From: Soeren Apel <redacted>
Date: Wed, 3 Dec 2014 09:39:41 +0000 (+0100)
Subject: View: Make horizontal arrow-key scrolling useful
X-Git-Tag: pulseview-0.3.0~408
X-Git-Url: https://sigrok.org/gitweb/?p=pulseview.git;a=commitdiff_plain;h=d7aae647fee176f7a0257f65b4e5d7fda81744c3

View: Make horizontal arrow-key scrolling useful

Currently, the horizontal scroll bar scrolls by a very small amount
of time when the arrow keys on the keyboard are used. This is because
View::horizontalScrollBar's single step size is never set.

In order to make the arrow keys become useful, this patch sets this
step size equal to the major tick width of the ruler. This results
in scrolling by a fair amount of time without losing track of the
context and also preserving the positions of the major ticks on
the ruler when scrolling.
---

diff --git a/pv/view/view.cpp b/pv/view/view.cpp
index fce5b18c..5877c22d 100644
--- a/pv/view/view.cpp
+++ b/pv/view/view.cpp
@@ -451,7 +451,10 @@ void View::update_scroll()
 	get_scroll_layout(length, offset);
 	length = max(length - areaSize.width(), 0.0);
 
+	int major_tick_distance = tick_period_ / scale_;
+
 	horizontalScrollBar()->setPageStep(areaSize.width() / 2);
+	horizontalScrollBar()->setSingleStep(major_tick_distance);
 
 	updating_scroll_ = true;