TKCLIENT(2) TKCLIENT(2)
NAME
tkclient: makedrawcontext, toplevel, onscreen, startinput,
wmctl, settitle, handler, snarfput, snarfget - window
manager interface for Tk applications.
SYNOPSIS
include "tkclient.m";
tkclient := load Tkclient Tkclient->PATH;
Resize,
Hide,
Help,
OK,
Plain: con 1 << iota;
Appl: con Resize | Hide;
init: fn();
makedrawcontext: fn(): ref Draw->Context;
toplevel: fn(ctxt: ref Draw->Context, topconfig: string,
title: string, buts: int): (ref Tk->Toplevel, chan of string);
onscreen: fn(top: ref Tk->Toplevel, how: string);
startinput: fn(top: ref Tk->Toplevel, devs: list of string);
wmctl: fn(top: ref Tk->Toplevel, request: string): string;
settitle: fn(top: ref Tk->Toplevel, name: string): string;
handler: fn(top: ref Tk->Toplevel, stop: chan of int);
snarfput: fn(buf: string);
snarfget: fn(): string;
DESCRIPTION
The Tkclient module provides routines for making windows
controlled by wm(1) containing tk(2) widgets.
Init should be called once to initialise the internal state
of tkclient.
Makedrawcontext establishes an initial connection with the
window manager, creating a new Draw context suitable for
creating new windows. It is only necessary to call this if
the application has not already been provided with a con-
text.
Toplevel creates a new window through ctxt. Topconfig gives
a list of frame(9) options that are applied to the new tk
window, as described in tk(2). Title gives a label that will
be displayed in the title bar of the window; buts determines
which buttons are created in the titlebar, a bitwise combi-
nation of the constants Resize, Help, OK, and Hide. If
Plain is given, the window is given no decoration at all.
Page 1 Plan 9 (printed 12/27/24)
TKCLIENT(2) TKCLIENT(2)
Toplevel returns a tuple, say (top, ctl), where top is the
newly created top level tk window, and ctl is a channel down
which requests from the title bar are sent. Messages
received on ctl should be processed by the application or
passed to the wmctl function. Requests are formatted as with
quoted in string(2). The messages include:
exit The window should be closed. Wmctl will kill all pro-
cesses in the current process group.
!move x y
The user has started to try to drag the window. X and
y give the location of the initial pointer click.
!size
The user wishes to resize the window.
help The help button has been clicked.
ok The OK button has been clicked.
hide The Hide button has been clicked. The window will be
deleted, and an entry shown on the toolbar.
In order to function correctly, an application should pro-
cess not only events from the title bar channel, but also
events from the Tk toplevel wreq channel, those received
from the window manager itself (via top.ctxt.ctl), and
pointer and keyboard events received from the window manager
(via top.ctxt.ptr and top.ctxt.kbd respectively). Control
events can be passed to wmctl; pointer and keyboard events
should be passed to their respective functions in tk(2).
When created, the window is not visible and will not receive
pointer or keyboard events. Onscreen makes it visible, and
possibly chooses a position and a size for it. How speci-
fies what sort of placement is required for the window; it
can be one of
place
tries to choose a suitable place on the screen with
respect to other windows; it may size the window as it
feels appropriate. This the default (if how is nil).
onscreen
tries to keep the position and size the same as speci-
fied on the window, adjusting them only to bring the
window fully on screen, and making sure that the window
is no bigger than the entire display.
exact
does not change the specified size or position of the
Page 2 Plan 9 (printed 12/27/24)
TKCLIENT(2) TKCLIENT(2)
window unless absolutely necessary.
Startinput informs the window manager that the window is
ready to the event types specified in devs. Currently under-
stood are kbd for keyboard events, and ptr for pointer
events.
The simplest well-behaved wm(1) client will therefore con-
tain:
(top, ctl) := tkclient->toplevel(ctxt, nil, "My Program", Tkclient->Appl);
# ... populate the window with tk widgets
tkclient->startinput(top, "ptr" :: "kbd" :: nil);
tkclient->onscreen(top, nil);
for(;;){
alt{
s := <-ctl or
s = <-top.ctxt.ctl or
s = <-top.wreq =>
tkclient->wmctl(top, s);
p := <-top.ctxt.ptr =>
tk->pointer(top, *p);
c := <-top.ctxt.kbd =>
tk->keyboard(top, c);
}
}
Settitle changes the name displayed in the title bar and the
window's name when it is in the task bar.
Snarfget and snarfput retrieve and replace the contents of
the window manager's snarf buffer.
FILES
/chan/snarf snarf buffer maintained by wm(1)
/chan/wm channel for interaction with wm(1)
SOURCE
/appl/lib/tkclient.b
SEE ALSO
wm(1), tk(2)
Page 3 Plan 9 (printed 12/27/24)