Auto merge of #9851 - pcwalton:overscroll, r=glennw

Implement support for overscrolling on the Mac.

Requires tomaka/glutin#734, servo/webrender_traits#14, and
servo/webrender#217.

r? whoever (waiting on the landing of the above)

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8 files changed, 153 insertions, 50 deletions

diff --git a/components/compositing/compositor.rs b/components/compositing/compositor.rs
index 793c72a5c0b..1a64c4bb8fb 100644
--- a/components/compositing/compositor.rs
+++ b/components/compositing/compositor.rs
@@ -53,7 +53,7 @@ use util::geometry::{PagePx, ScreenPx, ViewportPx};
 use util::opts;
 use util::print_tree::PrintTree;
 use webrender;
-use webrender_traits;
+use webrender_traits::{self, ScrollEventPhase};
 use windowing::{self, MouseWindowEvent, WindowEvent, WindowMethods, WindowNavigateMsg};
 
 #[derive(Debug, PartialEq)]
@@ -196,6 +196,9 @@ pub struct IOCompositor<Window: WindowMethods> {
     /// The id of the pipeline that was last sent a mouse move event, if any.
     last_mouse_move_recipient: Option<PipelineId>,
 
+    /// Whether a scroll is in progress; i.e. whether the user's fingers are down.
+    scroll_in_progress: bool,
+
     /// The webrender renderer, if enabled.
     webrender: Option<webrender::Renderer>,
 
@@ -203,6 +206,7 @@ pub struct IOCompositor<Window: WindowMethods> {
     webrender_api: Option<webrender_traits::RenderApi>,
 }
 
+#[derive(Copy, Clone)]
 pub struct ScrollZoomEvent {
     /// Change the pinch zoom level by this factor
     magnification: f32,
@@ -210,6 +214,8 @@ pub struct ScrollZoomEvent {
     delta: TypedPoint2D<DevicePixel, f32>,
     /// Apply changes to the frame at this location
     cursor: TypedPoint2D<DevicePixel, i32>,
+    /// The scroll event phase.
+    phase: ScrollEventPhase,
 }
 
 #[derive(PartialEq, Debug)]
@@ -427,6 +433,7 @@ impl<Window: WindowMethods> IOCompositor<Window> {
             surface_map: SurfaceMap::new(BUFFER_MAP_SIZE),
             pending_subpages: HashSet::new(),
             last_mouse_move_recipient: None,
+            scroll_in_progress: false,
             webrender: state.webrender,
             webrender_api: webrender_api,
         }
@@ -1184,8 +1191,16 @@ impl<Window: WindowMethods> IOCompositor<Window> {
                 }
             }
 
-            WindowEvent::Scroll(delta, cursor) => {
-                self.on_scroll_window_event(delta, cursor);
+            WindowEvent::Scroll(delta, cursor, phase) => {
+                match phase {
+                    TouchEventType::Move => self.on_scroll_window_event(delta, cursor),
+                    TouchEventType::Up | TouchEventType::Cancel => {
+                        self.on_scroll_end_window_event(delta, cursor);
+                    }
+                    TouchEventType::Down => {
+                        self.on_scroll_start_window_event(delta, cursor);
+                    }
+                }
             }
 
             WindowEvent::Zoom(magnification) => {
@@ -1368,6 +1383,7 @@ impl<Window: WindowMethods> IOCompositor<Window> {
                     magnification: magnification,
                     delta: scroll_delta,
                     cursor: cursor,
+                    phase: ScrollEventPhase::Move(true),
                 });
                 self.composite_if_necessary(CompositingReason::Zoom);
             }
@@ -1421,8 +1437,34 @@ impl<Window: WindowMethods> IOCompositor<Window> {
             magnification: 1.0,
             delta: delta,
             cursor: cursor,
+            phase: ScrollEventPhase::Move(self.scroll_in_progress),
         });
+        self.composite_if_necessary(CompositingReason::Scroll);
+    }
 
+    fn on_scroll_start_window_event(&mut self,
+                                    delta: TypedPoint2D<DevicePixel, f32>,
+                                    cursor: TypedPoint2D<DevicePixel, i32>) {
+        self.scroll_in_progress = true;
+        self.pending_scroll_zoom_events.push(ScrollZoomEvent {
+            magnification: 1.0,
+            delta: delta,
+            cursor: cursor,
+            phase: ScrollEventPhase::Start,
+        });
+        self.composite_if_necessary(CompositingReason::Scroll);
+    }
+
+    fn on_scroll_end_window_event(&mut self,
+                                  delta: TypedPoint2D<DevicePixel, f32>,
+                                  cursor: TypedPoint2D<DevicePixel, i32>) {
+        self.scroll_in_progress = false;
+        self.pending_scroll_zoom_events.push(ScrollZoomEvent {
+            magnification: 1.0,
+            delta: delta,
+            cursor: cursor,
+            phase: ScrollEventPhase::End,
+        });
         self.composite_if_necessary(CompositingReason::Scroll);
     }
 
