grady@fxgrp (Steven Grady) (11/10/88)
Ater reading and rereading (ad infinitum) the 1-page section (10.4) on accelerators in the Xt doc, I think I'm finally starting to understand them. The documentation is rather opaque, so I'm not sure about this, but tell me if I have this right. An accelerator is simply a registered set of translations which can be exported to other widgets. For instance, a menu widget might include a translation like "<Ctrl>X: itemX()" to indicate that hitting Ctrl-X invokes the itemX() function. This accelerator can be used after it has been installed in other widgets, using XtInstallAccelerators(). The destination widget, after this call, will have all the mappings of the accelerators of the source widget available. Thus, if I say "XtInstallAccelerators(textEditingWidget, menuWidget)", then all my accelerators for the menu widget will now be available from within the context of the text-editing widget. Do I have it right so far? OK, assuming I do.. What does it mean to "display" an accelerator? Why would a widget want to display its accelerators? What exactly does the display_accelerator function do? There is a variable used by some programs, XtInheritDisplayAccelerator, which is mentioned in the Xt doc, but not described. This variable is the only reference to accelerators I've found in _any_ of the X11 code. Makes it hard to learn by looking at examples.. Does anyone actually use accelerators? My other concern is the design of accelerators in general. My thought is that it would be better to allow have widgets make public (within the application) those functions that can be associated with accelerators. Then, any widget which wants to use an accelerator can bind to that action in a way similar to other translations, ie: program*textEditingWidget.translations: #override\ <Ctrl>X: program*menuWidget*itemX() This would allow different widgets to use different accelerators to access a function -- for instance, one widget could use "<Key>?" to pop up a help widget, whereas another could use "<Ctrl>H". To make an accelerator available to all widgets, you could simply say: program*translations: #augment\ <Ctrl>X: program*menuWidget*itemX() This method seems to me to be more general, and it also fits within the structure of normal translations.. Steven ...!ucbvax!grady grady@postgres.berkeley.edu
asente@decwrl.dec.com (Paul Asente) (11/15/88)
In article <861@fxgrp.UUCP> grady@fxgrp (Steven Grady) writes: >This accelerator can be used after it has been installed in >other widgets, using XtInstallAccelerators(). The destination >widget, after this call, will have all the mappings of the >accelerators of the source widget available. Thus, if I >say "XtInstallAccelerators(textEditingWidget, menuWidget)", >then all my accelerators for the menu widget will now be available >from within the context of the text-editing widget. > >Do I have it right so far? So far, so good. >OK, assuming I do.. What does it mean to "display" an accelerator? >Why would a widget want to display its accelerators? >What exactly does the display_accelerator function do? Often times a widget will want to display in itself some representation of the accelerator. For example, if you have a menu item accessible through the ^C accelerator, you might want to display the string "^C" in your menu item. The display_accelerator function gets called when a widget's accelerator is installed, and gets passed a text representation of the accelerator. It can do anything it wants with it, including ignoring it. >There is a variable used by some programs, XtInheritDisplayAccelerator, >which is mentioned in the Xt doc, but not described. >This variable is the only reference to accelerators I've found >in _any_ of the X11 code. Makes it hard to learn by looking >at examples.. Does anyone actually use accelerators? The built-in widgets (Core, Composite...) are basically prototypes; they normally have no actions, and thus, no accelerators. Displaying accelerators is meaningless for them, so they have NULL display_accelerator functions. XtInheritDisplayAccelerator, like other XtInherit values, specifies that a widget should inherit its parent's display_accelerator function. >My other concern is the design of accelerators in general. >My thought is that it would be better to allow have widgets >make public (within the application) those functions that >can be associated with accelerators. Then, any widget which >wants to use an accelerator can bind to that action in a way >similar to other translations, ie: > program*textEditingWidget.translations: #override\ > <Ctrl>X: program*menuWidget*itemX() What you specify for the toolkit is program*menuWidget.accelerator: <Ctrl>X:itemX() and install the accelerator for menuWidget in some other widget (e.g. textEditingWidget) in your code. >This would allow different widgets to use different accelerators >to access a function -- for instance, one widget could use >"<Key>?" to pop up a help widget, whereas another could use >"<Ctrl>H". To make an accelerator available to all widgets, >you could simply say: > program*translations: #augment\ > <Ctrl>X: program*menuWidget*itemX() One design aim was that a particular widget instance should always have the same accelerator anywhere it is available -- you don't want people to type one accelerator sequence one place and another one someplace else. You may disagree with this, but it seems a laudible goal. -paul asente
jpool@BBN.COM (Jeremy Pool) (05/05/89)
A few months back Ralph Swick posted an instructional example of how to use
accelerators. The example was a modification to x11r3/examples/Xaw/xboxes.c,
and showed how to attach Ctrl-c as an accelerator to the "quit" button of
this sample Xaw program. The modification was real simple: Just add:
XtInstallAccelerators(toplevel, q); /* q = the quit PushButton */
prior to realizing the widget hierarchy, and adding:
Demo*quit.accelerators: Ctrl<Key>c: set() notify()
to your resources.
