feat: align table cells according to indicators

## Details

This adds full support for rendering table cells using alignment
indicators and shifting text as needed to accomplish this. This works
with both the `padded` and `trimmed` cell styles.

An additional property `pipe_table.padding` was also added which
defaults to 1 and is used to determine the minimum padding needed within
each table cell. This works even if the cell underneath has no padding as
well as being shifted any amount in any direction. Centering in narrow
cells can sometimes look strange as the inability to use half widths
can make the off by one seem larger, but there's really no way around this
and most of the time it looks great. I'm pretty happy with this one :)

This also modifies the rendering of the center indicator in the
delimiter row to be 2 dashes on both ends of the cell rather than one in
the middle, I think this looks a little better.

Author: MeanderingProgrammer

CHANGELOG.md

@@ -12,11 +12,14 @@
   [965c222](https://github.com/MeanderingProgrammer/render-markdown.nvim/commit/965c222076b2d289ed498730845d533780f3c7c7)
 - code language name [#205](https://github.com/MeanderingProgrammer/render-markdown.nvim/issues/205)
   [18c7ef7](https://github.com/MeanderingProgrammer/render-markdown.nvim/commit/18c7ef71fb4b8d83cb0160adc9127fc4d65ca42e)
+- anti conceal per component [#204](https://github.com/MeanderingProgrammer/render-markdown.nvim/issues/204)
+  [fb6b3d1](https://github.com/MeanderingProgrammer/render-markdown.nvim/commit/fb6b3d145e5e12b838c0b84124354802f381b1af)
 
 ### Bug Fixes
 
 - bullet point right padding priority [#199](https://github.com/MeanderingProgrammer/render-markdown.nvim/issues/199)
   [b02c8ef](https://github.com/MeanderingProgrammer/render-markdown.nvim/commit/b02c8ef72b10537a346556696b6e7fb354c8771f)
+- window offset bottom calculation [e13ac2c](https://github.com/MeanderingProgrammer/render-markdown.nvim/commit/e13ac2c05d2f081453db1451ec07fbd8be33ceec)
 
 ## 7.3.0 (2024-10-04)
 

README.md

@@ -6,7 +6,7 @@ Plugin to improve viewing Markdown files in Neovim
 
 |           |         |
 | --------- | ------- |
-| ![Heading](https://github.com/user-attachments/assets/6d5ca2d3-3263-4ccd-beaf-b5795167d776) | ![Table](https://github.com/user-attachments/assets/7c7e6351-baff-4e72-b668-2e4fac76e276) |
+| ![Heading](https://github.com/user-attachments/assets/6d5ca2d3-3263-4ccd-beaf-b5795167d776) | ![Table](https://github.com/user-attachments/assets/b071b31f-fc17-4665-bf75-2e533eae4686) |
 | ![Quote](https://github.com/user-attachments/assets/dba88e99-bff5-4b33-9017-ab55c1058d21)   | ![LaTeX](https://github.com/user-attachments/assets/85bac8f1-c7df-4078-9e9c-374de9b08e03) |
 | ![Callout](https://github.com/user-attachments/assets/bea7e1b9-d77f-4c3f-abf8-f6262b05fad2) | |
 
@@ -33,7 +33,7 @@ Plugin to improve viewing Markdown files in Neovim
   - Checkboxes: icon, color, user defined states [^1]
   - Block quotes: icon, color, line breaks [^1]
   - Callouts: icon, color, user defined values, Github & Obsidian defaults
-  - Tables: border, color, alignment indicator, auto align cells always to left [^1]
+  - Tables: border, color, alignment indicator, auto align cells [^1]
   - Links [^1]: icon, color, user defined destinations
   - `LaTeX` blocks [^3]: renders formulas
   - Org indent mode [^1]: per level padding
@@ -431,6 +431,8 @@ require('render-markdown').setup({
         --  padded:  raw + cells are padded to maximum visual width for each column
         --  trimmed: padded except empty space is subtracted from visual width calculation
         cell = 'padded',
+        -- Amount of space to put between cell contents and border
+        padding = 1,
         -- Minimum column width to use for padded or trimmed cell
         min_width = 0,
         -- Characters used to replace table border
@@ -925,6 +927,8 @@ require('render-markdown').setup({
         --  padded:  raw + cells are padded to maximum visual width for each column
         --  trimmed: padded except empty space is subtracted from visual width calculation
         cell = 'padded',
+        -- Amount of space to put between cell contents and border
+        padding = 1,
         -- Minimum column width to use for padded or trimmed cell
         min_width = 0,
         -- Characters used to replace table border

