From 193fb6fcd5bd4d2917b1c4fff82bab6ec8819128 Mon Sep 17 00:00:00 2001
From: Rom Grk <romgrk.cc@gmail.com>
Date: Mon, 10 Apr 2023 15:55:33 -0400
Subject: [PATCH 01/11] refactor: move move_buffer to render.lua

---
 lua/barbar/api.lua       | 104 +---------------------------
 lua/barbar/ui/render.lua | 142 ++++++++++++++++++++++++++++++++-------
 2 files changed, 119 insertions(+), 127 deletions(-)

diff --git a/lua/barbar/api.lua b/lua/barbar/api.lua
index baf6d046..2ed48e58 100644
--- a/lua/barbar/api.lua
+++ b/lua/barbar/api.lua
@@ -1,8 +1,6 @@
 local char = string.char
 local max = math.max
 local min = math.min
-local table_insert = table.insert
-local table_remove = table.remove
 local table_sort = table.sort
 
 local buf_get_name = vim.api.nvim_buf_get_name --- @type function
@@ -16,12 +14,9 @@ local set_current_buf = vim.api.nvim_set_current_buf --- @type function
 -- TODO: remove `vim.fs and` after 0.8 release
 local normalize = vim.fs and vim.fs.normalize
 
-local animate = require'barbar.animate'
 local bbye = require'barbar.bbye'
 local Buffer = require'barbar.buffer'
-local config = require'barbar.config'
 local JumpMode = require'barbar.jump_mode'
-local Layout = require'barbar.ui.layout'
 local render = require'barbar.ui.render'
 local state = require'barbar.state'
 local utils = require'barbar.utils'
@@ -213,101 +208,6 @@ function api.goto_buffer_relative(steps)
   set_current_buf(state.buffers[(idx + steps - 1) % #state.buffers + 1])
 end
 
-local move_animation = nil --- @type nil|barbar.animate.state
-local move_animation_data = {
-  next_positions = nil, --- @type nil|integer[]
-  previous_positions = nil --- @type nil|integer[]
-}
-
---- An incremental animation for `move_buffer_animated`.
---- @return nil
-local function move_buffer_animated_tick(ratio, current_animation)
-  for _, current_number in ipairs(Layout.buffers) do
-    local current_data = state.get_buffer_data(current_number)
-
-    if current_animation.running == true then
-      current_data.position = animate.lerp(
-        ratio,
-        (move_animation_data.previous_positions or {})[current_number],
-        (move_animation_data.next_positions or {})[current_number]
-      )
-    else
-      current_data.position = nil
-      current_data.moving = false
-    end
-  end
-
-  render.update()
-
-  if current_animation.running == false then
-    move_animation = nil
-    move_animation_data.next_positions = nil
-    move_animation_data.previous_positions = nil
-  end
-end
-
-local MOVE_DURATION = 150
-
---- Move a buffer (with animation, if configured).
---- @param from_idx integer the buffer's original index.
---- @param to_idx integer the buffer's new index.
---- @return nil
-local function move_buffer(from_idx, to_idx)
-  to_idx = max(1, min(#state.buffers, to_idx))
-  if to_idx == from_idx then
-    return
-  end
-
-  local animation = config.options.animation
-  local buffer_number = state.buffers[from_idx]
-
-  local previous_positions
-  if animation == true then
-    previous_positions = Layout.calculate_buffers_position_by_buffer_number()
-  end
-
-  table_remove(state.buffers, from_idx)
-  table_insert(state.buffers, to_idx, buffer_number)
-  state.sort_pins_to_left()
-
-  if animation == true then
-    local current_index = utils.index_of(Layout.buffers, buffer_number)
-    local start_index = min(from_idx, current_index)
-    local end_index   = max(from_idx, current_index)
-
-    if start_index == end_index then
-      return
-    elseif move_animation ~= nil then
-      animate.stop(move_animation)
-    end
-
-    local next_positions = Layout.calculate_buffers_position_by_buffer_number()
-
-    for _, layout_bufnr  in ipairs(Layout.buffers) do
-      local current_data = state.get_buffer_data(layout_bufnr)
-
-      local previous_position = previous_positions[layout_bufnr]
-      local next_position     = next_positions[layout_bufnr]
-
-      if next_position ~= previous_position then
-        current_data.position = previous_positions[layout_bufnr]
-        current_data.moving = true
-      end
-    end
-
-    move_animation_data = {
-      previous_positions = previous_positions,
-      next_positions = next_positions,
-    }
-
-    move_animation =
-      animate.start(MOVE_DURATION, 0, 1, vim.v.t_float,
-        function(ratio, current_animation) move_buffer_animated_tick(ratio, current_animation) end)
-  end
-
-  render.update()
-end
-
 --- Move the current buffer to the index specified.
 --- @param idx integer
 --- @return nil
@@ -325,7 +225,7 @@ function api.move_current_buffer_to(idx)
     return notify_buffer_not_found(current_bufnr)
   end
 
-  move_buffer(from_idx, idx)
+  render.move_buffer(from_idx, idx)
 end
 
 --- Move the current buffer a certain number of times over.
@@ -341,7 +241,7 @@ function api.move_current_buffer(steps)
     return notify_buffer_not_found(current_bufnr)
   end
 
