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Diffstat (limited to 'contrib/ncurses/form/fty_generic.c')
| -rw-r--r-- | contrib/ncurses/form/fty_generic.c | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/contrib/ncurses/form/fty_generic.c b/contrib/ncurses/form/fty_generic.c new file mode 100644 index 000000000000..3e7a575a2623 --- /dev/null +++ b/contrib/ncurses/form/fty_generic.c @@ -0,0 +1,297 @@ +/**************************************************************************** + * Copyright (c) 2008-2009,2010 Free Software Foundation, Inc. * + * * + * Permission is hereby granted, free of charge, to any person obtaining a * + * copy of this software and associated documentation files (the * + * "Software"), to deal in the Software without restriction, including * + * without limitation the rights to use, copy, modify, merge, publish, * + * distribute, distribute with modifications, sublicense, and/or sell * + * copies of the Software, and to permit persons to whom the Software is * + * furnished to do so, subject to the following conditions: * + * * + * The above copyright notice and this permission notice shall be included * + * in all copies or substantial portions of the Software. * + * * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * + * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * + * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, * + * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * + * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR * + * THE USE OR OTHER DEALINGS IN THE SOFTWARE. * + * * + * Except as contained in this notice, the name(s) of the above copyright * + * holders shall not be used in advertising or otherwise to promote the * + * sale, use or other dealings in this Software without prior written * + * authorization. * + ****************************************************************************/ + +/*************************************************************************** +* * +* Author : Juergen Pfeifer * +* * +***************************************************************************/ + +#include "form.priv.h" + +MODULE_ID("$Id: fty_generic.c,v 1.5 2010/01/23 21:14:36 tom Exp $") + +/* + * This is not a full implementation of a field type, but adds some + * support for higher level languages with some restrictions to interop + * with C language. Especially the collection of arguments for the + * various fieldtypes is not based on the vararg C mechanism, but on a + * iterator based callback mechanism that allowes the high level language + * to provide the arguments as a structure. Most languages have mechanisms + * to layout structures so that they can be passed to C. + * The languages can register a new generic fieldtype dynamically and store + * a handle (key) to the calling object as an argument. Together with that + * it can register a freearg callback, so that the high level language + * remains in control of the memory management of the arguments they pass. + * The design idea is, that the high-level language - typically a OO + * language like C# or Java, uses it's own dispatching mechanisms + * (polymorphism) to call the proper check routines responsible for the + * argument type. So these language implement typically only one generic + * fieldtype they register with the forms library using this call. + * + * For that purpose we have extended the fieldtype struc by a new element + * that gets the arguments from a single struct passed by the caller. + * + */ +#if NCURSES_INTEROP_FUNCS + +/*--------------------------------------------------------------------------- +| Facility : libnform +| Function : static void *Generic_This_Type( void * arg ) +| +| Description : We interpret the passed arg just as a handle the +| calling language uses to keep track of its allocated +| argument structures. We can simply copy it back. +| +| Return Values : Pointer to argument structure ++--------------------------------------------------------------------------*/ +static void * +Generic_This_Type(void *arg) +{ + return (arg); +} + +/*--------------------------------------------------------------------------- +| Facility : libnform +| Function : FIELDTYPE *_nc_generic_fieldtype( +| bool (* const field_check)(FIELD *,const void *), +| bool (* const char_check) (int, const void *), +| bool (*const next)(FORM*,FIELD*,const void*), +| bool (*const prev)(FORM*,FIELD*,const void*), +| void (*freecallback)(void*)) +| +| Description : Create a new fieldtype. The application programmer must +| write a field_check and a char_check function and give +| them as input to this call. A callback to allow the +| release of the allocated memory must also be provided. +| For generic field types, we provide some more +| information about the field as parameters. +| +| If an error occurs, errno is set to +| E_BAD_ARGUMENT - invalid arguments +| E_SYSTEM_ERROR - system error (no memory) +| +| Return