benches/medium_table_spec.lua

@@ -4,7 +4,7 @@ local util = require('benches.util')
 
 describe('medium-table.md', function()
     it('default', function()
-        local base_marks = 240
+        local base_marks = 241
         util.less_than(util.setup('temp/medium-table.md'), 110)
         util.num_marks(base_marks)
 

benches/readme_spec.lua

@@ -4,7 +4,7 @@ local util = require('benches.util')
 
 describe('README.md', function()
     it('default', function()
-        local base_marks = 61
+        local base_marks = 66
         util.less_than(util.setup('README.md'), 50)
         util.num_marks(base_marks)
 

demo/run.py

@@ -2,15 +2,25 @@
 from argparse import ArgumentParser
 from pathlib import Path
 
+INFO: dict[str, tuple[int, str]] = dict(
+    heading_code=(550, "## Heading 2"),
+    list_table=(550, ""),
+    box_dash_quote=(250, ""),
+    latex=(250, ""),
+    callout=(750, ""),
+)
 
-def main(name: str, height: int, content: str):
+
+def main(name: str) -> None:
     in_file = Path(f"demo/{name}.md")
     assert in_file.exists()
 
     out_file = Path(f"demo/{name}.gif")
     if out_file.exists():
         out_file.unlink()
 
+    height, content = INFO[name]
+
     tape = Path("demo/demo.tape")
     tape.write_text(tape_content(in_file, out_file, height, content))
     result = subprocess.run(["vhs", tape])
@@ -52,8 +62,6 @@ def get_move(in_file: Path) -> str:
 
 if __name__ == "__main__":
     parser = ArgumentParser(description="Generate a demo recording using vhs")
-    parser.add_argument("--name", type=str, required=True)
-    parser.add_argument("--height", type=int, required=True)
-    parser.add_argument("--content", type=str, required=True)
+    parser.add_argument("--name", type=str, required=True, choices=INFO.keys())
     args = parser.parse_args()
-    main(args.name, args.height, args.content)
+    main(args.name)

doc/render-markdown.txt

@@ -59,7 +59,7 @@ Plugin to improve viewing Markdown files in Neovim
     - Checkboxes: icon, color, user defined states 
     - Block quotes: icon, color, line breaks 
     - Callouts: icon, color, user defined values, Github & Obsidian defaults
-    - Tables: border, color, alignment indicator, auto align cells always to left 
+    - Tables: border, color, alignment indicator, auto align cells 
     - Links : icon, color, user defined destinations
     - `LaTeX` blocks : renders formulas
     - Org indent mode : per level padding
@@ -480,6 +480,8 @@ Default Configuration ~
             --  padded:  raw + cells are padded to maximum visual width for each column
             --  trimmed: padded except empty space is subtracted from visual width calculation
             cell = 'padded',
+            -- Amount of space to put between cell contents and border
+            padding = 1,
             -- Minimum column width to use for padded or trimmed cell
             min_width = 0,
             -- Characters used to replace table border
@@ -958,6 +960,8 @@ Table Configuration ~
             --  padded:  raw + cells are padded to maximum visual width for each column
             --  trimmed: padded except empty space is subtracted from visual width calculation
             cell = 'padded',
+            -- Amount of space to put between cell contents and border
+            padding = 1,
             -- Minimum column width to use for padded or trimmed cell
             min_width = 0,
             -- Characters used to replace table border