-  move_buffer(idx, idx + steps)
+  render.move_buffer(idx, idx + steps)
 end
 
 --- Order the buffers by their buffer number.
diff --git a/lua/barbar/ui/render.lua b/lua/barbar/ui/render.lua
index fd32fe74..6d67c099 100644
--- a/lua/barbar/ui/render.lua
+++ b/lua/barbar/ui/render.lua
@@ -5,6 +5,7 @@
 local max = math.max
 local min = math.min
 local table_insert = table.insert
+local table_remove = table.remove
 
 local buf_get_option = vim.api.nvim_buf_get_option --- @type function
 local buf_is_valid = vim.api.nvim_buf_is_valid --- @type function
@@ -37,36 +38,35 @@ local Layout = require'barbar.ui.layout'
 local state = require'barbar.state'
 local utils = require'barbar.utils'
 
+--- @class barbar.ui.render
+local render = {}
+
+
+-- Animation durations & delays
+local OPEN_DELAY = 10
+local OPEN_DURATION = 150
+local MOVE_DURATION = 150
+local CLOSE_DURATION = 150
+local SCROLL_DURATION = 200
+
+
 --- Last value for tabline
 --- @type string
 local last_tabline = ''
 
---- Create valid `&tabline` syntax which highlights the next item in the tabline with the highlight `group` specified.
---- @param group string
---- @return string syntax
-local function wrap_hl(group)
-  return '%#' .. group .. '#'
-end
-
---- @class barbar.ui.render.animation
---- @field OPEN_DELAY integer
---- @field OPEN_DURATION integer
---- @field CLOSE_DURATION integer
---- @field SCROLL_DURATION integer
-local ANIMATION = {
-  OPEN_DELAY = 10,
-  OPEN_DURATION = 150,
-  CLOSE_DURATION = 150,
-  SCROLL_DURATION = 200,
-}
-
 --- @class barbar.ui.render.scroll
 --- @field current integer the place where the bufferline is currently scrolled to
 --- @field target integer the place where the bufferline is scrolled/wants to scroll to.
 local scroll = { current = 0, target = 0 }
 
---- @class barbar.ui.render
-local render = {}
+--- @type nil|barbar.animate.state
+local current_animation = nil
+
+local move_animation_data = {
+  next_positions = nil, --- @type nil|integer[]
+  previous_positions = nil --- @type nil|integer[]
+}
+
 
 --- An incremental animation for `close_buffer_animated`.
 --- @param bufnr integer
@@ -107,7 +107,7 @@ function render.close_buffer_animated(bufnr)
   buffer_data.width = current_width
 
   animate.start(
-    ANIMATION.CLOSE_DURATION, current_width, 0, vim.v.t_number,
+    CLOSE_DURATION, current_width, 0, vim.v.t_number,
     function(new_width, m)
       close_buffer_animated_tick(bufnr, new_width, m)
     end)
@@ -144,11 +144,11 @@ local function open_buffer_start_animation(layout, bufnr)
 
   defer_fn(function()
     animate.start(
-      ANIMATION.OPEN_DURATION, 1, target_width, vim.v.t_number,
+      OPEN_DURATION, 1, target_width, vim.v.t_number,
       function(new_width, animation)
         open_buffer_animated_tick(bufnr, new_width, animation)
       end)
-  end, ANIMATION.OPEN_DELAY)
+  end, OPEN_DELAY)
 end
 
 --- Open the `new_buffers` in the bufferline.
@@ -215,6 +215,91 @@ local function open_buffers(new_buffers)
   end
 end
 
+--- An incremental animation for `move_buffer_animated`.
+--- @return nil
+local function move_buffer_animated_tick(ratio, current_state)
+  for _, current_number in ipairs(Layout.buffers) do
+    local current_data = state.get_buffer_data(current_number)
+
+    if current_state.running == true then
+      current_data.position = animate.lerp(
+        ratio,
+        (move_animation_data.previous_positions or {})[current_number],
+        (move_animation_data.next_positions or {})[current_number]
+      )
+    else
+      current_data.position = nil
+    end
+  end
+
+  render.update()
+
+  if current_state.running == false then
+    current_animation = nil
+    move_animation_data.next_positions = nil
+    move_animation_data.previous_positions = nil
+  end
+end
+
+--- Move a buffer (with animation, if configured).
+--- @param from_idx integer the buffer's original index.
+--- @param to_idx integer the buffer's new index.
+--- @return nil
+function render.move_buffer(from_idx, to_idx)
+  to_idx = math.max(1, math.min(#state.buffers, to_idx))
+  if to_idx == from_idx then
+    return
+  end
+
+  local animation = config.options.animation
+  local buffer_number = state.buffers[from_idx]
+
+  local previous_positions
+  if animation == true then
+    previous_positions = Layout.calculate_buffers_position_by_buffer_number()
+  end
+
+  table_remove(state.buffers, from_idx)
+  table_insert(state.buffers, to_idx, buffer_number)
+  state.sort_pins_to_left()
+
+  if animation == true then
+    local current_index = utils.index_of(Layout.buffers, buffer_number)
+    local start_index = min(from_idx, current_index)
+    local end_index   = max(from_idx, current_index)
+
+    if start_index == end_index then
+      return
+    elseif current_animation ~= nil then
+      animate.stop(current_animation)
+    end
+
+    local next_positions = Layout.calculate_buffers_position_by_buffer_number()
+
+    for _, layout_bufnr  in ipairs(Layout.buffers) do
+      local current_data = state.get_buffer_data(layout_bufnr)
+
+      local previous_position = previous_positions[layout_bufnr]
+      local next_position     = next_positions[layout_bufnr]
+
+      if next_position ~= previous_position then
+        current_data.position = previous_positions[layout_bufnr]
+      end
+    end
+
+    move_animation_data = {
+      previous_positions = previous_positions,
+      next_positions = next_positions,
+    }
+
+    current_animation =
+      animate.start(MOVE_DURATION, 0, 1, vim.v.t_float,
+        move_buffer_animated_tick)
+  end
+
+  render.update()
+end
+
 --- Refresh the buffer list.
 --- @return integer[] state.buffers
 function render.get_updated_buffers(update_names)
@@ -322,7 +407,7 @@ function render.set_scroll(target)
   end
 
