fix: handle all visual modes when getting range

## Details

When getting the range of hidden lines for visual mode only the base
character-wise mode ('v') was handled.

This change adds support for line-wise ('V') and block-wise ('<C-v>').

Minor other changes:

- Moves the hidden calculation out of UI and into config
- Makes UI cache a class that creates new states if they are missing on
  get so that logic exists in a single place
- Rename `get_config` method in state module to just `get`

Author: MeanderingProgrammer

Diff for: CHANGELOG.md

@@ -9,10 +9,20 @@
 - table min width [f84eeae](https://github.com/MeanderingProgrammer/render-markdown.nvim/commit/f84eeaebac278e26bd2906fd47747631716a5edb)
 - new debug API for development [6f87257](https://github.com/MeanderingProgrammer/render-markdown.nvim/commit/6f8725746ecadae0ae5ab3e7a1a445dad6b2e231)
 - `render_modes` as a boolean [7493db6](https://github.com/MeanderingProgrammer/render-markdown.nvim/commit/7493db6d3fe3f6679549e6020498f72e97cd9b73)
+- anti conceal selected range in visual mode [#168](https://github.com/MeanderingProgrammer/render-markdown.nvim/issues/168)
+  [5ff191f](https://github.com/MeanderingProgrammer/render-markdown.nvim/commit/5ff191f0c7457ede2fd30ecf76ab16c65118b4ee)
+- disable rendering in diff mode [#169](https://github.com/MeanderingProgrammer/render-markdown.nvim/issues/169)
+  [01b38dc](https://github.com/MeanderingProgrammer/render-markdown.nvim/commit/01b38dcf7d0a99620547651fb59a3ba521ba12d5)
 
 ### Bug Fixes
 
 - indent with block widths [044f2d6](https://github.com/MeanderingProgrammer/render-markdown.nvim/commit/044f2d6d76712de69a79b25a7cd8311cb505a9f4)
+- nil buffer state [#171](https://github.com/MeanderingProgrammer/render-markdown.nvim/issues/171)
+  [#172](https://github.com/MeanderingProgrammer/render-markdown.nvim/pull/172)
+
+### Collaborator Shoutouts
+
+- @xudyang1
 
 ## 7.0.0 (2024-09-13)
 

Diff for: doc/render-markdown.txt

@@ -1,4 +1,4 @@
-*render-markdown.txt*         For 0.10.0        Last change: 2024 September 17
+*render-markdown.txt*         For 0.10.0        Last change: 2024 September 18
 
 ==============================================================================
 Table of Contents                          *render-markdown-table-of-contents*

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

@@ -40,4 +40,21 @@ function Config:render(mode)
     end
 end
 
+---@param mode string
+---@param row? integer
+---@return Range2?
+function Config:hidden(mode, row)
+    -- Anti-conceal is not enabled -> hide nothing
+    -- Row is not known means buffer is not active -> hide nothing
+    if not self.anti_conceal.enabled or row == nil then
+        return nil
+    end
+    if vim.tbl_contains({ 'v', 'V', '\22' }, mode) then
+        local start = vim.fn.getpos('v')[2] - 1
+        return { math.min(row, start), math.max(row, start) }
+    else
+        return { row - self.anti_conceal.above, row + self.anti_conceal.below }
+    end
+end
+
 return Config

Diff for: lua/render-markdown/core/extmark.lua

@@ -30,9 +30,9 @@ function Extmark:overlaps(row)
     return not (start_row > row or end_row <= row)
 end
 
----@param hide_range { [1]: integer, [2]: integer }?
-function Extmark:render(hide_range)
-    if self:should_show(hide_range) then
+---@param hidden Range2?
+function Extmark:render(hidden)
+    if self:should_show(hidden) then
         self:show()
     else
         self:hide()
@@ -62,15 +62,15 @@ function Extmark:hide()
 end
 
 ---@private
----@param hide_range { [1]: integer, [2]: integer }?
+---@param hidden Range2?
 ---@return boolean
-function Extmark:should_show(hide_range)
-    if hide_range == nil or not self.mark.conceal then
+function Extmark:should_show(hidden)
+    if hidden == nil or not self.mark.conceal then
         return true
     end
     -- Show mark if it is outside hidden range
     local row = self.mark.start_row
-    return row < hide_range[1] or row > hide_range[2]
+    return row < hidden[1] or row > hidden[2]
 end
 
 return Extmark

Diff for: lua/render-markdown/core/ui.lua

@@ -12,29 +12,43 @@ local builtin_handlers = {
     latex = require('render-markdown.handler.latex'),
 }
 
----@type table<integer, render.md.BufferState>
-local cache = {}
+---@class render.md.cache.Ui
+---@field states table<integer, render.md.BufferState>
+local Cache = {
+    states = {},
+}
+
+---@param buf integer
+---@return render.md.BufferState
+function Cache.get(buf)
+    local buffer_state = Cache.states[buf]
+    if buffer_state == nil then
+        buffer_state = BufferState.new(buf)
+        Cache.states[buf] = buffer_state
+    end
+    return buffer_state
+end
 
 ---@class render.md.Ui
 local M = {}
 
 M.namespace = vim.api.nvim_create_namespace('render-markdown.nvim')
 
 function M.invalidate_cache()
-    for buf, buffer_state in pairs(cache) do
+    for buf, buffer_state in pairs(Cache.states) do
         M.clear(buf, buffer_state)
     end
-    cache = {}
+    Cache.states = {}
 end
 
