Add support for callout syntax

# Details

Resolves: #20

Replaces `shortcut_link` text that matches callout keywords with
configured symbols / text and applies highlights.

Unfortunately highlighting the quote bar itself is NOT supported as
we need information from the inline parser to figure out what
the callout is, while the quote / bar itself is handled by the
standard block level markdown parser.

Passing information between the parsers is not really possible, as
far as I am aware.

Any other solution would rely on a text search and would get tricky
across multi line block quotes, which all callouts are.

Will create a separate issue to make the highlighting consistent.

Author: MeanderingProgrammer

README.md

@@ -19,6 +19,7 @@ Plugin to improve viewing Markdown files in Neovim
 - Updates table borders with better border characters, does NOT automatically align
 - Basic support for `LaTeX` if `pylatexenc` is installed on system
 - Disable rendering when file is larger than provided value
+- Support for [callouts](https://github.com/orgs/community/discussions/16925)
 
 # Dependencies
 
@@ -103,6 +104,8 @@ require('render-markdown').setup({
     -- Capture groups that get pulled from inline markdown
     inline_query = [[
         (code_span) @code
+
+        (shortcut_link) @callout
     ]],
     -- The level of logs to write to file: vim.fn.stdpath('state') .. '/render-markdown.log'
     -- Only intended to be used for plugin development / debugging
@@ -126,6 +129,14 @@ require('render-markdown').setup({
     },
     -- Character that will replace the > at the start of block quotes
     quote = '┃',
+    -- Symbol / text to use for different callouts
+    callout = {
+        note = '  Note',
+        tip = '  Tip',
+        important = '󰅾  Important',
+        warning = '  Warning',
+        caution = '󰳦  Caution',
+    },
     -- See :h 'conceallevel' for more information about meaning of values
     conceal = {
         -- conceallevel used for buffer when not being rendered, get user setting
@@ -175,6 +186,14 @@ require('render-markdown').setup({
         latex = '@markup.math',
         -- Quote character in a block quote
         quote = '@markup.quote',
+        -- Highlights to use for different callouts
+        callout = {
+            note = 'DiagnosticInfo',
+            tip = 'DiagnosticOk',
+            important = 'DiagnosticHint',
+            warning = 'DiagnosticWarn',
+            caution = 'DiagnosticError',
+        },
     },
 })
 ```

demo/demo.gif

@@ -9,9 +9,10 @@ def main(zoom: int, file: str, cast: str) -> None:
     pyautogui.hotkey("`", "c")
     time.sleep(1.0)
 
-    # Zoom in
-    for _ in range(zoom):
-        pyautogui.hotkey("command", "=")
+    # Zoom in / out
+    zoom_key = "=" if zoom >= 0 else "-"
+    for _ in range(abs(zoom)):
+        pyautogui.hotkey("command", zoom_key)
 
     # Start recording demo file
     # https://docs.asciinema.org/manual/cli/usage/

demo/record.py

@@ -20,6 +20,12 @@ if __name__ == "__main__":
     main()
 ```
 
+> [!NOTE]
+> [!TIP]
+> [!IMPORTANT]
+> [!WARNING]
+> [!CAUTION]
+
 - List Item 1: with [link](https://example.com)
 * List Item 2: with `inline` code
     * Nested List 1 Item 1

demo/sample.md

@@ -1,4 +1,4 @@
-*render-markdown.txt*            For 0.10.0           Last change: 2024 May 21
+*render-markdown.txt*            For 0.10.0           Last change: 2024 May 22
 
 ==============================================================================
 Table of Contents                          *render-markdown-table-of-contents*
@@ -40,6 +40,7 @@ Plugin to improve viewing Markdown files in Neovim
 - Updates table borders with better border characters, does NOT automatically align
 - Basic support for `LaTeX` if `pylatexenc` is installed on system
 - Disable rendering when file is larger than provided value
+- Support for callouts <https://github.com/orgs/community/discussions/16925>
 
 
 ==============================================================================
@@ -132,6 +133,8 @@ modified by the user.
         -- Capture groups that get pulled from inline markdown
         inline_query = [[
             (code_span) @code
+    
+            (shortcut_link) @callout
         ]],
         -- The level of logs to write to file: vim.fn.stdpath('state') .. '/render-markdown.log'
         -- Only intended to be used for plugin development / debugging
@@ -155,6 +158,14 @@ modified by the user.
         },
         -- Character that will replace the > at the start of block quotes
         quote = '┃',
+        -- Symbol / text to use for different callouts
+        callout = {
+            note = '  Note',
+            tip = '  Tip',
+            important = '󰅾  Important',
+            warning = '  Warning',
+            caution = '󰳦  Caution',
+        },
         -- See :h 'conceallevel' for more information about meaning of values
         conceal = {
             -- conceallevel used for buffer when not being rendered, get user setting
@@ -204,6 +215,14 @@ modified by the user.
             latex = '@markup.math',
             -- Quote character in a block quote
             quote = '@markup.quote',
+            -- Highlights to use for different callouts
+            callout = {
+                note = 'DiagnosticInfo',
+                tip = 'DiagnosticOk',
+                important = 'DiagnosticHint',
+                warning = 'DiagnosticWarn',
+                caution = 'DiagnosticError',
+            },
         },
     })
 <

doc/render-markdown.txt

@@ -1,5 +1,5 @@
 init := "tests/minimal.lua"
-default_zoom := "2"
+default_zoom := "-2"
 
 test:
   nvim --headless --noplugin -u {{init}} \

justfile

@@ -2,7 +2,7 @@ local logger = require('render-markdown.logger')
 local state = require('render-markdown.state')
 
