From cc373d2b309821db351216ecaf16d63446a61a61 Mon Sep 17 00:00:00 2001
From: Mark Sanders <mark.something@gmail.com>
Date: Fri, 12 Jul 2019 14:15:47 +0200
Subject: [PATCH] Fix relative scrolling when dragging the ScrollBar with the
 mouse.

---
 src/ui/ScrollBar.cpp | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/ui/ScrollBar.cpp b/src/ui/ScrollBar.cpp
index d38ae9a0..93d63479 100644
--- a/src/ui/ScrollBar.cpp
+++ b/src/ui/ScrollBar.cpp
@@ -30,14 +30,13 @@ void ScrollBar::onDragStart(const event::DragStart &e) {
 }
 
 void ScrollBar::onDragMove(const event::DragMove &e) {
-	const float sensitivity = 1.f;
-
 	ScrollWidget *scrollWidget = dynamic_cast<ScrollWidget*>(parent);
 	assert(scrollWidget);
+	math::Rect containerBox = scrollWidget->container->getChildrenBoundingBox();
 	if (orientation == HORIZONTAL)
-		scrollWidget->offset.x += sensitivity * e.mouseDelta.x;
+		scrollWidget->offset.x += (containerBox.size.x / box.size.x) * e.mouseDelta.x;
 	else
-		scrollWidget->offset.y += sensitivity * e.mouseDelta.y;
+		scrollWidget->offset.y += (containerBox.size.y / box.size.y) * e.mouseDelta.y;
 }
 
 void ScrollBar::onDragEnd(const event::DragEnd &e) {