Durden, Tiling Desktop Environment for Arcan

32c06879486a0259c57a3fe6f32a8a2d?s=47 Bjorn Stahl
November 19, 2015

Durden, Tiling Desktop Environment for Arcan


Bjorn Stahl

November 19, 2015


  1. Durden [Hacker-friendly] Desktop Environment for Arcan (first release, so be

    gentle) Demo Videos @ www.arcan-fe.com/videos ^^-- watch this before moving on
  2. Features • Keyboard Dominant (trying to assist you in using

    the mouse as little as possible). Primarily Tiled window management configuration - but normal “desktop- style” use also works • Zero-Config - inputs, visual features (animations), fonts etc. can all be tuned runtime without editing / rebuilding / reloading. • Complex cases, such as multiple heterogeneous displays (“mixed- DPI”) covered and prioritised • Global and Per Window clipboard with history • Highly configurable input model, rebind inputs globally and/or per window, support for game devices, switching keyboard layouts, ... • Fine grained control of individual window behavior in regard to locking, input translation, scaling, filtering, post-processing effects
  3. Layout Modes • Primary container is the ‘workspace’ • Up

    to 10 workspaces per display • Each workspace has:
 layout mode (tile, float, vtab, tab, fullscreen)
 current display
 preferred display
 possible background
 possible text tag

  4. Tile- Mode m1 + up/down/left/right : select m1 + m2

    + tab : insertion mode (v, h) switch m1 + m2 + up/down/left/right : resize m1 + m : merge or split subtree Also: Titlebar toggle on/off Swap left/right/up/down
  5. Float- Mode border-drag resize tbar-drag move tbar-dblclick toggle max. m1+m2

    | m2 | m1 + up/down/left/right : move, resize, select Position/Size tracked separately from other layout modes activate by clicking layout button
  6. Window Operations and Properties • Visual: Configurable border area (for

    gaps) border size (from 0 to gap_sz) workspace-transition animation, wallpaper • All Decorations are shader defined, can be made quite crazy :) • Custom tag to each window for searching / retrieval • Workspace Alert • Sound Controls (global or per window volume) • State Controls (suspend, resume, save, restore) • Remember Cursor Position, autolocking per window
  7. Global Menu, Window Menu, Launch Menu Default ( meta1 +

    g (main) or t (window) or d (launch) ) type to filter enter to launch selected both actions and groups can be bound to shortcut key arrow-keys to move selection [meta]escape to go back
  8. More Menus automation - bind action or target to: Widget

    Regions For image preview, keybinding helper, ... inactivity timer one-fire timer external command pipe periodic timer titlebar decoration icon statusbar button
  9. Widgets • Binds to one or many menu paths (e.g.

    !/global/input or special:bind_u8) • Generates dynamic helper contents that ties to widget regions
 Can be interactive (notes, todo, clock, cheat sheets, password generator, colour picker etc.) • Examples: (show existing bindings) (ASCII helper)
  10. Titlebar / Statusbar / IPC • Bind custom menu path

    to titlebar decoration button [left or right] • Can be hidden in tiled mode • 3 pipes (config/system/ipc): control [in], output [out], status [in] • control - activate menu path externally, output - write messages to external listener, status - modify statusbar • Statusbar can be externally modified (lemonbar- like protocol) • e.g. echo "hi %{F#00ffff} There | %{F-} %{Aclickme} Button" > ipc/status
 [ set bar to (hi There | Button) with "clickme" written to output pipe on click ]
  11. Multi-Display Setup • Arcan:egl-dri platform only one with hardware support

    at the moment (and related driver issues).. • Workspace is ‘homed’ to a display • Display disappears? workspace is adopted • Display reappears? workspace moves back home • Windows / Workspaces can be migrated to a display manually (global/ workspace/migrate/[display name] or target/window/migrate/[display name]) • Caveats: manual- scan for display changes as event-driven turned out driver-crash prone (global/display/rescan), poor identification (bad EDID values on reconnect breaks autohoming!) • Display properties (RGB layout, pixel density, font size) are communicated to window / workspace / external processes on migration
  12. Multi-Display / Quality • Every display - individual shader •

    For color- gamma- correction / special needs • Current arcan limitations makes ICC profile harder
 (no R10G10B10 or 3D LUT texture support) • Re- orientation • Per display : Toggle Horizontal / Vertical arrangement • Text • Font / Hinting / Size is managed per display, pushed to clients, synched on window- migration • Decoration, Font, Cursor follows display pixel density
  13. Sharing • One feature that covers: sharing**, streaming**, recording**, screenshots

    and magnification • m2: align to selected window canvas, 
 m1: switch anchor point, 
 mouse motion to resize • (currently poor sound-source control / mixing) ** spawns and forwards to encoding frameserver, will also be used for OCR and text to speech path: global/display/region/
  14. Input Features • Keyboard(s) (see global/input/keyboard/maps for load/save/modify) • key-press(+mods)

    maps to symbol and utf-8 sequence. • key-press/combination can be bound per window to label (each connection can dynamically communicate supported labels and datatype) • Sore spot: no good converter from X etc. to internal format (yet) • meta+key can be bound to target or global menu path (including setting a specific value, e.g. config/visual/mouse_scale=5) • per- window Bind UTF-8 overrides to Keymap or Global or Window
  15. Mouse / Game Devices • Cursor • Lock to Window

