Merge pull request #26 from jgmdev/navigate-plugin

Added navigate plugin

2 files changed, 148 insertions, 0 deletions

diff --git a/README.md b/README.md
index 91c5c0b..4af61c0 100644
--- a/README.md
+++ b/README.md
@@ -94,6 +94,7 @@ Plugin | Description
 [`memoryusage`](plugins/memoryusage.lua?raw=1) | Show memory usage in the status view
 [`motiontrail`](plugins/motiontrail.lua?raw=1) | Adds a motion-trail to the caret *([screenshot](https://user-images.githubusercontent.com/3920290/83256814-085ccb00-a1ab-11ea-9e35-e6633cbed1a9.gif))*
 [`nagbar`](https://github.com/takase1121/lite-nagbar)* | consistent and _beautiful_ confirmation dialogs for lite and lite-xl *([gif](https://raw.githubusercontent.com/takase1121/lite-nagbar/master/assets/preview.gif))*
+[`navigate`](plugins/navigate.lua?raw=1) | Allows moving back and forward between document positions, reducing the amount of scrolling
 [`openfilelocation`](plugins/openfilelocation.lua?raw=1) | Opens the parent directory of the current file in the file manager
 [`openselected`](plugins/openselected.lua?raw=1) | Opens the selected filename or url
 ~~[`projectmanager`](plugins/projectmanager.lua?raw=1)~~ | Integrated in lite-xl with improvements ~~Save projects and load/reload them quickly~~
diff --git a/plugins/navigate.lua b/plugins/navigate.lua
new file mode 100644
index 0000000..5d37e76
--- /dev/null
+++ b/plugins/navigate.lua
@@ -0,0 +1,147 @@
+-- mod-version:1 -- lite-xl 1.16
+
+local core = require "core"
+local common = require "core.common"
+local command = require "core.command"
+local config = require "core.config"
+local keymap = require "core.keymap"
+local DocView = require "core.docview"
+
+local navigate = {
+  list = {},
+  current = nil,
+  index = 0
+}
+
+--
+-- Private functions
+--
+local function get_active_view()
+  if getmetatable(core.active_view) == DocView then
+    return core.active_view
+  end
+  return nil
+end
+
+local function add(doc)
+  -- Make new navigation point last in list
+  if navigate.index > 0 and navigate.index < #navigate.list then
+    local list_len = #navigate.list
+    for index=navigate.index+1, list_len, 1 do
+      if navigate.list[index] then
+        table.remove(navigate.list, index)
+      end
+    end
+  end
+
+  local line, col = doc:get_selection()
+  table.insert(navigate.list, {
+    filename = doc.filename,
+    line = line,
+    col = col
+  })
+
+  navigate.current = navigate.list[#navigate.list]
+  navigate.index = #navigate.list
+end
+
+local function open_doc(doc)
+  core.root_view:open_doc(
+    core.open_doc(
+      common.home_expand(
+        doc.filename
+      )
+    )
+  )
+
+  local av_doc = get_active_view().doc
+  local line, col = av_doc:get_selection()
+  if doc.line ~= line or doc.col ~= col then
+    av_doc:set_selection(doc.line, doc.col, doc.line, doc.col)
+  end
+end
+
+--
+-- Public functions
+--
+function navigate.next()
+  if navigate.index < #navigate.list then
+    navigate.index = navigate.index + 1
+    navigate.current = navigate.list[navigate.index]
+    open_doc(navigate.current)
+  end
+end
+
+function navigate.prev()
+  if navigate.index > 1 then
+    navigate.index = navigate.index - 1
+    navigate.current = navigate.list[navigate.index]
+    open_doc(navigate.current)
+  end
+end
+
+--
+-- Thread
+--
+core.add_thread(function()
+  while true do
+    local av = get_active_view()
+    if av and av.doc and av.doc.filename then
+      local doc = av.doc
+      local line, col = doc:get_selection()
+      local current = navigate.current
+      if
+        not current
+        or
+        current.filename ~= doc.filename
+        or
+        current.line ~= line
+      then
+        add(doc)
+      else
+        current.col = col
+      end
+    end
+
+    if system.window_has_focus() then
+      coroutine.yield(0.5)
+    else
+      coroutine.yield(config.project_scan_rate)
+    end
+  end
+end)
+
+core.add_close_hook(function(doc)
+  local filename = doc.filename
+  local list = {table.unpack(navigate.list)}
+  for index, position in ipairs(list) do
+    if position.filename == filename then
+      if navigate.list[index] then
+        table.remove(navigate.list, index)
+      end
+    end
+  end
+end)
+
+--
+-- Commands
+--
+command.add("core.docview", {
+  ["navigate:previous"] = function()
+    navigate.prev()
+  end,
+
+  ["navigate:next"] = function()
+    navigate.next()
+  end,
+})
+
+--
+-- Default Keybindings
+--
+keymap.add {
+  ["alt+left"]    = "navigate:previous",
+  ["alt+right"]   = "navigate:next",
+}
+
+return navigate