NAME
EasyRequestArgs -- Easy alternative to autorequest(). (v36)
EasyRequest -- Varargs stub for EasyRequestArgs(). (V36)
SYNOPSIS
num = EasyRequestArgs( window, easystruct, idcmp_ptr, arglist )
D0 A0 A1 A2 A3
long easyrequestargs( struct window *, struct easystruct *,
ULONG *, aptr );
num = EasyRequest( window, easystruct, idcmp_ptr, arg1, arg2, ... )
long easyrequest( struct window *, struct easystruct *,
ULONG *, aptr, ... );
( from intuition.h )
struct easystruct {
ULONG es_StructSize;
ULONG es_Flags;
ubyte *es_title;
ubyte *es_textformat;
ubyte *es_gadgetformat;
};
FUNCTION
This function provides a simpler method of using a 'System
Requester' than provided by autorequest(). it performs layout
and size calculations sensitive to the current font and screen
resolution.
It provides for the descriptive 'body' text and the gadget
text to be constructed from 'printf' style format strings.
It also provides a general way for the requester to be
sensitive to particular IDCMP messages.
The first function listed is the actual Intuition library
function. It is passed the arguments for the formatting
operations as a pointer to the first argument.
The second function uses a C-style variable number of argument
(varargs) calling convention. It should be implemented as
a call to the first function, and might be supplied by your
compiler vendor, in amiga.lib, or using the first example below,
for most C compilers.
NOTE: The formatting is done by exec.library/rawdofmt(), so
be aware that to display a 32-bit integer argument, for
example, you must say "%ld", not "%d", since rawdofmt() is
"word-oriented."
NOTE: This function switches the processor stack to ensure
sufficient stack space for the function to complete.
EXAMPLES
/* varargs interface works for most C compilers */
EasyRequest( w, es, ip, arg1 )
struct window *w;
struct easystruct *es;
ULONG *ip;
int arg1;
{
return ( EasyRequestArgs( w, es, ip, &arg1 ) );
}
/*********************************************/
/* typical use */
struct easystruct volumees = {
sizeof (struct EasyStruct),
0,
"Volume Request",
"Please insert volume %s in any drive.",
"Retry|Cancel",
};
#define CANCEL (0)
Volume *
getVolume( volname )
ubyte *volname;
{
Volume *vptr;
Volume *findVolume();
uword reply;
ULONG iflags;
iflags = IDCMP_DISKINSERTED;
while ( ((vptr = findVolume( volname )) == NULL) &&
(EasyRequest( w, &volumeES, &iflags, volname ) != CANCEL) )
/* loop */ ;
/* note that in some circumstances, you will have to
re-initialize the value of 'iflags'. Here, it
is either unchanged, or returned as the single
IDCMPFlag value IDCMP_DISKINSERTED. If you combine
multiple IDCMPFlag values in 'iflags,' only
one will be returned, so you must reinitialize
'iflags' to be the combination.
*/
return ( vptr );
}
INPUTS
window = reference window pointer, determines the screen and
title of the requester window. This can be NULL, which
means the requester is to appear on the Workbench screen,
or default public screen, if defined.
IDCMP_ptr = Pointer to IDCMP flags that you want to terminate
the requester. This pointer may be NULL.
easyStruct = Pointer to easystruct structure with fields
interpreted as follows:
es_StructSize = sizeof (struct EasyStruct), for future extension.
es_Flags = 0 for now, in the future may specify other options.
es_Title = Title of system requester window. If this is NULL,
the title will be taken to be the same as the title of 'Window',
if provided, or else "System Request."
es_TextFormat = format string, a la rawdofmt(), for message in
requester body. Lines are separated by the newline character.
This character is represented in C by 'n', in the Amiga Shell
by "*N", etc. Formatting '%' functions are supported exactly
as in rawdofmt().
es_GadgetFormat = format string for gadgets. text for separate
gadgets is separated by '|'. format functions are supported.
You MUST specify at least one gadget.
ArgList = Arguments for format commands. Arguments for
GadFmt follow arguments for TextFmt.
RESULT
0, 1, ..., N = Successive GadgetID values, for the gadgets
you specify for the requester. NOTE: The numbering
from left to right is actually: 1, 2, ..., N, 0.
This is for compatibility with autorequest(), which has
FALSE for the rightmost gadget.
-1 = Means that one of the caller-supplied IDCMPFlags occurred.
The IDCMPFlag value is in the longword pointed to by IDCMP_ptr.
NOTES
When DOS brings up EasyRequests() on your process (eg.
"Please insert volume XXX in any drive", they normally come
up on the default public screen, which is usually the Workbench
screen. If you set your process pr_windowptr field to point to
one of your windows, then DOS will bring its requesters up on the
same screen as that window. A pr_WindowPtr of -1 prevents
requesters from coming up at all.
(Some FileSystem requesters cannot be redirected or supressed).
BUGS
Does not fall back to a recoverable alert if the requester
cannot be created.
Does not handle case when gadgets don't fit or window title
is too long, although it does trim trailing spaces from the
title for calculating dimensions.
PLANS
Possible enhancements include: centering of text, size-sensitive
layout, window-relative requester, vertical gadget layout,
window placement, more keyboard shortcuts.
We also reserve the use of the newline character ('n') in
gadget format strings for future use as a line separator.
SEE ALSO
exec.library/rawdofmt(), buildeasyrequestargs(), sysreqhandler(),
autorequest(), buildsysrequest()