82 lines
3.3 KiB
Markdown
82 lines
3.3 KiB
Markdown
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## Code overview
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The following is a brief code overview / general introduction for those wanting
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to hack on sway.
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### wlc
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In Wayland the compositor is the display server. That's a design decision that
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brings several advantages, but the downside is that all compositors need to
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implement an entire display server as well.
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To aid the situation there are several *wayland display servers* being
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implemented as libraries so that compositors can stick to doing compositing and
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leave the low level details to one of those libraries. In sway that library is
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`wlc`, and it handles tty switching, logind sessions, input, everything that
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deals with the GPU, and just about everything concerning the Wayland protocol
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itself (as of writing there's not a single call to any wayland functions inside
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of sway). sway communicates with wlc via a callback api found in
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`sway/handlers` (`wlc_interface`). The code in that file deals with all the
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entry points from wlc to sway.
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### Commands
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Being a tiling window manager, controlling it via commands is an important part
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of its functionality, and `sway/commands` which deals with that is by far the
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biggest file in the codebase.
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There are multiple ways to trigger a command: via the keyboard, via the config
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file, or via the IPC interface.
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### IPC
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i3 has an IPC interface (it creates a socket that applications can connect to
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and issue commands or queries via its protocol), and sway replicates that
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protocol (so e.g. `i3-msg` can be used with sway by simply changing the socket,
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e.g. `i3-msg -s $(sway --get-socketpath)`). The code for that lies in
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`sway/ipc`.
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### Config
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The config state and loading the config file lies in `sway/config`. Since the
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config file is simply a list of commands, that code mostly just parses the text
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and then hands commands off to `commands` for execution.
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### Pointer handling
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The mouse has buttons, state (due to buttons pressed, e.g. "dragging",
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"resizing" etc.) and movement. Most code related to that lies in
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`sway/input_state`.
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### Containers
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In traditional *floating* window managers, all windows (or *views* as they're
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called in sway) are placed anywhere on the screen. In a tiling window manager
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like sway the views are *arranged* by the compositor, and the user mostly just
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manipulates the arrangement via commands (floating views are also supported).
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In sway, each *output* (a physical monitor) has one or more *workspaces* which
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has one or more *views* (the actual windows). In order to keep track of the
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arrangement of the views, sway organizes everything in a tree of *containers*.
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Each of the previously mentioned things is a type of container. In addition
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there's a type of container called *container* which is needed to arrange other
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containers as siblings (horizontal or vertical layout), and a *root container*
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which exists for practical reasons.
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`sway/containers` contains the code for this and understanding containers is
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essential in understanding sway.
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Also, the code that actually arranges the different views lays in
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`sway/layout`.
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### Focus
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When changing workspace, changing output, changing view or just moving the
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pointer you change which view has *focus*. The code for handling this and
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e.g. deciding what view receives input events is handled in `sway/focus`.
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### Notes
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As sway is a work in progress, as of writing it is still not versioned. Use the
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`master` branch of sway and wlc for now.
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