feat: hover events

README.md

@@ -70,10 +70,17 @@ require('cokeline').setup({
     },
     {
       text = function(buffer) return buffer.filename .. ' ' end,
+	  style = function(buffer)
+        if buffer.is_hovered and not buffer.is_focused then
+		  return 'underline'
+		end
+	  end
     },
     {
       text = '',
-      delete_buffer_on_left_click = true,
+      on_click = function(_, _, _, _, buffer)
+		buffer:delete()
+	  end
     },
     {
       text = ' ',
@@ -367,10 +374,9 @@ them:
 
 ![unique-prefix](https://user-images.githubusercontent.com/38540736/226447822-3315ad2f-35c9-4fc3-a777-c01cd8f2fe46.gif)
 
-### Clickable buffers
+### Clickable and hoverable buffers
 
-You can switch focus between buffers with a left click and you can delete
-them with a right click:
+Each component can be given custom click and hover handlers, allowing for implementations of close buttons, diagnostic previews, and more.
 
 ![clickable-buffers](https://user-images.githubusercontent.com/38540736/226447799-e845d266-0658-44e3-bd89-f706577844bf.gif)
 
@@ -384,10 +390,9 @@ them with a right click:
 
 ## :mountain: Plans and Ideas
 
-- Statusline and Winbar
+- Statusline
 - More mouse events
   - Reorder with drag
-  - Hover events
 - Group buffers by tabpage
 - Non-buffer custom components
   - Right-side tabline components
@@ -406,9 +411,19 @@ plugin and a patched font (see [Nerd Fonts](https://www.nerdfonts.com/)).
 