 ---@class render.md.Cache
----@field expressions table<string,string[]>
+---@field expressions table<string, string[]>
 
 ---@type render.md.Cache
 local cache = {

lua/render-markdown/handler/latex.lua

@@ -10,6 +10,7 @@ M.render = function(namespace, root, buf)
     local highlights = state.config.highlights
     for id, node in state.inline_query:iter_captures(root, buf) do
         local capture = state.inline_query.captures[id]
+        local value = vim.treesitter.get_node_text(node, buf)
         local start_row, start_col, end_row, end_col = node:range()
         logger.debug_node(capture, node, buf)
 
@@ -19,6 +20,24 @@ M.render = function(namespace, root, buf)
                 end_col = end_col,
                 hl_group = highlights.code,
             })
+        elseif capture == 'callout' then
+            local value_to_key = {
+                ['[!NOTE]'] = 'note',
+                ['[!TIP]'] = 'tip',
+                ['[!IMPORTANT]'] = 'important',
+                ['[!WARNING]'] = 'warning',
+                ['[!CAUTION]'] = 'caution',
+            }
+            local key = value_to_key[value]
+            if key ~= nil then
+                local virt_text = { state.config.callout[key], highlights.callout[key] }
+                vim.api.nvim_buf_set_extmark(buf, namespace, start_row, start_col, {
+                    end_row = end_row,
+                    end_col = end_col,
+                    virt_text = { virt_text },
+                    virt_text_pos = 'overlay',
+                })
+            end
         else
             -- Should only get here if user provides custom capture, currently unhandled
             logger.error('Unhandled inline capture: ' .. capture)

lua/render-markdown/handler/markdown_inline.lua

@@ -4,6 +4,13 @@ local util = require('render-markdown.util')
 
 local M = {}
 
+---@class render.md.UserCallout
+---@field public note? string
+---@field public tip? string
+---@field public important? string
+---@field public warning? string
+---@field public caution? string
+
 ---@class render.md.UserTableHighlights
 ---@field public head? string
 ---@field public row? string
@@ -25,6 +32,7 @@ local M = {}
 ---@field public table? render.md.UserTableHighlights
 ---@field public latex? string
 ---@field public quote? string
+---@field public callout? render.md.UserCallout
 
 ---@class render.md.UserConceal
 ---@field public default? integer
@@ -47,6 +55,7 @@ local M = {}
 ---@field public bullets? string[]
 ---@field public checkbox? render.md.UserCheckbox
 ---@field public quote? string
+---@field public callout? render.md.UserCallout
 ---@field public conceal? render.md.UserConceal
 ---@field public table_style? 'full'|'normal'|'none'
 ---@field public highlights? render.md.UserHighlights
@@ -90,6 +99,8 @@ function M.setup(opts)
         ]],
         inline_query = [[
             (code_span) @code
+
+            (shortcut_link) @callout
         ]],
         log_level = 'error',
         file_types = { 'markdown' },
@@ -102,6 +113,13 @@ function M.setup(opts)
             checked = ' ',
         },
         quote = '┃',
+        callout = {
+            note = '  Note',
+            tip = '  Tip',
+            important = '󰅾  Important',
+            warning = '  Warning',
+            caution = '󰳦  Caution',
+        },
         conceal = {
             default = vim.opt.conceallevel:get(),
             rendered = 3,
@@ -132,6 +150,13 @@ function M.setup(opts)
             },
             latex = '@markup.math',
             quote = '@markup.quote',
+            callout = {
+                note = 'DiagnosticInfo',
+                tip = 'DiagnosticOk',
+                important = 'DiagnosticHint',
+                warning = 'DiagnosticWarn',
+                caution = 'DiagnosticError',
+            },
         },
     }
     state.config = vim.tbl_deep_extend('force', default_config, opts or {})

lua/render-markdown/init.lua

@@ -1,3 +1,10 @@
+---@class render.md.Callout
+---@field public note string
+---@field public tip string
+---@field public important string
+---@field public warning string
+---@field public caution string
+
 ---@class render.md.TableHighlights
 ---@field public head string
 ---@field public row string
@@ -19,6 +26,7 @@
 ---@field public table render.md.TableHighlights
 ---@field public latex string
 ---@field public quote string
+---@field public callout render.md.Callout
 
 ---@class render.md.Conceal
 ---@field public default integer
@@ -41,6 +49,7 @@
 ---@field public bullets string[]
 ---@field public checkbox render.md.Checkbox
 ---@field public quote string
+---@field public callout render.md.Callout
 ---@field public conceal render.md.Conceal
 ---@field public table_style 'full'|'normal'|'none'
 ---@field public highlights render.md.Highlights