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Treemacs layer

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1. Description

This layer sets up a file navigation and project explorer side-window via Treemacs.

1.1. Features:

A detailed overview of the features of Treemacs is available in the Treemacs readme. In short, Treemacs offers:

  • Simple and powerful navigation and ability to detail exactly how and where a file should be opened.
  • Good looking icons.
  • Display of multiple file trees organized as projects residing in a workspace.
  • Ability to show tags contained in files. Tags are provided by Imenu, so nearly every filetype is supported.
  • Mouse interface for single and double left clicks in line with modern GUI standards (clicking on an icon will also display the file's tags).
  • Location awareness: commands like find-file or magit-status will use the location of the node at point (with $HOME as fallback).
  • Optional fontifying of files based on their git status.
  • Optional collapsing of single-dir-child directories into one.
  • Doing both asynchronously for an imperceptible performance cost.
  • Optional follow-mode to automatically focus the currently selected file or tag.
  • Optional filewatch-mode to automatically refresh the view after (and only after) changes to the shown filesystem.

2. Install

To use this layer, add treemacs to dotspacemacs-configuration-layers in your dotspacemacs file.

3. Configuration

3.1. Follow mode

To have Treemacs automatically sync with your current:

  • Buffer's file, set the layer variable treemacs-use-follow-mode to t.
  • Tag, set the layer variable treemacs-use-follow-mode to tag.
(setq-default dotspacemacs-configuration-layers '(
  (treemacs :variables treemacs-use-follow-mode 'tag)))

Default is t.

3.2. File watch

To automatically refresh the Treemacs buffer when there is a change in the part of the file system shown by treemacs set the layer variable treemacs-use-filewatch-mode to non-nil.

(setq-default dotspacemacs-configuration-layers '(
  (treemacs :variables treemacs-use-filewatch-mode t)))

Default is t.

3.3. Scope Settings

By default treemacs buffers and their workspaces will be uniquely scoped within the current frame. As an alternative it is possible to scope treemacs to the currently active perspective, including the automatic creation of a workspace for every perspective. The scope type is determined by setting the layer variable treemacs-use-scope-type to either 'Frames or 'Perspectives.

Note that persective-based scoping will only take effect when persp-mode is actually first used.

(setq-default dotspacemacs-configuration-layers '(
  (treemacs :variables treemacs-use-scope-type 'Perspectives)))

Default is 'Frames.

3.4. Git mode

To enable Treemacs to check for the git status information of files and directories and highlight them accordingly, set the layer variable treemacs-use-git-mode to simple, extended, or deferred. See the Treemacs documentation for a more detailed explanation.

(setq-default dotspacemacs-configuration-layers '(
  (treemacs :variables treemacs-use-git-mode 'deferred)))

Default is nil.

3.5. Flattening of directories

This feature requires Python to be installed.

Treemacs tries to flatten empty directory names into one name. It is possible to control how deep Treemacs will search for empty directories by settings the layer variable treemacs-collapse-dirs to a positive number.

(setq-default dotspacemacs-configuration-layers '(
  (treemacs :variables treemacs-collapse-dirs 3)))

Default is 3 (or 0 when Python is not installed).

3.6. Locking width

To have the width of the treemacs window locked by default, so that it is not manually resizable, set the variable treemacs-lock-width to non-nil. It will still be resizable through Treemacs commands and key bindings.

(setq-default dotspacemacs-configuration-layers '(
  (treemacs :variables treemacs-lock-width t)))

Default is nil.

