feature: Improve table & code conceal behavior

## Details

Use the current conceal level + metadata to determine how to
render language headers and table cells.

For code blocks we simply check if the langauge element is likely
concealed and if it is not only render an icon isntead of an
icon + the language name.

For table cells things are a little more complicated, but boils
down to using `inline` extmarks to pad the table cells such that
they take up as much space as if nothing were concealed. This
is done through a new table cell style 'padded' which is also the
new default.

Since this relies on inline extmarks it only works with neovim
>= 0.10.0, but will not break for earlier versions, it just will
not perform the padding operation.

Since cells can be any inline code the extmarks we add which shift
text also need to be accounted for in addition to the conceals. This
is easy enough for now since we do not use inline marks much, only
for links really. But it is a point of fragility and means that
table rendering needs to know about the functionality of everything.
Still this is much better than the obtrusive overlay, which users
can continue to use if they prefer.

Author: MeanderingProgrammer

README.md

@@ -152,6 +152,8 @@ require('render-markdown').setup({
 
         (image) @image
     ]],
+    -- Query to be able to identify links in nodes
+    inline_link_query = '[(inline_link) (image)] @link',
     -- The level of logs to write to file: vim.fn.stdpath('state') .. '/render-markdown.log'
     -- Only intended to be used for plugin development / debugging
     log_level = 'error',
@@ -275,8 +277,9 @@ require('render-markdown').setup({
         style = 'full',
         -- Determines how individual cells of a table are rendered:
         --  overlay: writes completely over the table, removing conceal behavior and highlights
-        --  raw: replaces only the '|' characters in each row, leaving the cells completely unmodified
-        cell = 'overlay',
+        --  raw: replaces only the '|' characters in each row, leaving the cells unmodified
+        --  padded: raw + cells are padded with inline extmarks to make up for any concealed text
+        cell = 'padded',
         -- Characters used to replace table border
         -- Correspond to top(3), delimiter(3), bottom(3), vertical, & horizontal
         -- stylua: ignore
@@ -290,6 +293,8 @@ require('render-markdown').setup({
         head = '@markup.heading',
         -- Highlight for everything else, main table rows and the line below
         row = 'Normal',
+        -- Highlight for inline padding used to add back concealed space
+        filler = 'Conceal',
     },
     -- Callouts are a special instance of a 'block_quote' that start with a 'shortcut_link'
     -- Can specify as many additional values as you like following the pattern from any below, such as 'note'
@@ -505,8 +510,9 @@ require('render-markdown').setup({
         style = 'full',
         -- Determines how individual cells of a table are rendered:
         --  overlay: writes completely over the table, removing conceal behavior and highlights
-        --  raw: replaces only the '|' characters in each row, leaving the cells completely unmodified
-        cell = 'overlay',
+        --  raw: replaces only the '|' characters in each row, leaving the cells unmodified
+        --  padded: raw + cells are padded with inline extmarks to make up for any concealed text
+        cell = 'padded',
         -- Characters used to replace table border
         -- Correspond to top(3), delimiter(3), bottom(3), vertical, & horizontal
         -- stylua: ignore
@@ -520,6 +526,8 @@ require('render-markdown').setup({
         head = '@markup.heading',
         -- Highlight for everything else, main table rows and the line below
         row = 'Normal',
+        -- Highlight for inline padding used to add back concealed space
+        filler = 'Conceal',
     },
 })
 ```

demo/box_dash_quote.gif

@@ -17,8 +17,7 @@
 
 # Table
 
-| Heading 1    | Heading 2    |
-| ------------ | ------------ |
-| Row 1 Item 1 | Row 1 Item 2 |
-| Row 2 Item 1 | Row 2 Item 2 |
-| Row 3 Item 1 | Row 3 Item 2 |
+| `Inline Heading` | *Italic Heading*   |
+| ---------------- | ------------------ |
+| Regular Item     | **Bold Item**      |
+| `Item Inline`    | [Link Item](/test) |

demo/callout.gif

@@ -189,6 +189,8 @@ Full Default Configuration ~
 
             (image) @image
         ]],
+        -- Query to be able to identify links in nodes
+        inline_link_query = '[(inline_link) (image)] @link',
         -- The level of logs to write to file: vim.fn.stdpath('state') .. '/render-markdown.log'
         -- Only intended to be used for plugin development / debugging
         log_level = 'error',
@@ -312,8 +314,9 @@ Full Default Configuration ~
             style = 'full',
             -- Determines how individual cells of a table are rendered:
             --  overlay: writes completely over the table, removing conceal behavior and highlights
-            --  raw: replaces only the '|' characters in each row, leaving the cells completely unmodified
-            cell = 'overlay',
+            --  raw: replaces only the '|' characters in each row, leaving the cells unmodified
+            --  padded: raw + cells are padded with inline extmarks to make up for any concealed text
