feat: add highlighting of selected region (#88)

Author: stevanmilic

README.md

@@ -170,6 +170,10 @@ require('gitlinker').setup({
   -- print message in command line
   message = true,
 
+  -- highlights the linked line(s) by the time in ms
+  -- disable highlight by setting a value equal or less than 0
+  highlight_duration = 100,
+
   -- key mapping
   mapping = {
     ["<leader>gl"] = {

lua/gitlinker.lua

@@ -1,5 +1,6 @@
 local logger = require("gitlinker.logger")
 local Linker = require("gitlinker.linker").Linker
+local highlight = require("gitlinker.highlight")
 
 --- @alias Options table<any, any>
 --- @type Options
@@ -9,6 +10,11 @@ local Defaults = {
     --- @type boolean
     message = true,
 
+    -- highlight the linked region
+    --
+    --- @type integer
+    highlight_duration = 500,
+
     -- key mappings
     --
     --- @alias KeyMappingConfig {action:fun(url:string):nil,desc:string?}
@@ -130,6 +136,15 @@ local function setup(opts)
         end
     end
 
+    -- Configure highlight group
+    if Configs.highlight_duration >= 0 then
+        vim.api.nvim_set_hl(
+            0,
+            "NvimGitLinkerHighlightTextObject",
+            { link = "Search" }
+        )
+    end
+
     -- logger.debug("|setup| Configs:%s", vim.inspect(Configs))
 end
 
@@ -211,6 +226,10 @@ local function link(opts)
     if opts.action then
         opts.action(url)
     end
+    if opts.highlight_duration >= 0 then
+        highlight.show({ lstart = lk.lstart, lend = lk.lend })
+        vim.defer_fn(highlight.clear, opts.highlight_duration)
+    end
     if opts.message then
         local msg = lk.file_changed
                 and string.format(

lua/gitlinker/highlight.lua

@@ -0,0 +1,36 @@
+local M = {}
+
+-- Highlights the text selected by the specified range.
+--- @param range Range?
+M.show = function(range)
+    if not range then
+        return
+    end
+    local namespace = vim.api.nvim_create_namespace("NvimGitLinker")
+    local lstart, lend = range.lstart, range.lend
+    if lend and lend < lstart then
+        lstart, lend = lend, lstart
+    end
+    local pos1 = { lstart - 1, 1 }
+    local pos2 = { (lend or lstart) - 1, vim.fn.col("$") }
+    vim.highlight.range(
+        0,
+        namespace,
+        "NvimGitLinkerHighlightTextObject",
+        pos1,
+        pos2,
+        { inclusive = true }
+    )
+    -- Force the screen to highlight the text immediately
+    vim.cmd("redraw")
+end
+
+-- Clears the gitlinker highlights for the buffer.
+M.clear = function()
+    local namespace = vim.api.nvim_create_namespace("NvimGitLinker")
+    vim.api.nvim_buf_clear_namespace(0, namespace, 0, -1)
+    -- Force the screen to clear the highlight immediately
+    vim.cmd("redraw")
+end
+
+return M