   scroll_animation = animate.start(
-    ANIMATION.SCROLL_DURATION, scroll.current, target, vim.v.t_number,
+    SCROLL_DURATION, scroll.current, target, vim.v.t_number,
     set_scroll_tick)
 end
 
@@ -338,6 +423,13 @@ function render.set_tabline(s)
   end
 end
 
+--- Create valid `&tabline` syntax which highlights the next item in the tabline with the highlight `group` specified.
+--- @param group string
+--- @return string syntax
+local function wrap_hl(group)
+  return '%#' .. group .. '#'
+end
+
 --- Compute the buffer hl-groups
 --- @param layout barbar.ui.layout.data
 --- @param bufnrs integer[]

From bec4509fefce69c2cbedbc7abdad26cbb73b4b36 Mon Sep 17 00:00:00 2001
From: Rom Grk <romgrk.cc@gmail.com>
Date: Mon, 10 Apr 2023 16:02:20 -0400
Subject: [PATCH 02/11] refactor: use current_animation

---
 lua/barbar/animate.lua   |  5 ++++-
 lua/barbar/ui/render.lua | 10 +++++-----
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/lua/barbar/animate.lua b/lua/barbar/animate.lua
index 9ba4603c..0b47e384 100644
--- a/lua/barbar/animate.lua
+++ b/lua/barbar/animate.lua
@@ -92,9 +92,12 @@ function animate.start(duration, initial, final, type, callback)
   return state
 end
 
---- @param state barbar.animate.state
+--- @param state barbar.animate.state|nil
 --- @return nil
 function animate.stop(state)
+  if state == nil then
+    return
+  end
   if state.timer then
     state.timer:stop()
     state.timer:close()
diff --git a/lua/barbar/ui/render.lua b/lua/barbar/ui/render.lua
index 6d67c099..b4c340c6 100644
--- a/lua/barbar/ui/render.lua
+++ b/lua/barbar/ui/render.lua
@@ -106,7 +106,8 @@ function render.close_buffer_animated(bufnr)
   buffer_data.closing = true
   buffer_data.width = current_width
 
-  animate.start(
+  current_animation = animate.stop(current_animation)
+  current_animation = animate.start(
     CLOSE_DURATION, current_width, 0, vim.v.t_number,
     function(new_width, m)
       close_buffer_animated_tick(bufnr, new_width, m)
@@ -143,7 +144,8 @@ local function open_buffer_start_animation(layout, bufnr)
   buffer_data.width = 1
 
   defer_fn(function()
-    animate.start(
+    current_animation = animate.stop(current_animation)
+    current_animation = animate.start(
       OPEN_DURATION, 1, target_width, vim.v.t_number,
       function(new_width, animation)
         open_buffer_animated_tick(bufnr, new_width, animation)
@@ -235,7 +237,6 @@ local function move_buffer_animated_tick(ratio, current_state)
   render.update()
 
   if current_state.running == false then
-    current_animation = nil
     move_animation_data.next_positions = nil
     move_animation_data.previous_positions = nil
   end
@@ -270,8 +271,6 @@ function render.move_buffer(from_idx, to_idx)
 
     if start_index == end_index then
       return
-    elseif current_animation ~= nil then
-      animate.stop(current_animation)
     end
 
     local next_positions = Layout.calculate_buffers_position_by_buffer_number()
@@ -292,6 +291,7 @@ function render.move_buffer(from_idx, to_idx)
       next_positions = next_positions,
     }
 
+    current_animation = animate.stop(current_animation)
     current_animation =
       animate.start(MOVE_DURATION, 0, 1, vim.v.t_float,
         move_buffer_animated_tick)

From 6c6ef29d24e8534733a9c93a024fdddf9ba826d8 Mon Sep 17 00:00:00 2001
From: Rom Grk <romgrk.cc@gmail.com>
Date: Mon, 10 Apr 2023 16:19:01 -0400
Subject: [PATCH 03/11] refactor: move pin code in render.lua

---
 lua/barbar/api.lua       |  3 +-
 lua/barbar/ui/render.lua | 89 ++++++++++++++++++++++------------------
 2 files changed, 51 insertions(+), 41 deletions(-)

diff --git a/lua/barbar/api.lua b/lua/barbar/api.lua
index 2ed48e58..76598720 100644
--- a/lua/barbar/api.lua
+++ b/lua/barbar/api.lua
@@ -372,8 +372,7 @@ end
 --- @param buffer_number? integer
 --- @return nil
 function api.toggle_pin(buffer_number)
-  state.toggle_pin(buffer_number or 0)
-  render.update()
+  render.toggle_pin(buffer_number or 0)
 end
 
 return api
diff --git a/lua/barbar/ui/render.lua b/lua/barbar/ui/render.lua
index b4c340c6..e13d4a15 100644
--- a/lua/barbar/ui/render.lua
+++ b/lua/barbar/ui/render.lua
@@ -300,6 +300,56 @@ function render.move_buffer(from_idx, to_idx)
   render.update()
 end
 