    Center, Lock to Window, Remember Window Position, Motion Scaling, Autohide • Bind buttons to Target / Global Menu action • Gamepads, switches etc. • Known devices (platform+string identifier) has a map in devmaps and gets "auto slotted" • Slot is expanded into label translation (=> PLAYERn_BUTTON1) • Can also be bound to menu paths like normal presses:
 input/bind/custom takes 'n' repeated inputs
 but currently only rising edge triggered, not level (hold) or falling (release)
  16. Clipboard • Hides in Window menu (Clipboard/*) • Tracks both

    Local (per window) and Global (shared) • Conservative History (no accidental duplicates) • meta_1 - activate to copy from local to global • Captures / Tracks URLs separately
 presents as completion sets in open/remote or open/media • Paste Modes • Strip leading / trailing / repeating whitespace / linefeeds
  17. Lockscreen • configurable event hooks: n-failure, on-enter, on-accept • tracks

    / shows failed attempts count • one-time passwords • no PAM/what-have-you integration on purpose • authenticate to current desktop, not re-use system authentication primitives for something as mundane like “I needed to go to the bathroom” path: system/lock
  18. Timers • add time delay or event triggered menu path

    activation • can be periodic (run every n ticks) • can be idle 
 (run path#1 on enter-idle, path#2 on exit-idle) • and fire-once or repeated path: config/timers
  19. Safety Features • Requires keyboard present on init • 'n'

    presses without meta+ combination? query for rebind • Remove / Insert keyboard device resets rebind helper • Individual windows can be ‘delete protected’ • External Control Channel (if enabled) can run menu commands • current settings can be externally modified with arcan_db [ arcan_db drop_appl durden to reset ] • Run with arcan -b :self durden to relaunch and inherit external connections on script error
  20. First Launch • Assumed: arcan installation working, depending on OS,

    distribution, graphics set-up etc. this can be hairy (drm- kms on linux, device permisions etc.) • arcan /path/to/durden (if in APPLBASE, ~/.arcan/appl just arcan durden) • some basic things, m1+enter (terminal), m1+g (global menu) • if nothing happens, type frantically on the keyboard for some ~20 presses and it assumes your keybindings are broken and you see:
  21. Launch targets • Arcan is rather restrictive about executing things

    (for good reason) • There is a database that tracks what is permitted to be launched and with which arguments. • We call those ‘targets’ and ‘configurations’ (multiple per target). • There is a tool to manage this database, arcan_db (though distributions etc. might just want to handle this differently). • Database is used both for tracking user settings globally and individually for the targets / configurations. -b filename to switch • By default, it resides in your ~/.arcan/arcan.sqlite, but you can specify it somewhere else (and have multiple to switch between) with -d file
  22. Launch example • This uses the builtin support for libretro

    (libretro.com), the freeware game doukutsu (cave story) and the corresponding libretro core. arcan_db arcandb.sqlite add_target “cave story” “[ARCAN_RESOURCEPATH]/ cores/cave.dylib” RETRO “[ARCAN_RESOURCEPATH]/assets/cave/Doukutsu.exe” • the [ARCAN_RESOURCEPATH] will be expanded at runtime to the path set as resource path (arcan -p respath), the RETRO indicates the binary format (we want afsrv_game as loader) • now “cave story” will be available in my meta-d launch menu, in the way it was used in the demo video.
  23. egl-dri (kms) notes • Permissions (/dev/dri/card*, renderD*, /dev/input/* or inotify

    for device nodes in ARCAN_INPUT_SCANDIR ENV) • Need recent: (kernel >= 4.x, libdrm and MESA) + compatible card and luck (/s long live gpu drivers).. • OK (Intel), So-So (AMD), “Exotic” (Nvidia, egl-nvidia VIDEO_PLATFORM) • Environment tuning (primary): DISPLAY_CONNECTOR • Current limits: 1 GPU / instance, (but multiple concurrent instances possible), handles primary display connector loss poorly. • External Launch support not fully implemented (upgrade without losing state, temporarily release resources and hand over to other program etc.)
  24. Future • Most (all?) prominent features of other tiling window

    managers are in place (and quite a few more of our own). • Big improvements will be directed towards: • raising quality (redshift, color correction profiles, daltonization, latency vs. energy-efficiency tradeoffs) • controlled sharing (multimedia/VM state copy/paste, network transparency, LAN state migration, VM integration) • advanced input (macro record/replay, sticky combinations, tablet gestures, OCR, eye-trackers, OSD keyboard, keyboard to mouse) • Longer list in README.md (checklist and crazy ideas)
  25. Developer / Debugging • First Release, don’t expect perfection. •

    ulimit -c unlimited; ARCAN_LOGPATH=/some/path arcan -g -b :self durden &> mylog will retain most information • -b :self means fallback to self on script error • system/debug submenu comes with -g debuglevel (-g -g is too verbose) • What I do? 2 GPUs (i915 + AMD R380 atm.), 2 durden checkouts • 2nd instance with different envs/db that uses a different name for connection point (ARCAN_VIDEO_DEVICE, ARCAN_APPLTEMPPATH, ARCAN_RESOURCEPATH, ALSA_CARD, ARCAN_FRAMESERVER_DEBUGSTALL=1 + config/system/connection_path • started with added cmdline arg input_lock ; secret sauce - shares input device nodes with other instance, (see: keybindings.lua with input_lock_toggle and input_lock_on input_lock_off to control)

  26. More? • We’re just getting started (see arcan overview presentation)

    • See Features and Status in README.md in git repository for updates on status • #arcan on Freenode for complaining, helping out or idling :-)