feat: Show help hints

You can hide the help hints by setting `show_help_hints = false` in your
config.

Author: sindrets

README.md

@@ -162,6 +162,7 @@ require("diffview").setup({
   enhanced_diff_hl = false, -- See ':h diffview-config-enhanced_diff_hl'
   git_cmd = { "git" },      -- The git executable followed by default args.
   use_icons = true,         -- Requires nvim-web-devicons
+  show_help_hints = true,   -- Show hints for how to open the help panel
   watch_index = true,       -- Update views and index buffers when the git index changes.
   icons = {                 -- Only applies when use_icons is true.
     folder_closed = "",

doc/diffview_defaults.txt

@@ -10,6 +10,7 @@ require("diffview").setup({
   enhanced_diff_hl = false, -- See |diffview-config-enhanced_diff_hl|
   git_cmd = { "git" },      -- The git executable followed by default args.
   use_icons = true,         -- Requires nvim-web-devicons
+  show_help_hints = true,   -- Show hints for how to open the help panel
   watch_index = true,       -- Update views and index buffers when the git index changes.
   icons = {                 -- Only applies when use_icons is true.
     folder_closed = "",

lua/diffview/config.lua

@@ -39,6 +39,7 @@ M.defaults = {
   enhanced_diff_hl = false,
   git_cmd = { "git" },
   use_icons = true,
+  show_help_hints = true,
   watch_index = true,
   icons = {
     folder_closed = "",
@@ -331,6 +332,22 @@ function M.get_layout_keymaps(layout)
   end
 end
 
+function M.find_option_keymap(t)
+  for _, mapping in ipairs(t) do
+    if mapping[3] and mapping[3] == actions.options then
+      return mapping
+    end
+  end
+end
+
+function M.find_help_keymap(t)
+  for _, mapping in ipairs(t) do
+    if type(mapping[4]) == "table" and mapping[4].desc == "Open the help panel" then
+      return mapping
+    end
+  end
+end
+
 ---@param values vector
 ---@param no_quote? boolean
 ---@return string

lua/diffview/scene/views/diff/file_panel.lua

@@ -21,6 +21,7 @@ local M = {}
 ---@field render_data RenderData
 ---@field components CompStruct
 ---@field constrain_cursor function
+---@field help_mapping string
 local FilePanel = oop.create_class("FilePanel", Panel)
 
 FilePanel.winopts = vim.tbl_extend("force", Panel.winopts, {
@@ -79,6 +80,9 @@ function FilePanel:setup_buffer()
     local opt = vim.tbl_extend("force", default_opt, mapping[4] or {}, { buffer = self.bufid })
     vim.keymap.set(mapping[1], mapping[2], mapping[3], opt)
   end
+
+  local help_keymap = config.find_help_keymap(conf.keymaps.file_panel)
+  if help_keymap then self.help_mapping = help_keymap[2] end
 end
 
 function FilePanel:update_components()

lua/diffview/scene/views/diff/render.lua

@@ -126,7 +126,9 @@ return function(panel)
   end
 
   panel.render_data:clear()
+  local conf = config.get_config()
   local width = panel:get_width()
+
   if width == -1 then
     local panel_config = panel:get_config()
     width = panel_config.width
@@ -140,6 +142,12 @@ return function(panel)
     "DiffviewFilePanelRootPath"
   )
 
+  if conf.show_help_hints and panel.help_mapping then
+    comp:add_text("Help: ", "DiffviewFilePanelPath")
+    comp:add_line(panel.help_mapping, "DiffviewFilePanelCounter")
+    comp:add_line()
+  end
+
   if #panel.files.conflicting > 0 then
     comp = panel.components.conflicting.title.comp
     comp:add_text("Conflicts ", "DiffviewFilePanelTitle")

lua/diffview/scene/views/file_history/file_history_panel.lua

@@ -34,6 +34,7 @@ local perf_update = PerfTimer("[FileHistoryPanel] update")
 ---@field render_data RenderData
 ---@field option_panel FHOptionPanel
 ---@field option_mapping string
+---@field help_mapping string
 ---@field components CompStruct
 ---@field constrain_cursor function
 local FileHistoryPanel = oop.create_class("FileHistoryPanel", Panel.__get())
@@ -125,18 +126,18 @@ end
 
 function FileHistoryPanel:setup_buffer()
   local conf = config.get_config()
-  local option_rhs = config.actions.options
   local default_opt = { silent = true, nowait = true, buffer = self.bufid }
 
   for _, mapping in ipairs(conf.keymaps.file_history_panel) do
-    local lhs, rhs = mapping[2], mapping[3]
     local opt = vim.tbl_extend("force", default_opt, mapping[4] or {}, { buffer = self.bufid })
     vim.keymap.set(mapping[1], mapping[2], mapping[3], opt)
-
-    if rhs == option_rhs then
-      self.option_mapping = lhs
-    end
   end
+
+  local option_keymap = config.find_option_keymap(conf.keymaps.file_history_panel)
+  if option_keymap then self.option_mapping = option_keymap[2] end
+
+  local help_keymap = config.find_help_keymap(conf.keymaps.file_history_panel)
+  if help_keymap then self.help_mapping = help_keymap[2] end
 end
 
 function FileHistoryPanel:update_components()

lua/diffview/scene/views/file_history/render.lua

@@ -155,10 +155,12 @@ return {
 
     perf:reset()
     panel.render_data:clear()
+
     if not cache[panel] then
       prepare_panel_cache(panel)
     end
 
+    local conf = config.get_config()
     local comp = panel.components.header.comp
     local log_options = panel:get_log_options()
     local cached = cache[panel]
@@ -200,6 +202,12 @@ return {
       comp:ln()
     end
 
+    if conf.show_help_hints and panel.help_mapping then
+      comp:add_text("Help: ", "DiffviewFilePanelPath")
+      comp:add_text(panel.help_mapping, "DiffviewFilePanelCounter")
+      comp:ln()
+    end
+
     -- title
     comp = panel.components.log.title.comp
     comp:add_line()