+
+--- Toggle the `bufnr`'s "pin" state, visually.
+--- @param buffer_number integer
+--- @return nil
+function render.toggle_pin(buffer_number)
+  state.toggle_pin(buffer_number)
+  render.update()
+end
+
+
+--- Scroll the bufferline relative to its current position.
+--- @param n integer the amount to scroll by. Use negative numbers to scroll left, and positive to scroll right.
+--- @return nil
+function render.scroll(n)
+  render.set_scroll(max(0, scroll.target + n))
+end
+
+local scroll_animation = nil
+
+--- An incremental animation for `set_scroll`.
+--- @return nil
+local function set_scroll_tick(new_scroll, animation)
+  scroll.current = new_scroll
+  if animation.running == false then
+    scroll_animation = nil
+  end
+  render.update(nil, false)
+end
+
+--- Scrolls the bufferline to the `target`.
+--- @param target integer where to scroll to
+--- @return nil
+function render.set_scroll(target)
+  scroll.target = target
+
+  if not config.options.animation then
+    scroll.current = target
+    return render.update(nil, false)
+  end
+
+  if scroll_animation ~= nil then
+    animate.stop(scroll_animation)
+  end
+
+  scroll_animation = animate.start(
+    SCROLL_DURATION, scroll.current, target, vim.v.t_number,
+    set_scroll_tick)
+end
+
+
 --- Refresh the buffer list.
 --- @return integer[] state.buffers
 function render.get_updated_buffers(update_names)
@@ -372,45 +422,6 @@ function render.set_current_win_listed_buffer()
   return current
 end
 
---- Scroll the bufferline relative to its current position.
---- @param n integer the amount to scroll by. Use negative numbers to scroll left, and positive to scroll right.
---- @return nil
-function render.scroll(n)
-  render.set_scroll(max(0, scroll.target + n))
-end
-
-local scroll_animation = nil
-
---- An incremental animation for `set_scroll`.
---- @return nil
-local function set_scroll_tick(new_scroll, animation)
-  scroll.current = new_scroll
-  if animation.running == false then
-    scroll_animation = nil
-  end
-  render.update(nil, false)
-end
-
---- Scrolls the bufferline to the `target`.
---- @param target integer where to scroll to
---- @return nil
-function render.set_scroll(target)
-  scroll.target = target
-
-  if not config.options.animation then
-    scroll.current = target
-    return render.update(nil, false)
-  end
-
-  if scroll_animation ~= nil then
-    animate.stop(scroll_animation)
-  end
-
-  scroll_animation = animate.start(
-    SCROLL_DURATION, scroll.current, target, vim.v.t_number,
-    set_scroll_tick)
-end
-
 --- Sets and redraws `'tabline'` if `s` does not match the cached value.
 --- @param s? string
 --- @return nil

From fdf59acd4ee5fa0e66c95e85bc8a74d2a7843eea Mon Sep 17 00:00:00 2001
From: Rom Grk <romgrk.cc@gmail.com>
Date: Mon, 10 Apr 2023 16:31:46 -0400
Subject: [PATCH 04/11] feat: pin/unpin animation

---
 lua/barbar/state.lua     | 12 ++++++++----
 lua/barbar/ui/render.lua | 33 ++++++++++++++++++++++++++++++++-
 2 files changed, 40 insertions(+), 5 deletions(-)

diff --git a/lua/barbar/state.lua b/lua/barbar/state.lua
index d2ba105e..876d1dd1 100644
--- a/lua/barbar/state.lua
+++ b/lua/barbar/state.lua
@@ -69,16 +69,20 @@ local state = {
 
 --- Get the state of the `id`
 --- @param bufnr integer the `bufnr`
+--- @param data_by_bufnr? {[integer]: barbar.state.data}
 --- @return barbar.state.data
-function state.get_buffer_data(bufnr)
+function state.get_buffer_data(bufnr, data_by_bufnr)
   if bufnr == 0 then
     bufnr = get_current_buf()
   end
+  if data_by_bufnr == nil then
+    data_by_bufnr = state.data_by_bufnr
+  end
 
-  local data = state.data_by_bufnr[bufnr]
+  local data = data_by_bufnr[bufnr]
   if data == nil then
-    data = {closing = false, pinned = false}
-    state.data_by_bufnr[bufnr] = data
+    data = { closing = false, pinned = false }
+    data_by_bufnr[bufnr] = data
   end
 
   return data
diff --git a/lua/barbar/ui/render.lua b/lua/barbar/ui/render.lua
index e13d4a15..4d1e9904 100644
--- a/lua/barbar/ui/render.lua
+++ b/lua/barbar/ui/render.lua
@@ -48,6 +48,7 @@ local OPEN_DURATION = 150
 local MOVE_DURATION = 150
 local CLOSE_DURATION = 150
 local SCROLL_DURATION = 200
+local PIN_DURATION = 150
 
