From 7ad8a38ae578322af3376874f8723b0b8fe75407 Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Fri, 10 Sep 2010 11:44:46 +0000
Subject: [PATCH] Create temporary wxEventLoop in wxGenericProgressDialog if
 needed.

wxGenericProgressDialog needs to have an active event loop in order to repaint
itself and process clicks on its buttons but it's more helpful to create a
temporary event loop if there is no currently active one instead of just
asserting. In particular, this allows to use wxProgressDialog from overridden
wxApp::OnInit().

Add temporary event loop creation and remove the now unnecessary asserts
verifying that there is an active event loop as there always will be one.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65499 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---
 include/wx/generic/progdlgg.h |  6 ++++++
 src/generic/progdlgg.cpp      | 30 ++++++++++++++++++------------
 2 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/include/wx/generic/progdlgg.h b/include/wx/generic/progdlgg.h
index c8585ed15c..ba03308d49 100644
--- a/include/wx/generic/progdlgg.h
+++ b/include/wx/generic/progdlgg.h
@@ -15,6 +15,7 @@
 #include "wx/dialog.h"
 
 class WXDLLIMPEXP_FWD_CORE wxButton;
+class WXDLLIMPEXP_FWD_CORE wxEventLoop;
 class WXDLLIMPEXP_FWD_CORE wxGauge;
 class WXDLLIMPEXP_FWD_CORE wxStaticText;
 class WXDLLIMPEXP_FWD_CORE wxWindowDisabler;
@@ -197,6 +198,11 @@ private:
     // for wxPD_APP_MODAL case
     wxWindowDisabler *m_winDisabler;
 
+    // Temporary event loop created by the dialog itself if there is no
+    // currently active loop when it is created.
+    wxEventLoop *m_tempEventLoop;
+
+
     DECLARE_EVENT_TABLE()
     wxDECLARE_NO_COPY_CLASS(wxGenericProgressDialog);
 };
diff --git a/src/generic/progdlgg.cpp b/src/generic/progdlgg.cpp
index fbfb8a8e32..a3f0df2b4b 100644
--- a/src/generic/progdlgg.cpp
+++ b/src/generic/progdlgg.cpp
@@ -127,6 +127,7 @@ void wxGenericProgressDialog::Init(wxWindow *parent, int maximum, int style)
     m_hasSkipButton = false;
 
     m_winDisabler = NULL;
+    m_tempEventLoop = NULL;
 }
 
 wxGenericProgressDialog::wxGenericProgressDialog(wxWindow *parent,
@@ -160,6 +161,17 @@ void wxGenericProgressDialog::Create( const wxString& title,
     SetParent( GetParentForModalDialog(parent, style) );
     SetTitle( title );
 
+    // We need a running event loop in order to update the dialog and be able
+    // to process clicks on its buttons, so ensure that there is one running
+    // even if this means we have to start it ourselves (this happens most
+    // commonly during the program initialization, e.g. for the progress
+    // dialogs shown from overridden wxApp::OnInit()).
+    if ( !wxEventLoopBase::GetActive() )
+    {
+        m_tempEventLoop = new wxEventLoop;
+        wxEventLoop::SetActive(m_tempEventLoop);
+    }
+
     m_hasAbortButton = (style & wxPD_CAN_ABORT) != 0;
     m_hasSkipButton = (style & wxPD_CAN_SKIP) != 0;
 
@@ -466,9 +478,6 @@ wxGenericProgressDialog::Update(int value, const wxString& newmsg, bool *skip)
                 m_msg->SetLabel(_("Done."));
             }
 
-            wxCHECK_MSG(wxEventLoopBase::GetActive(), false,
-                        "wxGenericProgressDialog::Update needs a running event loop");
-
             // allow the window to repaint:
             // NOTE: since we yield only for UI events with this call, there
             //       should be no side-effects
@@ -528,9 +537,6 @@ bool wxGenericProgressDialog::Pulse(const wxString& newmsg, bool *skip)
 
 bool wxGenericProgressDialog::DoBeforeUpdate(bool *skip)
 {
-    wxCHECK_MSG(wxEventLoopBase::GetActive(), false,
-                "wxGenericProgressDialog::DoBeforeUpdate needs a running event loop");
-
     // we have to yield because not only we want to update the display but
     // also to process the clicks on the cancel and skip buttons
     // NOTE: using YieldFor() this call shouldn't give re-entrancy problems
@@ -551,9 +557,6 @@ bool wxGenericProgressDialog::DoBeforeUpdate(bool *skip)
 
 void wxGenericProgressDialog::DoAfterUpdate()
 {
-    wxCHECK_RET(wxEventLoopBase::GetActive(),
-                "wxGenericProgressDialog::DoAfterUpdate needs a running event loop");
-
     // allow the window to repaint:
     // NOTE: since we yield only for UI events with this call, there
     //       should be no side-effects
@@ -715,6 +718,12 @@ wxGenericProgressDialog::~wxGenericProgressDialog()
 {
     // normally this should have been already done, but just in case
     ReenableOtherWindows();
+
+    if ( m_tempEventLoop )
+    {
+        wxEventLoopBase::SetActive(NULL);
+        delete m_tempEventLoop;
+    }
 }
 
 void wxGenericProgressDialog::DisableOtherWindows()
@@ -798,9 +807,6 @@ void wxGenericProgressDialog::EnableClose()
 
 void wxGenericProgressDialog::UpdateMessage(const wxString &newmsg)
 {
-    wxCHECK_RET(wxEventLoopBase::GetActive(),
-                "wxGenericProgressDialog::UpdateMessage needs a running event loop");
-
     if ( !newmsg.empty() && newmsg != m_msg->GetLabel() )
     {
         m_msg->SetLabel(newmsg);
-- 
2.45.2