feat: anti conceal selected range in visual mode

## Details

Request: #168

Rather than removing marks on current row only, for visual mode
specifically use the range of the selected text.

This allows users to see what's actually being selected rather that
still being overlayed by marks.

All other modes continue to behave the same as before.

Moves the logic for caclulating the hidden range out of `extmark` module
and into `ui` since that now seems like a better fit.

Author: MeanderingProgrammer

lua/render-markdown/core/extmark.lua

@@ -30,10 +30,9 @@ function Extmark:overlaps(row)
     return not (start_row > row or end_row <= row)
 end
 
----@param config render.md.buffer.Config
----@param row? integer
-function Extmark:render(config, row)
-    if self:should_show(config.anti_conceal, row) then
+---@param hide_range { [1]: integer, [2]: integer }?
+function Extmark:render(hide_range)
+    if self:should_show(hide_range) then
         self:show()
     else
         self:hide()
@@ -62,27 +61,16 @@ function Extmark:hide()
     end
 end
 
----Render marks based on anti-conceal behavior and current row
 ---@private
----@param anti_conceal render.md.AntiConceal
----@param row? integer
+---@param hide_range { [1]: integer, [2]: integer }?
 ---@return boolean
-function Extmark:should_show(anti_conceal, row)
-    -- Anti-conceal is not enabled -> all marks should be shown
-    if not anti_conceal.enabled then
+function Extmark:should_show(hide_range)
+    if hide_range == nil or not self.mark.conceal then
         return true
     end
-    -- Row is not known means buffer is not active -> all marks should be shown
-    if row == nil then
-        return true
-    end
-    -- Mark is not concealable -> mark should always be shown
-    if not self.mark.conceal then
-        return true
-    end
-    -- Show mark if it is outside current row range
-    local mark_row = self.mark.start_row
-    return mark_row < row - anti_conceal.above or mark_row > row + anti_conceal.below
+    -- Show mark if it is outside hidden range
+    local row = self.mark.start_row
+    return row < hide_range[1] or row > hide_range[2]
 end
 
 return Extmark

lua/render-markdown/core/ui.lua

@@ -87,8 +87,9 @@ function M.update(buf, win, parse)
 
     local config = state.get_config(buf)
     local buffer_state = cache[buf]
+    local mode = vim.fn.mode(true)
 
-    local next_state = M.next_state(config, win)
+    local next_state = M.next_state(config, win, mode)
     if next_state ~= buffer_state.state then
         for name, value in pairs(config.win_options) do
             util.set_win(win, name, value[next_state])
@@ -102,8 +103,9 @@ 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)
         for _, mark in ipairs(buffer_state.marks) do
-            mark:render(config, row)
+            mark:render(hide_range)
         end
     else
         M.clear(buf, buffer_state)
@@ -113,8 +115,9 @@ end
 ---@private
 ---@param config render.md.buffer.Config
 ---@param win integer
+---@param mode string
 ---@return 'default'|'rendered'
-function M.next_state(config, win)
+function M.next_state(config, win, mode)
     if not state.enabled then
         return 'default'
     end
@@ -124,12 +127,34 @@ function M.next_state(config, win)
     if not util.view(win).leftcol == 0 then
         return 'default'
     end
-    if not config:render(vim.fn.mode(true)) then
+    if not config:render(mode) then
         return 'default'
     end
     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

lua/render-markdown/health.lua

@@ -4,7 +4,7 @@ local state = require('render-markdown.state')
 local M = {}
 
 ---@private
-M.version = '7.0.8'
+M.version = '7.0.9'
 
 function M.check()
     M.start('version')