sane-input-handler: express the logic in a way thats more immune to the previous class of quoting error

had to introduce some hacks to keep the debuggability though. i don't like it.

hosts/common/programs/sane-input-handler/sane-input-handler

@@ -57,11 +57,38 @@
 
 # increments to use for volume adjustment (in %)
 var VOL_INCR = 5
+var SEEK_INCR = 30
+var SEEK_DECR = 10
 var KEYBOARD = "${KEYBOARD:-wvkbd-mobintl}"
 var CAMERA = "${CAMERA:-org.postmarketos.Megapixels.desktop}"
 var VERBOSITY = 0
 var DRY_RUN = false
 
+# all known triggers:
+var Triggers = {
+  PowerTap1        : "power_tap_1",
+  PowerTap2        : "power_tap_2",
+  PowerHold        : "power_hold",
+  PowerTap1Hold    : "power_tap_1_hold",
+  PowerAndVolup    : "power_and_volup",
+  PowerAndVoldown  : "power_and_voldown",
+  PowerThenVolup   : "power_then_volup",
+  PowerThenVoldown : "power_and_voldown",
+  VolupTap1        : "volup_tap_1",
+  VolupTap2        : "volup_tap_2",
+  VolupTap3        : "volup_tap_3",
+  VolupHold1       : "volup_hold_1",
+  VolupHold2       : "volup_hold_2",
+  VolupHold3       : "volup_hold_3",
+  VoldownTap1      : "voldown_tap_1",
+  VoldownTap2      : "voldown_tap_2",
+  VoldownTap3      : "voldown_tap_3",
+  VoldownHold1     : "voldown_hold_1",
+  VoldownHold2     : "voldown_hold_2",
+  VoldownHold3     : "voldown_hold_3",
+  VoldownStart     : "voldown_start",
+}
+
 proc showHelp {
   echo "usage: sane-input-handler [--verbose [--verbose]] [--dry-run] <action>"
   echo ""
@@ -81,11 +108,23 @@ proc showHelp {
 }
 
 proc log (; ...stmts; level, context) {
-  var prefix = " $context:" if context else ""
+  var prefix = "";
-  var formatted = "$(pp value (stmts))"
+  var formatted = "";
+  if (stmts) {
+    setvar prefix = "$context: " if context else ""
+    setvar formatted = "$(pp value (stmts))"
+  } else {
+    # bare log statement; nothing to pretty-print
+    setvar formatted = context;
+  }
   echo "[$level] sane-input-handler: $prefix$formatted" >&2
 }
 
+proc die (context=""; ...stmts) {
+  log (level="ERRR", context=context, ...stmts)
+  exit 1
+}
+
 proc info (context=""; ...stmts) {
   log (level="INFO", context=context, ...stmts)
 }
@@ -115,13 +154,6 @@ proc effect (...args) {
   }
 }
 
-func traceFunc (funcName, fn, ...args) {
-  debug "$funcName" (...args)
-  var r = fn(...args)
-  debug "$[funcName] -> return" (r)
-  return (r)
-}
-
 ## HELPERS
 
 # swaySetOutput true|false
@@ -271,25 +303,6 @@ func isFullscreen () {
   return (memoize ("swayIsFullscreen", ^[swayIsFullscreen()]))
 }
 
-proc handleWith (; ...args) {
-  var state = ""
-  if (isFullscreen()) {
-    setvar state = "fullscreen+${state}"
-  }
-  if (isInhibited()) {
-    setvar state = "inhibited+${state}"
-  }
-  if (isAllOn()) {
-    setvar state = "${state}on"
-  } else {
-    setvar state = "${state}off"
-  }
-
-  info "handleWith" ("state=$state", "action=$action", ...args)
-  @[args]
-}
-
-
 ## HANDLERS
 proc ignore {
   :
@@ -297,9 +310,6 @@ proc ignore {
 proc inhibited {
   :
 }
-proc unmapped {
-  :
-}
 
 proc allOn {
   swaySetOutput true
@@ -311,9 +321,9 @@ proc allOff {
 }
 
 proc toggleKeyboard {
-  var keyboardPids = $(pidof "$KEYBOARD") => split(" ")
+  var keyboardPids = $(pidof "$KEYBOARD" || echo "") => split(" ")
   if (not keyboardPids) {
-    log ("cannot find $KEYBOARD")
+    info "toggleKeyboard: cannot find keyboard" (KEYBOARD)
     return
   }
 
