driver(3)
NAME
driver - command-processing loop of the form system
SYNOPSIS
#include <form.h> int form_driver(FORM *form, int c);
DESCRIPTION
Once a form has been posted (displayed), you should funnel input events to it through form_driver. This routine has three major input cases:
- - The input is a form navigation request. Navigation request codes
- are constants defined in <form.h>, which are distinct from the keyand character codes returned by wgetch.
- - The input is a printable character. Printable characters (which
- must be positive, less than 256) are checked according to the program's locale settings.
- - The input is the KEY_MOUSE special key associated with an mouse
- event.
- The form driver requests are as follows:
- REQ_NEXT_PAGE
- Move to the next page.
- REQ_PREV_PAGE
- Move to the previous page.
- REQ_FIRST_PAGE
- Move to the first page.
- REQ_LAST_PAGE
- Move to the last field.
- REQ_NEXT_FIELD
- Move to the next field.
- REQ_PREV_FIELD
- Move to the previous field.
- REQ_FIRST_FIELD
- Move to the first field.
- REQ_LAST_FIELD
- Move to the last field.
- REQ_SNEXT_FIELD
- Move to the sorted next field.
- REQ_SPREV_FIELD
- Move to the sorted previous field.
- REQ_SFIRST_FIELD
- Move to the sorted first field.
- REQ_SLAST_FIELD
- Move to the sorted last field.
- REQ_LEFT_FIELD
- Move left to a field.
- REQ_RIGHT_FIELD
- Move right to a field.
- REQ_UP_FIELD
- Move up to a field.
- REQ_DOWN_FIELD
- Move down to a field.
- REQ_NEXT_CHAR
- Move to the next char.
- REQ_PREV_CHAR
- Move to the previous char.
- REQ_NEXT_LINE
- Move to the next line.
- REQ_PREV_LINE
- Move to the previous line.
- REQ_NEXT_WORD
- Move to the next word.
- REQ_PREV_WORD
- Move to the previous word.
- REQ_BEG_FIELD
- Move to the beginning of the field.
- REQ_END_FIELD
- Move to the end of the field.
- REQ_BEG_LINE
- Move to the beginning of the line.
- REQ_END_LINE
- Move to the end of the line.
- REQ_LEFT_CHAR
- Move left in the field.
- REQ_RIGHT_CHAR
- Move right in the field.
- REQ_UP_CHAR
- Move up in the field.
- REQ_DOWN_CHAR
- Move down in the field.
- REQ_NEW_LINE
- Insert or overlay a new line.
- REQ_INS_CHAR
- Insert a blank at the cursor.
- REQ_INS_LINE
- Insert a blank line at the cursor.
- REQ_DEL_CHAR
- Delete character at the cursor.
- REQ_DEL_PREV
- Delete character before the cursor.
- REQ_DEL_LINE
- Delete line at the cursor.
- REQ_DEL_WORD
- Delete blank-delimited word at the cursor.
- REQ_CLR_EOL
- Clear to end of line from cursor.
- REQ_CLR_EOF
- Clear to end of field from cursor.
- REQ_CLR_FIELD
- Clear the entire field.
- REQ_OVL_MODE
- Enter overlay mode.
- REQ_INS_MODE
- Enter insert mode.
- REQ_SCR_FLINE
- Scroll the field forward a line.
- REQ_SCR_BLINE
- Scroll the field backward a line.
- REQ_SCR_FPAGE
- Scroll the field forward a page.
- REQ_SCR_BPAGE
- Scroll the field backward a page.
- REQ_SCR_FHPAGE
- Scroll the field forward half a page.
- REQ_SCR_BHPAGE
- Scroll the field backward half a page.
- REQ_SCR_FCHAR
- Scroll the field forward a character.
- REQ_SCR_BCHAR
- Scroll the field backward a character.
- REQ_SCR_HFLINE
- Horizontal scroll the field forward a line.
- REQ_SCR_HBLINE
- Horizontal scroll the field backward a line.
- REQ_SCR_HFHALF
- Horizontal scroll the field forward half a line.
- REQ_SCR_HBHALF
- Horizontal scroll the field backward half a line.
- REQ_VALIDATION
- Validate field.
- REQ_NEXT_CHOICE
- Display next field choice.
- REQ_PREV_CHOICE
- Display previous field choice.
- 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.
- MOUSE HANDLING
- If the second argument is the KEY_MOUSE special key, the associated mouse event is translated into one of the above pre-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 double-click anda REQ_FIRST_FIELD is generated for a triple-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 double-click anda REQ_LAST_FIELD is generated for a triple-click. - If you click at an field inside the display area of the form:
- the form cursor is positioned to that field.- If you double-click a field, the form cursor is positioned tothat field and E_UNKNOWN_COMMAND is returned. This return value makes sense, because a double click usually means that an field-specific action should be returned. It is exactly the purpose of this return value to signal that an application specific command should be executed.- If a translation into a request was done, form_driver returnsthe 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.
- APPLICATION-DEFINED COMMANDS
- If the second argument is neither printable nor one of the above predefined form requests, the driver assumes it is an application-specific command and returns E_UNKNOWN_COMMAND. Application-defined commands should be defined relative to MAX_COMMAND, the maximum value of these pre-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 out-of-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_REQUEST_DENIED
- The form driver could not process the request.
- E_SYSTEM_ERROR
- System error occurred (see errno).
- E_UNKNOWN_COMMAND
- The form driver code saw an unknown request code.
SEE ALSO
ncurses(3NCURSES), form(3FORM), wgetch(3X).
NOTES
The header file <form.h> automatically includes the header files
<curses.h>.
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.