choose implicit parent for the dialog boxes better, fixes weird focus jumps when using wxLog

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@16927 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -253,6 +253,7 @@ wxMSW:
 - fixed redraw problems in dynamically resized wxStaticText
 - improvements to wxWindows applications behaviour when the system colours
   are changed
+- choose implicit parent for the dialog boxes better
 - fixed wxProgressDialog for ranges > 65535
 - wxSpinButton and wxSpinCtrl now support full 32 bit range (if the version
   of comctl32.dll installed on the system supports it)

include/wx/msw/dialog.h

@@ -98,6 +98,12 @@ public:
 #endif // wxUSE_CTL3D
 
 protected:
+    // find the window to use as parent for this dialog if none has been
+    // specified explicitly by the user
+    //
+    // may return NULL
+    wxWindow *FindSuitableParent() const;
+
     // show modal dialog and enter modal loop
     void DoShowModal();
 

src/msw/dialog.cpp

@@ -194,6 +194,28 @@ bool wxDialog::IsModalShowing() const
     return wxModalDialogs.Find((wxDialog *)this) != NULL; // const_cast
 }
 
+wxWindow *wxDialog::FindSuitableParent() const
+{
+    // first try to use the currently active window
+    HWND hwndFg = ::GetForegroundWindow();
+    wxWindow *parent = hwndFg ? wxFindWinFromHandle((WXHWND)hwndFg)
+                              : NULL;
+    if ( !parent )
+    {
+        // next try the main app window
+        parent = wxTheApp->GetTopWindow();
+    }
+
+    // finally, check if the parent we found is really suitable
+    if ( !parent || parent == (wxWindow *)this || !parent->IsShown() )
+    {
+        // don't use this one
+        parent = NULL;
+    }
+
+    return parent;
+}
+
 void wxDialog::DoShowModal()
 {
     wxCHECK_RET( !IsModalShowing(), _T("DoShowModal() called twice") );
@@ -285,12 +307,7 @@ bool wxDialog::Show(bool show)
             // modal dialog needs a parent window, so try to find one
             if ( !GetParent() )
             {
-                wxWindow *parent = wxTheApp->GetTopWindow();
-                if ( parent && parent != this && parent->IsShown() )
-                {
-                    // use it
-                    m_parent = parent;
-                }
+                m_parent = FindSuitableParent();
             }
 
             DoShowModal();

src/msw/msgdlg.cpp

@@ -46,8 +46,7 @@ wxMessageDialog::wxMessageDialog(wxWindow *parent,
 
 int wxMessageDialog::ShowModal()
 {
-    wxWindow *winTop = wxTheApp->GetTopWindow();
-    if ( !winTop )
+    if ( !wxTheApp->GetTopWindow() )
     {
         // when the message box is shown from wxApp::OnInit() (i.e. before the
         // message loop is entered), this must be done or the next message box
@@ -58,11 +57,9 @@ int wxMessageDialog::ShowModal()
     }
 
     // use the top level window as parent if none specified
-    HWND hWnd = 0;
-    if ( m_parent )
-        hWnd = GetHwndOf(m_parent);
-    else if ( winTop )
-        hWnd = GetHwndOf(winTop);
+    if ( !m_parent )
+        m_parent = FindSuitableParent();
+    HWND hWnd = m_parent ? GetHwndOf(m_parent) : NULL;
 
     // translate wx style in MSW
     unsigned int msStyle = MB_OK;