justfile

@@ -36,31 +36,16 @@ cat-log:
 demo: demo-heading demo-list demo-box demo-latex demo-callout
 
 demo-heading:
-  python demo/run.py \
-    --name "heading_code" \
-    --height "550" \
-    --content "## Heading 2"
+  python demo/run.py --name "heading_code"
 
 demo-list:
-  python demo/run.py \
-    --name "list_table" \
-    --height "550" \
-    --content ""
+  python demo/run.py --name "list_table"
 
 demo-box:
-  python demo/run.py \
-    --name "box_dash_quote" \
-    --height "250" \
-    --content ""
+  python demo/run.py --name "box_dash_quote"
 
 demo-latex:
-  python demo/run.py \
-    --name "latex" \
-    --height "250" \
-    --content ""
+  python demo/run.py --name "latex"
 
 demo-callout:
-  python demo/run.py \
-    --name "callout" \
-    --height "750" \
-    --content ""
+  python demo/run.py --name "callout"

lua/render-markdown/health.lua

@@ -4,7 +4,7 @@ local state = require('render-markdown.state')
 local M = {}
 
 ---@private
-M.version = '7.3.8'
+M.version = '7.3.9'
 
 function M.check()
     M.start('version')

lua/render-markdown/init.lua

@@ -74,6 +74,7 @@ local M = {}
 ---@field public preset? render.md.table.Preset
 ---@field public style? render.md.table.Style
 ---@field public cell? render.md.table.Cell
+---@field public padding? integer
 ---@field public min_width? integer
 ---@field public border? string[]
 ---@field public alignment_indicator? string
@@ -542,6 +543,8 @@ M.default_config = {
         --  padded:  raw + cells are padded to maximum visual width for each column
         --  trimmed: padded except empty space is subtracted from visual width calculation
         cell = 'padded',
+        -- Amount of space to put between cell contents and border
+        padding = 1,
         -- Minimum column width to use for padded or trimmed cell
         min_width = 0,
         -- Characters used to replace table border

lua/render-markdown/render/table.lua

@@ -5,9 +5,10 @@ local str = require('render-markdown.core.str')
 
 ---@class render.md.table.Column
 ---@field row integer
----@field col integer
+---@field start_col integer
+---@field end_col integer
 ---@field width integer
----@field free integer
+---@field space { left: integer, right: integer }
 
 ---@class render.md.table.Row
 ---@field info render.md.NodeInfo
@@ -80,9 +81,13 @@ function Render:setup()
     end
     -- Store the max width information in the delimiter
     for _, row in ipairs(rows) do
-        for i, r_column in ipairs(row.columns) do
-            local d_column = delim.columns[i]
-            d_column.width = math.max(d_column.width, r_column.width)
+        for i, column in ipairs(row.columns) do
+            local delim_column, width = delim.columns[i], column.width
+            if self.table.cell == 'trimmed' then
+                local space_available = column.space.left + column.space.right - (2 * self.table.padding)
+                width = width - math.max(space_available, 0)
+            end
+            delim_column.width = math.max(delim_column.width, width)
         end
     end
 
@@ -143,19 +148,26 @@ function Render:parse_row(row, num_columns)
     end
     local columns = {}
     for i, cell in ipairs(cells) do
-        local width = pipes[i + 1].start_col - pipes[i].end_col
-        -- Account for double width glyphs by replacing cell spacing with width
+        local start_col, end_col = pipes[i].end_col, pipes[i + 1].start_col
+        -- Account for double width glyphs by replacing cell range with width
+        local width = end_col - start_col
         width = width - (cell.end_col - cell.start_col) + self.context:width(cell)
-        local free = 0
-        if self.table.cell == 'trimmed' then
-            -- Remove trailing spaces from width calculation except for 1
-            free = math.max(str.spaces('end', cell.text) - 1, 0)
-            width = width - free
-        end
+        local space = {
+            -- Left space comes from the gap between the node start and the pipe start
+            left = math.max(cell.start_col - start_col, 0),
+            -- Right space is attached to the node itself
+            right = math.max(str.spaces('end', cell.text), 0),
+        }
         if width < 0 then
             return nil
         end
-        table.insert(columns, { row = cell.start_row, col = cell.end_col, width = width, free = free })
+        table.insert(columns, {
+            row = cell.start_row,
+            start_col = cell.start_col,
+            end_col = cell.end_col,
+            width = width,
+            space = space,
+        })
     end
     return { info = row, pipes = pipes, columns = columns }
 end
@@ -198,22 +210,19 @@ function Render:delimiter()
     local delim, border = self.data.delim, self.table.border
 
