QMessageBox: Do last minute setup in setVisible instead of showEvent

The native message dialogs are shown in QMessageBox::setVisible,
instead of plumbed via e.g. QWidgetPrivate::show_sys (which is not
virtual). And we try to show the native dialog before we call the
base class QDialog::setVisible(), where we end up sending the show
event.

As the native dialogs might rely on the last minute setup of adding
an OK button or detecting the escape button, we need to do it in
setVisible instead.

We can not switch the order of showing the native dialogs after
calling the base class setVisible (and getting showEvent), as
we need to know whether the native dialog could be shown or not
to decide whether to show the fallback widget dialog.

The part from showEvent that added the detailsButton has been
removed, as we're already doing that in setDetailsText().

Pick-to: 6.5 6.6
Change-Id: I23f1d87d542d9dadfd71924f8119c22720f4b276
Reviewed-by: Oliver Eftevaag <oliver.eftevaag@qt.io>

1 files changed, 5 insertions, 6 deletions

diff --git a/src/widgets/dialogs/qmessagebox.cpp b/src/widgets/dialogs/qmessagebox.cpp
index ca7af90c15..ef1d8b04aa 100644
--- a/src/widgets/dialogs/qmessagebox.cpp
+++ b/src/widgets/dialogs/qmessagebox.cpp
@@ -1661,6 +1661,11 @@ void QMessageBoxPrivate::setVisible(bool visible)
 {
     Q_Q(QMessageBox);
 
+    // Last minute setup
+    if (autoAddOkButton)
+        q->addButton(QMessageBox::Ok);
+    detectEscapeButton();
+
     if (canBeNativeDialog())
         setNativeDialogVisible(visible);
 
@@ -1705,13 +1710,7 @@ QMessageBox::ButtonRole QMessageBox::buttonRole(QAbstractButton *button) const
 void QMessageBox::showEvent(QShowEvent *e)
 {
     Q_D(QMessageBox);
-    if (d->autoAddOkButton) {
-        addButton(Ok);
-    }
-    if (d->detailsButton)
-        addButton(d->detailsButton, QMessageBox::ActionRole);
     d->clickedButton = nullptr;
-    d->detectEscapeButton();
     d->updateSize();
 
 #if QT_CONFIG(accessibility)