feat: pinned buffers stay visible

lua/barbar/layout.lua

@@ -26,13 +26,13 @@ local SLASH_LEN = #'/'
 local SPACE_LEN = #' '
 
 --- @class barbar.layout.data
---- @field actual_width integer the `used_width` plus the `padding_width` allocated to each buffer
+--- @field actual_width integer the `base_widths_sum` plus the `padding_width` allocated to each buffer
 --- @field base_widths integer[] the minimum amount of space taken up by each buffer
 --- @field buffers_width integer the amount of space available to be taken up by buffers
 --- @field padding_width integer the amount of padding used on each side of each buffer
---- @field tabpages_width integer the amount of space taken up by the tabpage indicator
+--- @field pinned_widths integer[] the minimum amount of space taken up by each pinned buffer
 --- @field scroll_max integer the maximum position which can be scrolled to
---- @field used_width integer the sum of the `base_widths`
+--- @field tabpages_width integer the amount of space taken up by the tabpage indicator
 
 --- @class barbar.Layout
 --- @field buffers integer[] different from `state.buffers` in that the `hide` option is respected. Only updated when calling `calculate_buffers_width`.
@@ -44,24 +44,27 @@ function Layout.calculate()
   local available_width = get_option'columns'
   available_width = available_width - state.offset.width
 
-  local used_width, base_widths = Layout.calculate_buffers_width()
+  local pinned_widths_sum, pinned_widths, base_widths_sum, base_widths = Layout.calculate_buffers_width()
   local tabpages_width = Layout.calculate_tabpages_width()
 
-  local buffers_width = available_width - tabpages_width
-  local remaining_width = max(0, buffers_width - used_width)
+  local pinned_width = pinned_widths_sum + (#pinned_widths * config.options.minimum_padding * SIDES_OF_BUFFER)
+  local buffers_width = available_width - pinned_width - tabpages_width
+
+  local remaining_width = max(0, buffers_width - base_widths_sum)
   local remaining_width_per_buffer = floor(remaining_width / #base_widths)
   local remaining_padding_per_buffer = floor(remaining_width_per_buffer / SIDES_OF_BUFFER)
   local padding_width = max(config.options.minimum_padding, min(remaining_padding_per_buffer, config.options.maximum_padding))
-  local actual_width = used_width + (#base_widths * padding_width * SIDES_OF_BUFFER)
+  local actual_width = base_widths_sum + (#base_widths * padding_width * SIDES_OF_BUFFER)
 
   return {
     actual_width = actual_width,
     base_widths = base_widths,
     buffers_width = buffers_width,
     padding_width = padding_width,
+    pinned_widths = pinned_widths,
+    pinned_widths_sum = pinned_widths_sum,
     scroll_max = max(0, actual_width - buffers_width),
     tabpages_width = tabpages_width,
-    used_width = used_width,
   }
 end
 
@@ -124,28 +127,35 @@ function Layout.calculate_buffers_position_by_buffer_number()
 
   for i, buffer_number in ipairs(Layout.buffers) do
     positions[buffer_number] = current_position
-    local width = layout.base_widths[i] + (2 * layout.padding_width)
-    current_position = current_position + width
+    current_position = current_position + Layout.calculate_width(
+      layout.base_widths[i] or layout.pinned_widths[i],
+      layout.padding_width
+    )
   end
 
   return positions
 end
 
 --- Calculate the width of the buffers
---- @return integer sum, integer[] widths
+--- @return integer pinned_sum, integer[] pinned_widths, integer sum, integer[] other_widths
 function Layout.calculate_buffers_width()
   Layout.buffers = Buffer.hide(state.buffers)
 
-  local sum = 0
-  local widths = {}
+  local pinned_sum, sum = 0, 0
+  local pinned_widths, other_widths = {}, {}
 
   for i, bufnr in ipairs(Layout.buffers) do
     local width = Layout.calculate_buffer_width(bufnr, i)
-    sum = sum + width
-    table_insert(widths, width)
+    if state.get_buffer_data(bufnr).pinned then
+      pinned_sum = pinned_sum + width
+      pinned_widths[i] = width
+    else
+      sum = sum + width
+      other_widths[i] = width
+    end
   end
 
-  return sum, widths
+  return pinned_sum, pinned_widths, sum, other_widths
 end
 
 --- The number of characters needed to represent the tabpages.

lua/barbar/render.lua

@@ -14,6 +14,7 @@ local defer_fn = vim.defer_fn
 local get_current_buf = vim.api.nvim_get_current_buf --- @type function
 local get_option = vim.api.nvim_get_option --- @type function
 local has = vim.fn.has --- @type function
+local list_extend = vim.list_extend
 local list_tabpages = vim.api.nvim_list_tabpages --- @type function
 local list_wins = vim.api.nvim_list_wins --- @type function
 local set_current_win = vim.api.nvim_set_current_win --- @type function
@@ -526,6 +527,7 @@ local function generate_tabline(bufnrs, refocus)
   local accumulated_width = 0 --- the amount of width that has been accumulated while iterating
   local current_buffer_index = nil --- @type nil|integer
   local groups = {} --- @type barbar.render.group[]
+  local pinned_items = {} --- @type barbar.render.group[]
 
   for i, bufnr in ipairs(bufnrs) do
     local activity = Buffer.activities[Buffer.get_activity(bufnr)]
@@ -536,7 +538,7 @@ local function generate_tabline(bufnrs, refocus)
     )
     local buffer_name = buffer_data.name or '[no name]'
 
-    buffer_data.real_width = Layout.calculate_width(layout.base_widths[i], layout.padding_width)
+    buffer_data.real_width = Layout.calculate_width(layout.base_widths[i] or layout.pinned_widths[i], layout.padding_width)
     buffer_data.real_position = accumulated_width
 
     local icons_option = state.icons(bufnr, activity)
@@ -628,7 +630,8 @@ local function generate_tabline(bufnrs, refocus)
     local group = { --- @type barbar.render.group
       items = {left_separator, padding, buffer_index, buffer_number, icon, jump_letter, name},
       position = buffer_data.position or accumulated_width,
-      width = buffer_data.width or Layout.calculate_width(layout.base_widths[i], layout.padding_width)
+      --- @diagnostic disable-next-line: assign-type-mismatch it is assigned just earlier
+      width = buffer_data.width or buffer_data.real_width,
     }
 
     Buffer.for_each_counted_enabled_diagnostic(bufnr, icons_option.diagnostics, function(count, idx, option)
@@ -657,6 +660,11 @@ local function generate_tabline(bufnrs, refocus)
       end
     end
 
+    if buffer_data.pinned then
+      list_extend(pinned_items, group.items)
+      goto continue -- HACK: there is no `continue` keyword
+    end
+
     accumulated_width = accumulated_width + group.width
 
     local scroll_current = min(scroll.current, layout.scroll_max)
@@ -715,15 +723,9 @@ local function generate_tabline(bufnrs, refocus)
     end
   end
 
-  -- TODO: put pinned buffers here
-  -- if #scroll_locked.left > 0 then
-  --   local items = scroll_locked.left[1].items
-  --   for i = #scroll_locked.left, 2, -1 do
-  --     list_extend(items, scroll_locked.left[i].items)
-  --   end
-  --
-  --   result = result .. items_to_string(items)
-  -- end
+  if #pinned_items > 0 then
+    result = result .. items_to_string(pinned_items)
+  end
 
   -- Render bufferline string
   result = result .. items_to_string(bufferline_items)