 
 --- Last value for tabline
@@ -305,8 +306,38 @@ end
 --- @param buffer_number integer
 --- @return nil
 function render.toggle_pin(buffer_number)
+  local previous_data_by_bufnr = vim.deepcopy(state.data_by_bufnr)
+
   state.toggle_pin(buffer_number)
-  render.update()
+
+  current_animation = animate.stop(current_animation)
+  current_animation = animate.start(PIN_DURATION, 0, 1, vim.v.t_float,
+    function (ratio, current_state)
+      for _, current_number in ipairs(Layout.buffers) do
+        local previous_data = state.get_buffer_data(current_number, previous_data_by_bufnr)
+        local current_data  = state.get_buffer_data(current_number)
+
+        local previous_width    = previous_data.width    or previous_data.computed_width
+        local previous_position = previous_data.position or previous_data.computed_position
+
+        local next_width    = current_data.computed_width
+        local next_position = current_data.computed_position
+
+        if current_state.running == true then
+          if previous_width and next_width then
+            current_data.width = animate.lerp(ratio, previous_width,    next_width)
+          end
+          if previous_position and next_position then
+            current_data.position = animate.lerp(ratio, previous_position, next_position)
+          end
+        else
+          current_data.width = nil
+          current_data.position = nil
+        end
+      end
+
+      render.update()
+    end)
 end
 
 

From 763608b91c869a775932182e520fdd274ccdb2c5 Mon Sep 17 00:00:00 2001
From: Rom Grk <romgrk.cc@gmail.com>
Date: Mon, 10 Apr 2023 16:35:32 -0400
Subject: [PATCH 05/11] lint

---
 lua/barbar/ui/render.lua | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lua/barbar/ui/render.lua b/lua/barbar/ui/render.lua
index 4d1e9904..1672bcff 100644
--- a/lua/barbar/ui/render.lua
+++ b/lua/barbar/ui/render.lua
@@ -248,7 +248,7 @@ end
 --- @param to_idx integer the buffer's new index.
 --- @return nil
 function render.move_buffer(from_idx, to_idx)
-  to_idx = math.max(1, math.min(#state.buffers, to_idx))
+  to_idx = max(1, min(#state.buffers, to_idx))
   if to_idx == from_idx then
     return
   end

From ee8c66e563f6db3e816df4775691b7164d5553f6 Mon Sep 17 00:00:00 2001
From: Rom Grk <romgrk.cc@gmail.com>
Date: Mon, 10 Apr 2023 16:58:55 -0400
Subject: [PATCH 06/11] fix: respect options.animation = false

---
 lua/barbar/ui/render.lua | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lua/barbar/ui/render.lua b/lua/barbar/ui/render.lua
index 1672bcff..87e85410 100644
--- a/lua/barbar/ui/render.lua
+++ b/lua/barbar/ui/render.lua
@@ -310,6 +310,10 @@ function render.toggle_pin(buffer_number)
 
   state.toggle_pin(buffer_number)
 
+  if config.options.animation == false then
+    return
+  end
+
   current_animation = animate.stop(current_animation)
   current_animation = animate.start(PIN_DURATION, 0, 1, vim.v.t_float,
     function (ratio, current_state)

From 55244c96e1047a822566eac20b3d996532d8f87d Mon Sep 17 00:00:00 2001
From: Rom Grk <romgrk.cc@gmail.com>
Date: Mon, 10 Apr 2023 17:04:01 -0400
Subject: [PATCH 07/11] refactor: move stuff around

---
 lua/barbar/ui/render.lua | 102 ++++++++++++++++++---------------------
 1 file changed, 46 insertions(+), 56 deletions(-)

diff --git a/lua/barbar/ui/render.lua b/lua/barbar/ui/render.lua
index 87e85410..986fee09 100644
--- a/lua/barbar/ui/render.lua
+++ b/lua/barbar/ui/render.lua
@@ -63,11 +63,6 @@ local scroll = { current = 0, target = 0 }
 --- @type nil|barbar.animate.state
 local current_animation = nil
 
-local move_animation_data = {
-  next_positions = nil, --- @type nil|integer[]
-  previous_positions = nil --- @type nil|integer[]
-}
-
 
 --- An incremental animation for `close_buffer_animated`.
 --- @param bufnr integer
@@ -218,31 +213,6 @@ local function open_buffers(new_buffers)
   end
 end
 
---- An incremental animation for `move_buffer_animated`.
---- @return nil
-local function move_buffer_animated_tick(ratio, current_state)
-  for _, current_number in ipairs(Layout.buffers) do
-    local current_data = state.get_buffer_data(current_number)
-
-    if current_state.running == true then
-      current_data.position = animate.lerp(
-        ratio,
-        (move_animation_data.previous_positions or {})[current_number],
-        (move_animation_data.next_positions or {})[current_number]
-      )
-    else
-      current_data.position = nil
-    end
-  end
-
-  render.update()
-
-  if current_state.running == false then
-    move_animation_data.next_positions = nil
-    move_animation_data.previous_positions = nil
-  end
-end
-
 --- Move a buffer (with animation, if configured).
 --- @param from_idx integer the buffer's original index.
 --- @param to_idx integer the buffer's new index.
@@ -265,40 +235,60 @@ function render.move_buffer(from_idx, to_idx)
   table_insert(state.buffers, to_idx, buffer_number)
   state.sort_pins_to_left()
 
-  if animation == true then
-    local current_index = utils.index_of(Layout.buffers, buffer_number)
-    local start_index = min(from_idx, current_index)
-    local end_index   = max(from_idx, current_index)
+  if animation == false then
+    return render.update()
+  end
 
-    if start_index == end_index then
-      return
-    end
+  local current_index = utils.index_of(Layout.buffers, buffer_number)
+  local start_index = min(from_idx, current_index)
+  local end_index   = max(from_idx, current_index)
 
-    local next_positions = Layout.calculate_buffers_position_by_buffer_number()
+  if start_index == end_index then
+    return
+  end
 
