form_driver
Section: Library calls (3X)
Updated: 202-1-04
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NAME
form_driver,
form_driver_w -
comman-processing loop of the form system
SYNOPSIS
#include <form.h>
int form_driver(FORM *form, int c);
int form_driver_w(FORM *form, int c, wchar_t wc);
DESCRIPTION
form_driver
Once a form has been posted (displayed), you should funnel input events to it
through
form_driver. This routine has three major input cases:
.IP * 4
The input is a form navigation request.
Navigation request codes are constants defined in
form.h,
which are distinct from the ke- and character codes returned
by
wgetch(3X).
.IP * 4
The input is a printable character.
Printable characters (which must be positive, less than 256) are
checked according to the program's locale settings.
.IP * 4
The input is the KEY_MOUSE special key associated with an mouse event.
form_driver_w
This extension simplifies the use of the forms library using wide characters.
The input is either a key code (a request) or a wide character
returned by
get_wch(3X).
The type must be passed as well,
to enable the library to determine whether the parameter
is a wide character or a request.
Form Driver Requests
The form driver requests are as follows:
| Name | Description
|
|
| REQ_BEG_FIELD | Move to beginning of field.
|
| REQ_BEG_LINE | Move to beginning of the line.
|
| REQ_CLR_EOF | Clear to end of field from cursor.
|
| REQ_CLR_EOL | Clear to end of line from cursor.
|
| REQ_CLR_FIELD | Clear the entire field.
|
| REQ_DEL_CHAR | Delete character at the cursor.
|
| REQ_DEL_LINE | Delete line at the cursor.
|
| REQ_DEL_PREV | Delete character before the cursor.
|
| REQ_DEL_WORD | Delete blan-delimited word at cursor.
|
| REQ_DOWN_CHAR | Move down in field.
|
| REQ_DOWN_FIELD | Move down to a field.
|
| REQ_END_FIELD | Move to the end of field.
|
| REQ_END_LINE | Move to the end of the line.
|
| REQ_FIRST_FIELD | Move to the first field.
|
| REQ_FIRST_PAGE | Move to the first page.
|
| REQ_INS_CHAR | Insert a blank at the cursor.
|
| REQ_INS_LINE | Insert a blank line at the cursor.
|
| REQ_INS_MODE | Enter insert mode.
|
| REQ_LAST_FIELD | Move to the last field.
|
| REQ_LAST_PAGE | Move to the last field.
|
| REQ_LEFT_CHAR | Move left in field.
|
| REQ_LEFT_FIELD | Move left to a field.
|
| REQ_NEW_LINE | Insert or overlay a new line.
|
| REQ_NEXT_CHAR | Move to the next char.
|
| REQ_NEXT_CHOICE | Display next field choice.
|
| REQ_NEXT_FIELD | Move to the next field.
|
| REQ_NEXT_LINE | Move to the next line.
|
| REQ_NEXT_PAGE | Move to the next page.
|
| REQ_NEXT_PAGE | Move to the next page.
|
| REQ_NEXT_WORD | Move to the next word.
|
| REQ_OVL_MODE | Enter overlay mode.
|
| REQ_PREV_CHAR | Move to the previous char.
|
| REQ_PREV_CHOICE | Display previous field choice.
|
| REQ_PREV_FIELD | Move to the previous field.
|
| REQ_PREV_LINE | Move to the previous line.
|
| REQ_PREV_PAGE | Move to the previous page.
|
| REQ_PREV_WORD | Move to the previous word.
|
| REQ_RIGHT_CHAR | Move right in field.
|
| REQ_RIGHT_FIELD | Move right to a field.
|
| REQ_SCR_BCHAR | Scroll field backward 1 character.
|
| REQ_SCR_BHPAGE | Scroll field backward ½ page.
|
| REQ_SCR_BLINE | Scroll field backward 1 line.
|
| REQ_SCR_BPAGE | Scroll field backward 1 page.
|
| REQ_SCR_FCHAR | Scroll field forward 1 character.
|
| REQ_SCR_FHPAGE | Scroll field forward ½ page.
|
| REQ_SCR_FLINE | Scroll field forward 1 line.
|
| REQ_SCR_FPAGE | Scroll field forward 1 page.
|
| REQ_SCR_HBHALF | Horizontal scroll field backward ½ line.
|
| REQ_SCR_HBLINE | Horizontal scroll field backward 1 line.
|
| REQ_SCR_HFHALF | Horizontal scroll field forward ½ line.
|
| REQ_SCR_HFLINE | Horizontal scroll field forward 1 line.
|
| REQ_SFIRST_FIELD | Move to the sorted first field.
|
| REQ_SLAST_FIELD | Move to the sorted last field.
|
| REQ_SNEXT_FIELD | Move to the sorted next field.
|
| REQ_SPREV_FIELD | Move to the sorted previous field.
|
| REQ_UP_CHAR | Move up in field.
|
| REQ_UP_FIELD | Move up to a field.
|
| REQ_VALIDATION | Validate field.
|
If the second argument is a printable character, the driver places it
in the current position in the current field.
