X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/ceb71775b49c111a201765e736f543da72d902e4..f9133b32002a600cb48dd05fbcce1ab3ed684dba:/include/wx/vscroll.h

diff --git a/include/wx/vscroll.h b/include/wx/vscroll.h
index a48faef6e3..1cdc9d1e48 100644
--- a/include/wx/vscroll.h
+++ b/include/wx/vscroll.h
@@ -12,6 +12,10 @@
 #ifndef _WX_VSCROLL_H_
 #define _WX_VSCROLL_H_
 
+#if defined(__GNUG__) && !defined(__APPLE__)
+#pragma interface "vscroll.h"
+#endif
+
 #include "wx/panel.h"           // base class
 
 // ----------------------------------------------------------------------------
@@ -144,6 +148,16 @@ protected:
     // usual
     virtual void OnGetLinesHint(size_t lineMin, size_t lineMax) const { }
 
+    // when the number of lines changes, we try to estimate the total height
+    // of all lines which is a rather expensive operation in terms of lines
+    // access, so if the user code may estimate the average height
+    // better/faster than we do, it should override this function to implement
+    // its own logic
+    //
+    // this function should return the best guess for the total height it may
+    // make
+    virtual wxCoord EstimateTotalHeight() const;
+
 
     // the event handlers
     void OnSize(wxSizeEvent& event);