-    for _, layout_bufnr  in ipairs(Layout.buffers) do
-      local current_data = state.get_buffer_data(layout_bufnr)
+  local next_positions = Layout.calculate_buffers_position_by_buffer_number()
 
-      local previous_position = previous_positions[layout_bufnr]
-      local next_position     = next_positions[layout_bufnr]
+  for _, layout_bufnr  in ipairs(Layout.buffers) do
+    local current_data = state.get_buffer_data(layout_bufnr)
 
-      if next_position ~= previous_position then
-        current_data.position = previous_positions[layout_bufnr]
-      end
+    local previous_position = previous_positions[layout_bufnr]
+    local next_position     = next_positions[layout_bufnr]
+
+    if next_position ~= previous_position then
+      current_data.position = previous_positions[layout_bufnr]
     end
+  end
 
-    move_animation_data = {
-      previous_positions = previous_positions,
-      next_positions = next_positions,
-    }
+  local move_animation_data = {
+    previous_positions = previous_positions,
+    next_positions = next_positions,
+  }
 
-    current_animation = animate.stop(current_animation)
-    current_animation =
-      animate.start(MOVE_DURATION, 0, 1, vim.v.t_float,
-        move_buffer_animated_tick)
-  end
+  current_animation = animate.stop(current_animation)
+  current_animation = animate.start(MOVE_DURATION, 0, 1, vim.v.t_float,
+    function(ratio, current_state)
+      for _, current_number in ipairs(Layout.buffers) do
+        local current_data = state.get_buffer_data(current_number)
 
-  render.update()
+        if current_state.running == true then
+          current_data.position = animate.lerp(
+            ratio,
+            (move_animation_data.previous_positions or {})[current_number],
+            (move_animation_data.next_positions or {})[current_number]
+          )
+        else
+          current_data.position = nil
+        end
+      end
+
+      render.update()
+
+      if current_state.running == false then
+        move_animation_data.next_positions = nil
+        move_animation_data.previous_positions = nil
+      end
+    end)
 end
 
 
@@ -311,7 +301,7 @@ function render.toggle_pin(buffer_number)
   state.toggle_pin(buffer_number)
 
   if config.options.animation == false then
-    return
+    return render.update()
   end
 
   current_animation = animate.stop(current_animation)

From a963a8313ed66e646ccb6d89dab8e104ff09ae14 Mon Sep 17 00:00:00 2001
From: Rom Grk <romgrk.cc@gmail.com>
Date: Mon, 10 Apr 2023 17:18:00 -0400
Subject: [PATCH 08/11] fix: last separator logic

---
 lua/barbar/ui/render.lua | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/lua/barbar/ui/render.lua b/lua/barbar/ui/render.lua
index 986fee09..30c08a05 100644
--- a/lua/barbar/ui/render.lua
+++ b/lua/barbar/ui/render.lua
@@ -43,12 +43,14 @@ local render = {}
 
 
 -- Animation durations & delays
-local OPEN_DELAY = 10
-local OPEN_DURATION = 150
-local MOVE_DURATION = 150
-local CLOSE_DURATION = 150
+local BUFFER_OP_DURATION = 150
+
+local OPEN_DELAY      = 10 -- Let autocmds & other plugins run, avoids jank
+local OPEN_DURATION   = BUFFER_OP_DURATION
+local MOVE_DURATION   = BUFFER_OP_DURATION
+local CLOSE_DURATION  = BUFFER_OP_DURATION
+local PIN_DURATION    = BUFFER_OP_DURATION
 local SCROLL_DURATION = 200
-local PIN_DURATION = 150
 
 
 --- Last value for tabline
@@ -687,6 +689,7 @@ local function generate_tabline(bufnrs, refocus)
   do
     --- @type barbar.ui.container
     local content = { { hl = HL.FILL, text = (' '):rep(layout.buffers.width) } }
+    local max_used_position = 0
 
     do
       local current_container = nil
@@ -697,6 +700,7 @@ local function generate_tabline(bufnrs, refocus)
             content,
             container.position - scroll.current,
             container.nodes)
+          max_used_position = max(max_used_position, container.position + container.width)
         else
           current_container = container
         end
@@ -708,17 +712,19 @@ local function generate_tabline(bufnrs, refocus)
           content,
           container.position - scroll.current,
           container.nodes)
+        max_used_position = max(max_used_position, container.position + container.width)
       end
     end
 
     do
       local inactive_separator = config.options.icons.inactive.separator.left
+      local max_actual_position = max_used_position - scroll.current
       if inactive_separator ~= nil and #containers > 0 and
-        layout.buffers.unpinned_width + strwidth(inactive_separator) <= layout.buffers.unpinned_allocated_width
+        max_actual_position + strwidth(inactive_separator) <= layout.buffers.width
       then
         content = Nodes.insert(
           content,
-          layout.buffers.used_width,
+          max_actual_position,
           { text = inactive_separator, hl = HL.SIGN_INACTIVE })
       end
     end

From 64bb3707716ee7be1c99c67bb681823cb282e7db Mon Sep 17 00:00:00 2001
From: Rom Grk <romgrk.cc@gmail.com>
Date: Tue, 11 Apr 2023 08:46:32 -0400
Subject: [PATCH 09/11] fix: rendering order

