From fc5e74e45707b78da3c57c9389d5f4f64fbcda7f Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Wed, 26 Dec 2018 11:03:36 +0530
Subject: [PATCH] Report momentum scrolling status of scroll events on cocoa

---
 glfw/cocoa_window.m | 11 +++++++++++
 glfw/glfw3.h        |  7 ++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/glfw/cocoa_window.m b/glfw/cocoa_window.m
index 5106586a3..95ef935d4 100644
--- a/glfw/cocoa_window.m
+++ b/glfw/cocoa_window.m
@@ -923,6 +923,17 @@ is_ascii_control_char(char x) {
         if (yscale > 0) deltaY *= yscale;
     }
 
+    switch([event momentumPhase]) {
+        case NSEventPhaseBegan:
+            flags |= (1 << 1); break;
+        case NSEventPhaseChanged:
+            flags |= (2 << 1); break;
+        case NSEventPhaseEnded:
+            flags |= (3 << 1); break;
+        default:
+            break;
+    }
+
     if (fabs(deltaX) > 0.0 || fabs(deltaY) > 0.0)
         _glfwInputScroll(window, deltaX, deltaY, flags);
 }
diff --git a/glfw/glfw3.h b/glfw/glfw3.h
index 9bb691bdd..741cd8f83 100644
--- a/glfw/glfw3.h
+++ b/glfw/glfw3.h
@@ -1380,7 +1380,12 @@ typedef void (* GLFWcursorenterfun)(GLFWwindow*,int);
  *  @param[in] window The window that received the event.
  *  @param[in] xoffset The scroll offset along the x-axis.
  *  @param[in] yoffset The scroll offset along the y-axis.
- *  @param[in] flags A bit-mask providing extra data about the event. flags & 1 will be true if and only if the offset values are "high-precision". Typically pixel values. Otherwise the offset values are number of lines.
+ *  @param[in] flags A bit-mask providing extra data about the event.
+ *  flags & 1 will be true if and only if the offset values are "high-precision".
+ *  Typically pixel values. Otherwise the offset values are number of lines.
+ *  (flags >> 1) & 3 will have value 1 for start of momentum scrolling,
+ *  value 2 for momentum scrolling in progress and value 3 for momentum
+ *  scrolling ended.
  *
  *  @sa @ref scrolling
  *  @sa @ref glfwSetScrollCallback