Merge pull request #160 from shadmansaleh/conditional_component_loading

CONTRIBUTING.md

@@ -12,6 +12,11 @@ please use lua-format before creating a pr :smile:
 * refer to example below to see how themes are defined
 * take 4 screenshots showing a different vim modes (normal, insert, visual, replace)
 * add your theme with screenshots attached to [THEMES.md](./THEMES.md) while maintaining alphabetical order
+* If the colorscheme you're trying to add already support lightline. You can use
+[lightline2lualine theme converter](https://gist.github.com/shadmansaleh/000871c9a608a012721c6acc6d7a19b9) to easily port the theme to lualine.
+
+**Note to colorscheme authors** : If you want to support lualine. You can put your
+lualine theme at lua/lualine/themes/{your_colorscheme}.lua in you repo.
 
 <details>
 <summary><b>theme example</b></summary>

README.md

@@ -24,6 +24,13 @@ Here is a preview of how lualine can look like.
 
 Screenshots of all available themes are listed in [THEMES.md](./THEMES.md)
 
+For those who want to break the norms. You can create custom looks in lualine .
+
+**Example** :
+
+- [evil_lualine](https://gist.github.com/shadmansaleh/cd526bc166237a5cbd51429cc1f6291b)
+![evil_lualine_image](https://user-images.githubusercontent.com/13149513/113875129-4453ba00-97d8-11eb-8f21-94a9ef565db3.png)
+
 ## Performance compared to other plugins
 Unlike other statusline plugins lualine loads only defined components, nothing else.
 
@@ -81,6 +88,28 @@ All available themes are listed in [THEMES.md](./THEMES.md)
 
 Please create a pr if you managed to port a popular theme before me, [here is how to do it](./CONTRIBUTING.md).
 
+<details>
+<summary>Tweeking themes</summary>
+
+You like a theme but would like to tweek some colors.
+You can do that in your config easily.
+
+Example:
+```lua
+local custom_gruvbox = require'lualine.themes.gruvbox'
+
+-- Chnage the background of lualine_c section for normal mode
+custom_gruvbox.normal.c.bg = '#112233' -- rgb colors are supported
+
+require'lualine'.setup{
+  options = { theme  = custom_gruvbox },
+  ...
+}
+```
+You can checkout structure of a lualine theme [here](https://github.com/hoob3rt/lualine.nvim/blob/master/CONTRIBUTING.md#adding-a-theme)
+
+</details>
+
 ### Changing separators
 Lualine defines two kinds of seperators. One is for sections and other is for components. Default section seperators are '', '' and component separators are '', ''.
 They require powerline patched fonts. But you can easily change yours to something else like below
@@ -170,7 +199,7 @@ sections = {lualine_a = {'FugitiveHead'}}
 <details>
 <summary><b>Using variables as lualine component</b></summary>
 
-You can use variables from vim and lua globals as a lualine component
+You can use variables from vim a lualine component
 Variables from g:, v:, t:, w:, b:, o, go:, vo:, to:, wo:, bo: scopes
 can be used. Scopes ending with o are options usualy accessed with `&` in vimscript
 
@@ -180,39 +209,79 @@ sections = {lualine_a = {'g:coc_status', 'bo:filetype'}}
 
 </details>
 
+<details>
+<summary><b>Using lua expressions as lualine component</b></summary>
+
+You can use any valid lua expression as a component . This allows global
+variables to be used as  a component too. Even require statements can be used to access values returned by specific scripts.
+One liner functions can be inlined by utilizeing this .
+
+For exmaple this will show day of the week.
+And 2nd one will display current value of global variabke data.
+
+```lua
+sections = {lualine_c = {"os.data('%a')", 'data'}}
+```
+
+</details>
+
 <details>
 <summary><b>Options for components</b></summary>
 
 ### Available options:
 
+Options can change the way a component behave.
+There are two kinds of options some that work on every kind of component.
+Even the ones you create like custom function component . And some that only
+work on specific component.
+Detailed list of available options are given below.
+
 #### Global options
+These options are available for all components.
 
