added SetCriticalWindow() and AllowProcessing(): this allows to freeze all events except those for the specified window

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@34861 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/evtloop.h

@@ -38,12 +38,35 @@ public:
     // process a single message
     virtual void ProcessMessage(WXMSG *msg);
 
+    // set the critical window: this is the window such that all the events
+    // except those to this window (and its children) stop to be processed
+    // (typical examples: assert or crash report dialog)
+    //
+    // calling this function with NULL argument restores the normal event
+    // handling
+    static void SetCriticalWindow(wxWindow *win) { ms_winCritical = win; }
+
+    // return true if there is no critical window or if this window is [a child
+    // of] the critical one
+    static bool AllowProcessing(wxWindow *win)
+    {
+        return !ms_winCritical || IsChildOfCriticalWindow(win);
+    }
+
 protected:
-    // should we exit the loop?
+    // check if the given window is a child of ms_winCritical (which must be
-    bool m_shouldExit;
+    // non NULL)
+    static bool IsChildOfCriticalWindow(wxWindow *win);
+
+
+    // critical window or NULL
+    static wxWindow *ms_winCritical;
 
     // the loop exit code
     int m_exitcode;
+
+    // should we exit the loop?
+    bool m_shouldExit;
 };
 
 #endif // _WX_MSW_EVTLOOP_H_

src/msw/evtloop.cpp

@@ -85,6 +85,7 @@ private:
 // ============================================================================
 
 wxEventLoop *wxEventLoopBase::ms_activeLoop = NULL;
+wxWindow *wxEventLoop::ms_winCritical = NULL;
 
 // ----------------------------------------------------------------------------
 // ctor/dtor
@@ -111,10 +112,24 @@ void wxEventLoop::ProcessMessage(WXMSG *msg)
     }
 }
 
+bool wxEventLoop::IsChildOfCriticalWindow(wxWindow *win)
+{
+    while ( win )
+    {
+        if ( win == ms_winCritical )
+            return true;
+
+        win = win->GetParent();
+    }
+
+    return false;
+}
+
 bool wxEventLoop::PreProcessMessage(WXMSG *msg)
 {
     HWND hwnd = msg->hwnd;
-    wxWindow *wndThis = wxGetWindowFromHWND((WXHWND)hwnd);
+    wxWindow * const wndThis = wxGetWindowFromHWND((WXHWND)hwnd);
+    wxWindow *wnd;
 
     // this may happen if the event occurred in a standard modeless dialog (the
     // only example of which I know of is the find/replace dialog) - then call
@@ -132,6 +147,17 @@ bool wxEventLoop::PreProcessMessage(WXMSG *msg)
         return hwnd && ::IsDialogMessage(hwnd, msg) != 0;
     }
 
+    if ( !AllowProcessing(wndThis) )
+    {
+        // not a child of critical window, so we eat the event but take care to
+        // stop an endless stream of WM_PAINTs which would have resulted if we
+        // didn't validate the invalidated part of the window
+        if ( msg->message == WM_PAINT )
+            ::ValidateRect(hwnd, NULL);
+
+        return true;
+    }
+
 #if wxUSE_TOOLTIPS
     // we must relay WM_MOUSEMOVE events to the tooltip ctrl if we want it to
     // popup the tooltip bubbles
@@ -154,8 +180,6 @@ bool wxEventLoop::PreProcessMessage(WXMSG *msg)
     }
 
     // try translations first: the accelerators override everything
-    wxWindow *wnd;
-
     for ( wnd = wndThis; wnd; wnd = wnd->GetParent() )
     {
         if ( wnd->MSWTranslateMessage((WXMSG *)msg))