From b757f618f0b12d66dbdfa9b63c5928b4c4692573 Mon Sep 17 00:00:00 2001
From: Francesco Abbate <francesco.bbt@gmail.com>
Date: Tue, 29 Dec 2020 16:44:31 +0100
Subject: [PATCH] Import workspace plugin from franko/lite-plugins

---
 data/plugins/workspace.lua | 164 +++++++++++++++++++++++++++++++++++++
 1 file changed, 164 insertions(+)
 create mode 100644 data/plugins/workspace.lua

diff --git a/data/plugins/workspace.lua b/data/plugins/workspace.lua
new file mode 100644
index 00000000..822291b0
--- /dev/null
+++ b/data/plugins/workspace.lua
@@ -0,0 +1,164 @@
+local core = require "core"
+local DocView = require "core.docview"
+
+local workspace_filename = ".lite_workspace.lua"
+
+
+local function serialize(val)
+  if type(val) == "string" then
+    return string.format("%q", val)
+  elseif type(val) == "table" then
+    local t = {}
+    for k, v in pairs(val) do
+      table.insert(t, "[" .. serialize(k) .. "]=" .. serialize(v))
+    end
+    return "{" .. table.concat(t, ",") .. "}"
+  end
+  return tostring(val)
+end
+
+
+local function has_no_locked_children(node)
+  if node.locked then return false end
+  if node.type == "leaf" then return true end
+  return has_no_locked_children(node.a) and has_no_locked_children(node.b)
+end
+
+
+local function get_unlocked_root(node)
+  if node.type == "leaf" then
+    return not node.locked and node
+  end
+  if has_no_locked_children(node) then
+    return node
+  end
+  return get_unlocked_root(node.a) or get_unlocked_root(node.b)
+end
+
+
+local function save_view(view)
+  local mt = getmetatable(view)
+  if mt == DocView then
+    return {
+      type = "doc",
+      active = (core.active_view == view),
+      filename = view.doc.filename,
+      selection = { view.doc:get_selection() },
+      scroll = { x = view.scroll.to.x, y = view.scroll.to.y },
+      text = not view.doc.filename and view.doc:get_text(1, 1, math.huge, math.huge)
+    }
+  end
+  for name, mod in pairs(package.loaded) do
+    if mod == mt then
+      return {
+        type = "view",
+        active = (core.active_view == view),
+        module = name
+      }
+    end
+  end
+end
+
+
+local function load_view(t)
+  if t.type == "doc" then
+    local ok, doc = pcall(core.open_doc, t.filename)
+    if not ok then
+      return DocView(core.open_doc())
+    end
+    local dv = DocView(doc)
+    if t.text then doc:insert(1, 1, t.text) end
+    doc:set_selection(table.unpack(t.selection))
+    dv.last_line, dv.last_col = doc:get_selection()
+    dv.scroll.x, dv.scroll.to.x = t.scroll.x, t.scroll.x
+    dv.scroll.y, dv.scroll.to.y = t.scroll.y, t.scroll.y
+    return dv
+  end
+  return require(t.module)()
+end
+
+
+local function save_node(node)
+  local res = {}
+  res.type = node.type
+  if node.type == "leaf" then
+    res.views = {}
+    for _, view in ipairs(node.views) do
+      local t = save_view(view)
+      if t then
+        table.insert(res.views, t)
+        if node.active_view == view then
+          res.active_view = #res.views
+        end
+      end
+    end
+  else
+    res.divider = node.divider
+    res.a = save_node(node.a)
+    res.b = save_node(node.b)
+  end
+  return res
+end
+
+
+local function load_node(node, t)
+  if t.type == "leaf" then
+    local res
+    for _, v in ipairs(t.views) do
+      local view = load_view(v)
+      if v.active then res = view end
+      node:add_view(view)
+    end
+    if t.active_view then
+      node:set_active_view(node.views[t.active_view])
+    end
+    return res
+  else
+    node:split(t.type == "hsplit" and "right" or "down")
+    node.divider = t.divider
+    local res1 = load_node(node.a, t.a)
+    local res2 = load_node(node.b, t.b)
+    return res1 or res2
+  end
+end
+
+
+local function save_workspace()
+  local root = get_unlocked_root(core.root_view.root_node)
+  local fp = io.open(workspace_filename, "w")
+  if fp then
+    fp:write("return ", serialize(save_node(root)), "\n")
+    fp:close()
+  end
+end
+
+
+local function load_workspace()
+  local ok, t = pcall(dofile, workspace_filename)
+  os.remove(workspace_filename)
+  if ok then
+    local root = get_unlocked_root(core.root_view.root_node)
+    local active_view = load_node(root, t)
+    if active_view then
+      core.set_active_view(active_view)
+    end
+  end
+end
+
+
+local run = core.run
+
+function core.run(...)
+  if #core.docs == 0 then
+    core.try(load_workspace)
+
+    local original_on_quit = core.on_quit
+    function core.on_quit()
+      save_workspace()
+      original_on_quit()
+    end
+  end
+
+  core.run = run
+  return core.run(...)
+end