+            cell = 'padded',
             -- Characters used to replace table border
             -- Correspond to top(3), delimiter(3), bottom(3), vertical, & horizontal
             -- stylua: ignore
@@ -327,6 +330,8 @@ Full Default Configuration ~
             head = '@markup.heading',
             -- Highlight for everything else, main table rows and the line below
             row = 'Normal',
+            -- Highlight for inline padding used to add back concealed space
+            filler = 'Conceal',
         },
         -- Callouts are a special instance of a 'block_quote' that start with a 'shortcut_link'
         -- Can specify as many additional values as you like following the pattern from any below, such as 'note'
@@ -547,8 +552,9 @@ TABLES                                          *render-markdown-setup-tables*
             style = 'full',
             -- Determines how individual cells of a table are rendered:
             --  overlay: writes completely over the table, removing conceal behavior and highlights
-            --  raw: replaces only the '|' characters in each row, leaving the cells completely unmodified
-            cell = 'overlay',
+            --  raw: replaces only the '|' characters in each row, leaving the cells unmodified
+            --  padded: raw + cells are padded with inline extmarks to make up for any concealed text
+            cell = 'padded',
             -- Characters used to replace table border
             -- Correspond to top(3), delimiter(3), bottom(3), vertical, & horizontal
             -- stylua: ignore
@@ -562,6 +568,8 @@ TABLES                                          *render-markdown-setup-tables*
             head = '@markup.heading',
             -- Highlight for everything else, main table rows and the line below
             row = 'Normal',
+            -- Highlight for inline padding used to add back concealed space
+            filler = 'Conceal',
         },
     })
 <

demo/heading_code.gif

@@ -27,7 +27,7 @@ demo-callout:
 demo file rows content:
   rm -f demo/{{file}}.gif
   python demo/record.py \
-    --cols "55" \
+    --cols "60" \
     --rows {{rows}} \
     --file demo/{{file}}.md \
     --cast {{file}}.cast \

demo/latex.gif

@@ -103,20 +103,27 @@ M.render_node = function(namespace, buf, capture, node)
         if not util.has_10 then
             return
         end
-        -- Fenced code blocks will pick up varying amounts of leading white space depending on
-        -- the context they are in. This gets lumped into the delimiter node and as a result,
-        -- after concealing, the extmark will be left shifted. Logic below accounts for this.
-        local padding = 0
-        local code_block = ts.parent_in_section(info.node, 'fenced_code_block')
-        if code_block ~= nil then
-            padding = str.leading_spaces(ts.info(code_block, buf).text)
+
+        local icon_text = icon .. ' '
+        if ts.concealed(buf, info) > 0 then
+            -- Fenced code blocks will pick up varying amounts of leading white space depending on
+            -- the context they are in. This gets lumped into the delimiter node and as a result,
+            -- after concealing, the extmark will be left shifted. Logic below accounts for this.
+            local padding = 0
+            local code_block = ts.parent_in_section(info.node, 'fenced_code_block')
+            if code_block ~= nil then
+                padding = str.leading_spaces(ts.info(code_block, buf).text)
+            end
+            icon_text = str.pad(icon_text .. info.text, padding)
         end
+
         local highlight = { icon_highlight }
         if code.style == 'full' then
             highlight = { icon_highlight, code.highlight }
         end
+
         vim.api.nvim_buf_set_extmark(buf, namespace, info.start_row, info.start_col, {
-            virt_text = { { str.pad(icon .. ' ' .. info.text, padding), highlight } },
+            virt_text = { { icon_text, highlight } },
             virt_text_pos = 'inline',
         })
     elseif capture == 'list_marker' then
@@ -220,31 +227,19 @@ M.render_node = function(namespace, buf, capture, node)
                 return
             end
 
-            ---@param row integer
-            ---@param s string
-            ---@return integer
-            local function get_row_width(row, s)
-                local result = vim.fn.strdisplaywidth(s)
-                if pipe_table.cell == 'raw' then
-                    result = result - ts.concealed(buf, row, s)
-                end
-                return result
-            end
-
             local delim = ts.info(delim_node, buf)
-            local delim_width = get_row_width(delim.start_row, delim.text)
-
             local lines = vim.api.nvim_buf_get_lines(buf, info.start_row, info.end_row, true)
-            local start_width = get_row_width(info.start_row, list.first(lines))
-            local end_width = get_row_width(info.end_row - 1, list.last(lines))
 
+            local delim_width = vim.fn.strdisplaywidth(delim.text)
+            local start_width = vim.fn.strdisplaywidth(list.first(lines))
+            local end_width = vim.fn.strdisplaywidth(list.last(lines))
             if delim_width ~= start_width or start_width ~= end_width then
                 return
             end
 
