Use the scroll hack

mk/sub.mk

@@ -42,6 +42,7 @@ DEPS_rust-glut += \
 
 DEPS_rust-layers += \
 	rust-azure \
+	rust-cocoa \
 	rust-geom \
 	rust-glut \
 	rust-opengles \
@@ -130,6 +131,10 @@ DEPS_rust-layers += \
 	rust-core-text \
 	$(NULL)
 
+DEPS_rust-glut += \
+    rust-cocoa \
+    $(NULL)
+
 endif
 
 ifeq ($(CFG_OSTYPE),unknown-linux-gnu)

src/components/main/platform/common/glut_windowing.rs

@@ -16,6 +16,7 @@ use geom::point::Point2D;
 use geom::size::Size2D;
 use glut::glut::{DOUBLE, WindowHeight, WindowWidth};
 use glut::glut;
+use glut::machack;
 
 /// A structure responsible for setting up and tearing down the entire windowing system.
 pub struct Application;
@@ -78,14 +79,16 @@ impl WindowMethods<Application> for Window {
         do glut::keyboard_func |key, _, _| {
             window.handle_key(key)
         }
-        do glut::mouse_func |_, _, x, y| {
-            window.handle_click(x, y);
-            window.start_drag(x, y)
-        }
-        do glut::motion_func |x, y| {
-            window.continue_drag(x, y)
+        do glut::mouse_func |button, _, x, y| {
+            if button < 3 {
+                window.handle_click(x, y);
+            } else {
+                window.handle_scroll(if button == 4 { -30.0 } else { 30.0 });
+            }
         }
 
+        machack::perform_scroll_wheel_hack();
+
         window
     }
 
@@ -152,20 +155,11 @@ impl Window {
         }
     }
 
-    /// Helper function to start a drag.
-    fn start_drag(&mut self, x: c_int, y: c_int) {
-        self.drag_origin = Point2D(x, y)
-    }
-
-    /// Helper function to continue a drag.
-    fn continue_drag(&mut self, x: c_int, y: c_int) {
-        let new_point = Point2D(x, y);
-        let delta = new_point - self.drag_origin;
-        self.drag_origin = new_point;
-
+    /// Helper function to handle a scroll.
+    fn handle_scroll(&mut self, delta: f32) {
         match self.scroll_callback {
             None => {}
-            Some(callback) => callback(Point2D(delta.x as f32, delta.y as f32)),
+            Some(callback) => callback(Point2D(0.0, delta)),
         }
     }
 

src/platform/macos/rust-cocoa

@@ -1 +1 @@
-Subproject commit 61c99b4b1aa8653b8ee8511b6c15099de441ac44
+Subproject commit ff8e2a63938ded5d2688619680a981c73d25080d

src/support/glut/rust-glut

@@ -1 +1 @@
-Subproject commit eb35e3957834264e99f42274f9c5c442e747ed3b
+Subproject commit 969af0260ef38d2c80ef2f51037da7ed1fc5cc85