From ec41c8b1202942bcaee6059c44a333e3b1b852d5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stevan=20Mili=C4=87?= <stevan.milic@yahoo.com>
Date: Sat, 9 Jul 2022 20:55:43 +0200
Subject: [PATCH] feat: add highlighting of selected region #57

---
 README.md                |  5 ++++-
 doc/gitlinker.txt        |  3 +++
 lua/gitlinker.lua        |  5 +++++
 lua/gitlinker/buffer.lua | 28 ++++++++++++++++++++++++++++
 lua/gitlinker/opts.lua   |  6 ++++++
 5 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 4db4a989..1a90bef9 100644
--- a/README.md
+++ b/README.md
@@ -70,7 +70,7 @@ require"gitlinker".setup()
 - `<leader>gy` for normal and visual mode
 
 When used, it will copy the generated url to your clipboard and print it in
-`:messages`.
+`:messages` with highlight of the selected region.
 
 - In normal mode, it will add the current line number to the url
 - In visual mode , it will add the line range of the visual selection to the url
@@ -126,6 +126,9 @@ require"gitlinker".setup({
     action_callback = require"gitlinker.actions".copy_to_clipboard,
     -- print the url after performing the action
     print_url = 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,
   },
   callbacks = {
         ["github.com"] = require"gitlinker.hosts".get_github_type_url,
diff --git a/doc/gitlinker.txt b/doc/gitlinker.txt
index 478133c1..0d88e9f2 100644
--- a/doc/gitlinker.txt
+++ b/doc/gitlinker.txt
@@ -124,6 +124,9 @@ Here’s all the options with their defaults:
       action_callback = require"gitlinker.actions".copy_to_clipboard,
       -- print the url after performing the action
       print_url = 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,
       -- mapping to call url generation
       mappings = "<leader>gy"
     },
diff --git a/lua/gitlinker.lua b/lua/gitlinker.lua
index c1b64fcb..f16dad6a 100644
--- a/lua/gitlinker.lua
+++ b/lua/gitlinker.lua
@@ -124,6 +124,11 @@ function M.get_buf_range_url(mode, user_opts)
 
   local url = matching_callback(url_data)
 
+  if user_opts.highlight_duration >= 0 then
+    buffer.highlight_range(url_data)
+    vim.defer_fn(buffer.clear_highlights, user_opts.highlight_duration)
+  end
+
   if user_opts.action_callback then
     user_opts.action_callback(url)
   end
diff --git a/lua/gitlinker/buffer.lua b/lua/gitlinker/buffer.lua
index a2e04bb4..35562212 100644
--- a/lua/gitlinker/buffer.lua
+++ b/lua/gitlinker/buffer.lua
@@ -24,4 +24,32 @@ function M.get_range(mode, add_current_line_on_normal_mode)
   return { lstart = lstart, lend = lend }
 end
 
+--[[
+Highlights the text selected by the specified range.
+]]
+M.highlight_range = function(range)
+  local namespace = vim.api.nvim_create_namespace("NvimGitLinker")
+  local pos1 = { range.lstart - 1, 1 }
+  local pos2 = { (range.lend or range.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_highlights = 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
diff --git a/lua/gitlinker/opts.lua b/lua/gitlinker/opts.lua
index ad58dd18..8487d8dd 100644
--- a/lua/gitlinker/opts.lua
+++ b/lua/gitlinker/opts.lua
@@ -5,6 +5,7 @@ local defaults = {
   add_current_line_on_normal_mode = true, -- if true adds the line nr in the url for normal mode
   action_callback = require("gitlinker.actions").copy_to_clipboard, -- callback for what to do with the url
   print_url = true, -- print the url after action
+  highlight_duration = 100, -- highlight the linked region
 }
 
 local opts
@@ -14,6 +15,11 @@ function M.setup(user_opts)
     opts = vim.tbl_deep_extend("force", {}, defaults)
   end
   opts = vim.tbl_deep_extend("force", opts, user_opts or {})
+
+  -- Configure highlight group
+  if user_opts.highlight_duration >= 0 then
+    vim.api.nvim_set_hl(0, "NvimGitLinkerHighlightTextObject", {link = "Search"})
+  end
 end
 
 function M.get()