@@ -1432,19 +1474,41 @@ impl<Window: WindowMethods> IOCompositor<Window> {
         match self.webrender_api {
             Some(ref webrender_api) => {
                 // Batch up all scroll events into one, or else we'll do way too much painting.
-                let mut total_delta = None;
-                let mut last_cursor = Point2D::zero();
+                let mut last_combined_event: Option<ScrollZoomEvent> = None;
                 for scroll_event in self.pending_scroll_zoom_events.drain(..) {
-                    let this_delta = scroll_event.delta / self.scene.scale;
-                    last_cursor = scroll_event.cursor.as_f32() / self.scene.scale;
-                    match total_delta {
-                        None => total_delta = Some(this_delta),
-                        Some(ref mut total_delta) => *total_delta = *total_delta + this_delta,
+                    let this_delta = scroll_event.delta;
+                    let this_cursor = scroll_event.cursor;
+                    if let Some(combined_event) = last_combined_event {
+                        if combined_event.phase != scroll_event.phase {
+                            webrender_api.scroll(
+                                (combined_event.delta / self.scene.scale).to_untyped(),
+                                (combined_event.cursor.as_f32() / self.scene.scale).to_untyped(),
+                                combined_event.phase);
+                            last_combined_event = None
+                        }
+                    }
+
+                    match last_combined_event {
+                        None => {
+                            last_combined_event = Some(ScrollZoomEvent {
+                                magnification: scroll_event.magnification,
+                                delta: this_delta,
+                                cursor: this_cursor,
+                                phase: scroll_event.phase,
+                            })
+                        }
+                        Some(ref mut last_combined_event) => {
+                            last_combined_event.delta = last_combined_event.delta + this_delta;
+                        }
                     }
                 }
+
                 // TODO(gw): Support zoom (WR issue #28).
-                if let Some(total_delta) = total_delta {
-                    webrender_api.scroll(total_delta.to_untyped(), last_cursor.to_untyped());
+                if let Some(combined_event) = last_combined_event {
+                    webrender_api.scroll(
+                        (combined_event.delta / self.scene.scale).to_untyped(),
+                        (combined_event.cursor.as_f32() / self.scene.scale).to_untyped(),
+                        combined_event.phase);
                 }
             }
             None => {
@@ -1617,6 +1681,7 @@ impl<Window: WindowMethods> IOCompositor<Window> {
             magnification: magnification,
             delta: Point2D::typed(0.0, 0.0), // TODO: Scroll to keep the center in view?
             cursor:  Point2D::typed(-1, -1), // Make sure this hits the base layer.
+            phase: ScrollEventPhase::Move(true),
         });
         self.composite_if_necessary(CompositingReason::Zoom);
     }
@@ -2016,6 +2081,7 @@ impl<Window: WindowMethods> IOCompositor<Window> {
         self.composition_request = CompositionRequest::NoCompositingNecessary;
         self.process_pending_scroll_events();
         self.process_animations();
+        self.start_scrolling_bounce_if_necessary();
 
         Ok(rv)
     }
@@ -2221,6 +2287,21 @@ impl<Window: WindowMethods> IOCompositor<Window> {
             print_tree.add_item(layer_string);
         }
     }
+
+    fn start_scrolling_bounce_if_necessary(&mut self) {
+        if self.scroll_in_progress {
+            return
+        }
+
+        match self.webrender {
+            Some(ref webrender) if webrender.layers_are_bouncing_back() => {}
+            _ => return,
+        }
+
+        if let Some(ref webrender_api) = self.webrender_api {
+            webrender_api.tick_scrolling_bounce_animations()
+        }
+    }
 }
 
