feat: make padding highlight configurable

## Details

Issue: #176

Currently all the padding added by this plugin is hard coded to the
highlight group `Normal`. This is by convention the value used for
backgrounds which allows us to create empty space.

However in floating windows like LSP hover docs the background uses the
`NormalFloat` highlight instead.

To fix this add a new top level configuration for `padding` with a
single key for `highlight`. This by default is set to `Normal`.

Updates the default override for `nofile` to use the `NormalFloat` value
instead which should fix any background color issues with LSP hover docs.

Author: MeanderingProgrammer

Diff for: CHANGELOG.md

@@ -2,6 +2,11 @@
 
 ## Pre-release
 
+### Features
+
+- `pipe_table.cell` value `trimmed` [#175](https://github.com/MeanderingProgrammer/render-markdown.nvim/issues/175)
+  [c686970](https://github.com/MeanderingProgrammer/render-markdown.nvim/commit/c68697085441d03a20eee15d4d78e2e5a771569a)
+
 ## 7.1.0 (2024-09-19)
 
 ### Features

Diff for: README.md

@@ -218,6 +218,10 @@ require('render-markdown').setup({
         -- Number of lines below cursor to show
         below = 0,
     },
+    padding = {
+        -- Highlight to use when adding whitespace, should match background
+        highlight = 'Normal',
+    },
     latex = {
         -- Whether LaTeX should be rendered, mainly used for health check
         enabled = true,
@@ -541,12 +545,15 @@ require('render-markdown').setup({
     -- More granular configuration mechanism, allows different aspects of buffers
     -- to have their own behavior. Values default to the top level configuration
     -- if no override is provided. Supports the following fields:
-    --   enabled, max_file_size, debounce, render_modes, anti_conceal, heading, code,
+    --   enabled, max_file_size, debounce, render_modes, anti_conceal, padding, heading, code,
     --   dash, bullet, checkbox, quote, pipe_table, callout, link, sign, indent, win_options
     overrides = {
         -- Overrides for different buftypes, see :h 'buftype'
         buftype = {
-            nofile = { sign = { enabled = false } },
+            nofile = {
+                padding = { highlight = 'NormalFloat' },
+                sign = { enabled = false },
+            },
         },
         -- Overrides for different filetypes, see :h 'filetype'
         filetype = {},

Diff for: doc/render-markdown.txt

@@ -264,6 +264,10 @@ Full Default Configuration ~
             -- Number of lines below cursor to show
             below = 0,
         },
+        padding = {
+            -- Highlight to use when adding whitespace, should match background
+            highlight = 'Normal',
+        },
         latex = {
             -- Whether LaTeX should be rendered, mainly used for health check
             enabled = true,
@@ -587,12 +591,15 @@ Full Default Configuration ~
         -- More granular configuration mechanism, allows different aspects of buffers
         -- to have their own behavior. Values default to the top level configuration
         -- if no override is provided. Supports the following fields:
-        --   enabled, max_file_size, debounce, render_modes, anti_conceal, heading, code,
+        --   enabled, max_file_size, debounce, render_modes, anti_conceal, padding, heading, code,
         --   dash, bullet, checkbox, quote, pipe_table, callout, link, sign, indent, win_options
         overrides = {
             -- Overrides for different buftypes, see :h 'buftype'
             buftype = {
-                nofile = { sign = { enabled = false } },
+                nofile = {
+                    padding = { highlight = 'NormalFloat' },
+                    sign = { enabled = false },
+                },
             },
             -- Overrides for different filetypes, see :h 'filetype'
             filetype = {},

Diff for: lua/render-markdown/handler/markdown.lua

@@ -122,13 +122,13 @@ function Handler:list_marker(info)
         if bullet.left_pad > 0 then
             self.marks:add(false, info.start_row, 0, {
                 priority = 0,
-                virt_text = { { str.pad(bullet.left_pad), 'Normal' } },
+                virt_text = { { str.pad(bullet.left_pad), self.config.padding.highlight } },
                 virt_text_pos = 'inline',
             })
         end
         if bullet.right_pad > 0 then
             self.marks:add(true, info.start_row, info.end_col - 1, {
-                virt_text = { { str.pad(bullet.right_pad), 'Normal' } },
+                virt_text = { { str.pad(bullet.right_pad), self.config.padding.highlight } },
                 virt_text_pos = 'inline',
             })
         end

