.TH "FBB::OneKey" "3bobcat" "2005\-2023" "libbobcat\-dev_6\&.04\&.00" "One keystroke input"

.PP 
.SH "NAME"
FBB::OneKey \- Single keystroke input, not requiring `Return\(cq\&
.PP 
.SH "SYNOPSIS"
\fB#include <bobcat/onekey>\fP
.br 
Linking option: \fI\-lbobcat\fP
.PP 
.SH "DESCRIPTION"
\fBOneKey\fP objects may be used to realize `direct keyboard input\(cq\&: a
pressed key becomes available without the need for pressing \fIEnter\fP\&. The
characters are obtained from the standard input stream\&. Direct key entry
remains in effect for as long as the \fBOneKey\fP object exists\&. Once the object
is destroyed the standard input stream will return to its default mode of
operation, in which input is `confirmed\(cq\& by a newline character\&.
.PP 
.SH "NAMESPACE"
\fBFBB\fP
.br 
All constructors, members, operators and manipulators, mentioned in this
man\-page, are defined in the namespace \fBFBB\fP\&.
.PP 
.SH "INHERITS FROM"
\-
.PP 
.SH "ENUMERATION"
The \fBOneKey::Mode\fP enumeration is used to control echoing of returned
characters\&. It has two values:
.IP o 
\fBOFF\fP: returned characters are \fInot\fP echoed to the standard
output stream;
.IP o 
\fBON\fP: returned characters \fIare\fP echoed to the standard output
stream\&.
.SH "CONSTRUCTORS"
.IP o 
\fBOneKey(OneKey::Mode state = OneKey::OFF)\fP:
.br 
This constructor initializes the \fBOneKey\fP input object\&. By
default, entered characters are not echoed\&. By constructing the object
with the \fBOneKey::ON\fP argument, entered characters are echoed to
the standard output stream\&.
.IP 
This construct throws an \fIException\fP exception if it not properly
complete\&. The constructor may fail for the following reasons:
.IP o 
the standard input stream is not a tty (e\&.g\&., when the
standard input stream is redirected to a file);
.IP o 
the current state of the standard input stream can\(cq\&t be
determined;
.IP o 
the standard input stream\(cq\&s state can\(cq\&t be changed to the
`direct keyboard input\(cq\& mode\&.

.PP 
Copy and move constructors (and assignment operators) are not available\&.
.PP 
.SH "MEMBER FUNCTIONS"
.IP o 
\fBint get() const\fP:
.br 
Returns the next character from the standard input stream, without the
need for pressing \fIEnter\fP\&.
.IP o 
\fBvoid setEcho(OneKey::Mode state)\fP:
.br 
Changes the echo\-state of the \fBOneKey\fP object\&. The argument may be
either \fBOneKey::ON\fP or \fBOneKey::OFF\fP\&.

.PP 
.SH "EXAMPLE"
.nf 
/*
                              driver\&.cc
*/

#include <iostream>
#include <string>
#include <bobcat/onekey>

using namespace std;
using namespace FBB;

int main()
{
    try
    {
        OneKey onekey;

        cout << \(dq\&Usage: 1: next chars are echoed, 0: no echo, q: quits\en\(dq\&;

        while (true)
        {
            char c;

            cout << \(dq\&ready\&.\&.\&.\en\(dq\&;
            cout << \(dq\&Got character \(cq\&\(dq\& << (c = onekey\&.get()) << \(dq\&\(cq\&\en\(dq\&;

            switch (c)
            {
                case \(cq\&1\(cq\&:
                    onekey\&.setEcho(OneKey::ON);
                break;

                case \(cq\&0\(cq\&:
                    onekey\&.setEcho(OneKey::OFF);
                break;

                case \(cq\&q\(cq\&:
                return 0;
            }
        }
    }
    catch (exception const &e)
    {
        cout << e\&.what() << endl;
        return 1;
    }
}

.fi 

.PP 
.SH "FILES"
\fIbobcat/onekey\fP \- defines the class interface
.PP 
.SH "SEE ALSO"
\fBbobcat\fP(7), \fBtty\fP(3bobcat)
.PP 
.SH "BUGS"
None Reported\&.
.PP 
.SH "BOBCAT PROJECT FILES"

.PP 
.IP o 
\fIhttps://fbb\-git\&.gitlab\&.io/bobcat/\fP: gitlab project page;
.IP o 
\fIbobcat_6\&.04\&.00\-x\&.dsc\fP: detached signature;
.IP o 
\fIbobcat_6\&.04\&.00\-x\&.tar\&.gz\fP: source archive;
.IP o 
\fIbobcat_6\&.04\&.00\-x_i386\&.changes\fP: change log;
.IP o 
\fIlibbobcat1_6\&.04\&.00\-x_*\&.deb\fP: debian package containing the
libraries;
.IP o 
\fIlibbobcat1\-dev_6\&.04\&.00\-x_*\&.deb\fP: debian package containing the
libraries, headers and manual pages;

.PP 
.SH "BOBCAT"
Bobcat is an acronym of `Brokken\(cq\&s Own Base Classes And Templates\(cq\&\&.
.PP 
.SH "COPYRIGHT"
This is free software, distributed under the terms of the
GNU General Public License (GPL)\&.
.PP 
.SH "AUTHOR"
Frank B\&. Brokken (\fBf\&.b\&.brokken@rug\&.nl\fP)\&.
.PP