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/** \brief terminal.h */ // -*-c++-*-
// Copyright (C) 2010 Daniel Burrows
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; see the file COPYING. If not, write to
// the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
// Boston, MA 02111-1307, USA.
#ifndef APTITUDE_CMDLINE_SCREEN_WIDTH_H
#define APTITUDE_CMDLINE_SCREEN_WIDTH_H
#include <boost/shared_ptr.hpp>
#include <cwidget/generic/util/exception.h>
#include <iosfwd>
/** Thrown when we get EOF on stdin. Should never be thrown
* to the cwidget::toplevel.
*
* \todo It would be nice if this was a std::exception; watch out for
* places that just catch cw::util::Exception, though.
*/
class StdinEOFException : public cwidget::util::Exception
{
public:
std::string errmsg() const;
};
namespace aptitude
{
namespace cmdline
{
/** \brief Abstraction of the I/O device used for the command-line
* code.
*
* Virtual interfaces are used so that we can dummy them out for
* testing (see mocks/terminal.h). Using several virtual
* interfaces allows code to specify more precisely which
* functionality is required, so we don't have to
*/
// @{
/** \brief Interface representing the ability to write to the
* terminal.
*/
class terminal_output
{
public:
virtual ~terminal_output();
/** \brief Check whether the output stream seems to be connected
* to a terminal.
*
* Normally maps to isatty(1).
*/
virtual bool output_is_a_terminal() = 0;
/** \brief Write some text to the terminal. */
virtual void write_text(const std::wstring &msg) = 0;
/** \brief Return the cursor to the beginning of the current
* line.
*
* Like writing '\r'. Might not have an effect unless you call
* flush_output().
*/
virtual void move_to_beginning_of_line() = 0;
/** \brief Flush the output device.
*
* Writing '\n' is assumed to implicitly flush it (as on a
* standard terminal), but this is necessary if you want to
* ensure that something like a prompt or a progress bar is
* printed.
*/
virtual void flush() = 0;
};
/** \brief Interface representing the ability to read from the
* terminal.
*/
class terminal_input
{
public:
~terminal_input();
/** \brief Prompt for a line of input from the terminal device.
*
* \param msg A message to display as the prompt string. The
* cursor will be positioned immediately to the
* right of this message.
*
* \return a single line of user input.
*
* \throw StdinEOFException if EOF is encountered before the
* end of the current line.
*
* \note The StdinEOFException is normally just passed along
* until it reaches main(), which prints an appropriate message
* and aborts the program.
*/
virtual std::wstring prompt_for_input(const std::wstring &msg) = 0;
};
/** \brief Interface representing the ability to read the
* characteristics of the terminal.
*/
class terminal_metrics
{
public:
~terminal_metrics();
/** \brief Retrieve the current screen width.
*
* This might make system calls and return a different result
* each time, so don't call it in a tight loop -- cache the
* value up-front.
*
* A default value is returned if the output doesn't appear to
* be a tty.
*/
virtual unsigned int get_screen_width() = 0;
};
/** \brief Locale functionality related to the terminal (thus,
* primarily LC_CTYPE).
*
* This is wrapped up so that the unit tests can verify the
* code's output behavior without depending on the value of the
* system locale or the set of locale definitions that are
* installed on the system.
*/
class terminal_locale
{
public:
virtual ~terminal_locale();
/** \brief Return the number of terminal columns occupied by a
* wide character.
*/
virtual int wcwidth(wchar_t ch) = 0;
};
// @}
/** \brief Master interface representing all the terminal
* capabilities at once.
*
* This should normally not be passed as a parameter to
* functions; it exists so that create_terminal() has a return
* type.
*/
class terminal_io : public terminal_input,
public terminal_locale,
public terminal_metrics,
public terminal_output
{
};
/** \brief Create a terminal object attached to the standard I/O
* streams and using the system locale definitions.
*/
boost::shared_ptr<terminal_io> create_terminal();
}
}
#endif // APTITUDE_CMDLINE_SCREEN_WIDTH_H
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