     local sections = Iter.list.map(delim.columns, function(column)
-        local indicator = self.table.alignment_indicator
+        local indicator, box = self.table.alignment_indicator, border[11]
         -- If column is small there's no good place to put the alignment indicator
         -- Alignment indicator must be exactly one character wide
         -- Do not put an indicator for default alignment
-        if column.width < 4 or str.width(indicator) ~= 1 or column.alignment == 'default' then
-            return border[11]:rep(column.width)
+        if column.width < 3 or str.width(indicator) ~= 1 or column.alignment == 'default' then
+            return box:rep(column.width)
         end
-        -- Handle the various alignmnet possibilities
-        local left = border[11]:rep(math.floor(column.width / 2))
-        local right = border[11]:rep(math.ceil(column.width / 2) - 1)
         if column.alignment == 'left' then
-            return indicator .. left .. right
+            return indicator .. box:rep(column.width - 1)
         elseif column.alignment == 'right' then
-            return left .. right .. indicator
+            return box:rep(column.width - 1) .. indicator
         else
-            return left .. indicator .. right
+            return indicator .. box:rep(column.width - 2) .. indicator
         end
     end)
 
@@ -246,22 +255,22 @@ function Render:row(row)
         end
     end
 
-    -- Use low priority to include pipe marks
     if vim.tbl_contains({ 'trimmed', 'padded' }, self.table.cell) then
         for i, column in ipairs(row.columns) do
-            local offset = delim.columns[i].width - column.width - column.free
-            if offset > 0 then
-                self.marks:add(true, column.row, column.col, {
-                    priority = 0,
-                    virt_text = { { str.pad(offset), self.table.filler } },
-                    virt_text_pos = 'inline',
-                })
-            elseif offset < 0 then
-                self.marks:add(true, column.row, column.col + offset, {
-                    priority = 0,
-                    end_col = column.col,
-                    conceal = '',
-                })
+            local delim_column = delim.columns[i]
+            local filler = delim_column.width - column.width
+            if delim_column.alignment == 'center' then
+                local shift = math.floor((filler + column.space.right - column.space.left) / 2)
+                self:shift(column, 'left', shift)
+                self:shift(column, 'right', filler - shift)
+            elseif delim_column.alignment == 'right' then
+                local shift = column.space.right - self.table.padding
+                self:shift(column, 'left', filler + shift)
+                self:shift(column, 'right', -shift)
+            else
+                local shift = column.space.left - self.table.padding
+                self:shift(column, 'left', -shift)
+                self:shift(column, 'right', filler + shift)
             end
         end
     end
@@ -276,6 +285,28 @@ function Render:row(row)
     end
 end
 
+---Use low priority to include pipe marks
+---@private
+---@param column render.md.table.Column
+---@param side 'left'|'right'
+---@param amount integer
+function Render:shift(column, side, amount)
+    local col = side == 'left' and column.start_col or column.end_col
+    if amount > 0 then
+        self.marks:add(true, column.row, col, {
+            priority = 0,
+            virt_text = { { str.pad(amount), self.table.filler } },
+            virt_text_pos = 'inline',
+        })
+    elseif amount < 0 then
+        self.marks:add(true, column.row, col + amount, {
+            priority = 0,
+            end_col = col,
+            conceal = '',
+        })
+    end
+end
+
 ---@private
 function Render:full()
     local delim, rows, border = self.data.delim, self.data.rows, self.table.border