EasyRequestArgs.md

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;
    };

Links: Window Window EasyStruct Window Window EasyStruct EasyStruct

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 'n'. 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.

Args = 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 AutoRequests 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