feat: add overlap statusline setting for vertical=bottom

Author: willothy

doc/incline.txt

@@ -261,9 +261,8 @@ window.margin.vertical~
   - If an `int >= 0`, the value is used for both the top and bottom margin.
   - If a table, both `top` and `bottom` fields must be present.
 
-  If `window.placement.vertical` is `top` and 'laststatus' is `3`, you can set
-  `window.overlap.borders` to `true` to allow Incline statuslines to overlap
-  window borders.
+  If 'laststatus' is `3`, you can set `window.overlap.borders` to `true`
+  to allow Incline statuslines to overlap window borders.
 
                                        *incline-config-window.margin.horizontal*
 window.margin.horizontal~
@@ -280,11 +279,11 @@ window.margin.horizontal~
 window.overlap~
   Type:    `table`
   Valid:   `table { tabline: bool, winbar: bool, borders: bool }`
-  Default: `{ tabline: false, winbar: false, borders: true }`
+  Default: `{ tabline: false, winbar: false, borders: true, statusline: false }`
 
   Controls which bars and lines the inline windows are allowed to overlap.
   - `tabline` takes priority over `winbar` for windows at the top of the tabpage,
-    if both are set.
+    if both are set and `vertical == "top"`.
   - `borders` takes priority for windows below the top of the tabpage.
 
                                      *incline-config-window.winhighlight*

lua/incline/config/init.lua

@@ -34,6 +34,7 @@ M.schema = Schema(function(s)
         winbar = s:entry(false, vx.bool),
         tabline = s:entry(false, vx.bool),
         borders = s:entry(true, vx.bool),
+        statusline = s:entry(false, vx.bool),
       },
       placement = {
         vertical = s:entry('top', vx.any { 'top', 'bottom' }),

lua/incline/winline.lua

@@ -96,7 +96,26 @@ function Winline:get_win_geom_row()
       return cw.margin.vertical.top
     end
   elseif placement.vertical == 'bottom' then
-    return a.nvim_win_get_height(self.target_win) - cw.margin.vertical.bottom
+    if
+      vim.o.laststatus ~= 3
+      or (
+        (
+          a.nvim_win_get_position(self.target_win)[1]
+          + a.nvim_win_get_height(self.target_win)
+          + 1 -- for global status
+        ) == vim.o.lines
+      )
+    then
+      if config.window.overlap.statusline then
+        return a.nvim_win_get_height(self.target_win) - cw.margin.vertical.bottom
+      else
+        return a.nvim_win_get_height(self.target_win) - (cw.margin.vertical.bottom + 1)
+      end
+    elseif vim.o.laststatus == 3 and config.window.overlap.borders then
+      return a.nvim_win_get_height(self.target_win) - cw.margin.vertical.bottom
+    end
+
+    return a.nvim_win_get_height(self.target_win) - (cw.margin.vertical.bottom + 1)
   end
   assert(false, 'invalid value for placement.vertical: ' .. tostring(placement.vertical))
 end