 fn find_layer_with_pipeline_and_layer_id_for_layer(layer: Rc<Layer<CompositorData>>,
diff --git a/components/compositing/windowing.rs b/components/compositing/windowing.rs
index 944431799c0..fc5a45dc7b1 100644
--- a/components/compositing/windowing.rs
+++ b/components/compositing/windowing.rs
@@ -63,7 +63,7 @@ pub enum WindowEvent {
     Touch(TouchEventType, TouchId, TypedPoint2D<DevicePixel, f32>),
     /// Sent when the user scrolls. The first point is the delta and the second point is the
     /// origin.
-    Scroll(TypedPoint2D<DevicePixel, f32>, TypedPoint2D<DevicePixel, i32>),
+    Scroll(TypedPoint2D<DevicePixel, f32>, TypedPoint2D<DevicePixel, i32>, TouchEventType),
     /// Sent when the user zooms.
     Zoom(f32),
     /// Simulated "pinch zoom" gesture for non-touch platforms (e.g. ctrl-scrollwheel).
diff --git a/components/servo/Cargo.lock b/components/servo/Cargo.lock
index 04129feb28f..022b80b08d6 100644
--- a/components/servo/Cargo.lock
+++ b/components/servo/Cargo.lock
@@ -788,7 +788,7 @@ dependencies = [
  "net_traits 0.0.1",
  "script_traits 0.0.1",
  "servo-egl 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "servo-glutin 0.4.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "servo-glutin 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "style_traits 0.0.1",
  "url 0.5.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "util 0.0.1",
@@ -1854,7 +1854,7 @@ dependencies = [
 
 [[package]]
 name = "servo-glutin"
-version = "0.4.9"
+version = "0.4.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "android_glue 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1896,7 +1896,7 @@ dependencies = [
  "servo-egl 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "servo-fontconfig 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "servo-freetype-sys 2.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "servo-glutin 0.4.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "servo-glutin 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "x11 2.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -2292,7 +2292,7 @@ dependencies = [
 [[package]]
 name = "webrender"
 version = "0.1.0"
-source = "git+https://github.com/servo/webrender#38031eed57b2df8a57e4cff576e2b5b6f2cd8316"
+source = "git+https://github.com/servo/webrender#9309d52279a73ea15f955424899fed9b9ab70c95"
 dependencies = [
  "app_units 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-graphics 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2313,7 +2313,7 @@ dependencies = [
 [[package]]
 name = "webrender_traits"
 version = "0.1.0"
-source = "git+https://github.com/servo/webrender_traits#94f16f55e65d735a9c1dc38733937cb2774322e1"
+source = "git+https://github.com/servo/webrender_traits#a4d2e91915512c3d6b08d0d391221bb240d972d5"
 dependencies = [
  "app_units 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-graphics 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/ports/cef/Cargo.lock b/ports/cef/Cargo.lock
index 55bc0699a01..6ef78957d39 100644
--- a/ports/cef/Cargo.lock
+++ b/ports/cef/Cargo.lock
@@ -708,7 +708,7 @@ dependencies = [
  "net_traits 0.0.1",
  "script_traits 0.0.1",
  "servo-egl 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "servo-glutin 0.4.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "servo-glutin 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "style_traits 0.0.1",
  "url 0.5.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "util 0.0.1",
@@ -1758,7 +1758,7 @@ dependencies = [
 
 [[package]]
 name = "servo-glutin"
-version = "0.4.9"
+version = "0.4.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "android_glue 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1800,7 +1800,7 @@ dependencies = [
  "servo-egl 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "servo-fontconfig 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "servo-freetype-sys 2.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "servo-glutin 0.4.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "servo-glutin 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "x11 2.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -2168,7 +2168,7 @@ dependencies = [
 [[package]]
 name = "webrender"
 version = "0.1.0"
-source = "git+https://github.com/servo/webrender#38031eed57b2df8a57e4cff576e2b5b6f2cd8316"
+source = "git+https://github.com/servo/webrender#9309d52279a73ea15f955424899fed9b9ab70c95"
 dependencies = [
  "app_units 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-graphics 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2189,7 +2189,7 @@ dependencies = [
 [[package]]
 name = "webrender_traits"
 version = "0.1.0"
-source = "git+https://github.com/servo/webrender_traits#94f16f55e65d735a9c1dc38733937cb2774322e1"
+source = "git+https://github.com/servo/webrender_traits#a4d2e91915512c3d6b08d0d391221bb240d972d5"
 dependencies = [
  "app_units 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-graphics 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/ports/cef/browser_host.rs b/ports/cef/browser_host.rs
index 73ddfdb0676..bbf776ee839 100644
--- a/ports/cef/browser_host.rs
+++ b/ports/cef/browser_host.rs
@@ -15,7 +15,7 @@ use euclid::point::Point2D;
 use euclid::size::Size2D;
 use libc::{c_double, c_int};
 use msg::constellation_msg::{self, KeyModifiers, KeyState};
-use script_traits::MouseButton;
+use script_traits::{MouseButton, TouchEventType};
 use std::cell::{Cell, RefCell};
 