Diff for: lua/render-markdown/health.lua

@@ -4,7 +4,7 @@ local state = require('render-markdown.state')
 local M = {}
 
 ---@private
-M.version = '7.1.2'
+M.version = '7.1.3'
 
 function M.check()
     M.start('version')

Diff for: lua/render-markdown/init.lua

@@ -144,6 +144,9 @@ local M = {}
 ---@field public backgrounds? string[]
 ---@field public foregrounds? string[]
 
+---@class (exact) render.md.UserPadding
+---@field public highlight? string
+
 ---@class (exact) render.md.UserAntiConceal
 ---@field public enabled? boolean
 ---@field public above? integer
@@ -159,6 +162,7 @@ local M = {}
 ---@field public debounce? integer
 ---@field public render_modes? string[]|boolean
 ---@field public anti_conceal? render.md.UserAntiConceal
+---@field public padding? render.md.UserPadding
 ---@field public heading? render.md.UserHeading
 ---@field public code? render.md.UserCode
 ---@field public dash? render.md.UserDash
@@ -285,6 +289,10 @@ M.default_config = {
         -- Number of lines below cursor to show
         below = 0,
     },
+    padding = {
+        -- Highlight to use when adding whitespace, should match background
+        highlight = 'Normal',
+    },
     latex = {
         -- Whether LaTeX should be rendered, mainly used for health check
         enabled = true,
@@ -608,12 +616,15 @@ M.default_config = {
     -- More granular configuration mechanism, allows different aspects of buffers
     -- to have their own behavior. Values default to the top level configuration
     -- if no override is provided. Supports the following fields:
-    --   enabled, max_file_size, debounce, render_modes, anti_conceal, heading, code,
+    --   enabled, max_file_size, debounce, render_modes, anti_conceal, padding, heading, code,
     --   dash, bullet, checkbox, quote, pipe_table, callout, link, sign, indent, win_options
     overrides = {
         -- Overrides for different buftypes, see :h 'buftype'
         buftype = {
-            nofile = { sign = { enabled = false } },
+            nofile = {
+                padding = { highlight = 'NormalFloat' },
+                sign = { enabled = false },
+            },
         },
         -- Overrides for different filetypes, see :h 'filetype'
         filetype = {},

Diff for: lua/render-markdown/render/base.lua

@@ -46,7 +46,7 @@ end
 function Base:indent_virt_line(line, level)
     local amount = self:indent(level)
     if amount > 0 then
-        table.insert(line, 1, { str.pad(amount), 'Normal' })
+        table.insert(line, 1, { str.pad(amount), self.config.padding.highlight })
     end
     return line
 end

Diff for: lua/render-markdown/render/code.lua

@@ -163,10 +163,10 @@ function Render:background(icon_added)
             hl_eol = true,
         })
         if self.code.width == 'block' then
-            -- Overwrite anything beyond width with Normal
+            -- Overwrite anything beyond width with padding highlight
             self.marks:add(false, row, self.data.col, {
                 priority = 0,
-                virt_text = { { padding, 'Normal' } },
+                virt_text = { { padding, self.config.padding.highlight } },
                 virt_text_win_col = width + self.data.indent,
             })
         end
@@ -189,8 +189,9 @@ function Render:left_pad(add_background)
 
     -- Use low priority to include other marks in padding when code block is at edge
     local priority = self.data.col == 0 and 0 or nil
-    local outer_text = { str.pad(self.data.col), 'Normal' }
-    local left_text = { str.pad(self.code.left_pad), add_background and self.code.highlight or 'Normal' }
+    local outer_text = { str.pad(self.data.col), self.config.padding.highlight }
+    local background = add_background and self.code.highlight or self.config.padding.highlight
+    local left_text = { str.pad(self.code.left_pad), background }
 
     for row = self.data.start_row, self.data.end_row - 1 do
         local virt_text = {}

