From 2596e9fb2c6f7c999cdf1ffaa62b043e1bb4ce1e Mon Sep 17 00:00:00 2001
From: =?utf8?q?V=C3=A1clav=20Slav=C3=ADk?= <vslavik@fastmail.fm>
Date: Wed, 29 Sep 2004 21:07:48 +0000
Subject: [PATCH] fixed flicker during MDI children creation: the frame is now
 created hidden and shown in idle time to maintain backward compatibility

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@29549 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---
 include/wx/msw/mdi.h |  3 +++
 src/msw/mdi.cpp      | 20 ++++++++++++++++++--
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/include/wx/msw/mdi.h b/include/wx/msw/mdi.h
index a6fc56445b..04705e7aa9 100644
--- a/include/wx/msw/mdi.h
+++ b/include/wx/msw/mdi.h
@@ -174,6 +174,8 @@ public:
     bool ResetWindowStyle(void *vrect);
 
     void OnIdle(wxIdleEvent& event);
+    
+    virtual bool Show(bool show = true);
 
 protected:
     virtual void DoGetPosition(int *x, int *y) const;
@@ -187,6 +189,7 @@ protected:
     void Init();
 
 private:
+    bool m_needsInitialShow; // Show must be called in idle time after Creation
     bool m_needsResize; // flag which tells us to artificially resize the frame
 
     DECLARE_EVENT_TABLE()
diff --git a/src/msw/mdi.cpp b/src/msw/mdi.cpp
index 4bbb0a2b56..3d2ac43e30 100644
--- a/src/msw/mdi.cpp
+++ b/src/msw/mdi.cpp
@@ -670,6 +670,7 @@ bool wxMDIParentFrame::MSWTranslateMessage(WXMSG* msg)
 void wxMDIChildFrame::Init()
 {
     m_needsResize = true;
+    m_needsInitialShow = true;
 }
 
 bool wxMDIChildFrame::Create(wxMDIParentFrame *parent,
@@ -681,7 +682,6 @@ bool wxMDIChildFrame::Create(wxMDIParentFrame *parent,
                              const wxString& name)
 {
   SetName(name);
-  wxWindowBase::Show(true); // MDI child frame starts off shown
 
   if ( id != wxID_ANY )
     m_windowId = id;
@@ -725,7 +725,7 @@ bool wxMDIChildFrame::Create(wxMDIParentFrame *parent,
   else
       mcs.cy = CW_USEDEFAULT;
 
-  DWORD msflags = WS_OVERLAPPED | WS_CLIPCHILDREN | WS_VISIBLE ;
+  DWORD msflags = WS_OVERLAPPED | WS_CLIPCHILDREN;
   if (style & wxMINIMIZE_BOX)
     msflags |= WS_MINIMIZEBOX;
   if (style & wxMAXIMIZE_BOX)
@@ -773,6 +773,12 @@ wxMDIChildFrame::~wxMDIChildFrame()
     MSWDestroyWindow();
 }
 
+bool wxMDIChildFrame::Show(bool show)
+{
+    m_needsInitialShow = false;
+    return wxFrame::Show(show);
+}
+
 // Set the client size (i.e. leave the calculation of borders etc.
 // to wxWidgets)
 void wxMDIChildFrame::DoSetClientSize(int width, int height)
@@ -1303,6 +1309,16 @@ void wxMDIClientWindow::DoSetSize(int x, int y, int width, int height, int sizeF
 
 void wxMDIChildFrame::OnIdle(wxIdleEvent& event)
 {
+    // wxMSW prior to 2.5.3 created MDI child frames as visible, which resulted
+    // in flicker e.g. when the frame contained controls with non-trivial
+    // layout. Since 2.5.3, the frame is created hidden as all other top level
+    // windows. In order to maintain backward compatibility, the frame is shown
+    // in OnIdle, unless Show(false) was called by the programmer before.
+    if ( m_needsInitialShow )
+    {
+        Show(true);
+    }
+    
     // MDI child frames get their WM_SIZE when they're constructed but at this
     // moment they don't have any children yet so all child windows will be
     // positioned incorrectly when they are added later - to fix this, we
-- 
2.45.2