From 5e96c47d2e25414d0f2a182791ff049dd9393f7f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Boldizs=C3=A1r=20Lipka?= <lipkab@zoho.com>
Date: Fri, 14 Mar 2014 22:48:44 +0100
Subject: [PATCH] Support for SDL2's mouse wheel event in the GUI1 scrollbar.

---
 src/widgets/scrollbar.cpp | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/widgets/scrollbar.cpp b/src/widgets/scrollbar.cpp
index beaf575e5267..38f761fe1a00 100644
--- a/src/widgets/scrollbar.cpp
+++ b/src/widgets/scrollbar.cpp
@@ -375,6 +375,21 @@ void scrollbar::handle_event(const SDL_Event& event)
 		}
 		break;
 	}
+#if SDL_VERSION_ATLEAST(2,0,0)
+	case SDL_MOUSEWHEEL:
+	{
+		const SDL_MouseWheelEvent& e = event.wheel;
+		int x, y;
+		SDL_GetMouseState(&x, &y);
+		bool on_groove = point_in_rect(x, y, groove);
+		if (on_groove && e.y < 0) {
+			move_position(scroll_rate_);
+		} else if (on_groove && e.y > 0) {
+			move_position(-scroll_rate_);
+		}
+		break;
+	}
+#endif
 	default:
 		break;
 	}