From 1ce8cd1d8219b028c861808c4f0c9c895b06742b Mon Sep 17 00:00:00 2001
From: Guldoman <giulio.lettieri@gmail.com>
Date: Tue, 22 Oct 2024 19:05:07 +0200
Subject: [PATCH] Add `minimum_thumb_size` and
 `{contracted,expanded}_scrollbar_margin` to `Scrollbar` (#1589)

* Add `minimum_thumb_size` to `Scrollbar`

* Add `{contracted,expanded}_scrollbar_margin` to `Scrollbar`
---
 data/core/scrollbar.lua | 18 ++++++++++++++----
 data/core/style.lua     |  3 +++
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/data/core/scrollbar.lua b/data/core/scrollbar.lua
index 29352dd4..03ca33c0 100644
--- a/data/core/scrollbar.lua
+++ b/data/core/scrollbar.lua
@@ -25,6 +25,9 @@ local Scrollbar = Object:extend()
 ---@field force_status "expanded" | "contracted" | false @Force the scrollbar status
 ---@field expanded_size number? @Override the default value specified by `style.expanded_scrollbar_size`
 ---@field contracted_size number? @Override the default value specified by `style.scrollbar_size`
+---@field minimum_thumb_size number? @Override the default value specified by `style.minimum_thumb_size`
+---@field contracted_margin number? @Override the default value specified by `style.contracted_scrollbar_margin`
+---@field expanded_margin number? @Override the default value specified by `style.expanded_scrollbar_margin`
 
 ---@param options ScrollbarOptions
 function Scrollbar:new(options)
@@ -62,6 +65,12 @@ function Scrollbar:new(options)
   self.contracted_size = options.contracted_size
   ---@type number? @Override the default value specified by `style.expanded_scrollbar_size`
   self.expanded_size = options.expanded_size
+  ---@type number? @Override the default value specified by `style.minimum_thumb_size`
+  self.minimum_thumb_size = options.minimum_thumb_size
+  ---@type number? @Override the default value specified by `style.contracted_scrollbar_margin`
+  self.contracted_margin = options.contracted_margin
+  ---@type number? @Override the default value specified by `style.expanded_scrollbar_margin`
+  self.expanded_margin = options.expanded_margin
 end
 
 
@@ -116,7 +125,7 @@ function Scrollbar:_get_thumb_rect_normal()
   end
   local scrollbar_size = self.contracted_size or style.scrollbar_size
   local expanded_scrollbar_size = self.expanded_size or style.expanded_scrollbar_size
-  local along_size = math.max(20, nr.along_size * nr.along_size / sz)
+  local along_size = math.max(self.minimum_thumb_size or style.minimum_thumb_size, nr.along_size * nr.along_size / sz)
   local across_size = scrollbar_size
   across_size = across_size + (expanded_scrollbar_size - scrollbar_size) * self.expand_percent
   return
@@ -159,13 +168,14 @@ end
 
 function Scrollbar:_overlaps_normal(x, y)
   local sx, sy, sw, sh = self:_get_thumb_rect_normal()
-  local scrollbar_size = self.contracted_size or style.scrollbar_size
+  local scrollbar_margin =      self.expand_percent  * (self.expanded_margin or style.expanded_scrollbar_margin) +
+                           (1 - self.expand_percent) * (self.contracted_margin or style.contracted_scrollbar_margin)
   local result
-  if x >= sx - scrollbar_size * 3 and x <= sx + sw and y >= sy and y <= sy + sh then
+  if x >= sx - scrollbar_margin and x <= sx + sw and y >= sy and y <= sy + sh then
     result = "thumb"
   else
     sx, sy, sw, sh = self:_get_track_rect_normal()
-    if x >= sx - scrollbar_size * 3 and x <= sx + sw and y >= sy and y <= sy + sh then
+    if x >= sx - scrollbar_margin and x <= sx + sw and y >= sy and y <= sy + sh then
       result = "track"
     end
   end
diff --git a/data/core/style.lua b/data/core/style.lua
index 8f174315..447fd7d2 100644
--- a/data/core/style.lua
+++ b/data/core/style.lua
@@ -4,6 +4,9 @@ local style = {}
 style.divider_size = common.round(1 * SCALE)
 style.scrollbar_size = common.round(4 * SCALE)
 style.expanded_scrollbar_size = common.round(12 * SCALE)
+style.minimum_thumb_size = common.round(20 * SCALE)
+style.contracted_scrollbar_margin = common.round(8 * SCALE)
+style.expanded_scrollbar_margin = common.round(12 * SCALE)
 style.caret_width = common.round(2 * SCALE)
 style.tab_width = common.round(170 * SCALE)