-Global options change behaviour of all suported components.
-All of these options can also be specifically set to all supported components, full example below.
-
-##### Available global options
 Option   | Default | Behaviour | Supported components
-:------: | :------: | :----------: | :-----:
+:------: | :------: | :------: | :--------:
 icons_enabled      | true     |  Displays icons on components You should have nerd-fonts supported fonts to see icons properly. | branch, fileformat, filetype, location, diagnostics
-padding | 1 | Adds padding to the left and right of components | all
+icon | Differs for each component | Displays an icon in front of the component | All
-left_padding | 1 | Adds padding to the left of components | all
+padding | 1 | Adds padding to the left and right of components | All
-right_padding | 1 | Adds padding to the right of components | all
+left_padding | 1 | Adds padding to the left of components | All
-upper | false | Changes components to be uppercase | all
+right_padding | 1 | Adds padding to the right of components | All
-lower | false | Changes components to be lowercase | all
+separator | (component_separators) | which separator to use at end of component | all
-format | nil | Takes a function . The funtion gets the result of component as argument and it's return value is displayed. So this function can parse and format the output as user wants. | all
+upper | false | Changes components to be uppercase | All
-##### Global options example
+lower | false | Changes components to be lowercase | All
+format | nil | Takes a function . The funtion gets the result of component as argument and it's return value is displayed. So this function can parse and format the output as user wants. | All
+condition | nil | Takes a function. The component is loaded if the function returns true otherwise not. It can be used to load some comoonents on specific cases. | All
+color | nil | Sets custom color for the component in this format<br></br>`color = {fg = '#rrggbb', bg= '#rrggbb', gui='style'}`<br></br>The fields of color table are optional and default to theme <br></br>Color option can also be a string containing highlight group name `color = "WarningMsg"`. One neat trick set the color to highlight group name then change that highlight with :hi command to change color of that component at runtime. | All
+
+#### Using global options
+Global options can be set in two ways. One is as part of options table in setup.
+
 ```lua
-options = {icons_enabled = true}
+require'lualine'.setup{
+  options = {
+    icons_enabled = true,
+    padding = 2,
+  }
+}
+```
+When set this way these values work as default for all component.
+These defaults can be overwritten by setting option as part of component
+configuration like following.
+
+```lua
+lualine_a = {
+  -- Displays only first char of mode name
+  {'mode', format=function(mode_name) return mode_name:sub(1,1) end},
+  -- Disables icon for branch component
+  {'branch', icons_enabled=false},
+},
+lualine_c = {
+  -- Displays filename only when window is wider then 80
+  {'filename', condition=function() return vim.fn.winwidth(0) > 80 end},
+}
 ```
 
 #### Component specific options
-As mentioned above, all global options can be applied to specific components.
-However there are some options which are component-only (you cannot set them as globals)
-Option   | Default | Behaviour
-:------: | :------: | :----:
-icon | Differs for each component | Displays an icon in front of the component
-color | nil | Sets custom color for the component in this format<br></br>`color = {fg = '#rrggbb', bg= '#rrggbb', gui='style'}`<br></br>The fields of color table are optional and default to theme
-
 In addition, some components have unique options.
 
 * `diagnostics` component options
@@ -245,6 +314,8 @@ color_removed | `DiffDelete` foreground color | changes diff's removed section f
 symbols | `{added = '+', modified = '~', removed = '-'}` | changes diff's symbols | table containing on or more symbols |
 
