Ubuntu Manpage: notcurses_reader - high level widget for collecting input

Provided by: libnotcurses-core-dev_3.0.7+dfsg.1-1ubuntu1_amd64

NAME

       notcurses_reader - high level widget for collecting input

SYNOPSIS

       #include <notcurses/notcurses.h>

              struct ncplane;
              struct ncreader;
              struct notcurses;

              #define NCREADER_OPTION_HORSCROLL 0x0001
              #define NCREADER_OPTION_VERSCROLL 0x0002
              #define NCREADER_OPTION_NOCMDKEYS 0x0004
              #define NCREADER_OPTION_CURSOR    0x0008

              typedef struct ncreader_options {
                uint64_t tchannels; // channels used for input
                uint32_t tattrword; // attributes used for input
                uint64_t flags;     // bitfield over NCREADER_OPTION_*
              } ncreader_options;

       struct ncreader* ncreader_create(struct notcurses* nc, const ncreader_options* opts);

       int ncreader_clear(struct ncreader* n);

       struct ncplane* ncreader_plane(struct ncreader* n);

       int ncreader_move_left(struct ncreader* n);

       int ncreader_move_right(struct ncreader* n);

       int ncreader_move_up(struct ncreader* n);

       int ncreader_move_down(struct ncreader* n);

       int ncreader_write_egc(struct ncreader* n, const char* egc);

       bool ncreader_offer_input(struct ncreader* n, const ncinput* ni);

       char* ncreader_contents(const struct ncreader* n);

       void ncreader_destroy(struct ncreader* n, char contents);**

DESCRIPTION

The ncreader widget supports free-form, multi-line input. It supports navigation with the
arrow keys and scrolling. While the visible portion of the ncreader is always the same
size (defined by the provided ncplane), the actual text backing this visible region can
grow arbitrarily large if scrolling is enabled.

The following option flags are supported:

• NCREADER_OPTION_HORSCROLL: The visual area will be backed by a plane that can grow
arbitrarily wide.

• NCREADER_OPTION_VERSCROLL: The visual area will be backed by a plane that can grow
arbitrarily high.

• NCREADER_OPTION_NOCMDKEYS: The typical keyboard shortcuts (see below) will not be
honored.

• NCREADER_OPTION_CURSOR: The terminal's cursor will be made visible across the life of
the ncreader, and its location will be managed.

The contents of the ncreader can be retrieved with ncreader_contents.

The ncreader consists of at least one ncplane (the visible editing area). If the ncreader
supports scrolling, it will consist of two ncplanes, one of which will be kept outside the
rendering area (and will thus be invisible). ncreader_plane always returns the visible
plane.

ncreader_clear drops all input from the ncreader, restoring it to the same pristine
condition in which it was returned by ncreader_create.

Unlike most widgets' input handlers, ncreader_offer_input will consume most inputs. The
arrow keys navigate. Backspace consumes the EGC to the left of the cursor, if one exists.
Enter moves to the first column of the next line (if the cursor is already on the bottom
line, the plane must have scrolling enabled, or the cursor will not advance, though the
Enter will still be consumed). Otherwise, most inputs will be reproduced onto the
ncreader (though see NOTES below).

All the ncreader's content is returned from ncreader_contents, preserving whitespace.

"Emacs-style" keyboard shortcuts similar to those supported by readline(3) and most shells
are supported unless NCREADER_OPTION_NOCMDKEYS is provided to ncreader_create.

NOTES

       Support for NCREADER_OPTION_VERSCROLL is not yet implemented.

       ncreader does not buffer inputs in order to assemble EGCs from them.  If inputs are to  be
       processed  as EGCs (as they should), the caller would need assemble the grapheme clusters.
       Of course, there is not yet any API through which multi-codepoint EGCs could  be  supplied
       to ncreader.

       There is not yet any support for word-wrapping.  This will likely come in the future.

RETURN VALUES

AUTHORS