 0;
+            data.is_closing = false;
             return false;
         }
     }
@@ -8438,7 +8437,7 @@ bool QWidgetPrivate::close_helper(CloseMode mode)
 
 
     if (!that.isNull()) {
-        data.is_closing = 0;
+        data.is_closing = false;
         if (q->testAttribute(Qt::WA_DeleteOnClose)) {
             q->setAttribute(Qt::WA_DeleteOnClose, false);
             q->deleteLater();
@@ -8472,13 +8471,23 @@ bool QWidgetPrivate::close_helper(CloseMode mode)
 
 bool QWidget::close()
 {
+    return d_func()->close();
+}
+
+bool QWidgetPrivate::close()
+{
+    if (data.is_closing)
+        return true;
+
+    data.is_closing = true;
+
     // Close native widgets via QWindow::close() in order to run QWindow
-    // close code. The QWidget-specific close code in close_helper() will
+    // close code. The QWidget-specific close code in handleClose() will
     // in this case be called from the Close event handler in QWidgetWindow.
     if (QWindow *widgetWindow = windowHandle())
         return widgetWindow->close();
 
-    return d_func()->close_helper(QWidgetPrivate::CloseWithEvent);
+    return handleClose(QWidgetPrivate::CloseWithEvent);
 }
 
 /*!

src/widgets/kernel/qwidget_p.h

@@ -236,13 +236,6 @@ public:
     Q_DECLARE_FLAGS(DrawWidgetFlags, DrawWidgetFlag)
     Q_FLAG(DrawWidgetFlags)
 
-    enum CloseMode {
-        CloseNoEvent,
-        CloseWithEvent,
-        CloseWithSpontaneousEvent
-    };
-    Q_ENUM(CloseMode)
-
     enum Direction {
         DirectionNorth = 0x01,
         DirectionEast = 0x10,
@@ -374,7 +367,14 @@ public:
     const QRegion &getOpaqueChildren() const;
     void setDirtyOpaqueRegion();
 
-    bool close_helper(CloseMode mode);
+    bool close();
+    enum CloseMode {
+        CloseNoEvent,
+        CloseWithEvent,
+        CloseWithSpontaneousEvent
+    };
+    Q_ENUM(CloseMode)
+    bool handleClose(CloseMode mode);
 
     void setWindowIcon_helper();
     void setWindowIcon_sys();

src/widgets/kernel/qwidgetwindow.cpp

@@ -841,9 +841,9 @@ void QWidgetWindow::handleResizeEvent(QResizeEvent *event)
 void QWidgetWindow::handleCloseEvent(QCloseEvent *event)
 {
     Q_D(QWidgetWindow);
-    bool is_closing = m_widget->d_func()->close_helper(d->inClose ? QWidgetPrivate::CloseWithEvent
+    bool accepted = m_widget->d_func()->handleClose(d->inClose ? QWidgetPrivate::CloseWithEvent
                                                                   : QWidgetPrivate::CloseWithSpontaneousEvent);
-    event->setAccepted(is_closing);
+    event->setAccepted(accepted);
 }
 
 #if QT_CONFIG(wheelevent)