Manipulating soft labels
Curses provides subroutines for manipulating soft function-key labels.
These labels appear at the bottom of the screen and give applications, such as editors, a more user-friendly look. To use soft labels, you must call the slk_init subroutine before calling the initscr or newterm subroutines.
| Subroutine | Description |
|---|---|
| slk_clear | Clears soft labels from the screen. |
| slk_init | Initializes soft function key labels. |
| slk_label | Returns the current label. |
| slk_noutrefresh | Refreshes soft labels. This subroutine is functionally equivalent to the wnoutrefresh subroutine. |
| slk_refresh | Refreshes soft labels. This subroutine is functionally equivalent to the refresh subroutine. |
| slk_restore | Restores the soft labels to the screen after a call to the slk_clear subroutine. |
| slk_set | Sets a soft label. |
| slk_touch | Updates soft labels on the next call to the slk_noutrefresh subroutine. |
To manage soft labels, curses reduces the size of the stdscr by one line. It reserves this line for use by the soft-label functions. This reservation means that the LINES environment variable is also reduced. Many terminals support built-in soft labels. If built-in soft labels are supported, curses uses them. Otherwise, curses simulates the soft-labels with software.
Because many terminals that support soft labels have 8 labels, curses follows the same standard. A label string is restricted to 8 characters. Curses arranges labels in one of two patterns: 3-2-3 (3 left, 2 center, 3 right) or 4-4 (4 left, 4 right).
To specify a string for a particular label, call the slk_set subroutine. This subroutine also instructs curses to left-justify, right-justify, or center the string on the label. To obtain a label name before it was justified by the slk_set subroutine, use the slk_label subroutine. The slk_clear and slk_restore subroutines clear and restore soft labels respectively. Normally, to update soft labels, your program should call the slk_noutrefresh subroutine for each label and then use a single call to the slk_refresh subroutine to perform the actual output. To output all the soft labels on the next call to the slk_noutrefresh subroutine, use the slk_touch subroutine.