Added template functions as a casting-macro replacement.

(bzr r13061)

2 files changed, 33 insertions, 3 deletions

diff --git a/src/ui/tools/tool-base.h b/src/ui/tools/tool-base.h
index a4a27a06c..79bdfe89d 100644
--- a/src/ui/tools/tool-base.h
+++ b/src/ui/tools/tool-base.h
@@ -215,9 +215,31 @@ void sp_toggle_dropper(SPDesktop *dt);
 
 bool sp_event_context_knot_mouseover(ToolBase *ec);
 
+} // namespace Tools
+
+//#include <type_traits>
+
+namespace Tool {
+
+template<class Derived, typename T>
+bool is_a(const T* t) {
+    //static_assert(std::is_base_of<Tools::ToolBase, Derived>(), "Destination type not derived from ToolBase.");
+    //static_assert(std::is_convertible<const Tools::ToolBase*, const T*>(), "Cannot cast passed pointer to ToolBase*.");
+
+    return dynamic_cast<const Derived*>(static_cast<const Tools::ToolBase*>(t)) != NULL;
 }
+
+template<class Derived, typename T>
+Derived* to(T* t) {
+    //static_assert(std::is_base_of<Tools::ToolBase, Derived>(), "Destination type not derived from ToolBase.");
+    //static_assert(std::is_convertible<Tools::ToolBase*, T*>(), "Cannot cast passed pointer to ToolBase*.");
+
+    return dynamic_cast<Derived*>(static_cast<Tools::ToolBase*>(t));
 }
-}
+
+} // namespace Tool
+} // namespace UI
+} // namespace Inkscape
 
 #endif // SEEN_SP_EVENT_CONTEXT_H
 
diff --git a/src/widgets/pencil-toolbar.cpp b/src/widgets/pencil-toolbar.cpp
index e8296f735..7ad23bbbd 100644
--- a/src/widgets/pencil-toolbar.cpp
+++ b/src/widgets/pencil-toolbar.cpp
@@ -102,8 +102,16 @@ static void freehand_mode_changed(EgeSelectOneAction* act, GObject* tbl)
 
     // in pen tool we have more options than in pencil tool; if one of them was chosen, we do any
     // preparatory work here
-    if (SP_IS_PEN_CONTEXT(desktop->event_context)) {
-        Inkscape::UI::Tools::PenTool *pc = SP_PEN_CONTEXT(desktop->event_context);
+    //if (SP_IS_PEN_CONTEXT(desktop->event_context)) {
+    //    Inkscape::UI::Tools::PenTool *pc = SP_PEN_CONTEXT(desktop->event_context);
+    //    sp_pen_context_set_polyline_mode(pc);
+    //}
+
+    using namespace Inkscape::UI;
+    using Inkscape::UI::Tools::PenTool;
+
+    if (Tool::is_a<PenTool>(desktop->event_context)) {
+        PenTool* pc = Tool::to<PenTool>(desktop->event_context);
         sp_pen_context_set_polyline_mode(pc);
     }
 }