             local headings = vim.split(delim.text, '|', { plain = true, trimempty = true })
-            local lengths = vim.tbl_map(function(part)
-                return border[11]:rep(vim.fn.strdisplaywidth(part))
+            local lengths = vim.tbl_map(function(cell)
+                return border[11]:rep(vim.fn.strdisplaywidth(cell))
             end, headings)
 
             local line_above = border[1] .. table.concat(lengths, border[2]) .. border[3]
@@ -278,30 +273,6 @@ M.render_node = function(namespace, buf, capture, node)
             })
         end
 
-        ---@param row_info render.md.NodeInfo
-        ---@param highlight string
-        local function render_table_row(row_info, highlight)
-            if pipe_table.cell == 'overlay' then
-                vim.api.nvim_buf_set_extmark(buf, namespace, row_info.start_row, row_info.start_col, {
-                    end_row = row_info.end_row,
-                    end_col = row_info.end_col,
-                    virt_text = { { row_info.text:gsub('|', border[10]), highlight } },
-                    virt_text_pos = 'overlay',
-                })
-            elseif pipe_table.cell == 'raw' then
-                for i = 1, #row_info.text do
-                    if row_info.text:sub(i, i) == '|' then
-                        vim.api.nvim_buf_set_extmark(buf, namespace, row_info.start_row, i - 1, {
-                            end_row = row_info.end_row,
-                            end_col = i - 1,
-                            virt_text = { { border[10], highlight } },
-                            virt_text_pos = 'overlay',
-                        })
-                    end
-                end
-            end
-        end
-
         if pipe_table.style == 'full' then
             render_table_full()
         end
@@ -312,9 +283,9 @@ M.render_node = function(namespace, buf, capture, node)
             if row_type == 'pipe_table_delimiter_row' then
                 render_table_delimiter(row_info)
             elseif row_type == 'pipe_table_header' then
-                render_table_row(row_info, pipe_table.head)
+                M.render_table_row(namespace, buf, row_info, pipe_table.head)
             elseif row_type == 'pipe_table_row' then
-                render_table_row(row_info, pipe_table.row)
+                M.render_table_row(namespace, buf, row_info, pipe_table.row)
             else
                 -- Should only get here if markdown introduces more row types, currently unhandled
                 logger.error('Unhandled markdown row type: ' .. row_type)
@@ -326,4 +297,65 @@ M.render_node = function(namespace, buf, capture, node)
     end
 end
 
+---@param namespace integer
+---@param buf integer
+---@param info render.md.NodeInfo
+---@param highlight string
+M.render_table_row = function(namespace, buf, info, highlight)
+    ---@param text string
+    ---@return integer
+    local function inline_width(text)
+        local query = state.inline_link_query
+        local tree = vim.treesitter.get_string_parser(text, 'markdown_inline')
+        local result = 0
+        for id in query:iter_captures(tree:parse()[1]:root(), text) do
+            if query.captures[id] == 'link' then
+                result = result + vim.fn.strdisplaywidth(state.config.link.hyperlink)
+            end
+        end
+        return result
+    end
+
+    local pipe_table = state.config.pipe_table
+    local border = pipe_table.border
+
+    if vim.tbl_contains({ 'raw', 'padded' }, pipe_table.cell) then
+        for cell in info.node:iter_children() do
+            local cell_info = ts.info(cell, buf)
+            local cell_type = cell_info.node:type()
+            if cell_type == '|' then
+                vim.api.nvim_buf_set_extmark(buf, namespace, cell_info.start_row, cell_info.start_col, {
+                    end_row = cell_info.end_row,
+                    end_col = cell_info.end_col,
+                    virt_text = { { border[10], highlight } },
+                    virt_text_pos = 'overlay',
+                })
+            elseif cell_type == 'pipe_table_cell' then
+                if pipe_table.cell == 'padded' then
+                    -- Requires inline extmarks
+                    if util.has_10 then
+                        local concealed = ts.concealed(buf, cell_info) - inline_width(cell_info.text)
+                        if concealed > 0 then
+                            vim.api.nvim_buf_set_extmark(buf, namespace, cell_info.start_row, cell_info.end_col, {
+                                virt_text = { { str.pad('', concealed), pipe_table.filler } },
+                                virt_text_pos = 'inline',
+                            })
+                        end
+                    end
+                end
+            else
+                -- Should only get here if markdown introduces more cell types, currently unhandled
+                logger.error('Unhandled markdown cell type: ' .. cell_type)
+            end
+        end
+    elseif pipe_table.cell == 'overlay' then
+        vim.api.nvim_buf_set_extmark(buf, namespace, info.start_row, info.start_col, {
+            end_row = info.end_row,
+            end_col = info.end_col,
+            virt_text = { { info.text:gsub('|', border[10]), highlight } },
+            virt_text_pos = 'overlay',
+        })
+    end
+end
+
 return M