ir — Inferno 1.1ed

ir

Synopsis

include   "ir.m";
ir     := load Ir Ir->PATH;    # for real remotes
simir  := load Ir Ir->SIMPATH; # for keyboard simulator

init:      fn(irc: chan of int): int;
translate: fn(key: int)        : int;

Description

Programs running with the Limbo Prefab Modules toolkit are controlled by an infrared remote control device. If such a device is not present, the system may simulate it from the keyboard by loading the module in file Ir->SIMPATH. The Ir module defines codes for representing the remote control keys (see below). They are typically sent over the Context.cir (see context ) channel, which is managed by mux.


init	The `init` function takes the appropriate actions to initialize the device, and then spawns a process to return the codes on the irc channel. This is done for both the real and simulated devices. `Init` is typically invoked once, such as by mux, and the codes are then multiplexed between the applications. Most programs need not call init.
translate	The `translate` function converts the device's raw codes into the constants defined by the module. For example, with the simulated remote control, `translate('3')` returns Three. `Translate` is only necessary for programs that wish to manage their own simulation of the remote control.

Codes


		Keyboard Equivalent
ChanUP, ChanDN	The Channel-Up and Channel-Down buttons.	`r` and c
Enter	The Enter button.	SPACE bar
EOF	An end of file from the remote device. After sending one, no more codes will be sent on irc.
Error	An unknown or invalid input from the remote device.
FF, Rew	The Fast-Forward and Rewind buttons.	`k` and j
Mute	The Mute button.	none
Power	The Power button.	`Delete` key
Rcl	The Recall button. Typical applications do not see this command. Instead, the mux program intercepts the command and reactivates its menu.	x
Record	The Record button.	none
Select	The Select button.	`Return` or `Enter` key
Up, Dn	The Up and Down buttons.	`i` and m
VolUP, VolDN	The Volume-Up and Volume-Down buttons.	`t` and v
Zero, One, Two, etc.	The digit buttons, 0 through 9.	corresponding numeral keys

Examples

Application programs using the remote control run under mux, which creates a graphics context for the application. This context includes channels to the mux program and to the Ir device: Draw->Context.ctomux and Draw->Context.cir. The following example establishes communication with mux and then reads Ir commands until it sees Enter.

implement Command;
 
include "sys.m"; 
include "draw.m"; 
include "ir.m"; 
Command: module 
{
  init: fn(ref Draw->Context; list of string);
};
init(ctxt: ref Draw->Context; argv: list of string); 
{
  sys:= load Sys Sys->PATH;  
  # Tell mux to start sending input.  
  ctxt.ctomux <-= Draw->AMstartinput;  
   for(;;) {   
       key:= <-ctxt.cir;   
        sys->print("command %d\n", key);   
         if(key == Ir->Enter)    
              break;  
   }  
# Tell mux this thread is going away.  
ctxt.ctomux <-= Draw->AMexit; 
}

Programs such as mux that drive the remote control directly must load the appropriate module and initialize it. This example uses the absence of a simulator module to infer that a real remote control is available.

implement Irtest; 
include "sys.m"; 
include "draw.m"; 
include "ir.m"; 
Irtest: module 
{  
   init: fn(ctxt: ref Draw->Context, argv: list of string); 
}; 
init(nil: ref Draw->Context, nil: list of string) 
{   
    sys:= load Sys Sys->PATH;   
    # First try the keyboard Ir simulator.   
    # If that is not present, use Ir directly.   
    ir:= load Ir Ir->SIMPATH;   
    if(ir == nil)     
        ir = load Ir Ir->PATH;   
    if(ir == nil){     
        sys->print("Ir module not loaded: %r\n");     
        return;   
    }   
irc:= chan of int;   
if(ir->init(irc) < 0){     
      sys->print("Can't initialize Ir device: %r\n");     
        return;   
    }   
      for(;;){     
              irval:= <-irc;     
      sys->print("command %d\n", irval);   
    } 
}

Museum

ir — Inferno 1.1ed

ir

Synopsis

Description

Codes

Examples

See Also