@@ -344,11 +354,11 @@ proc restartBonsai {
 }
 
 proc seekForward {
-  effect playerctl position 30+
+  effect playerctl position "$SEEK_INCR"+
 }
 
 proc seekBackward {
-  effect playerctl position 10-
+  effect playerctl position "$SEEK_DECR"-
 }
 
 proc killWindow {
@@ -389,158 +399,161 @@ proc killRofi {
   effect killall -9 rofi
 }
 
-## DISPATCHERS
+# index of all possible responses, to allow lookup by-name
-
+var Responses = {
-func mapDefault (action) {
+  allOn: allOn,
-  case (action) {
+  allOff: allOff,
-    ("power_tap_2") {
+  toggleKeyboard: toggleKeyboard,
-      # power twice => screenoff
+  togglePlayback: togglePlayback,
-      return ("allOff")
+  volumeUp: volumeUp,
-    }
+  volumeDown: volumeDown,
-    ("power_hold") {
+  restartBonsai: restartBonsai,
-      # power twice => toggle media player
+  seekForward: seekForward,
-      return ("togglePlayback")
+  seekBackward: seekBackward,
-    }
+  killWindow: killWindow,
-    / ^ 'volup_hold_' d+ $ / {
+  takeScreenshot: takeScreenshot,
-      return ("seekForward")
+  openCamera: openCamera,
-    }
+  rotateCCW: rotateCCW,
-    / ^ 'voldown_hold_' d+ $ / {
+  rotateCW: rotateCW,
-      return ("seekBackward")
+  openFilebrowser: openFilebrowser,
+  openFilebrowserWithApps: openFilebrowserWithApps,
+  openTerminal: openTerminal,
+  killRofi: killRofi,
 }
 
