+ // all tests below have to deal with various bugs/misfeatures of
+ // IsDialogMessage(): we have to prevent it from being called from our
+ // MSWProcessMessage() in some situations
+
+ // don't let IsDialogMessage() get VK_ESCAPE as it _always_ eats the
+ // message even when there is no cancel button and when the message is
+ // needed by the control itself: in particular, it prevents the tree in
+ // place edit control from being closed with Escape in a dialog
+ if ( msg->message == WM_KEYDOWN && msg->wParam == VK_ESCAPE )
+ {
+ return false;
+ }
+
+ // ::IsDialogMessage() is broken and may sometimes hang the application by
+ // going into an infinite loop when it tries to find the control to give
+ // focus to when Alt-<key> is pressed, so we try to detect [some of] the
+ // situations when this may happen and not call it then
+ if ( msg->message != WM_SYSCHAR )
+ return true;
+
+ // assume we can call it by default
+ bool canSafelyCallIsDlgMsg = true;
+
+ HWND hwndFocus = ::GetFocus();
+
+ // if the currently focused window itself has WS_EX_CONTROLPARENT style,
+ // ::IsDialogMessage() will also enter an infinite loop, because it will
+ // recursively check the child windows but not the window itself and so if
+ // none of the children accepts focus it loops forever (as it only stops
+ // when it gets back to the window it started from)
+ //
+ // while it is very unusual that a window with WS_EX_CONTROLPARENT
+ // style has the focus, it can happen. One such possibility is if
+ // all windows are either toplevel, wxDialog, wxPanel or static
+ // controls and no window can actually accept keyboard input.
+#if !defined(__WXWINCE__)
+ if ( ::GetWindowLong(hwndFocus, GWL_EXSTYLE) & WS_EX_CONTROLPARENT )
+ {
+ // pessimistic by default
+ canSafelyCallIsDlgMsg = false;
+ for ( wxWindowList::compatibility_iterator node = GetChildren().GetFirst();
+ node;
+ node = node->GetNext() )
+ {
+ wxWindow * const win = node->GetData();
+ if ( win->CanAcceptFocus() &&
+ !(::GetWindowLong(GetHwndOf(win), GWL_EXSTYLE) &
+ WS_EX_CONTROLPARENT) )
+ {
+ // it shouldn't hang...
+ canSafelyCallIsDlgMsg = true;
+
+ break;
+ }
+ }
+ }
+#endif // !__WXWINCE__
+
+ if ( canSafelyCallIsDlgMsg )
+ {
+ // ::IsDialogMessage() can enter in an infinite loop when the
+ // currently focused window is disabled or hidden and its
+ // parent has WS_EX_CONTROLPARENT style, so don't call it in
+ // this case
+ while ( hwndFocus )
+ {
+ if ( !::IsWindowEnabled(hwndFocus) ||
+ !::IsWindowVisible(hwndFocus) )
+ {
+ // it would enter an infinite loop if we do this!
+ canSafelyCallIsDlgMsg = false;
+
+ break;
+ }
+
+ if ( !(::GetWindowLong(hwndFocus, GWL_STYLE) & WS_CHILD) )
+ {
+ // it's a top level window, don't go further -- e.g. even
+ // if the parent of a dialog is disabled, this doesn't
+ // break navigation inside the dialog
+ break;
+ }
+
+ hwndFocus = ::GetParent(hwndFocus);
+ }
+ }
+
+ return canSafelyCallIsDlgMsg;
projects / wxWidgets.git / blobdiff