I have found two problems in trying to repeat, and modify, this example.
1) I was able to get the accelerator to work only if I installed it on the
top-most box widget in the widget hierarchy, but not if I installed it
on toplevel (as shown) or on the viewport which is toplevel's child and
the box widget's parent. I can't figure out any obvious reason for
this, as I would have expected the keyboard event to have been passed
up the hierarchy, even to toplevel, until it found a widget with a
translation for this event. Am I missing something here?
2) An installed accelerator works even when the source widget is
insensitive. The Intrinsics documentation doesn't appear to address
this issue, but the behavior displayed (at least by the MIT Intrinsics
implementation) seems counterintuitive. If a button is insensitive,
and therefore not dispatching to action procedures, wouldn't you expect
not to be able to dispatch to those same action procedures via an
accelerator? Must I put an extra check into all widget action
procedures, to check for widget sensitivity?
-- Jeremy Pool (jpool@bbn.com)kochhar@endor.harvard.edu (Sandeep Kochhar) (08/04/89)
hi! can anyone send me a small example of how to use accelerators? or can you give me some idea of how to use XtInstallAccelerator etc. in the following case: I have widgets A and B, and I want a button1down event on widget A to have the same effect as if button1down occured on B. Thanks in advance. Sandeep Kochhar (617) 495-9515 mail: kochhar@harvard.harvard.edu Harvard University kochhar@harvard.csnet 33 Oxford st, kochhar@harvard.uucp Cambridge, Ma 02138 kochhar@harvard.bitnet "If you didn't get this message, please let me know."
gtl@stiatl.UUCP (George Li) (12/05/89)
I'm having problems defining accelerators for widgets and
getting the action procedures to execute. I have been able to
define accelerators whose procedure name strings are
defined by the particular widget class. For example,
"<Key>H: set() notify() unset()" is a valid accelerator for a
command widget. However, if I define my own action procedure and
reference it in an accelerator as in "<Key>H: mutilate()", the
installed accelerator has no effect (the procedure associated
with the mutilate action isn't called).
I've added the action (trying both XtAddAction() and
XtAppAddAction()) with no success.
Since an accelerator is just a translation table and you can
define your own action procedures for translation tables, shouldn't
I be able to define my own action procedures for accelerators?
I'm using X11R3 (Athena widgets) on a Sun 386i with 4.0.2.
