context

Synopsis

include "draw.m";
draw:= load Draw Draw->PATH;
Context: adt
{
  screen:  ref Screen;
  display: ref Display;
  cir:     chan of int;
  ckbd:    chan of int;
  cptr:    chan of ref Pointer;
  ctoappl: chan of int;
  ctomux:  chan of int;
};

Description

The Context abstract data type encapsulates the data types and channels used by an interactive application. A reference to the Context is passed as the first argument to an application when it begins execution:

include "draw.m"; 
Command: module 
{
     init:  fn(nil: ref Draw->Context; nil: list of string);
};

Most programs do not create Contexts but rather inherit one from their parent, typically a shell or window system.

General Interfaces

screen

The `Screen` adt to which the application is connected; may be nil. See screen.

display

The `Display` adt to which the application is connected; may be nil. See display.

screen	The `Screen` adt to which the application is connected; may be nil. See screen.
display	The `Display` adt to which the application is connected; may be nil. See display.

MUX Interfaces

cir

A channel of type `int` that delivers events from an infrared remote control device, if one is present. See the discussion below and ir for more information.

ckbd

A channel of type `int` that delivers keystrokes from a keyboard.

cptr

A channel of type `ref` Pointer that delivers events from a pointing device such as a mouse.

ctoappl

A channel of type `int` that delivers control messages to the application from the Mux application multiplexer. One message is defined:

MAtop

Requests the application to make its set of windows fully visible.

ctomux

A channel of type `int` used by the application to send messages to the Mux regarding the application's use of system devices. The defined messages are:

AMstartir

The application is ready to accept IR-data on the `cir` channel.

AMstartkbd

The application is ready to accept keyboard data on the `ckbd` channel.

AMstartptr

The application is ready to accept `Pointer` data on the `cptr` channel.

AMnewpin

The application needs a PIN.

AMexit

An application should send this message before it exits, to allow the Mux to recover resources.

cir	A channel of type `int` that delivers events from an infrared remote control device, if one is present. See the discussion below and ir for more information.
ckbd	A channel of type `int` that delivers keystrokes from a keyboard.
cptr	A channel of type `ref` Pointer that delivers events from a pointing device such as a mouse.
ctoappl	A channel of type `int` that delivers control messages to the application from the Mux application multiplexer. One message is defined:
	MAtop	Requests the application to make its set of windows fully visible.
ctomux	A channel of type `int` used by the application to send messages to the Mux regarding the application's use of system devices. The defined messages are:
	AMstartir	The application is ready to accept IR-data on the `cir` channel.
	AMstartkbd	The application is ready to accept keyboard data on the `ckbd` channel.
	AMstartptr	The application is ready to accept `Pointer` data on the `cptr` channel.
	AMnewpin	The application needs a PIN.
	AMexit	An application should send this message before it exits, to allow the Mux to recover resources.

context

Synopsis

Description

General Interfaces screen The Screen adt to which the application is connected; may be nil. See screen. display The Display adt to which the application is connected; may be nil. See display.

See Also ir for description of the cir channel.

General Interfaces

screen

The `Screen` adt to which the application is connected; may be nil. See screen.

display

The `Display` adt to which the application is connected; may be nil. See display.

See Also

ir

for description of the cir channel.