adding handler function

src/Affection/MouseInteractable.hs

@@ -18,3 +18,25 @@ class MouseClickable a us where
     -> SDL.InputMotion -- The 'SDL.InputMotion' of the click
     -> Int             -- The number of clicks
     -> Affection us ()
+
+-- | A helper function that checks wether provided clickables have been clicked.
+-- This function does not consume provided events, but passes them on.
+handleMouseClicks
+  :: (Foldable t, MouseClickable clickable us)
+  => SDL.Event                    -- ^ Piped event in
+  -> t clickable                  -- ^ 'MouseClickable' elemt to be checked
+  -> Affection us SDL.Event       -- ^ Unaltered event
+handleMouseClicks e clickables =
+  case SDL.eventPayload e of
+    SDL.MouseButtonEvent dat -> do
+      mapM_ (\clickable -> do
+        let SDL.P (SDL.V2 x y) = SDL.mouseButtonEventPos dat
+        onClick
+          clickable
+          (SDL.mouseButtonEventButton dat)
+          (fromIntegral x, fromIntegral y)
+          (SDL.mouseButtonEventMotion dat)
+          (fromIntegral $ SDL.mouseButtonEventClicks dat)
+        ) clickables
+      return e
+    _ -> return e