3.7. Theme

To use the `all-the-icons` theme rather than the default one, set the `treemacs-use-all-the-icons-theme` variable:

(setq-default dotspacemacs-configuration-layers '(
  (treemacs :variables treemacs-use-all-the-icons-theme t)))

4. Key bindings

4.1. Global

Key binding Description
M-0 Selected the treemacs window. Actually selects window #10, which is always assigned to treemacs.
SPC 0 Open treemacs in the current directory. When not visiting a file use $HOME as fallback. With a prefix arg manually select the root instead.
SPC f B Find and select a bookmark. If it cannot be found rebuild view with the bookmark's location as root. Also open the bookmark with a prefix arg.
SPC f t Hide/show existing treemacs buffer. Create one for the current directory if no buffer exists.
SPC f T Manually focus the treemacs view on the currently selected file. Not needed when treemacs-follow-mode is enabled.
SPC f M-t Manually focus the treemacs view on the currently selected file and tag.
SPC p t Hide/show existing treemacs buffer. Add the current project to treemacs if not already added.

4.2. Inside Treemacs

Treemacs will use either j/k or n/p to go to the next/previous line, depending on whether vim/hybrid editing style is used. Likewise refresh is only bound to g when emacs editing style is used, since under vim g is a prefix for many other commands.

Key binding Description
? Summon the helpful hydra to show you the treemacs keymap.
M-j/M-n Select next node at the same depth as currently selected node, if possible.
j/n Goto next line.
k/p Goto previous line.
M-J/N Go to the next line in next-window.
M-K/P Go to the previous line in next-window..
M-j/M-n Select next node at the same depth as currently selected node, if possible.
M-k/M-p Select previous node at the same depth as currently selected node, if possible.
C-c C-p a Select a new project to add to the treemacs workspace.
C-c C-p p Select a projectile project to add to the workspace.
C-c C-p d Remove project at point from the workspace.
C-c C-p r Rename project at point.
w Set a new value for the width of the treemacs window.
TAB Do what I mean (as defined in treemacs-TAB-actions-config). Prefers expanding nodes by default.
RET Do what I mean (as defined in treemacs-RET-actions-config). Prefers visiting nodes by default.
mouse1 Move point to clicked line
2x mouse1 Do what I mean (as defined in treemacs-doubleclick-actions-config). Behaves like RET by default.
g/r/gr Refresh and rebuild the treemacs buffer.
d Delete node at point. A delete action must always be confirmed. Directories are deleted recursively.
cf Create a file.
cd Create a directory.
R Rename the currently selected node. Reload buffers visiting renamed files or files in renamed directories.
u Select parent of selected node, if possible.
q Hide/show an existing treemacs buffer.
Q Kill the treemacs buffer.
ov Open current file or tag by vertically splitting next-window.
oh Open current file or tag by horizontally splitting next-window.
oo Open current file or tag, performing no split and using next-window directly.
oaa Open current file or tag, using ace-window to decide which window to open the file in.
oah Open current file or tag by horizontally splitting a window selected by ace-window.
oav Open current file or tag by vertically splitting a window selected by ace-window.
ox Open current file according to its mime type in an external application. Linux, Windows and macOS are supported.
tf Toggle treemacs-follow-mode.
ta Toggle treemacs-filewatch-mode.
tg Toggle git-mode.
th Toggle the hiding and displaying of dotfiles.
tw Toggle whether the treemacs buffer should have a fixed width.
tv Toggle treemacs-fringe-indicator-mode
yr Copy the relative path of the nearest project node at point.
ya Copy the absolute path of the node at point.

4.2.1. Ace mode to open files

It is possible to open the file under cursor in exact the window you want. By default you have to press o a a to run ace selection mode and choose the window with keys a s d f. That behavior can be changed in two ways.

  1. Set ace mode as default action

    It is possible to set ace mode as default action for pressing RET on a file. To do this add following configuration to your dotfile.

    (with-eval-after-load 'treemacs
      (treemacs-define-RET-action 'file-node-closed #'treemacs-visit-node-ace)
      (treemacs-define-RET-action 'file-node-open #'treemacs-visit-node-ace))
  2. Use digits in ace mode

    Just add the following to use digits instead of a s d f in ace (window selection) mode. Please note that the following code changes ace mode globally.

    (setq aw-keys '(?1 ?2 ?3 ?4 ?5 ?6 ?7 ?8 ?9 ?0))

Author: root

Created: 2024-06-14 Fri 18:50