# Paneru
A sliding, tiling window manager for MacOS.
## About
Paneru is a MacOS window manager that arranges windows on an infinite strip,
extending to the right. A core principle is that opening a new window will
**never** cause existing windows to resize, maintaining your layout stability.
Each monitor operates with its own independent window strip, ensuring that
windows remain confined to their respective displays and do not "overflow" onto
adjacent monitors.
## Why Paneru?
- **Optimal for Large Displays:** Standard tiling window managers can be
suboptimal for large displays, often resulting in either huge maximized
windows or numerous tiny, unusable windows. Paneru addresses this by
providing a more flexible and practical arrangement.
- **Improved Small Display Usability:** On smaller displays (like laptops),
traditional tiling can make windows too small to be productive, forcing users
to constantly maximize. Paneru's sliding strip approach aims to provide a
better experience without this compromise.
- **Niri-like Behavior on MacOS:** Inspired by the user experience of [Niri],
Paneru aims to bring a similar scrollable tiling workflow to MacOS.
- **Focus follows mouse on MacOS:** Very useful for people who would like to
avoid an extra click.
- **Sliding windows with touchpad:** Using a touchpad is quite natural for
navigation of the window pane.
- **Learning Opportunity:** This project serves as a hands-on opportunity to
delve into the MacOS API and Objective-C, as well as to deepen understanding
and practice Rust programming.
## Inspiration
The fundamental architecture and window management techniques are heavily
inspired by [Yabai], another excellent MacOS window manager. Studying its
source code has provided invaluable insights into managing windows on MacOS,
particularly regarding undocumented functions.
The innovative concept of managing windows on a sliding strip is directly
inspired by [Niri] and [PaperWM.spoon].
## Installation
Paneru is built using Rust's `cargo`. It can be installed directly from
`crates.io` or if you need the latest version, by fetching the source from Github.
### Installing from Crates.io
```shell
$ cargo install paneru
```
### Installing from Github
```shell
$ git clone https://github.com/karinushka/paneru.git
$ cd paneru
$ cargo build --release
$ cargo install --path .
```
It can run directly from the command line or as a service.
Note, that you will need to grant acessibility priviledge to the binary.
### Configuration
To configure Paneru, create a configuration file named `.paneru` in your home
directory (`~/.paneru`). You can use the following example configuration as a
starting point:
```
# syntax=toml
#
# Example configuration for Paneru.
#
[options]
# Enables focus follows mouse. Set to false or remove the line to disable.
focus_follows_mouse = true
# How many fingers to use for moving windows left and right.
# Make sure that it doesn't clash with OS setting for workspace switching.
# Values lower than 3 will be ignored.
# Remove the line to disable the gesture feature.
# Apple touchpads support gestures with more than five fingers (!),
# but it is probably not that useful to use two hands :)
swipe_gesture_fingers = 4
[bindings]
# Moves the focus between windows.
window_focus_west = "cmd - h"
window_focus_east = "cmd - l"
window_focus_north = "cmd - k"
window_focus_south = "cmd - j"
# Swaps windows in chosen direction.
window_swap_west = "alt - h"
window_swap_east = "alt - l"
# Jump to the left-most or right-most windows.
window_focus_first = "cmd + shift - h"
window_focus_last = "cmd + shift - l"
# Move the current window into the left-most or right-most positions.
window_swap_first = "alt + shift - h"
window_swap_last = "alt + shift - l"
# Centers the current window on screen.
window_center = "alt - c"
# Shuffles between predefined window sizes: 25%, 33%, 50%, 66% and 75%.
window_resize = "alt - r"
# Toggles the window for management. If unmanaged, the window will be "floating".
window_manage = "ctrl + alt - t"
# Stacks and unstacks a window into the left column. Each window gets a 1/N of the height.
window_stack = "alt - ]"
window_unstack = "alt + shift - ]"
# Quits the window manager.
quit = "ctrl + alt - q"
```
Paste this into your terminal to create a default configuration file:
```
$ cat > ~/.paneru <<EOF
# ... paste the above configuration here ...
EOF
```
**Live Reloading:** Configuration changes made to your `~/.paneru` file are
automatically reloaded while Paneru is running. This is extremely useful for
tweaking keyboard bindings and other settings without restarting the
application. The settings can be changed while Paneru is running - they will
be automatically reloaded.
### Running as a service
```shell
$ paneru install
$ paneru start
```
### Running in the foreground
```shell
$ paneru
```
## Recommended System Options
Paneru window manager requires accessibility access (just like all the other third party window managers for MacOS).
Once it runs you may get a dialog window asking for permissions.
Check your system settings for "Displays have separate spaces". It should be
enabled - this allows Paneru to manage the spaces independently.
Paneru is by default using a "three finger" swipe gesture to slide the windows left or right.
If you have the same gesture configured to swipe workspaces, change it in the
system settings to a "four fingers" gesture. Otherwise you will trigger both at the same time, resulting in a weird sliding effect.
Alternatively change the `if fingers.len() != 3` in the code to 4 and recompile.
## Future Enhancements
- More commands for manipulating windows: fullscreen, finegrained size adjustments, etc.
- Scriptability. A nice feature would be to use Lua for configuration and simple scripting,
like triggering and positioning specific windows or applications.
## Communication
There is a public Matrix room [`#paneru:matrix.org`](https://matrix.to/#/%23paneru%3Amatrix.org). Join and ask any questions.
## Architecture Overview
The overall architecture is layered, with a platform interaction layer at the base.
This bottom layer, primarily within `platform.rs`, interfaces directly with the MacOS operating system via Objective-C and Core Graphics APIs.
It runs the main RunLoop in the main thread, receiving OS-level events and acting as the bridge between the operating system and the application's logic.
Events captured by this layer, such as window events, application state changes, and mouse events, are then pushed into a multiple-producer single-consumer (MPSC) queue.
Higher layers of the application consume events from this queue.
These layers include the `WindowManager`, `ProcessManager`, and various event handlers.
The `WindowManager` is responsible for tracking and manipulating window states, while the `ProcessManager` handles the lifecycle of applications.
Event handlers in modules like `events.rs` interpret the raw events and orchestrate the appropriate responses within the application.
This design promotes a decoupled architecture, allowing modules to operate independently while reacting to system-level changes.
## Tile Scrollably Elsewhere
Here are some other projects which implement a similar workflow:
- [Niri]: a scrollable tiling Wayland compositor.
- [PaperWM]: scrollable tiling on top of GNOME Shell.
- [karousel]: scrollable tiling on top of KDE.
- [papersway]: scrollable tiling on top of sway/i3.
- [hyprscroller] and [hyprslidr]: scrollable tiling on top of Hyprland.
- [PaperWM.spoon]: scrollable tiling on top of MacOS.
[Yabai]: https://github.com/koekeishiya/yabai
[Niri]: https://github.com/YaLTeR/niri
[PaperWM]: https://github.com/paperwm/PaperWM
[karousel]: https://github.com/peterfajdiga/karousel
[papersway]: https://spwhitton.name/tech/code/papersway/
[hyprscroller]: https://github.com/dawsers/hyprscroller
[hyprslidr]: https://gitlab.com/magus/hyprslidr
[PaperWM.spoon]: https://github.com/mogenson/PaperWM.spoon