 pub struct ServoCefBrowserHost {
@@ -469,7 +469,9 @@ full_cef_class_impl! {
             let delta_y: c_int = delta_y;
             let delta = Point2D::typed(delta_x as f32, delta_y as f32);
             let origin = Point2D::typed((*event).x as i32, (*event).y as i32);
-            this.downcast().send_window_event(WindowEvent::Scroll(delta, origin))
+            this.downcast().send_window_event(WindowEvent::Scroll(delta,
+                                                                  origin,
+                                                                  TouchEventType::Move))
         }}
 
         fn get_zoom_level(&this,) -> c_double {{
diff --git a/ports/glutin/window.rs b/ports/glutin/window.rs
index a2550d76f77..e604e11a1a4 100644
--- a/ports/glutin/window.rs
+++ b/ports/glutin/window.rs
@@ -16,6 +16,7 @@ use gleam::gl;
 use glutin;
 #[cfg(feature = "window")]
 use glutin::{Api, ElementState, Event, GlRequest, MouseButton, VirtualKeyCode, MouseScrollDelta};
+use glutin::{TouchPhase};
 use layers::geometry::DevicePixel;
 use layers::platform::surface::NativeDisplay;
 #[cfg(feature = "window")]
@@ -23,6 +24,8 @@ use msg::constellation_msg::{KeyState, NONE, CONTROL, SHIFT, ALT, SUPER};
 use msg::constellation_msg::{self, Key};
 use net_traits::net_error_list::NetError;
 #[cfg(feature = "window")]
+use script_traits::TouchEventType;
+#[cfg(feature = "window")]
 use std::cell::{Cell, RefCell};
 use std::os::raw::c_void;
 #[cfg(all(feature = "headless", target_os = "linux"))]
@@ -226,23 +229,18 @@ impl Window {
                 self.event_queue.borrow_mut().push(
                     WindowEvent::MouseWindowMoveEventClass(Point2D::typed(x as f32, y as f32)));
             }
-            Event::MouseWheel(delta) => {
+            Event::MouseWheel(delta, phase) => {
                 let (dx, dy) = match delta {
                     MouseScrollDelta::LineDelta(dx, dy) => (dx, dy * LINE_HEIGHT),
                     MouseScrollDelta::PixelDelta(dx, dy) => (dx, dy),
                 };
-                self.scroll_window(dx, dy);
+                let phase = glutin_phase_to_touch_event_type(phase);
+                self.scroll_window(dx, dy, phase);
             },
             Event::Touch(touch) => {
-                use glutin::TouchPhase;
-                use script_traits::{TouchEventType, TouchId};
-
-                let phase = match touch.phase {
-                    TouchPhase::Started => TouchEventType::Down,
-                    TouchPhase::Moved => TouchEventType::Move,
-                    TouchPhase::Ended => TouchEventType::Up,
-                    TouchPhase::Cancelled => TouchEventType::Cancel,
-                };
+                use script_traits::TouchId;
+
+                let phase = glutin_phase_to_touch_event_type(touch.phase);
                 let id = TouchId(touch.id as i32);
                 let point = Point2D::typed(touch.location.0 as f32, touch.location.1 as f32);
                 self.event_queue.borrow_mut().push(WindowEvent::Touch(phase, id, point));
@@ -266,10 +264,11 @@ impl Window {
     }
 
     /// Helper function to send a scroll event.
-    fn scroll_window(&self, dx: f32, dy: f32) {
+    fn scroll_window(&self, dx: f32, dy: f32, phase: TouchEventType) {
         let mouse_pos = self.mouse_pos.get();
         let event = WindowEvent::Scroll(Point2D::typed(dx as f32, dy as f32),
-                                        Point2D::typed(mouse_pos.x as i32, mouse_pos.y as i32));
+                                        Point2D::typed(mouse_pos.x as i32, mouse_pos.y as i32),
+                                        phase);
         self.event_queue.borrow_mut().push(event);
     }
 