 
+Component specific options can only be set with component configs.
+
 ##### Component options example
 ```lua
 sections = {

doc/lualine.txt

@@ -111,6 +111,25 @@ All available themes are listed in THEMES.md (./THEMES.md)
 Please create a pr if you managed to port a popular theme before me, here is
 how to do it (./CONTRIBUTING.md).
 
+Tweeking themes~
+
+You like a theme but would like to tweek some colors.
+You can do that in your config easily.
+
+Example:
+>
+    local custom_gruvbox = require'lualine.themes.gruvbox'
+
+    -- Chnage the background of lualine_c section for normal mode
+    custom_gruvbox.normal.c.bg = '#112233' -- rgb colors are supported
+
+    require'lualine'.setup{
+      options = { theme  = custom_gruvbox },
+      ...
+    }
+<
+You can checkout structure of a lualine theme [here](https://github.com/hoob3rt/lualine.nvim/blob/master/CONTRIBUTING.md#adding-a-theme)
+
 CHANGING SEPARATOR IN SECTION                       *lualine_changing_separator*
 
 Lualine defines two kinds of seperators. One is for sections and other is
@@ -193,13 +212,27 @@ You can use vim functions as a lualine component
 
 Using variables as lualine component~
 
-You can use variables from vim and lua globals as a lualine component
+You can use variables from vim. Variables from g:, v:, t:,
-Variables from g:, v:, t:, w:, b:, o, go:, vo:, to:, wo:, bo: scopes
+w:, b:, o, go:, vo:, to:, wo:, bo: scopes can be used.
-can be used. Scopes ending with o are options usualy accessed with `&` in vimscript
+Scopes ending with o are options usualy accessed with `&` in
+vimscript
 
 >
     sections = {lualine_a = {'g:coc_status', 'bo:filetype'}}
 <
+Using lua expressions as lualine component~
+
+You can use any valid lua expression as a component . This
+allows global variables to be used as  a component too. Even
+require statements can be used to access values returned by
+specific scripts.  One liner functions can be inlined by
+utilizeing this .
+
+For exmaple this will show day of the week.  And 2nd one
+will display current value of global variabke data.
+>
+    sections = {lualine_c = {"os.data('%a')", 'data'}}
+<
 
 --------------------------------------------------------------------------------
 CUSTOM OPTIONS FOR COMPONENTS                        *lualine_custom_options*
@@ -208,11 +241,17 @@ CUSTOM OPTIONS FOR COMPONENTS                        *lualine_custom_options*
 Options for components~
 ======================
 
-Global options~
+Available options:~
-----------------------
 
-Global options change behaviour of all suported components.
+Options can change the way a component behave.
-All of these options can also be specifically set to all supported components.
+There are two kinds of options some that work on every kind of component.
+Even the ones you create like custom function component . And some that only
+work on specific component.
+Detailed list of available options are given below.
+
+Global options~
+
+These options are available for all components.
 
 option       (default_value)
 ------       ---------------
@@ -222,6 +261,10 @@ option       (default_value)
     You should have nerd-fonts supported fonts to see icons properly.
     Supported components: branch, fileformat, filetype, location, diagnostics
 
+  • icon          (depends on component)
+    displays an icon infront of a component
+    Supported components: all
+
   • padding       (1)
     spaces on left and right
     Supported components: all
@@ -234,6 +277,10 @@ option       (default_value)
     spaces on right
     Supported components: all
 
+  • separator (component_separators)
+    which separator to use at end of component
+    Supported components: all
+
   • upper         (false)
     Displayed in upper case
     Supported components: all
@@ -263,12 +310,53 @@ option       (default_value)
   • icon          (differs for each component)
     displays an icon infront of a component
 
-  • color         (nil)
+  • condition     (nil)
+    Takes a function. The component is loaded if the function
+    returns true otherwise not. It can be used to load some
+    comoonents on specific cases.
+
+  • color         (Theme colors)
     color option can be used to set custom color to a component
     Color format:
     `lua color = {fg = '#rrggbb', bg= '#rrggbb', gui='style'}`
     the members of color table are optional and default to theme
+    Color option can also be a string containing highlight group name >
+    color = "WarningMsg"` 
+<    One neat trick set the color to highlight group name then change
+    that highlight with :hi command to change color of that component
+    at runtime.
 
+Using global options~
+
+Global options can be set in two ways. One is as part of options table in setup.
+
+>
+    require'lualine'.setup{
+      options = {
+        icons_enabled = true,
+        padding = 2,
+      }
+    }
+<
+When set this way these values work as default for all component.
+These defaults can be overwritten by setting option as part of component
+configuration like following.
+
+>
+    lualine_a = {
+      -- Displays only first char of mode name
+      {'mode', format=function(mode_name) return mode_name:sub(1,1) end},
+      -- Disables icon for branch component
+      {'branch', icons_enabled=false},
+    },
+    lualine_c = {
+      -- Displays filename only when window is wider then 80
+      {'filename', condition=function() return vim.fn.winwidth(0) > 80 end},
+    }
+<
+
+
+Component specific options~
 
 In addition, some components have unique options.
 
@@ -347,6 +435,7 @@ In addition, some components have unique options.
       changes diff's symbols
       Color in `#rrggbb` format
 <
+Component specific options can only be set with component configs.
 
 Example:~
 >
@@ -484,4 +573,4 @@ Vimscript config example
