Reset the pager in case the current page does not exist anymore. Closes #64

Author: nohal

include/pager.h

@@ -84,6 +84,9 @@ class Pager : public wxEvtHandler {
     /// @return page number
     const int GetCurrentPage() { return m_current_page; }
 
+    /// Reset currently displayed page number
+    void ResetCurrentPage() { SetCurrentPage(*m_pages.begin()); }
+
     /// Adds a page
     /// @param pg Page number
     void AddPage(const int pg) { m_pages.insert(pg); }

src/dashboardsk.cpp

@@ -60,15 +60,20 @@ void DashboardSK::Draw(dskDC* dc, PlugIn_ViewPort* vp, int canvasIndex)
     }
     m_displayed_pages[canvasIndex]->Draw(dc, vp, canvasIndex);
     Dashboard::ClearOffsets();
+    bool drawn = false;
     for (auto dashboard : m_dashboards) {
         if (!m_frozen
             && m_displayed_pages[canvasIndex]->GetCurrentPage()
                 == dashboard->GetPageNr()) {
             dashboard->Draw(dc, vp, canvasIndex);
+            drawn = true;
         } else {
             dashboard->ProcessData();
         }
     }
+    if (!drawn) {
+        m_displayed_pages[canvasIndex]->ResetCurrentPage();
+    }
 }
 
 void DashboardSK::ReadConfig(wxJSONValue& config)