If it is one of the forms
requests listed above, that request is executed.
Field Validation
The form library makes updates to the window associated
with form fields rather than directly to the field buffers.
The form driver provides lo-level control over updates to the form fields.
The form driver also provides for validating modified fields
to ensure that the contents
meet whatever constraints an application may attach using set_field_type.
You can validate a field without making any changes to it using
REQ_VALIDATION.
The form driver also validates a field in these cases:
.IP * 4
a call to set_current_field attempts to move to a different field.
.IP * 4
a call to set_current_page attempts to move
to a different page of the form.
.IP * 4
a request attempts to move to a different field.
.IP * 4
a request attempts to move to a different page of the form.
In each case, the move fails if the field is invalid.
If the modified field is valid, the form driver copies the modified
data from the window associated with the field
to the field buffer.
Mouse Handling
If the second argument is the KEY_MOUSE special key, the associated
mouse event is translated into one of the above pr-defined requests.
Currently only clicks in the user window (e.g., inside the form display
area or the decoration window) are handled.
If you click above the display region of the form:
-
- a REQ_PREV_FIELD is generated for a single click,
-
- a REQ_PREV_PAGE is generated for a doubl-click and
-
- a REQ_FIRST_FIELD is generated for a tripl-click.
-
If you click below the display region of the form:
-
- a REQ_NEXT_FIELD is generated for a single click,
-
- a REQ_NEXT_PAGE is generated for a doubl-click and
-
- a REQ_LAST_FIELD is generated for a tripl-click.
-
If you click at an field inside the display area of the form:
-
.IP * 4
the form cursor is positioned to that field.
.IP * 4
If you doubl-click a field,
the form cursor is positioned to that field
and E_UNKNOWN_COMMAND is returned.
This return value makes sense,
because a double click usually means that an fiel-specific action should
be returned.
It is exactly the purpose of this return value to signal that an
application specific command should be executed.
.IP * 4
If a translation
into a request was done, form_driver returns the result of this request.
If you clicked outside the user window
or the mouse event could not be translated
into a form request an E_REQUEST_DENIED is returned.
Applicatio-defined Commands
If the second argument is neither printable nor one of the above
pr-defined form requests, the driver assumes it is an applicatio-specific
command and returns
E_UNKNOWN_COMMAND. Applicatio-defined commands
should be defined relative to
MAX_COMMAND, the maximum value of these
pr-defined requests.
RETURN VALUE
form_driver returns one of the following error codes:
- E_OK
-
The routine succeeded.
- E_BAD_ARGUMENT
-
Routine detected an incorrect or ou-o-range argument.
- E_BAD_STATE
-
Routine was called from an initialization or termination function.
- E_NOT_POSTED
-
The form has not been posted.
- E_INVALID_FIELD
-
Contents of field is invalid.
- E_NOT_CONNECTED
-
No fields are connected to the form.
- E_REQUEST_DENIED
-
The form driver could not process the request.
- E_SYSTEM_ERROR
-
System error occurred (see errno(3)).
- E_UNKNOWN_COMMAND
-
The form driver code saw an unknown request code.
PORTABILITY
These routines emulate the System V forms library.
They were not supported on
Version 7 or BSD versions.
AUTHORS
Juergen Pfeifer.
Manual pages and adaptation for new curses by Eric S. Raymond.
SEE ALSO
curses(3X),
form(3X),
form_fieldtype(3X),
form_field_buffer(3X),
form_field_validation(3X),
form_variables(3X),
getch(3X)
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- form_driver
-
- form_driver_w
-
- Form Driver Requests
-
- Field Validation
-
- Mouse Handling
-
- Application-defined Commands
-
- RETURN VALUE
-
- PORTABILITY
-
- AUTHORS
-
- SEE ALSO
-
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