Get rid of copypasted code between isWindowBlocked's overrides

The code in QGuiApplication::isWindowBlocked and
QApplication::isWindowBlocked is very similar, a result of copying and
pasting. Due to the copying it is difficult to modify the code and the
implementation is hard to comprehend, too.
There are ultimately only two parts that are different. First is that
QApplication's override may also specify a certain window as
non-blockable if it is a popup window. Second, default modality is
computed in QApplication if a modal window does not have one assigned.
The differing parts have been extracted following the template method
design pattern.

Pick-to: 6.4
Change-Id: I3b9aa206a3c7211fe022730943bf6f76aa5ae6d2
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 4 insertions, 1 deletions

diff --git a/src/gui/kernel/qguiapplication_p.h b/src/gui/kernel/qguiapplication_p.h
index 3b30c14dbe..8309e2bfa7 100644
--- a/src/gui/kernel/qguiapplication_p.h
+++ b/src/gui/kernel/qguiapplication_p.h
@@ -188,7 +188,10 @@ public:
     static void showModalWindow(QWindow *window);
     static void hideModalWindow(QWindow *window);
     static void updateBlockedStatus(QWindow *window);
-    virtual bool isWindowBlocked(QWindow *window, QWindow **blockingWindow = nullptr) const;
+
+    virtual Qt::WindowModality defaultModality() const;
+    virtual bool windowNeverBlocked(QWindow *window) const;
+    bool isWindowBlocked(QWindow *window, QWindow **blockingWindow = nullptr) const;
     virtual bool popupActive() { return false; }
     virtual bool closeAllPopups() { return false; }