todo: open hexer on visual selection

README.md

@@ -42,6 +42,8 @@ For example, `:Hexer "0x45"` would produce the following table:
 └─────┴─────┴────┴─────────┴─────┘
 ```
 
+You can also run `:Hexer` on a highlighted selection in visual mode, allowing for an easier time looking at unfamiliar code. The argument is restricted from being multiple lines, and it is unadvisable to try and parse a string which is too long.
+
 ## Installation
 *We do be kinda lazy.*
 
@@ -59,20 +61,20 @@ return {
 
 Hexer also exposes two lua functions:
 ```lua
--- open() works the same way as the `:Hexer` command, with both nil representing no argument.
+-- open() parses the passed string arg and opens the hexr buffer, with nil or an empty string representing retaining the past table.
 require("hexer"):open(arg)
 -- close() is how the hexer buffer closes normally. Useful if you want to remap your own close keys.
--- Note that a BufLeave autocmd is with this already set
+-- Note that a BufLeave autocmd is already set for if you leave hexer or open another buffer with it open.
 require("hexer"):close()
 ```
 
 This plugin doesn't take advantage of any special lazy.nvim stuff, just use your other plugin manager's default method.
 
 ## TODO
 - [ ] Handle negative numbers more gracefully
-- [ ] Open hexer on highlighted selection
+- [x] Open hexer on highlighted selection
 - [ ] Create abstraction for representation format
 - [ ] Create config for representation format
 - [ ] Create config for hexer popup options
 - [ ] Expand into some binary operations?
-
+- [ ] Gracefully handle abnormal ascii characters

lua/hexer/init.lua

@@ -13,8 +13,26 @@ function M.setup()
     M._display:_setup_window()
 
     vim.api.nvim_create_user_command("Hexer", function(opts)
-        M._display:hexer_open(opts.args)
-    end, { nargs = "?" })
+        local str = opts.args or ""
+
+        -- Means that a range was supplied to the command, AKA called in visual mode
+        if opts.count ~= -1 then
+            local s_start = vim.fn.getpos("'<")
+            local s_end = vim.fn.getpos("'>")
+            local text = vim.api.nvim_buf_get_text(0, s_start[2] - 1, s_start[3] - 1, s_end[2] - 1, s_end[3], {})[1]
+
+            if text ~= "" then
+                if s_start[2] ~= s_end[2] then
+                    vim.notify("Hexer can only operate on single-line strings!", vim.log.levels.ERROR)
+                    return
+                else
+                    str = text
+                end
+            end
+        end
+
+        M._display:hexer_open(str)
+    end, { nargs = "?", range = true })
 end
 
 return M