support clicking in scrollbar to move cursor/view

1 files changed, 22 insertions, 1 deletions

diff --git a/osd.lua b/osd.lua
index 3be5e2d..35115a1 100644
--- a/osd.lua
+++ b/osd.lua
@@ -419,6 +419,7 @@ function mt:draw_scrollbar(state)
 	local opts = #menu.options
 	local lines = self:menu_lines(state)
 	if opts <= lines then
+		self.scrollbar_coords = nil
 		return
 	end
 
@@ -427,6 +428,12 @@ function mt:draw_scrollbar(state)
 	local w = self.padding - 4
 	local hh = math.max(config.font_size / 2, h * lines / opts)
 	local pos = (h - hh) * (menu.view_top - 1) / (opts - lines)
+	self.scrollbar_coords = {
+		x1 = 2,
+		y1 = top,
+		x2 = 2 + w,
+		y2 = top + h,
+	}
 
 	return (
 		-- bg
@@ -603,7 +610,7 @@ function mt:is_hidden()
 	return self.fg.hidden
 end
 
-function mt:get_mouse_line(mpos)
+function mt:mouse_menu_line(mpos)
 	local x = mpos.x / self.scale
 	local w = self.width / self.scale
 	if x < self.padding or x > w - self.padding then
@@ -618,6 +625,20 @@ function mt:get_mouse_line(mpos)
 	return line
 end
 
+function mt:mouse_scrollbar_ratio(mpos)
+	local x = mpos.x / self.scale
+	local y = mpos.y / self.scale
+	local coords = self.scrollbar_coords
+
+	if not coords or x < coords.x1 or x > coords.x2 or
+			y < coords.y1 or y > coords.y2 then
+		return
+	end
+
+	local ratio = (y - coords.y1) / (coords.y2 - coords.y1)
+	return math.max(0, math.min(1, ratio))
+end
+
 function mt:mouse_over_button_area(mpos)
 	if not mpos.hover then
 		return false