 #### Lua
 
-If you ported your Neovim config to Lua and use
-[packer.nvim](https://github.com/wbthomason/packer.nvim) as your plugin
-manager you can install this plugin with:
+##### With lazy.nvim
+
+```lua
+{
+  "willothy/nvim-cokeline",
+  dependencies = {
+    "kyazdani42/nvim-web-devicons",
+  },
+  config = true
+}
+```
+
+##### With packer.nvim
 
 ```lua
 vim.opt.termguicolors = true
@@ -586,6 +601,13 @@ buffer = {
   -- The buffer is the last visible buffer in the tab bar
   is_last     = true | false,
 
+  -- The mouse is hovering over the buffer
+  -- This is a special variable in that it will only be true for the hovered *component*
+  -- on render. This is to allow components to respond to hover events individually without managing
+  -- component state.
+  -- If you just need the hovered bufnr, you can use `require('cokeline.hover').hovered().bufnr`
+  is_hovered  = true | false
+
   -- The buffer's type as reported by `:echo &buftype`.
   type = 'string',
 
@@ -721,6 +743,12 @@ Every component passed to the `components` list has to be a table of the form:
   -- buffer is a Buffer object, not a bufnr
   on_click = nil | function(idx, clicks, buttons, modifiers, buffer)
 
+  -- Called on a component when hovered
+  on_mouse_enter = nil | function(buffer)
+
+  -- Called on a component when unhovered
+  on_mouse_leave = nil | function(buffer)
+
   truncation = {
     -- default: index of the component in the `components` table (1 for the
     -- first component, 2 for the second, etc.).

lua/cokeline/buffers.lua

@@ -209,6 +209,7 @@ Buffer.new = function(b)
     is_last = false,
     is_modified = opts.modified,
     is_readonly = opts.readonly,
+    is_hovered = false,
     path = b.name,
     unique_prefix = "",
     filename = filename,
@@ -348,8 +349,9 @@ local move_buffer = function(buffer, target_valid_index)
   cmd("redrawtabline")
 end
 
+---@param unsorted bool
 ---@return Buffer[]
-local get_valid_buffers = function()
+local get_valid_buffers = function(unsorted)
   local buffers = map(function(b)
     return Buffer.new(b)
   end, fn.getbufinfo({ buflisted = 1 }))
@@ -364,14 +366,16 @@ local get_valid_buffers = function()
 
   buffers = compute_unique_prefixes(buffers)
 
-  if _G.cokeline.config.buffers.new_buffers_position == "last" then
-    sort(buffers, sort_by_new_after_last)
-  elseif _G.cokeline.config.buffers.new_buffers_position == "next" then
-    sort(buffers, sort_by_new_after_current)
-  elseif _G.cokeline.config.buffers.new_buffers_position == "directory" then
-    sort(buffers, sort_by_directory)
-  elseif _G.cokeline.config.buffers.new_buffers_position == "number" then
-    sort(buffers, sort_by_number)
+  if not unsorted then
+    if _G.cokeline.config.buffers.new_buffers_position == "last" then
+      sort(buffers, sort_by_new_after_last)
+    elseif _G.cokeline.config.buffers.new_buffers_position == "next" then
+      sort(buffers, sort_by_new_after_current)
+    elseif _G.cokeline.config.buffers.new_buffers_position == "directory" then
+      sort(buffers, sort_by_directory)
+    elseif _G.cokeline.config.buffers.new_buffers_position == "number" then
+      sort(buffers, sort_by_number)
+    end
   end
 
   order = {}
@@ -386,9 +390,10 @@ local get_valid_buffers = function()
   return buffers
 end
 
+---@param unsorted boolean
 ---@return Buffer[]
-local get_visible_buffers = function()
-  _G.cokeline.valid_buffers = get_valid_buffers()
+local get_visible_buffers = function(unsorted)
+  _G.cokeline.valid_buffers = get_valid_buffers(unsorted)
 
   _G.cokeline.visible_buffers = not _G.cokeline.config.buffers.filter_visible
       and _G.cokeline.valid_buffers

lua/cokeline/components.lua

@@ -15,6 +15,8 @@ local map = vim.tbl_map
 ---@field fg  string|fun(buffer:Buffer): string
 ---@field bg  string|fun(buffer:Buffer): string
 ---@field on_click ClickHandler | nil
+---@field on_mouse_enter MouseEnterHandler | nil
+---@field on_mouse_leave MouseLeaveHandler | nil
 ---@field delete_buffer_on_left_click  boolean Use the component as a close button ()
 ---@field truncation  table
 ---@field idx  number
@@ -37,7 +39,9 @@ Component.new = function(c, i, default_hl)
     bg = c.bg or default_hl.bg or "NONE",
     style = c.style or default_hl.style or "NONE",
     delete_buffer_on_left_click = c.delete_buffer_on_left_click or false,
-    on_click = c.on_click or nil,
+    on_click = c.on_click,
+    on_mouse_enter = c.on_mouse_enter,
+    on_mouse_leave = c.on_mouse_leave,
     truncation = {
       priority = c.truncation and c.truncation.priority or i,
       direction = c.truncation and c.truncation.direction or "right",
@@ -57,6 +61,7 @@ end
 ---@param context RenderContext
 ---@return Component
 Component.render = function(self, context)
+  ---@return string
   local evaluate = function(field)