---
 lua/barbar/ui/render.lua | 55 +++++++++++++++++++---------------------
 1 file changed, 26 insertions(+), 29 deletions(-)

diff --git a/lua/barbar/ui/render.lua b/lua/barbar/ui/render.lua
index 30c08a05..d1e95fdb 100644
--- a/lua/barbar/ui/render.lua
+++ b/lua/barbar/ui/render.lua
@@ -321,10 +321,10 @@ function render.toggle_pin(buffer_number)
 
         if current_state.running == true then
           if previous_width and next_width then
-            current_data.width = animate.lerp(ratio, previous_width,    next_width)
+            current_data.width = math.floor(animate.lerp(ratio, previous_width, next_width, vim.v.t_float))
           end
           if previous_position and next_position then
-            current_data.position = animate.lerp(ratio, previous_position, next_position)
+            current_data.position = math.ceil(animate.lerp(ratio, previous_position, next_position, vim.v.t_float))
           end
         else
           current_data.width = nil
@@ -638,6 +638,10 @@ local function get_bufferline_containers(layout, bufnrs, refocus)
     local right_separator = { hl = left_separator.hl, text = icons_option.separator.right }
 
     list_extend(container.nodes, { padding, button, right_separator })
+    if container_width then
+      container.nodes = Nodes.slice_right(container.nodes, container_width)
+    end
+
     table_insert(pinned and pinned_containers or containers, container)
 
     if done then
@@ -663,7 +667,7 @@ local HL = {
 --- @return nil|string syntax
 local function generate_tabline(bufnrs, refocus)
   local layout = Layout.calculate()
-  local pinned_containers, containers = get_bufferline_containers(layout, bufnrs, refocus)
+  local pinned_containers, unpinned_containers = get_bufferline_containers(layout, bufnrs, refocus)
 
   -- Create actual tabline string
   local result = ''
@@ -689,11 +693,22 @@ local function generate_tabline(bufnrs, refocus)
   do
     --- @type barbar.ui.container
     local content = { { hl = HL.FILL, text = (' '):rep(layout.buffers.width) } }
+
+    local current_container = nil
     local max_used_position = 0
 
+    if #pinned_containers > 0 then
+      for _, container in ipairs(pinned_containers) do
+        if container.activity ~= Buffer.activities.Current then
+          content = Nodes.insert_many(content, container.position, container.nodes)
+        else
+          current_container = container
+        end
+      end
+    end
+
     do
-      local current_container = nil
-      for _, container in ipairs(containers) do
+      for _, container in ipairs(unpinned_containers) do
         -- We insert the current buffer after the others so it's always on top
         if container.activity ~= Buffer.activities.Current then
           content = Nodes.insert_many(
@@ -705,21 +720,18 @@ local function generate_tabline(bufnrs, refocus)
           current_container = container
         end
       end
+    end
 
-      if current_container ~= nil then
-        local container = current_container
-        content = Nodes.insert_many(
-          content,
-          container.position - scroll.current,
-          container.nodes)
-        max_used_position = max(max_used_position, container.position + container.width)
-      end
+    if current_container ~= nil then
+      local container = current_container
+      content = Nodes.insert_many(content, container.position, container.nodes)
+      max_used_position = max(max_used_position, container.position + container.width)
     end
 
     do
       local inactive_separator = config.options.icons.inactive.separator.left
       local max_actual_position = max_used_position - scroll.current
-      if inactive_separator ~= nil and #containers > 0 and
+      if inactive_separator ~= nil and #unpinned_containers > 0 and
         max_actual_position + strwidth(inactive_separator) <= layout.buffers.width
       then
         content = Nodes.insert(
@@ -729,21 +741,6 @@ local function generate_tabline(bufnrs, refocus)
       end
     end
 
-    if #pinned_containers > 0 then
-      local current_container = nil
-      for _, container in ipairs(pinned_containers) do
-        if container.activity ~= Buffer.activities.Current then
-          content = Nodes.insert_many(content, container.position, container.nodes)
-        else
-          current_container = container
-        end
-      end
-      if current_container ~= nil then
-        local container = current_container
-        content = Nodes.insert_many(content, container.position, container.nodes)
-      end
-    end
-
     local filler = { { hl = HL.FILL, text = (' '):rep(layout.buffers.width) } }
     content = Nodes.insert_many(filler, 0, content)
     content = Nodes.slice_right(content, layout.buffers.width)

From 0d2263cd647b1107a965741f9cb495fd5088be08 Mon Sep 17 00:00:00 2001
From: Rom Grk <romgrk.cc@gmail.com>
Date: Tue, 11 Apr 2023 08:56:00 -0400
Subject: [PATCH 10/11] feat: improve pin animation

---
 lua/barbar/state.lua     | 10 ++++++----
 lua/barbar/ui/render.lua | 28 +++++++++++++++++-----------
 2 files changed, 23 insertions(+), 15 deletions(-)

diff --git a/lua/barbar/state.lua b/lua/barbar/state.lua
index 876d1dd1..4170e5e0 100644
--- a/lua/barbar/state.lua
+++ b/lua/barbar/state.lua
@@ -31,13 +31,15 @@ local CACHE_PATH = vim.fn.stdpath('cache') .. '/barbar.json'
 --------------------------------
 
 --- @class barbar.state.data
---- @field closing boolean whether the buffer is being closed
 --- @field name? string the name of the buffer
---- @field position? integer the absolute position of the buffer
---- @field computed_position? integer the real position of the buffer
---- @field computed_width? integer the width of the buffer plus invisible characters
 --- @field pinned boolean whether the buffer is pinned
+--- @field closing boolean whether the buffer is being closed
 --- @field width? integer the width of the buffer minus invisible characters
+--- @field padding? integer the padding width for one side
+--- @field position? integer the absolute position of the buffer
+--- @field computed_width? integer the logical width of the buffer plus invisible characters
+--- @field computed_padding? integer the logical padding of the buffer
+--- @field computed_position? integer the logical position of the buffer
 