-    / ^ 'volup_tap_' d+ $ / {
+func Handler_exec(self) {
-      return ("volumeUp")
+  var resp = self.response
+  resp  #< this executes the response
 }
-    / ^ 'voldown_tap_' d+ $ / {
+
-      return ("volumeDown")
+var Handler = Object(null, {
+  # methods
+  exec: Handler_exec,
+  # instance state
+  trigger: null, #< name of action the _user_ performed
+  response: null, #< bound proc to invoke in response to the trigger
+  name: null, #< friendly name of response; should just be the stringified form of `response`
+  screen: false, #< screen must be on for this response to trigger
+  fullscreen: false, #< desktop view must be fullscreen for this response to trigger
+  sys_menu: false, #< system menu must be active for this response to trigger
+  off: false, #< screen must be off for this response to trigger
+})
+
+func Dispatcher_add_handler(self, trigger, response; screen=false, fullscreen=false, sys_menu=false, off=false) {
+  call self.handlers[trigger]->append(Object(Handler, {
+    trigger: trigger,
+    response: Responses[response],
+    name: response,
+    screen: screen,
+    fullscreen: fullscreen,
+    sys_menu: sys_menu,
+    off: off,
+  }))
 }
+
+func Dispatcher_new() {
+  var handlers = {}
+  for _k, v in (Triggers) {
+    setvar handlers[v] = []
+  }
+  return (Object(Dispatcher, { handlers: handlers }))
+}
+
+func Dispatcher_default() {
+  var inst = Dispatcher.new()
+
+  call inst->add_handler(Triggers.PowerHold,        "togglePlayback",  fullscreen=true, screen=true, off=true)
+  call inst->add_handler(Triggers.VolupHold1,       "seekForward",     fullscreen=true, off=true)
+  call inst->add_handler(Triggers.VolupHold2,       "seekForward",     fullscreen=true, off=true)
+  call inst->add_handler(Triggers.VolupHold3,       "seekForward",     fullscreen=true, off=true)
+  call inst->add_handler(Triggers.VoldownHold1,     "seekBackward",    fullscreen=true, off=true)
+  call inst->add_handler(Triggers.VoldownHold2,     "seekBackward",    fullscreen=true, off=true)
+  call inst->add_handler(Triggers.VoldownHold3,     "seekBackward",    fullscreen=true, off=true)
+  call inst->add_handler(Triggers.VolupTap1,        "volumeUp",        fullscreen=true, off=true)
+  call inst->add_handler(Triggers.VolupTap2,        "volumeUp",        fullscreen=true, off=true)
+  call inst->add_handler(Triggers.VolupTap3,        "volumeUp",        fullscreen=true, off=true)
+  call inst->add_handler(Triggers.VoldownTap1,      "volumeDown",      fullscreen=true, off=true)
+  call inst->add_handler(Triggers.VoldownTap2,      "volumeDown",      fullscreen=true, off=true)
+  call inst->add_handler(Triggers.VoldownTap3,      "volumeDown",      fullscreen=true, off=true)
+
+  call inst->add_handler(Triggers.PowerTap1,        "allOn",           off=true)
+  call inst->add_handler(Triggers.PowerTap1Hold,    "restartBonsai",   off=true)
+
+  call inst->add_handler(Triggers.PowerTap2,        "allOff",          fullscreen=true, screen=true, off=true)
+  call inst->add_handler(Triggers.PowerTap1Hold,    "killWindow",      fullscreen=true, screen=true)
+  call inst->add_handler(Triggers.PowerThenVolup,   "rotateCCW",       fullscreen=true, screen=true)
+  call inst->add_handler(Triggers.PowerThenVoldown, "rotateCW",        fullscreen=true, screen=true)
+
+  call inst->add_handler(Triggers.PowerAndVolup,    "takeScreenshot",  screen=true)
+  call inst->add_handler(Triggers.PowerAndVoldown,  "openCamera",      screen=true)
+  call inst->add_handler(Triggers.VolupTap1,        "openFilebrowser", screen=true)
+  call inst->add_handler(Triggers.VolupHold1,       "openFilebrowserWithApps", screen=true)
+  call inst->add_handler(Triggers.VoldownStart,     "toggleKeyboard",  screen=true)
+  call inst->add_handler(Triggers.VoldownHold1,     "openTerminal",    screen=true)
+
+  call inst->add_handler(Triggers.PowerTap1Hold,    "killRofi",        sys_menu=true)
+
+  return (inst)
+}
+
+func Dispatcher_get(self, trigger) {
+  var candidates = self.handlers[trigger]
+
+  var applicable = []
+  for c in (candidates) {
+    # TODO: this logic can be optimized!
+    var match = false
+    if (isAllOn()) {
+      if (isFullscreen()) {
+        verbose "state = fullscreen"
+        setvar match = c.fullscreen
+      } elif (isInhibited()) {
+        verbose "state = inhibited"
+        setvar match = c.sys_menu
+      } else {
+        verbose "state = screen"
+        setvar match = c.screen
+      }
+    } else {
+      verbose "state = off"
+      setvar match = c.off
+    }
+    if (match) {
+      debug "Dispatcher.get: found applicable" (c)
+      call applicable->append(c)
     }
   }
 