 ---@param buf integer
 ---@return integer, render.md.Mark[]
 function M.get_row_marks(buf)
-    local buffer_state, row = cache[buf], util.cursor_row(buf)
-    if buffer_state == nil or row == nil then
+    local row = util.cursor_row(buf)
+    if row == nil then
         return 0, {}
     end
-    local marks = {}
+    local marks, buffer_state = {}, Cache.get(buf)
     for _, extmark in ipairs(buffer_state.marks or {}) do
         if extmark:overlaps(row) then
             table.insert(marks, extmark.mark)
@@ -61,9 +75,7 @@ function M.debounce_update(buf, win, event, change)
         return
     end
 
-    local config = state.get_config(buf)
-    local buffer_state = cache[buf] or BufferState.new(buf)
-    cache[buf] = buffer_state
+    local config, buffer_state = state.get(buf), Cache.get(buf)
 
     if not change and Context.contains_range(buf, win) then
         vim.schedule(function()
@@ -85,12 +97,7 @@ function M.update(buf, win, parse)
         return
     end
 
-    local config = state.get_config(buf)
-    local buffer_state = cache[buf]
-    if not buffer_state then
-        buffer_state = BufferState.new(buf)
-        cache[buf] = buffer_state
-    end
+    local config, buffer_state = state.get(buf), Cache.get(buf)
     local mode = vim.fn.mode(true)
 
     local next_state = M.next_state(config, win, mode)
@@ -107,9 +114,9 @@ function M.update(buf, win, parse)
             buffer_state.marks = M.parse_buffer(buf, win)
         end
         local row = util.cursor_row(buf, win)
-        local hide_range = M.hide_range(config.anti_conceal, mode, row)
+        local hidden = config:hidden(mode, row)
         for _, mark in ipairs(buffer_state.marks) do
-            mark:render(hide_range)
+            mark:render(hidden)
         end
     else
         M.clear(buf, buffer_state)
@@ -137,28 +144,6 @@ function M.next_state(config, win, mode)
     return 'rendered'
 end
 
----@private
----@param config render.md.AntiConceal
----@param mode string
----@param row? integer
----@return { [1]: integer, [2]: integer }?
-function M.hide_range(config, mode, row)
-    -- Anti-conceal is not enabled -> hide nothing
-    if not config.enabled then
-        return nil
-    end
-    -- Row is not known means buffer is not active -> hide nothing
-    if row == nil then
-        return nil
-    end
-    if mode == 'v' then
-        local start = vim.fn.getpos('v')[2] - 1
-        return { math.min(row, start), math.max(row, start) }
-    else
-        return { row - config.above, row + config.below }
-    end
-end
-
 ---@private
 ---@param buf integer
 ---@param win integer

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

@@ -17,7 +17,7 @@ Handler.__index = Handler
 function Handler.new(buf)
     local self = setmetatable({}, Handler)
     self.marks = list.new_marks()
-    self.config = state.get_config(buf)
+    self.config = state.get(buf)
     self.context = Context.get(buf)
     self.renderers = {
         code = require('render-markdown.render.code'),

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

@@ -16,7 +16,7 @@ Handler.__index = Handler
 function Handler.new(buf)
     local self = setmetatable({}, Handler)
     self.marks = list.new_marks()
-    self.config = state.get_config(buf)
+    self.config = state.get(buf)
     self.context = Context.get(buf)
     return self
 end

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

@@ -4,7 +4,7 @@ local state = require('render-markdown.state')
 local M = {}
 
 ---@private
-M.version = '7.0.9'
+M.version = '7.0.10'
 
 function M.check()
     M.start('version')

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

@@ -56,7 +56,7 @@ function M.attach(buf)
     if not M.should_attach(buf) then
         return
     end
-    local config = state.get_config(buf)
+    local config = state.get(buf)
     local events = { 'BufWinEnter', 'BufLeave', 'CursorHold', 'CursorMoved' }
     local change_events = { 'DiffUpdated', 'ModeChanged', 'TextChanged' }
     if config:render('i') then
@@ -95,7 +95,7 @@ function M.should_attach(buf)
         return false
     end
 
-    local config = state.get_config(buf)
+    local config = state.get(buf)
     if not config.enabled then
         log.debug_buf(log_name, buf, 'skip', 'state disabled')
         return false

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

@@ -68,7 +68,7 @@ end
 
 ---@param buf integer
 ---@return render.md.buffer.Config
-function M.get_config(buf)
+function M.get(buf)
     local config = configs[buf]
     if config == nil then
         local buf_config = M.default_buffer_config()

Diff for: tests/state_spec.lua

@@ -23,10 +23,10 @@ describe('state', function()
     it('valid', function()
         eq(0, #validate())
         vim.bo.buftype = ''
-        eq(true, state.get_config(0).sign.enabled)
+        eq(true, state.get(0).sign.enabled)
         state.invalidate_cache()
         vim.bo.buftype = 'nofile'
-        eq(false, state.get_config(0).sign.enabled)
+        eq(false, state.get(0).sign.enabled)
 
         eq(0, #validate({ callout = { note = { raw = 'value' } } }))