Values : Fieldtype pointer or NULL if error occurred ++--------------------------------------------------------------------------*/ +NCURSES_EXPORT(FIELDTYPE *) +_nc_generic_fieldtype(bool (*const field_check) (FORM *, FIELD *, const void *), + bool (*const char_check) (int, FORM *, FIELD *, const + void *), + bool (*const next) (FORM *, FIELD *, const void *), + bool (*const prev) (FORM *, FIELD *, const void *), + void (*freecallback) (void *)) +{ + int code = E_SYSTEM_ERROR; + FIELDTYPE *res = (FIELDTYPE *)0; + + T((T_CALLED("_nc_generic_fieldtype(%p,%p,%p,%p,%p)"), + field_check, char_check, next, prev, freecallback)); + + if (field_check || char_check) + { + res = typeMalloc(FIELDTYPE, 1); + + if (res) + { + *res = *_nc_Default_FieldType; + res->status |= (_HAS_ARGS | _GENERIC); + res->fieldcheck.gfcheck = field_check; + res->charcheck.gccheck = char_check; + res->genericarg = Generic_This_Type; + res->freearg = freecallback; + res->enum_next.gnext = next; + res->enum_prev.gprev = prev; + code = E_OK; + } + } + else + code = E_BAD_ARGUMENT; + + if (E_OK != code) + SET_ERROR(code); + + returnFieldType(res); +} + +/*--------------------------------------------------------------------------- +| Facility : libnform +| Function : static TypeArgument *GenericArgument( +| const FIELDTYPE* typ, +| int (*argiterator)(void**), +| int* err) +| +| Description : The iterator callback must browse through all fieldtype +| parameters that have an argument associated with the +| type. The iterator returns 1 if the operation to get +| the next element was successfull, 0 otherwise. If the +| iterator could move to the next argument, it fills +| the void* pointer representing the argument into the +| location provided as argument to the iterator. +| The err reference is used to keep track of errors. +| +| Return Values : Pointer to argument structure ++--------------------------------------------------------------------------*/ +static TypeArgument * +GenericArgument(const FIELDTYPE *typ, + int (*argiterator) (void **), int *err) +{ + TypeArgument *res = (TypeArgument *)0; + + if (typ != 0 && (typ->status & _HAS_ARGS) != 0 && err != 0 && argiterator != 0) + { + if (typ->status & _LINKED_TYPE) + { + /* Composite fieldtypes keep track internally of their own memory */ + TypeArgument *p = typeMalloc(TypeArgument, 1); + + if (p) + { + p->left = GenericArgument(typ->left, argiterator, err); + p->right = GenericArgument(typ->right, argiterator, err); + return p; + } + else + *err += 1; + } + else + { + assert(typ->genericarg != (void *)0); + if (typ->genericarg == 0) + *err += 1; + else + { + void *argp; + int valid = argiterator(&argp); + + if (valid == 0 || argp == 0 || + !(res = (TypeArgument *)typ->genericarg(argp))) + { + *err += 1; + } + } + } + } + return res; +} + +/*--------------------------------------------------------------------------- +| Facility : libnform +| Function : int _nc_set_generic_fieldtype( +| FIELD* field, +| FIELDTYPE* ftyp, +| int (*argiterator)(void**)) +| +| Description : Assign the fieldtype to the field and use the iterator +| mechanism to get the arguments when a check is +| performed. +| +| Return Values : E_OK if all went well +| E_SYSTEM_ERROR if an error occurred ++--------------------------------------------------------------------------*/ +NCURSES_EXPORT(int) +_nc_set_generic_fieldtype(FIELD *field, + FIELDTYPE *ftyp, + int (*argiterator) (void **)) +{ + int code = E_SYSTEM_ERROR; + int err = 0; + + if (field) + { + if (field && field->type) + _nc_Free_Type(field); + + field->type = ftyp; + if (ftyp) + { + if (argiterator) + { + /* The precondition is that the iterator is reset */ + field->arg = (void *)GenericArgument(field->type, argiterator, &err); + + if (err) + { + _nc_Free_Argument(field->type, (TypeArgument *)(field->arg)); + field->type = (FIELDTYPE *)0; + field->arg = (void *)0; + } + else + { + code = E_OK; + if (field->type) + field->type->ref++; + } + } + } + else + { + field->arg = (void *)0; + code = E_OK; + } + } + return code; +} + +/*--------------------------------------------------------------------------- +| Facility : libnform +| Function : WINDOW* _nc_form_cursor( +| FORM* form, +| int *pRow, int *pCol) +| +| Description : Get the current position of the form cursor position +| We also return the field window +| +| Return Values : The fields Window or NULL on error ++--------------------------------------------------------------------------*/ +NCURSES_EXPORT(WINDOW *) +_nc_form_cursor(const FORM *form, int *pRow, int *pCol) +{ + int code = E_SYSTEM_ERROR; + WINDOW *res = (WINDOW *)0; + + if (!(form == 0 || pRow == 0 || pCol == 0)) + { + *pRow = form->currow; + *pCol = form->curcol; + res = form->w; + code = E_OK; + } + if (code != E_OK) + SET_ERROR(code); + return res; +} + +#else +extern void _nc_fty_generic(void); +void +_nc_fty_generic(void) +{ +} +#endif + +/* fty_generic.c ends here */ |