RCU::Context - Remote Control Unit Interface
Create a new key context.
Bind the given action to an event (see EVENT SYNTAX, below, for an explanation of this string).
action must be one of the following:
A code-reference This code reference will be called with the event name, generating rcu, timestamp and any additional arguments (usually none) fiven to the inject method. "enter", $context "enter*", $context Enter the given context object. The forms with an appended star "re-exec" the event in the new context. "leave" "leave*" leave the current context (restoring the context active before it was "enter"'ed) "switch", $context "switch*", $context switch to the given context object
For every keypress, only the first (in order of their definition) matching event handler is being executed.
Simulate the given event (see "EVENT SYNTAX", below).
"Enter" ("Leave") the context (and create an <enter> (<leave>") event). Not usually called by application code.
The simplest way to specify events is using the (cooked) keyname, e.g. the event
cd-shuffle occurs when the key named "cd-shuffle" was pressed down.
Since events are regular expressions, you have to quote any special characters (like
. stop at keys boundaries) if you want to use them. On the other hand, regexes give you great freedom, if you specify the event:
... you can then use "$1" in your callback to find out which digit was pressed.
You can prefix a keyname with a "~" which means the key was released (deactivates, switched off) instead of being pressed. If you want to force interpretation as a key-down event you can prefix the keyname with an "=" character.
Every key will always generate two events: one key-down (activate) event when it is pressed and one "~" (key-up) event when it is released again. It is not possible that two keys are active at the same time.
To make matters slightly more complicated, you can also prepend a "history" of key names (all seperated by ":") before the current event. This means that the event depends on previous key-presses (no prefix characters are there).
Examples (all key names are, of course, hypothetical):
<enter> enter the current context key-ff the fast forward key was pressed down =key-ff same as above ~key-rev the "rev"-key was released key-tuner:key-4 first the tuner key was pressed (and released), then "4" key-tuner:~key-4 first the tuner key was pressed, then "4" was released k1:k2:k3 the keys "1", "2" were pressed and released, then "3" was pressed.
For those of you who need it...
event := history prefix eventname history := <empty> | keyname ":" history prefix := <empty> | "=" | "~" eventname := keyname | "<enter>" | "<leave>" keyname := any string consisting of printable, non-whitespace characters without ":"
This perl extension was written by Marc Lehmann <email@example.com>.