     return (type(field) == "string" and field)
       or (type(field) == "function" and field(context.provider))

lua/cokeline/config.lua

@@ -63,12 +63,23 @@ local defaults = {
     },
     {
       text = function(buffer)
-        return buffer.filename .. " "
+        return buffer.filename
+      end,
+      style = function(buffer)
+        if buffer.is_hovered and not buffer.is_focused then
+          return "underline"
+        end
+        return nil
       end,
     },
+    {
+      text = " ",
+    },
     {
       text = "",
-      delete_buffer_on_left_click = true,
+      on_click = function(_, _, _, _, buffer)
+        buffer:delete()
+      end,
     },
     {
       text = " ",

lua/cokeline/handlers.lua

@@ -3,6 +3,8 @@ local buffers = require("cokeline/buffers")
 
 ---@alias ClickHandler fun(button_id: number, clicks: number, button: string, modifiers: string, buffer: Buffer): void
 ---@alias WrappedClickHandler fun(buffer: Buffer): ClickHandler
+---@alias MouseEnterHandler fun(buffer: Buffer)
+---@alias MouseLeaveHandler fun(buffer: Buffer)
 
 ---@class Handlers Singleton event handler manager
 ---@field click WrappedClickHandler[]
@@ -14,22 +16,6 @@ local Handlers = {
   },
 }
 
----@param handler ClickHandler
----@param kind string
----@param idx number
-local function register(handler, kind, idx)
-  -- for global handlers
-  if idx == nil then
-    idx = kind
-    kind = nil
-  end
-  rawset(Handlers.private[kind], idx, function(buffer)
-    return function(minwid, clicks, button, modifiers)
-      return handler(minwid, clicks, button, modifiers, buffer)
-    end
-  end)
-end
-
 ---@param kind string
 ---@param idx number
 local function unregister(kind, idx)
@@ -44,7 +30,11 @@ end
 ---@param idx number
 ---@param handler ClickHandler
 function Handlers.click:register(idx, handler)
-  register(handler, "click", idx)
+  rawset(Handlers.private.click, idx, function(buffer)
+    return function(minwid, clicks, button, modifiers)
+      return handler(minwid, clicks, button, modifiers, buffer)
+    end
+  end)
 end
 
 ---Unregister a click handler

lua/cokeline/hover.lua

@@ -0,0 +1,92 @@
+local M = {}
+
+local version = vim.version()
+
+local buffers = require("cokeline.buffers")
+local rendering = require("cokeline.rendering")
+
+function M.hovered()
+  return _G.cokeline.__hovered
+end
+
+function M.get_current(col)
+  local bufs = buffers.get_visible(true)
+  if not bufs then
+    return
+  end
+  local components = rendering.prepare(buffers.get_visible())
+
+  local current_width = 0
+  for _, component in ipairs(components) do
+    current_width = current_width + component.width
+    if current_width >= col then
+      return component
+    end
+  end
+end
+
+local function on_hover(current)
+  local hovered = _G.cokeline.__hovered
+  if vim.o.showtabline == 0 then
+    return
+  end
+  if current.screenrow == 1 then
+    local component = M.get_current(current.screencol)
+
+    if not component then
+      if hovered ~= nil then
+        local buf = buffers.get_buffer(hovered.bufnr)
+        if buf then
+          buf.is_hovered = false
+          if hovered.on_mouse_leave then
+            hovered.on_mouse_leave(buf)
+          end
+        end
+        _G.cokeline.__hovered = nil
+      end
+      vim.cmd.redrawtabline()
+      return
+    end
+
+    local buf = buffers.get_buffer(component.bufnr)
+    if buf then
+      buf.is_hovered = true
+      if component.on_mouse_enter then
+        component.on_mouse_enter(buf)
+      end
+      _G.cokeline.__hovered = {
+        index = component.index,
+        bufnr = buf.number,
+        on_mouse_leave = component.on_mouse_leave,
+      }
+    end
+    vim.cmd.redrawtabline()
+  elseif hovered ~= nil then
+    local buf = buffers.get_buffer(hovered.bufnr)
+    if buf then
+      buf.is_hovered = false
+      if hovered.on_mouse_leave then
+        hovered.on_mouse_leave(buf)
+      end
+    end
+    _G.cokeline.__hovered = nil
+    vim.cmd.redrawtabline()
+  end
+end
+
+function M.setup()
+  if version.minor < 8 then
+    return
+  end
+
+  vim.keymap.set({ "", "i" }, "<MouseMove>", function()
+    local ok, pos = pcall(vim.fn.getmousepos)
+    if not ok then
+      return
+    end
+    on_hover(pos)
+    return "<MouseMove>"
+  end, { expr = true })
+end
+
+return M

lua/cokeline/init.lua

@@ -3,6 +3,7 @@ local buffers = require("cokeline/buffers")
 local config = require("cokeline/config")
 local mappings = require("cokeline/mappings")
 local rendering = require("cokeline/rendering")
+local hover = require("cokeline/hover")
 
 local opt = vim.opt
 
@@ -31,6 +32,7 @@ local setup = function(preferences)
   _G.cokeline.config = config.get(preferences or {})
   augroups.setup()
   mappings.setup()
+  hover.setup()
 
   opt.showtabline = 2
   opt.tabline = "%!v:lua.cokeline.tabline()"