Page overlap: add "Horizontal line" marker (#10401)

frontend/apps/reader/modules/readerview.lua

@@ -211,6 +211,9 @@ function ReaderView:paintTo(bb, x, y)
             local center_offset = bit.rshift(self.arrow.height, 1)
             -- Paint at the proper y origin depending on wheter we paged forward (dim_area.y == 0) or backward
             self.arrow:paintTo(bb, 0, self.dim_area.y == 0 and self.dim_area.h - center_offset or self.dim_area.y - center_offset)
+        elseif self.page_overlap_style == "line" then
+            bb:paintRect(0, self.dim_area.y == 0 and self.dim_area.h or self.dim_area.y,
+                self.dim_area.w, Size.line.medium, Blitbuffer.COLOR_BLACK)
         end
     end
     -- draw saved highlight
@@ -616,19 +619,19 @@ function ReaderView:drawHighlightRect(bb, _x, _y, rect, drawer, draw_note_mark)
     if drawer == "lighten" then
         bb:lightenRect(x, y, w, h, self.highlight.lighten_factor)
     elseif drawer == "underscore" then
-        bb:paintRect(x, y + h - 1, w, 2, Blitbuffer.COLOR_GRAY)
+        bb:paintRect(x, y + h - 1, w, Size.line.medium, Blitbuffer.COLOR_GRAY)
     elseif drawer == "strikeout" then
         local line_y = y + math.floor(h / 2) + 1
         if self.ui.paging then
             line_y = line_y + 2
         end
-        bb:paintRect(x, line_y, w, 2, Blitbuffer.COLOR_BLACK)
+        bb:paintRect(x, line_y, w, Size.line.medium, Blitbuffer.COLOR_BLACK)
     elseif drawer == "invert" then
         bb:invertRect(x, y, w, h)
     end
     if draw_note_mark then
         if self.highlight.note_mark == "underline" then
-            bb:paintRect(x, y + h - 1, w, 2, Blitbuffer.COLOR_BLACK)
+            bb:paintRect(x, y + h - 1, w, Size.line.medium, Blitbuffer.COLOR_BLACK)
         else
             local note_mark_pos_x
             if self.ui.paging or

frontend/ui/elements/page_overlap.lua

@@ -1,7 +1,8 @@
+local FFIUtil = require("ffi/util")
 local ReaderUI = require("apps/reader/readerui")
 local UIManager = require("ui/uimanager")
 local _ = require("gettext")
-local T = require("ffi/util").template
+local T = FFIUtil.template
 
 local PageOverlap = {
     text = _("Page overlap"),
@@ -72,8 +73,9 @@ You can set how many lines are shown.]]),
 local page_overlap_styles = {
     arrow = _("Arrow"),
     dim = _("Gray out"),
+    line = _("Horizontal line"),
 }
-for k, v in pairs(page_overlap_styles) do
+for k, v in FFIUtil.orderedPairs(page_overlap_styles) do
     table.insert(PageOverlap.sub_item_table, {
         text_func = function()
             local text = v