@@ -736,23 +735,33 @@ impl WindowMethods for Window {
 
             (NONE, Key::PageDown) |
             (NONE, Key::Space) => {
-                self.scroll_window(0.0, -self.framebuffer_size().as_f32().to_untyped().height + 2.0 * LINE_HEIGHT);
+                self.scroll_window(0.0,
+                                   -self.framebuffer_size()
+                                        .as_f32()
+                                        .to_untyped()
+                                        .height + 2.0 * LINE_HEIGHT,
+                                   TouchEventType::Move);
             }
             (NONE, Key::PageUp) |
             (SHIFT, Key::Space) => {
-                self.scroll_window(0.0, self.framebuffer_size().as_f32().to_untyped().height - 2.0 * LINE_HEIGHT);
+                self.scroll_window(0.0,
+                                   self.framebuffer_size()
+                                       .as_f32()
+                                       .to_untyped()
+                                       .height - 2.0 * LINE_HEIGHT,
+                                   TouchEventType::Move);
             }
             (NONE, Key::Up) => {
-                self.scroll_window(0.0, 3.0 * LINE_HEIGHT);
+                self.scroll_window(0.0, 3.0 * LINE_HEIGHT, TouchEventType::Move);
             }
             (NONE, Key::Down) => {
-                self.scroll_window(0.0, -3.0 * LINE_HEIGHT);
+                self.scroll_window(0.0, -3.0 * LINE_HEIGHT, TouchEventType::Move);
             }
             (NONE, Key::Left) => {
-                self.scroll_window(LINE_HEIGHT, 0.0);
+                self.scroll_window(LINE_HEIGHT, 0.0, TouchEventType::Move);
             }
             (NONE, Key::Right) => {
-                self.scroll_window(-LINE_HEIGHT, 0.0);
+                self.scroll_window(-LINE_HEIGHT, 0.0, TouchEventType::Move);
             }
 
             _ => {
@@ -923,6 +932,16 @@ impl CompositorProxy for GlutinCompositorProxy {
     }
 }
 
+#[cfg(feature = "window")]
+fn glutin_phase_to_touch_event_type(phase: TouchPhase) -> TouchEventType {
+    match phase {
+        TouchPhase::Started => TouchEventType::Down,
+        TouchPhase::Moved => TouchEventType::Move,
+        TouchPhase::Ended => TouchEventType::Up,
+        TouchPhase::Cancelled => TouchEventType::Cancel,
+    }
+}
+
 // These functions aren't actually called. They are here as a link
 // hack because Skia references them.
 
diff --git a/ports/gonk/Cargo.lock b/ports/gonk/Cargo.lock
index 298de62fb40..1d2e33a6a5a 100644
--- a/ports/gonk/Cargo.lock
+++ b/ports/gonk/Cargo.lock
@@ -1738,7 +1738,7 @@ dependencies = [
 
 [[package]]
 name = "servo-glutin"
-version = "0.4.9"
+version = "0.4.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "android_glue 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1780,7 +1780,7 @@ dependencies = [
  "servo-egl 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "servo-fontconfig 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "servo-freetype-sys 2.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "servo-glutin 0.4.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "servo-glutin 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "x11 2.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -2117,7 +2117,7 @@ dependencies = [
 [[package]]
 name = "webrender"
 version = "0.1.0"
-source = "git+https://github.com/servo/webrender#38031eed57b2df8a57e4cff576e2b5b6f2cd8316"
+source = "git+https://github.com/servo/webrender#9309d52279a73ea15f955424899fed9b9ab70c95"
 dependencies = [
  "app_units 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-graphics 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2138,7 +2138,7 @@ dependencies = [
 [[package]]
 name = "webrender_traits"
 version = "0.1.0"
-source = "git+https://github.com/servo/webrender_traits#94f16f55e65d735a9c1dc38733937cb2774322e1"
+source = "git+https://github.com/servo/webrender_traits#a4d2e91915512c3d6b08d0d391221bb240d972d5"
 dependencies = [
  "app_units 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-graphics 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/ports/gonk/src/input.rs b/ports/gonk/src/input.rs
index e40900f7acf..fd6ee3a14fc 100644
--- a/ports/gonk/src/input.rs
+++ b/ports/gonk/src/input.rs
@@ -6,7 +6,7 @@ use compositing::windowing::{WindowEvent, MouseWindowEvent};
 use errno::errno;
 use euclid::point::Point2D;
 use libc::{c_int, c_long, time_t};
-use script_traits::MouseButton;
+use script_traits::{MouseButton, TouchEventType};
 use std::fs::File;
 use std::io::Read;
 use std::mem::{size_of, transmute, zeroed};
@@ -185,7 +185,8 @@ fn read_input_device(device_path: &Path,
                         println!("Touch move x: {}, y: {}", slotA.x, slotA.y);
                         sender.send(
                             WindowEvent::Scroll(Point2D::typed((slotA.x - last_x) as f32, (slotA.y - last_y) as f32),
-                                                Point2D::typed(slotA.x, slotA.y))).ok().unwrap();
+                                                Point2D::typed(slotA.x, slotA.y),
+                                                TouchEventType::Move)).ok().unwrap();
                         last_x = slotA.x;
                         last_y = slotA.y;
                         if touch_count >= 2 {