Fix pause when inactive for new wxWidgets

Handle the Iconize event to pause when "pause when inactive" is enabled,
to work around a change in recent versions of wxWidgets that ignore this
unfocus event.

Fix #1494.

Signed-off-by: Rafael Kitover <rkitover@gmail.com>

src/wx/wxvbam.cpp

@@ -985,6 +985,7 @@ EVT_MOVE(MainFrame::OnMove)
 EVT_MOVE_START(MainFrame::OnMoveStart)
 EVT_MOVE_END(MainFrame::OnMoveEnd)
 EVT_SIZE(MainFrame::OnSize)
+EVT_ICONIZE(MainFrame::OnIconize)
 
 #if defined(__WXMSW__)
 
@@ -1088,6 +1089,17 @@ void MainFrame::OnSize(wxSizeEvent& event)
     OPTION(kGeomFullScreen) = IsFullScreen();
 }
 
+void MainFrame::OnIconize(wxIconizeEvent& event)
+{
+    if (!init_complete_) {
+        return;
+    }
+
+    if (OPTION(kPrefPauseWhenInactive)) {
+        panel->Pause();
+    }
+}
+
 wxString MainFrame::GetGamePath(wxString path)
 {
     wxString game_path = path;

src/wx/wxvbam.h

@@ -360,6 +360,8 @@ private:
     void OnMoveStart(wxMoveEvent& event);
     void OnMoveEnd(wxMoveEvent& event);
     void OnSize(wxSizeEvent& event);
+    void OnIconize(wxIconizeEvent& event);
+
     // Load a named wxDialog from the XRC file
     wxDialog* LoadXRCDialog(const char* name);