1 files changed, 32 insertions, 0 deletions
diff --git a/src/coord/translate.rs b/src/coord/translate.rs
new file mode 100644
index 0000000..32888be
--- /dev/null
+++ b/src/coord/translate.rs
@@ -0,0 +1,32 @@
+use plotters_backend::BackendCoord;
+use std::ops::Deref;
+
+/// The trait that translates some customized object to the backend coordinate
+pub trait CoordTranslate {
+    type From;
+
+    /// Translate the guest coordinate to the guest coordinate
+    fn translate(&self, from: &Self::From) -> BackendCoord;
+}
+
+impl<C, T> CoordTranslate for T
+where
+    C: CoordTranslate,
+    T: Deref<Target = C>,
+{
+    type From = C::From;
+    fn translate(&self, from: &Self::From) -> BackendCoord {
+        self.deref().translate(from)
+    }
+}
+
+/// The trait indicates that the coordinate system supports reverse transform
+/// This is useful when we need an interactive plot, thus we need to map the event
+/// from the backend coordinate to the logical coordinate
+pub trait ReverseCoordTranslate: CoordTranslate {
+    /// Reverse translate the coordinate from the drawing coordinate to the
+    /// logic coordinate.
+    /// Note: the return value is an option, because it's possible that the drawing
+    /// coordinate isn't able to be represented in te guest coordinate system
+    fn reverse_translate(&self, input: BackendCoord) -> Option<Self::From>;
+}