add a ui (wip)

lua/dep/ui/page.lua

@@ -0,0 +1,84 @@
+---@class chunk: table
+---@field [1] string text to be displayed
+---@field [2] string neovim highlight group to use
+
+---@class page
+---@field name string name of the ui page
+---@field kb string keybind of the page
+---@field content chunk[]|chunk[][] all the chunks
+---@field hlns number highlight namespace
+---@field pre_draw function things to do prior to drawing to the buffer
+---@field post_draw function things to do post drawing to the buffer
+local page = {}
+
+--- create a new page
+---@param name string the name of the page
+---@param kb string keybind to change to the page
+---@return page page
+function page:new(name, kb)
+  local o = {}
+  self.__index = self
+  setmetatable(o, self)
+
+  o.hlns = vim.api.nvim_create_namespace("DepUi")
+  o.name = name
+  o.kb = kb
+  o.content = {}
+
+  return o
+end
+
+--- add a new line to the page
+---@param line chunk|chunk[] new line
+function page:new_line(line)
+  table.insert(self.content, line)
+end
+
+--- draw the page to the given buffer
+---@param bufnr number buffer number
+function page:draw(bufnr)
+  -- try to run pre_draw steps
+  if self.pre_draw then
+    self.pre_draw()
+  end
+
+  -- ready all information for rendering
+  for i, chunk in ipairs(self.content) do
+    local linenr = i - 1
+    local text = ""
+    local hls = {}
+
+    if type(chunk[1]) == "table" then
+      local j = 0
+      for _, ch in ipairs(chunk) do
+        text = text..ch[1]
+        table.insert(hls, { ch[2], j, j + #ch[1] })
+        j = j + #ch[1]
+      end
+    elseif type(chunk[1]) == "string" then
+      text = chunk[1]
+      table.insert(hls, { chunk[2], 0, #text })
+    end
+
+    -- draw the text to the buffer
+    vim.api.nvim_buf_set_lines(bufnr, linenr, -1, false, { text })
+
+    -- highlight the buffer
+    for _, hl in ipairs(hls) do
+      vim.api.nvim_buf_set_extmark(bufnr, self.hlns, linenr, hl[2], {
+        hl_mode = "replace",
+        hl_group = hl[1],
+        end_col = hl[3],
+        end_row = linenr
+      })
+    end
+
+  end
+
+  -- try to run post_draw steps
+  if self.post_draw then
+    self.post_draw()
+  end
+end
+
+return page