From 7886ff9acdbc4961359725536c1a15e2cbb3d4f5 Mon Sep 17 00:00:00 2001
From: Patrick Walton <pcwalton@mimiga.net>
Date: Wed, 2 Mar 2016 16:13:13 -0800
Subject: [PATCH] Add phases to wheel events.

Needed for apps to support overscroll on the Mac.
---
 src/api/cocoa/mod.rs      | 13 +++++++++----
 src/api/wayland/events.rs |  6 ++++--
 src/api/win32/callback.rs |  3 ++-
 src/api/x11/input.rs      |  5 +++--
 src/events.rs             |  2 +-
 5 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/src/api/cocoa/mod.rs b/src/api/cocoa/mod.rs
index abcd7354..db3f7498 100644
--- a/src/api/cocoa/mod.rs
+++ b/src/api/cocoa/mod.rs
@@ -42,10 +42,10 @@ use std::sync::Mutex;
 use std::ascii::AsciiExt;
 use std::ops::Deref;
 
-use events::Event::{Awakened, MouseInput, MouseMoved, ReceivedCharacter, KeyboardInput, MouseWheel, Closed, Focused, TouchpadPressure};
 use events::ElementState::{Pressed, Released};
-use events::MouseButton;
-use events;
+use events::Event::{Awakened, MouseInput, MouseMoved, ReceivedCharacter, KeyboardInput};
+use events::Event::{MouseWheel, Closed, Focused, TouchpadPressure};
+use events::{self, MouseButton, TouchPhase};
 
 pub use self::monitor::{MonitorId, get_available_monitors, get_primary_monitor};
 pub use self::headless::HeadlessContext;
@@ -891,7 +891,12 @@ unsafe fn NSEventToEvent(window: &Window, nsevent: id) -> Option<Event> {
                 LineDelta(scale_factor * nsevent.scrollingDeltaX() as f32,
                           scale_factor * nsevent.scrollingDeltaY() as f32)
             };
-            Some(MouseWheel(delta))
+            let phase = match nsevent.phase() {
+                NSEventPhaseMayBegin | NSEventPhaseBegan => TouchPhase::Started,
+                NSEventPhaseEnded => TouchPhase::Ended,
+                _ => TouchPhase::Moved,
+            };
+            Some(MouseWheel(delta, phase))
         },
         NSEventTypePressure => {
             Some(TouchpadPressure(nsevent.pressure(), nsevent.stage()))
diff --git a/src/api/wayland/events.rs b/src/api/wayland/events.rs
index 8b180205..5e0c3fd0 100644
--- a/src/api/wayland/events.rs
+++ b/src/api/wayland/events.rs
@@ -1,5 +1,6 @@
 use std::collections::HashSet;
 
+use TouchPhase;
 use Event as GlutinEvent;
 use ElementState;
 use MouseButton;
@@ -98,7 +99,8 @@ pub fn translate_event(
                             WlPointerAxis::HorizontalScroll => {
                                 MouseScrollDelta::PixelDelta(0.0, amplitude as f32)
                             }
-                        }
+                        },
+                        TouchPhase::Moved
                     ), surface))
                 } else {
                     None
@@ -107,4 +109,4 @@ pub fn translate_event(
         },
         _ => None
     }
-}
\ No newline at end of file
+}
diff --git a/src/api/win32/callback.rs b/src/api/win32/callback.rs
index 0215c9f9..2d10699d 100644
--- a/src/api/win32/callback.rs
+++ b/src/api/win32/callback.rs
@@ -134,12 +134,13 @@ pub unsafe extern "system" fn callback(window: winapi::HWND, msg: winapi::UINT,
         winapi::WM_MOUSEWHEEL => {
             use events::Event::MouseWheel;
             use events::MouseScrollDelta::LineDelta;
+            use events::TouchPhase;
 
             let value = (wparam >> 16) as i16;
             let value = value as i32;
             let value = value as f32 / winapi::WHEEL_DELTA as f32;
 
-            send_event(window, MouseWheel(LineDelta(0.0, value)));
+            send_event(window, MouseWheel(LineDelta(0.0, value), TouchPhase::Moved));
 
             0
         },
diff --git a/src/api/x11/input.rs b/src/api/x11/input.rs
index 2ebc9897..a05b22e1 100644
--- a/src/api/x11/input.rs
+++ b/src/api/x11/input.rs
@@ -201,7 +201,7 @@ impl XInputEventHandler {
                             } else {
                                 -1.0
                             };
-                            Some(MouseWheel(LineDelta(0.0, delta)))
+                            Some(MouseWheel(LineDelta(0.0, delta), TouchPhase::Moved))
                         } else {
                             // emulated button event from a touch/smooth-scroll
                             // event. Ignore these events and handle scrolling
@@ -235,7 +235,8 @@ impl XInputEventHandler {
                 }
 
                 if scroll_delta.0.abs() > 0.0 || scroll_delta.1.abs() > 0.0 {
-                    Some(MouseWheel(LineDelta(scroll_delta.0 as f32, scroll_delta.1 as f32)))
+                    Some(MouseWheel(LineDelta(scroll_delta.0 as f32, scroll_delta.1 as f32),
+                                    TouchPhase::Moved))
                 } else {
                     let new_cursor_pos = (event_data.event_x, event_data.event_y);
                     if new_cursor_pos != self.current_state.cursor_pos {
diff --git a/src/events.rs b/src/events.rs
index ecc10418..8049c167 100644
--- a/src/events.rs
+++ b/src/events.rs
@@ -31,7 +31,7 @@ pub enum Event {
     MouseMoved((i32, i32)),
 
     /// A mouse wheel movement or touchpad scroll occurred.
-    MouseWheel(MouseScrollDelta),
+    MouseWheel(MouseScrollDelta, TouchPhase),
 
     /// An event from the mouse has been received.
     MouseInput(ElementState, MouseButton),