 --- @class barbar.state.offset.side
 --- @field hl? string the highlight group to use
diff --git a/lua/barbar/ui/render.lua b/lua/barbar/ui/render.lua
index d1e95fdb..1721ee4d 100644
--- a/lua/barbar/ui/render.lua
+++ b/lua/barbar/ui/render.lua
@@ -314,20 +314,26 @@ function render.toggle_pin(buffer_number)
         local current_data  = state.get_buffer_data(current_number)
 
         local previous_width    = previous_data.width    or previous_data.computed_width
+        local previous_padding  = previous_data.padding  or previous_data.computed_padding
         local previous_position = previous_data.position or previous_data.computed_position
 
         local next_width    = current_data.computed_width
+        local next_padding  = current_data.computed_padding
         local next_position = current_data.computed_position
 
         if current_state.running == true then
           if previous_width and next_width then
             current_data.width = math.floor(animate.lerp(ratio, previous_width, next_width, vim.v.t_float))
           end
+          if previous_padding and next_padding then
+            current_data.padding = math.floor(animate.lerp(ratio, previous_padding, next_padding, vim.v.t_float))
+          end
           if previous_position and next_position then
             current_data.position = math.ceil(animate.lerp(ratio, previous_position, next_position, vim.v.t_float))
           end
         else
           current_data.width = nil
+          current_data.padding = nil
           current_data.position = nil
         end
       end
@@ -495,10 +501,12 @@ local function get_bufferline_containers(layout, bufnrs, refocus)
 
     if pinned then
       buffer_data.computed_position = accumulated_pinned_width
-      buffer_data.computed_width    = Layout.calculate_width(layout.buffers.base_widths[i], config.options.minimum_padding)
+      buffer_data.computed_padding  = config.options.minimum_padding
+      buffer_data.computed_width    = Layout.calculate_width(layout.buffers.base_widths[i], buffer_data.computed_padding)
     else
       buffer_data.computed_position = accumulated_unpinned_width + layout.buffers.pinned_width
-      buffer_data.computed_width    = Layout.calculate_width(layout.buffers.base_widths[i], layout.buffers.padding)
+      buffer_data.computed_padding  = layout.buffers.padding
+      buffer_data.computed_width    = Layout.calculate_width(layout.buffers.base_widths[i], buffer_data.computed_padding)
     end
 
     local container_width = buffer_data.width or buffer_data.computed_width
@@ -616,7 +624,10 @@ local function get_bufferline_containers(layout, bufnrs, refocus)
     local left_separator = { hl = clickable .. hl_sign, text = icons_option.separator.left }
 
     --- @type barbar.ui.node
-    local padding = { hl = buffer_hl, text = pinned and pinned_pad_text or unpinned_pad_text }
+    local padding = { hl = buffer_hl, text =
+      buffer_data.padding and (' '):rep(buffer_data.padding) or
+                   pinned and pinned_pad_text or
+                              unpinned_pad_text }
 
     local container = { --- @type barbar.ui.container
       activity = activity,
@@ -793,14 +804,9 @@ local function generate_tabline(bufnrs, refocus)
   end
 
   -- NOTE: For development or debugging purposes, the following code can be used:
-  -- ```lua
-  -- local text = Nodes.to_raw_string(bufferline_nodes, true)
-  -- if layout.buffers.unpinned_width + strwidth(inactive_separator) <= layout.buffers.unpinned_allocated_width and #items > 0 then
-  --   text = text .. Nodes.to_raw_string({{ text = inactive_separator or '', hl = wrap_hl('BufferInactiveSign') }}, true)
-  -- end
-  -- local data = vim.json.encode({ metadata = 42 })
-  -- fs.write('barbar.debug.txt', text .. ':' .. data .. '\n', 'a')
-  -- ```
+  -- local containers = { unpack(pinned_containers), unpack(unpinned_containers) }
+  -- local data = vim.json.encode(containers)
+  -- fs.write('barbar.debug.txt', result .. ':' .. data .. '\n', 'a')
 
   return result .. HL.FILL
 end

From f2fedbd92a49bed0fe4ca096264f846ab489f741 Mon Sep 17 00:00:00 2001
From: Rom Grk <romgrk.cc@gmail.com>
Date: Tue, 11 Apr 2023 09:00:57 -0400
Subject: [PATCH 11/11] fix: last separator

---
 lua/barbar/ui/render.lua | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lua/barbar/ui/render.lua b/lua/barbar/ui/render.lua
index 1721ee4d..169674ab 100644
--- a/lua/barbar/ui/render.lua
+++ b/lua/barbar/ui/render.lua
@@ -742,7 +742,10 @@ local function generate_tabline(bufnrs, refocus)
     do
       local inactive_separator = config.options.icons.inactive.separator.left
       local max_actual_position = max_used_position - scroll.current
-      if inactive_separator ~= nil and #unpinned_containers > 0 and
+      local total_containers = #pinned_containers + #unpinned_containers
+      if
+        inactive_separator ~= nil and
+        total_containers > 0 and
         max_actual_position + strwidth(inactive_separator) <= layout.buffers.width
       then
         content = Nodes.insert(