From 41c0e498139a7610af0cd2061d5279cc22be538d Mon Sep 17 00:00:00 2001
From: wangqr <wangqr@wangqr.tk>
Date: Sat, 26 Oct 2019 02:44:40 -0400
Subject: [PATCH] Only expand thumb at Paint

This will give a more natural indication of where the position is. When dragging with mouse, now the thumb block will always center under the mouse position.

Fix wangqr/Aegisub#26
---
 src/audio_display.cpp | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/audio_display.cpp b/src/audio_display.cpp
index 6548d4814..cdc942692 100644
--- a/src/audio_display.cpp
+++ b/src/audio_display.cpp
@@ -154,7 +154,7 @@ class AudioDisplay::AudioDisplayScrollbar final : public AudioDisplayInteraction
 	// Recalculate thumb bounds from position and length data
 	void RecalculateThumb()
 	{
-		thumb.width = std::max<int>(min_width, (int64_t)bounds.width * page_length / data_length);
+		thumb.width = int((int64_t)bounds.width * page_length / data_length);
 		thumb.height = height;
 		thumb.x = int((int64_t)bounds.width * position / data_length);
 		thumb.y = bounds.y;
@@ -264,7 +264,12 @@ public:
 
 		dc.SetPen(wxPen(colours.Light()));
 		dc.SetBrush(wxBrush(colours.Light()));
-		dc.DrawRectangle(thumb);
+
+		// Paint the thumb at least min_width, expand to both left and right
+		if (thumb.width < min_width)
+			dc.DrawRectangle(wxRect(thumb.x - (min_width - thumb.width) / 2, thumb.y, min_width, thumb.height));
+		else
+			dc.DrawRectangle(thumb);
 	}
 };