menu_driver(3)menu_driver(3)NAMEmenu_driver - command-processing loop of the menu system
SYNOPSIS
#include <menu.h>
int menu_driver(MENU *menu, int c);
DESCRIPTION
Once a menu has been posted (displayed), you should funnel
input events to it through menu_driver. This routine has
three major input cases; either the input is a menu navi-
gation request, it's a printable ASCII character or it is
the KEY_MOUSE special key associated with an mouse event.
The menu driver requests are as follows:
REQ_LEFT_ITEM
Move left to an item.
REQ_RIGHT_ITEM
Move right to an item.
REQ_UP_ITEM
Move up to an item.
REQ_DOWN_ITEM
Move down to an item.
REQ_SCR_ULINE
Scroll up a line.
REQ_SCR_DLINE
Scroll down a line.
REQ_SCR_DPAGE
Scroll down a page.
REQ_SCR_UPAGE
Scroll up a page.
REQ_FIRST_ITEM
Move to the first item.
REQ_LAST_ITEM
Move to the last item.
REQ_NEXT_ITEM
Move to the next item.
REQ_PREV_ITEM
Move to the previous item.
REQ_TOGGLE_ITEM
Select/deselect an item.
1
menu_driver(3)menu_driver(3)
REQ_CLEAR_PATTERN
Clear the menu pattern buffer.
REQ_BACK_PATTERN
Delete the previous character from the pattern
buffer.
REQ_NEXT_MATCH
Move to the next item matching the pattern match.
REQ_PREV_MATCH
Move to the previous item matching the pattern match.
If the second argument is a printable ASCII character, the
code appends it to the pattern buffer and attempts to move
to the next item matching the new pattern. If there is no
such match, menu_driver returns E_NO_MATCH and deletes the
appended character from the buffer.
If the second argument is one of the above pre-defined
requests, the corresponding action is performed.
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 menu display area or the decora-
tion window) are handled. If you click above the display
region of the menu, a REQ_SCR_ULINE is generated, if you
doubleclick a REQ_SCR_UPAGE is generated and if you
tripleclick a REQ_FIRST_ITEM is generated. If you click
below the display region of the menu, a REQ_SCR_DLINE is
generated, if you doubleclick a REQ_SCR_DPAGE is generated
and if you tripleclick a REQ_LAST_ITEM is generated. If
you click at an item inside the display area of the menu,
the menu cursor is positioned to that item. If you double-
click at an item a REQ_TOGGLE_ITEM is generated and
E_UNKNOWN_COMMAND is returned. This return value makes
sense, because a double click usually means that an item-
specific action should be returned. It's exactly the pur-
pose of this return value to signal that an application
specific command should be executed. If a translation into
a request was done, menu_driver returns the result of this
request. If you clicked outside the user window or the
mouse event couldn't be translated into a menu request an
E_REQUEST_DENIED is returned.
If the second argument is neither printable ASCII nor one
of the above pre-defined menu requests or KEY_MOUSE, the
drive 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.
2
menu_driver(3)menu_driver(3)RETURN VALUEmenu_driver return one of the following error codes:
E_OK The routine succeeded.
E_SYSTEM_ERROR
System error occurred (see errno).
E_BAD_ARGUMENT
Routine detected an incorrect or out-of-range argu-
ment.
E_BAD_STATE
Routine was called from an initialization or termina-
tion function.
E_NOT_POSTED
The menu has not been posted.
E_UNKNOWN_COMMAND
The menu driver code saw an unknown request code.
E_NO_MATCH
Character failed to match.
E_REQUEST_DENIED
The menu driver could not process the request.
SEE ALSOcurses(3), menu(3X).
NOTES
The header file <menu.h> automatically includes the header
files <curses.h>.
PORTABILITY
These routines emulate the System V menu library. They
were not supported on Version 7 or BSD versions. The sup-
port for mouse events is ncurses specific.
AUTHORS
Juergen Pfeifer. Manual pages and adaptation for new
curses by Eric S. Raymond.
3
