feat(ex.progress): the new component to show the progress in differen…

…t modes

.

README.md

@@ -12,6 +12,7 @@ for `lualine.nvim` with additional components.
     - [ex.spellcheck](#exspellcheck)
     - [ex.cwd](#excwd)
     - [ex.location](#exlocation)
+    - [ex.progress](#exprogress)
     - [ex.relative_filename](#exrelative_filename)
     - [ex.git.branch](#exgitbranch)
     - [ex.lsp.single](#exlspsingle)
@@ -167,6 +168,42 @@ sections = {
 }
 ```
 
+### ex.progress
+
+This component shows the progress in the file. It has two pre-build modes: 'percent' and 'bar'. The first
+one is similar to the default `progress` component, but in the second 'bar' mode the progress is
+shown as a progress bar.
+
+| mode | example |
+|:---:|:---:|
+| `'percent'` | <img height=18 alt="ex progress-percent" src="https://github.com/dokwork/lualine-ex/assets/6939832/fa2413c7-dd03-474f-8152-d9b8f4d026ef"> |
+| `'bar'` | <img height=18 alt="ex progress-bar" src="https://github.com/dokwork/lualine-ex/assets/6939832/df29650a-3fa9-422b-940f-956079f3a8bb"> |
+
+```lua
+sections = {
+  lualine_a = {
+    {
+      'ex.progress',
+
+      -- How to show the progress. It may be the one of two string constants:
+      -- 'percent' or 'bar'. In the 'percent' mode the progress is shown as percent of the file.
+      -- In the 'bar' mode it's shown as the vertical bar. Also, it can be a table with symbols
+      -- which will be taken to show according to the progress, or a function, which receive three
+      -- arguments: the component itself, the cursor line and total lines count in the file.
+      mode = 'percent',
+
+      -- This string will be shown when the cursor is on the first line of the file. Set `false`
+      -- to turn this logic off.
+      top = 'Top',
+
+      -- This string will be shown when the cursor is on the last line of the file. Set `false`
+      -- to turn this logic off.
+      bottom = 'Bot'
+    }
+  }
+}
+```
+
 ### ex.relative_filename
 
 This component shows a `filename`: a file name and a path to the current file relative to the

lua/lualine/components/ex/progress.lua

@@ -0,0 +1,48 @@
+-- stylua: ignore start
+local progress_bar = { '█', '▇', '▆', '▅', '▄', '▃', '▂', '▁', ' ' }
+-- stylua: ignore end
+
+local Progress = require('lualine.ex.component'):extend({
+    mode = 'percent',
+    top = 'Top',
+    bottom = 'Bot',
+})
+
+local function mode_percent(self, line, total)
+    if (line == total) and self.options.bottom then
+        return self.options.bottom
+    end
+    if (line == 1) and self.options.top then
+        return self.options.top
+    end
+    return string.format('%3d%%%%', 99 * line / total + 1)
+end
+
+local function mode_table(t)
+    return function(self, line, total)
+        if (line == total) and self.options.bottom then
+            return self.options.bottom
+        end
+        if (line == 1) and self.options.top then
+            return self.options.top
+        end
+        local idx = math.floor(line * (#t - 1) / total) + 1
+        return t[idx]
+    end
+end
+
+function Progress:post_init()
+    if type(self.options.mode) == 'string' then
+        self.options.mode = (self.options.mode == 'bar') and mode_table(progress_bar)
+            or mode_percent
+    end
+    if type(self.options.mode) == 'table' then
+        self.options.mode = mode_table(self.options.mode)
+    end
+end
+
+function Progress:update_status()
+    return self.options.mode(self, vim.fn.line('.'), vim.fn.line('$'))
+end
+
+return Progress

tests/components/progress_spec.lua

@@ -0,0 +1,92 @@
+local l = require('tests.ex.lualine')
+local t = require('tests.ex.busted') --:ignore_all_tests()
+
+local eq = assert.are.equal
+
+local orig = {
+    line = vim.fn.line,
+}
+local mock = {
+    line = {},
+}
+
+local component_name = 'ex.progress'
+
+describe(component_name, function()
+    before_each(function()
+        vim.fn.line = function(arg)
+            return mock.line[arg]
+        end
+    end)
+
+    after_each(function()
+        vim.fn.line = orig.line
+    end)
+
+    describe('in "percent" (default) mode', function()
+        it('should show "Top" when the cursor is on bottom of the buffer', function()
+            -- { line, total, expected percent }
+            local cases = {
+                { 1, 100, 'Top' },
+                { 1, 1000, 'Top' },
+                { 2, 1000, '  1%%' },
+            }
+            for _, case in ipairs(cases) do
+                mock.line['.'] = case[1]
+                mock.line['$'] = case[2]
+                local c = l.render_component(component_name)
+                eq(case[3], c, vim.inspect(case))
+            end
+        end)
+        it('should show "Bot" when the cursor is on bottom of the buffer', function()
+            -- { line, total, expected percent }
+            local cases = {
+                { 100, 100, 'Bot' },
+                { 1000, 1000, 'Bot' },
+                { 999, 1000, ' 99%%' },
+            }
+            for _, case in ipairs(cases) do
+                mock.line['.'] = case[1]
+                mock.line['$'] = case[2]
+                local c = l.render_component(component_name)
+                eq(case[3], c, vim.inspect(case))
+            end
+        end)
+        it('should show expected persentage of the buffer', function()
+            -- { line, total, expected percent }
+            local cases = {
+                { 1, 100, 1 },
+                { 100, 100, 100 },
+                { 17, 111, 16 },
+            }
+            for _, case in ipairs(cases) do
+                mock.line['.'] = case[1]
+                mock.line['$'] = case[2]
+                local c = l.render_component(component_name, { top = false, bottom = false })
+                eq(string.format('%3d%%%%', case[3]), c, vim.inspect(case))
+            end
+        end)
+    end)
+
+    describe('in "bar" mode, or "tabe" mode', function()
+        it('should show appropriate symbol', function()
+            -- { line, total, expected percent }
+            local cases = {
+                { 1, 100, '█' },
+                { 100, 100, ' ' },
+                { 99, 100, '▁' },
+                { 7, 9, '▂' },
+                { 19, 31, '▄' },
+            }
+            for _, case in ipairs(cases) do
+                mock.line['.'] = case[1]
+                mock.line['$'] = case[2]
+                local c = l.render_component(
+                    component_name,
+                    { top = false, bottom = false, mode = 'bar' }
+                )
+                eq(case[3], c, vim.inspect(case))
+            end
+        end)
+    end)
+end)