-func mapOff (action) {
+  case (len(applicable)) {
-  case (action) {
+    (0) {
-    ("power_tap_1") {
+      debug "Dispatcher.get: no applicable candidates for trigger" (trigger)
-      # power once => unlock
+      return (null)
-      return ("allOn")
     }
-    ("power_tap_1_hold") {
+    (1) {
-      # power tap->hold: escape hatch for when bonsaid locks up
+      var a = applicable[0]
-      return ("restartBonsai")
+      verbose "Dispatcher.get: filtered to 1 candidate" (trigger, a)
-    }
+      return (a)
-  }
-}
-
-func mapOn (action) {
-  case (action) {
-    # power_tap_1: intentional default to no-op (it's important this be unmapped, because events can be misordered with power_tap_1 arriving *after* power_tap_2)
-    # power_tap_2: intentional default to screenoff
-    ("power_tap_1_hold") {
-      # power tap->hold: kill active window
-      # TODO: disable this if locked (with e.g. schlock, swaylock, etc)
-      return ("killWindow")
-    }
-    ("power_and_volup") {
-      # power (hold) -> volup: take screenshot
-      return ("screenshot")
-    }
-    ("power_and_voldown") {
-      # power (hold) -> voldown: open camera
-      return ("openCamera")
-    }
-    ("power_then_volup") {
-      # power (tap) -> volup: rotate CCW
-      return ("rotateCCW")
-    }
-    ("power_then_voldown") {
-      # power (tap) -> voldown: rotate CW
-      return ("rotateCW")
-    }
-
-    ("volup_tap_1") {
-      # volume up once: filesystem browser
-      return ("openFilebrowser")
-    }
-    ("volup_hold_1") {
-      # volume up hold: browse files and apps
-      return ("openFilebrowserWithApps")
-    }
-
-    ("voldown_start") {
-      # volume down once: toggle keyboard
-      return ("toggleKeyboard")
-    }
-    ("voldown_hold_1") {
-      # hold voldown to launch terminal
-      # note we already triggered the keyboard; that's fine: usually keyboard + terminal go together :)
-      return ("openTerminal")
-    }
-    ("voldown_tap_1") {
-      # swallow, to prevent keyboard from also triggering media controls
-      return ("ignore")
-    }
-    / ^ 'volup_hold_' d+ $ / {
-      # swallow, to prevent app launcher from also triggering media controls
-      return ("ignore")
-    }
-    / ^ 'voldown_hold_' d+ $ / {
-      # swallow, to prevent terminal from also triggering media controls
-      return ("ignore")
-    }
-  }
-}
-
-func mapFullscreen (action) {
-  case (action) {
-    ("power_tap_1_hold") {
-      # power tap->hold: kill active window
-      return ("killWindow")
-    }
-    ("power_then_volup") {
-      # power (tap) -> volup: rotate CCW
-      return ("rotateCCW")
-    }
-    ("power_then_voldown") {
-      # power (tap) -> voldown: rotate CW
-      return ("rotateCW")
-    }
-  }
-}
-
-func mapInhibited (action) {
-  case (action) {
-    ("power_tap_1_hold") {
-      # power hold: escape hatch in case rofi has hung
-      return ("killRofi")
     }
     (else) {
-      # eat everything else (and let rofi consume it)
+      # TODO: this should be a static assertion, not a runtime check!
-      return ("inhibited")
+      die "Dispatcher.get: filtered to multiple candidates" (trigger, applicable)
     }
   }
 }
 
-func mapToplevel (action) {
+var Dispatcher = Object(null, {
-  var mappedTo = null
+  ## class methods
-  if (isAllOn()) {
+  default: Dispatcher_default,
-    if (isInhibited()) {
+  new: Dispatcher_new,
-      setvar mappedTo = traceFunc("mapInhibited", mapInhibited, action)
+  ## methods
-    } elif (isFullscreen()) {
+  "M/add_handler": Dispatcher_add_handler,
-      setvar mappedTo = traceFunc("mapFullscreen", mapFullscreen, action)
+  get: Dispatcher_get,
-    } else {
+  ## instance state
-      setvar mappedTo = traceFunc("mapOn", mapOn, action)
+  handlers: {}  # trigger -> List[Handler]
-    }
+})
-  } else {
-    setvar mappedTo = traceFunc("mapOff", mapOff, action)
-  }
 
-  if (mappedTo === null) {
-    setvar mappedTo = traceFunc("mapDefault", mapDefault, action)
-  }
 
-  return (mappedTo)
+var trigger = null
-}
-
-var action = null
 var doShowHelp = false
 proc parseArgs (; ...args) {
   for arg in (args) {
@@ -555,7 +568,7 @@ proc parseArgs (; ...args) {
         setglobal VERBOSITY += 1
       }
       (else) {
-        setglobal action = "$arg"
+        setglobal trigger = "$arg"
       }
     }
   }
@@ -569,7 +582,10 @@ if is-main {
     exit 0
   }
 
-  var handler = mapToplevel (action) or "unmapped"
+  var dispatcher = Dispatcher.default()
-
+  var handler = dispatcher.get(trigger)
-  handleWith (handler)
+  info "handling" (trigger, handler and handler.name)
+  if (handler) {
+    call handler.exec()
+  }
 }