Add RangeTraits class which automatically clamps the value of resources

and start using it.

2 files changed, 39 insertions, 0 deletions

diff --git a/src/FbTk/ResTraits.hh b/src/FbTk/ResTraits.hh
index 19decb5..e1c3871 100644
--- a/src/FbTk/ResTraits.hh
+++ b/src/FbTk/ResTraits.hh
@@ -28,6 +28,7 @@
 #include "FbString.hh"
 #include "Luamm.hh"
 #include "StringUtil.hh"
+#include "Util.hh"
 
 namespace FbTk {
 
@@ -226,6 +227,41 @@ private:
     std::string m_delim;
 };
 
+template<typename Traits>
+class RangeTraits: private Traits {
+public:
+    typedef typename Traits::Type Type;
+
+    RangeTraits(const Type &min, const Type &max, const Traits &traits = Traits())
+        : Traits(traits), m_min(min), m_max(max)
+    { assert(m_min <= m_max); }
+
+    std::string toString(const Type &x) const {
+        assert(x >= m_min);
+        assert(x <= m_max);
+
+        return Traits::toString(x);
+    }
+
+    void toLua(const Type &x, lua::state &l) const {
+        assert(x >= m_min);
+        assert(x <= m_max);
+
+        Traits::toLua(x, l);
+    }
+
+    Type fromString(const std::string &x) const {
+        return FbTk::Util::clamp(Traits::fromString(x), m_min, m_max);
+    }
+
+    Type fromLua(lua::state &l) const {
+        return FbTk::Util::clamp(Traits::fromLua(l), m_min, m_max);
+    }
+
+private:
+    Type m_min, m_max;
+};
+
 } // end namespace FbTk
 
 #endif // FBTK_RESTRAITS_HH
diff --git a/src/FbTk/Resource.hh b/src/FbTk/Resource.hh
index c6f12d6..37a7ed3 100644
--- a/src/FbTk/Resource.hh
+++ b/src/FbTk/Resource.hh
@@ -281,6 +281,9 @@ typedef Resource<int, IntTraits<int> > IntResource;
 typedef Resource<unsigned int, IntTraits<unsigned int> > UIntResource;
 typedef Resource<std::string, StringTraits> StringResource;
 
+typedef RangeTraits<IntTraits<int> > RangedIntTraits;
+typedef Resource<int, RangedIntTraits> RangedIntResource;
+
 } // end namespace FbTk
 
 #endif // FBTK_RESOURCE_HH