X-Git-Url: https://ncurses.scripts.mit.edu/?a=blobdiff_plain;f=man%2Fform_fieldtype.3x;h=767c3fcfafcdbe02f56d8e41c99eb42950def67a;hb=c2650100f80134924eda8f22cd7cc1d1d919ee3d;hp=d5b7cefa841d0849408097b22d67ceb13703319c;hpb=7884aa084f9440fd964f14fe31853a5f85db5104;p=ncurses.git diff --git a/man/form_fieldtype.3x b/man/form_fieldtype.3x index d5b7cefa..767c3fcf 100644 --- a/man/form_fieldtype.3x +++ b/man/form_fieldtype.3x @@ -28,7 +28,11 @@ .\" authorization. * .\"*************************************************************************** .\" -.\" $Id: form_fieldtype.3x,v 1.23 2020/10/24 09:05:17 tom Exp $ +.\" $Id: form_fieldtype.3x,v 1.28 2020/12/12 17:11:21 tom Exp $ +.de bP +.ie n .IP \(bu 4 +.el .IP \(bu 2 +.. .TH form_fieldtype 3X "" .SH NAME \fBform_fieldtype\fR \- define validation-field types @@ -55,47 +59,71 @@ \fBFIELDTYPE *link_fieldtype(FIELDTYPE *\fP\fItype1\fP\fB,\fP \fBFIELDTYPE *\fP\fItype2\fP\fB);\fP .SH DESCRIPTION +.SS new_fieldtype The function \fBnew_fieldtype\fR creates a new field type usable for data validation. -You supply it with \fIfield_check\fR, a predicate to check the +Its parameters are function pointers: +.TP 5 +\fIfield_check\fR +This function checks the validity of an entered data string whenever the user attempts to leave a field. +It has two arguments: +.RS +.bP The (FIELD *) argument is passed in so the validation predicate can see the -field's buffer, sizes and other attributes; the second argument is an +field's buffer, sizes and other attributes. +.bP +The second argument is an argument-block structure, about which more below. +.RE +.TP 5 +\fIchar_check\fR +This function validates input characters as they are entered. +The form library passes it the character to be checked +and a pointer to an argument-block structure. +.SS free_fieldtype .PP -You also supply \fBnew_fieldtype\fR with \fIchar_check\fR, -a function to validate input characters as they are entered; it will be passed -the character to be checked and a pointer to an argument-block structure. -.PP -The function \fBfree_fieldtype\fR frees the space allocated for a given -validation type. +The \fBfree_fieldtype\fR function +frees the space allocated for a given validation type by \fBnew_fieldtype\fP. +.SS set_fieldtype_arg .PP The function \fBset_fieldtype_arg\fR associates -three storage-management functions with a field type. -The \fImake_arg\fR function is automatically applied to the +three storage-management functions with a field type: +.TP 5 +\fImake_arg\fR +This function is automatically applied to the list of arguments you give \fBset_field_type\fR when attaching validation -to a field; its job is to bundle these into an allocated argument-block -object which can later be passed to validation predicated. -The other two hook arguments should copy and free argument-block structures. -They will be used by the forms-driver code. -You must supply the \fImake_arg\fR function, -the other two are optional, you may supply NULL for them. -In this case it is assumed +to a field. +It stores the arguments in an allocated argument-block +object which is used when validating input. +.TP 5 +\fIcopy_arg\fR +This function may be used by applications to copy argument-blocks. +.TP 5 +\fIfree_arg\fR +Frees an argument-block structure. +.PP +You must supply the \fImake_arg\fR function. +The other two are optional: you may supply NULL for them. +In this case, the form library assumes that \fImake_arg\fR does not allocate memory but simply loads the argument into a single scalar value. -.PP -The function \fBlink_fieldtype\fR creates -a new field type from the two given types. -They are connected by an logical 'OR'. +.SS set_fieldtype_choice .PP The form driver requests \fBREQ_NEXT_CHOICE\fR and \fBREQ_PREV_CHOICE\fR assume that the possible values of a field form an ordered set, and provide the forms user with a way to move through the set. +.PP The \fBset_fieldtype_choice\fR function allows forms programmers to define successor and predecessor functions for the field type. These functions take the field pointer and an argument-block structure as arguments. +.SS link_fieldtype +.PP +The function \fBlink_fieldtype\fR creates +a new field type from the two given types. +They are connected by an logical 'OR'. .SH RETURN VALUE The pointer-valued routines return NULL on error. They set \fBerrno\fP according to their success: @@ -127,14 +155,12 @@ The field is the current field. .B E_SYSTEM_ERROR System error occurred (see \fBerrno\fR(3)). .SH SEE ALSO -\fBcurses\fR(3X), \fBform\fR(3X). +\fBcurses\fR(3X), +\fBform\fR(3X), +\fBform_field_validation\fR(3X). .SH NOTES The header file \fB\fR automatically includes the header file \fB\fR. -.PP -All of the \fB(char *)\fR arguments of these functions should actually be -\fB(void *)\fR. The type has been left uncorrected for strict compatibility -with System V. .SH PORTABILITY These routines emulate the System V forms library. They were not supported on