From 8c246e1cb8b1870e35aebe2c01a77950a5fc1df3 Mon Sep 17 00:00:00 2001
From: Thomas Goyne <plorkyeran@aegisub.org>
Date: Thu, 26 Jan 2012 22:46:09 +0000
Subject: [PATCH] Make shift-scrollwheel scroll the grid a page at a time.
 Closes #1407.

Originally committed to SVN as r6372.
---
 aegisub/src/base_grid.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/aegisub/src/base_grid.cpp b/aegisub/src/base_grid.cpp
index fbdcf262d..0954b8354 100644
--- a/aegisub/src/base_grid.cpp
+++ b/aegisub/src/base_grid.cpp
@@ -781,8 +781,8 @@ void BaseGrid::OnMouseEvent(wxMouseEvent &event) {
 	// Mouse wheel
 	if (event.GetWheelRotation() != 0) {
 		if (ForwardMouseWheelEvent(this, event)) {
-			int step = 3 * event.GetWheelRotation() / event.GetWheelDelta();
-			ScrollTo(yPos - step);
+			int step = shift ? h / lineHeight - 2 : 3;
+			ScrollTo(yPos - step * event.GetWheelRotation() / event.GetWheelDelta());
 		}
 		return;
 	}