A small sample below:
/******************************************************************/
#include <stdio.h>
#include "Intrinsic.h"
#include "StringDefs.h"
#include "Command.h"
#include "Desk.h"
Widget toplevel;
Widget desk;
Widget button1;
Widget button2;
extern void helpproc();
main (argc, argv)
int argc;
char **argv;
{
int n;
Arg args[20];
static Arg deskargs[] = {
{XtNwidth,(XtArgVal)600},
{XtNheight,(XtArgVal)400},
};
/**********************************************************/
static XtActionsRec actionsTable[] = {
{"help_action",helpproc}
};
static char defaultAccelerators[]="#override\n <Key>L: help_action()";
/************************************************************/
toplevel = XtInitialize(argv[0], "test", NULL, 0, &argc, argv);
desk = XtCreateManagedWidget("desk", deskWidgetClass,
toplevel, deskargs, XtNumber(deskargs));
n = 0;
XtSetArg(args[n], XtNwidth, 70); n++;
XtSetArg(args[n], XtNheight, 20); n++;
XtSetArg(args[n], XtNx, 100); n++;
XtSetArg(args[n], XtNy, 280); n++;
XtSetArg(args[n],XtNaccelerators,XtParseAcceleratorTable(defaultAccelerators));n++;
button1=XtCreateWidget("button1",commandWidgetClass,desk,args,n);
n=0;
XtSetArg(args[n], XtNwidth, 70); n++;
XtSetArg(args[n], XtNheight, 20); n++;
XtSetArg(args[n], XtNx, 300); n++;
XtSetArg(args[n], XtNy, 280); n++;
button2=XtCreateWidget("button2",commandWidgetClass,desk,args,n);
XtAddActions(actionsTable,XtNumber(actionsTable));
XtInstallAccelerators(button2,button1);
XtManageChild(button1);
XtManageChild(button2);
XtRealizeWidget(toplevel);
XtMainLoop();
}
void helpproc(widget, xev, params, num_params)
Widget widget;
XEvent *xev;
String *params;
Cardinal *num_params;
{
printf("helpproc\n");
}
--
George Li gatech!stiatl!gtl
Sales Technologies, Inc
3399 Peachtree Rd, NE
Atlanta, GA 30306gates@CSCSUN1.LARC.NASA.GOV (Ray Gates) (09/26/90)
This question concerns the use of accelerators......specifically, it concerns using accelerators to add a keyboard interface to the R4 SimpleMenu widget. The goal is to associate the callback routines of the menu entries (smeBSB objects) with keyboard entries in another widget. Attempts to this point have been unsuccessful..... The R4 docs do not list accelerators as allowable resources for the menu objects.....Is this the problem????? If not, can anyone give me an idea on how to associate the accelerators with the smeBSB objects in the SimpleMenu........... THANKS......... -- _______________________________________________________________________________ | Ray Gates "Mama, mama, many worlds | CSC/NASA-Langley have come since I first | gates@cscsun1.larc.nasa.gov left home." | (128.155.42.32) | Phone: 804.865.1725 ------------------------------------------------------------------------------- DISCLAIMER: The comments/opinions contained within are my own and do not necessarily represent the opinions of my employer(s). -------------------------------------------------------------------------------
converse@EXPO.LCS.MIT.EDU (09/26/90)
> This question concerns the use of accelerators > to add a keyboard interface to the R4 SimpleMenu widget. > The goal is to associate the callback routines of the menu entries > (smeBSB objects) with keyboard entries in another widget. R4 xmh has accelerators for many menu commands. It also allows the user to create buttons for the same commands, similar to the R3 interface. > The R4 docs do not list accelerators as allowable resources for the menu > objects.....Is this the problem????? No; there is an accelerator resource associated with the Simple Menu widget that you can use. The accelerators are associated with the menu, not with the individual menu entries, because the SmeBSBObjectClass (the Athena widget set simple menu entry object class name) is not a subclass of Core. > If not, can anyone give me an idea on how to associate the accelerators > with the smeBSB objects in the SimpleMenu........... Eyeball the accelerator resources in clients/xmh/Xmh.ad.
pete@iris49.UUCP (Pete Ware) (09/27/90)
gates> From: Ray Gates <riscc1!cscsun1.larc.nasa.gov!gates@bioc1.biosym.com> gates> Date: Wed, 26 Sep 90 10:44:07 EDT gates> If not, can anyone give me an idea on how to associate the accelerators gates> with the smeBSB objects in the SimpleMenu........... Unfortunately, you can't. smeBSB are objects (gadgets) and do not have a window associated with them. Accelerators only work with window objects (widgets). --pete Pete Ware / Biosym / San Diego CA / (619) 546-5532 uucp: scripps.edu!bioc1!pete Internet: bioc1!pete@scripps.edu
ta_k@maths.su.oz.au (Katya Ta) (05/22/91)
Hi again,
If you install an Accelerator for a widget, for example that if
some key is pressed a particular action is done. The widget passed to
the action is it the one where the event occured or the widget which
has the acclerator installed? thanks a lot
bye Katya
--
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/ __ | Katya Ta
---- |__| __|__ University of Sydney
-- |__| | Australia
-- |__| \| (ta_k@maths.su.oz.au)
__ /| |
|__| _/ | | <-- Chay(Cantonese) == Ta.(Vietnamese) :)
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