Diff for: lua/render-markdown/render/heading.lua

@@ -149,10 +149,10 @@ function Render:background(width)
             hl_eol = true,
         })
         if self.data.heading_width == 'block' then
-            -- Overwrite anything beyond width with Normal
+            -- Overwrite anything beyond width with padding highlight
             self.marks:add(true, row, 0, {
                 priority = 0,
-                virt_text = { { str.pad(vim.o.columns * 2), 'Normal' } },
+                virt_text = { { str.pad(vim.o.columns * 2), self.config.padding.highlight } },
                 virt_text_win_col = win_col,
             })
         end

Diff for: lua/render-markdown/render/section.lua

@@ -64,7 +64,7 @@ function Render:render()
     for row = start_row, end_row do
         self.marks:add(false, row, 0, {
             priority = 0,
-            virt_text = { { str.pad(self.indent.per_level * self.level_change), 'Normal' } },
+            virt_text = { { str.pad(self.indent.per_level * self.level_change), self.config.padding.highlight } },
             virt_text_pos = 'inline',
         })
     end

Diff for: lua/render-markdown/render/table.lua

@@ -325,7 +325,7 @@ function Render:full()
     ---@param above boolean
     ---@param chars { [1]: string, [2]: string, [3]: string }
     local function table_border(info, above, chars)
-        local line = spaces > 0 and { { str.pad(spaces), 'Normal' } } or {}
+        local line = spaces > 0 and { { str.pad(spaces), self.config.padding.highlight } } or {}
         local highlight = above and self.table.head or self.table.row
         table.insert(line, { chars[1] .. table.concat(sections, chars[2]) .. chars[3], highlight })
         self.marks:add(false, info.start_row, info.start_col, {

Diff for: lua/render-markdown/state.lua

@@ -95,6 +95,7 @@ function M.default_buffer_config()
         debounce = config.debounce,
         render_modes = config.render_modes,
         anti_conceal = config.anti_conceal,
+        padding = config.padding,
         heading = config.heading,
         code = config.code,
         dash = config.dash,
@@ -225,6 +226,13 @@ function M.validate()
             })
         end
 
+        local padding = config.padding
+        if padding ~= nil then
+            append_errors(path .. '.padding', padding, {
+                highlight = { padding.highlight, 'string', nilable },
+            })
+        end
+
         local heading = config.heading
         if heading ~= nil then
             append_errors(path .. '.heading', heading, {
@@ -414,6 +422,7 @@ function M.validate()
         debounce = { config.debounce, 'number' },
         render_modes = string_array(config.render_modes, { 'boolean' }, false),
         anti_conceal = { config.anti_conceal, 'table' },
+        padding = { config.padding, 'table' },
         heading = { config.heading, 'table' },
         code = { config.code, 'table' },
         dash = { config.dash, 'table' },
@@ -471,6 +480,7 @@ function M.validate()
                 debounce = { override.debounce, 'number', true },
                 render_modes = string_array(override.render_modes, {}, true),
                 anti_conceal = { override.anti_conceal, 'table', true },
+                padding = { override.padding, 'table', true },
                 heading = { override.heading, 'table', true },
                 code = { override.code, 'table', true },
                 dash = { override.dash, 'table', true },

Diff for: lua/render-markdown/types.lua

@@ -119,6 +119,9 @@
 ---@field public backgrounds string[]
 ---@field public foregrounds string[]
 
+---@class (exact) render.md.Padding
+---@field public highlight string
+
 ---@class (exact) render.md.AntiConceal
 ---@field public enabled boolean
 ---@field public above integer
@@ -134,6 +137,7 @@
 ---@field public debounce integer
 ---@field public render_modes string[]|boolean
 ---@field public anti_conceal render.md.AntiConceal
+---@field public padding render.md.Padding
 ---@field public heading render.md.Heading
 ---@field public code render.md.Code
 ---@field public dash render.md.Dash