Assert raisied when closing multi-level modal dialog recursively

[Assen Mladenov]

Hi,

I need to close (stacked) modal dialogs programmatically and I try doing that in a recursive fashion, starting from the one on top.

Here is the piece of code that is executed on the main event loop (the app's):

static void closeAllDialogsRec(wxWindow* parent, wxApp *app) {

    auto pclNode = parent->GetChildren().GetFirst();

    while (pclNode) {

        auto dlg = wxDynamicCast(pclNode->GetData(), wxDialog);

        if (dlg && dlg->IsModal()) {

            closeAllDialogsRec(dlg, app);

            app->CallAfter([dlg, app]() mutable {

                wxCommandEvent evt(wxEVT_CLOSE_WINDOW);

                wxQueueEvent(dlg, evt.Clone());

                });

            break;

        }

        pclNode = pclNode->GetNext();

    }

}

The issue is that the top one's event loop is active and it can be closed, but the for the others below, their event loops are still inactive and it fails for them. So on theory, we have to wait until the next dialog becomes "active" and then close it only then. How though ?

There is extra info in  https://forums.wxwidgets.org/viewtopic.php?t=50669

Best regards,

Assen

[Vadim Zeitlin]

On Fri, 17 Apr 2026 00:47:54 -0700 (PDT) Assen Mladenov wrote:

AM> I need to close (stacked) modal dialogs programmatically and I try doing
AM> that in a recursive fashion, starting from the one on top.

Why can't you just call EndModal() if you have the pointers to all dialogs
already?

AM> Here is the piece of code that is executed on the main event loop (the
AM> app's):
AM>
AM> static void closeAllDialogsRec(wxWindow* parent, wxApp *app) {
AM> auto pclNode = parent->GetChildren().GetFirst();
AM> while (pclNode) {
AM> auto dlg = wxDynamicCast(pclNode->GetData(), wxDialog);
AM> if (dlg && dlg->IsModal()) {
AM> closeAllDialogsRec(dlg, app);
AM> app->CallAfter([dlg, app]() mutable {
AM> wxCommandEvent evt(wxEVT_CLOSE_WINDOW);
AM> wxQueueEvent(dlg, evt.Clone());
AM> });
AM> break;
AM> }
AM> pclNode = pclNode->GetNext();
AM> }
AM> }
AM>
AM> The issue is that the top one's event loop is active and it can be closed,
AM> but the for the others below, their event loops are still inactive and it
AM> fails for them. So on theory, we have to wait until the next dialog becomes
AM> "active" and then close it only then. How though ?

You probably need to close one dialog at a time, i.e. return to the main
event loop after closing the first dialog and then redoing it again as long
as there are more dialogs, but this risks being messy.

Regards,
VZ

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