     lua require("lualine").setup()
 <
 -------------------------------------------------------------------------------
-vim:tw=80:sw=4:ts=8:noet:ft=help:norl:noet:
+vim:tw=80:sw=4:ts=8:noet:ft=help:norl:et:

doc/tags

@@ -14,7 +14,7 @@ lualine_loading_plugin_extensions	lualine.txt	/*lualine_loading_plugin_extension
 lualine_lualine.nvim	lualine.txt	/*lualine_lualine.nvim*
 lualine_nvim	lualine.txt	/*lualine_nvim*
 lualine_packer.nvim	lualine.txt	/*lualine_packer.nvim*
-lualine_performance_comparism	lualine.txt	/*lualine_performance_comparism*
+lualine_performance_comparison	lualine.txt	/*lualine_performance_comparison*
 lualine_screenshots	lualine.txt	/*lualine_screenshots*
 lualine_setting_theme	lualine.txt	/*lualine_setting_theme*
 lualine_starting_lualine	lualine.txt	/*lualine_starting_lualine*

lua/lualine/component.lua

@@ -37,11 +37,13 @@ local Component = {
 
   create_option_highlights = function(self)
     -- set custom highlights
-    if self.options.color then
+    if type(self.options.color) == 'table' then
       self.options.color_highlight = highlight.create_component_highlight_group(
                                          self.options.color,
                                          self.options.component_name,
                                          self.options)
+    elseif type(self.options.color) == 'string' then
+      self.options.color_highlight_link = self.options.color
     end
   end,
 
@@ -80,6 +82,8 @@ local Component = {
     if self.options.color_highlight then
       self.status = highlight.component_format_highlight(
                         self.options.color_highlight) .. self.status
+    elseif self.options.color_highlight_link then
+      self.status = '%#' .. self.options.color_highlight_link ..'#'.. self.status
     end
     self.status = self.status .. default_highlight
   end,
@@ -118,6 +122,9 @@ local Component = {
   -- Driver code of the class
   draw = function(self, default_highlight)
     self.status = ''
+    if self.options.condition ~= nil and self.options.condition() ~= true then 
+      return self.status
+    end
     local status = self:update_status()
     if self.options.format then status = self.options.format(status or '') end
     if type(status) == 'string' and #status > 0 then

lua/lualine/components/special/eval_func_component.lua

@@ -2,22 +2,13 @@ local EvalFuncComponent = require('lualine.component'):new()
 
 EvalFuncComponent.update_status = function(self)
   local component = self.options[1]
-  local ok, status = EvalFuncComponent.evallua(component)
+  local ok, status = pcall(EvalFuncComponent.eval_lua, component)
   if not ok then status = EvalFuncComponent.vim_function(component) end
   return status
 end
 
-EvalFuncComponent.evallua = function(code)
+EvalFuncComponent.eval_lua = function(code)
-  if loadstring(string.format('return %s ~= nil', code)) and
+  return tostring(loadstring('return '..code)())
-      loadstring(string.format([[return %s ~= nil]], code))() then
-    -- lua veriable component
-    return true, loadstring(string.format(
-                                [[
-    local ok, return_val = pcall(tostring, %s)
-    if ok then return return_val end
-    return '']], code))()
-  end
-  return false, ''
 end
 
 EvalFuncComponent.vim_function = function(name)

lua/lualine/highlight.lua

@@ -5,16 +5,21 @@ local utils_colors = require 'lualine.utils.cterm_colors'
 local utils = require 'lualine.utils.utils'
 local section_highlight_map = {x = 'c', y = 'b', z = 'a'}
 local active_theme = nil
+local cterm_colors = false
 
 function M.highlight(name, foreground, background, gui, reload)
   local command = {'highlight', name}
   if foreground and foreground ~= 'none' then
-    table.insert(command, 'ctermfg=' .. utils_colors.get_cterm_color(foreground))
     table.insert(command, 'guifg=' .. foreground)
+    if cterm_colors then
+      table.insert(command, 'ctermfg=' .. utils_colors.get_cterm_color(foreground))
+    end
   end
   if background and background ~= 'none' then
-    table.insert(command, 'ctermbg=' .. utils_colors.get_cterm_color(background))
     table.insert(command, 'guibg=' .. background)
+    if cterm_colors then
+      table.insert(command, 'ctermbg=' .. utils_colors.get_cterm_color(background))
+    end
   end
   if gui then
     table.insert(command, 'cterm=' .. gui)
@@ -29,6 +34,7 @@ end
 function M.create_highlight_groups(theme)
   utils.clear_highlights()
   active_theme = theme
+  cterm_colors = not vim.o.termguicolors
   for mode, sections in pairs(theme) do
     for section, colorscheme in pairs(sections) do
       local highlight_group_name = {'lualine', section, mode}

lua/lualine/init.lua

@@ -251,19 +251,17 @@ end
 
 local function set_tabline()
   if next(config.tabline) ~= nil then
-    _G.lualine_tabline = tabline
+    vim.o.tabline = "%!v:lua.require'lualine'.tabline()"
-    vim.o.tabline = '%!v:lua.lualine_tabline()'
     vim.o.showtabline = 2
   end
 end
 
 local function set_statusline()
   if next(config.sections) ~= nil or next(config.inactive_sections) ~= nil then
-    _G.lualine_statusline = status_dispatch
+    vim.o.statusline = "%!v:lua.require'lualine'.statusline()"
-    vim.o.statusline = '%!v:lua.lualine_statusline()'
     vim.api.nvim_exec([[
-    autocmd lualine WinLeave,BufLeave * lua vim.wo.statusline=lualine_statusline()
+    autocmd lualine WinLeave,BufLeave * lua vim.wo.statusline=require'lualine'.statusline()
-    autocmd lualine WinEnter,BufEnter * setlocal statusline=%!v:lua.lualine_statusline()
+    autocmd lualine WinEnter,BufEnter * set statusline<
     ]], false)
   end
 end
@@ -279,4 +277,8 @@ local function setup(user_config)
   set_tabline()
 end
 
-return {setup = setup}
+return {
+  setup = setup,
+  statusline = status_dispatch,
+  tabline = tabline,
+}