TerminalCharacterDecoder.h

/*
    This file is part of Konsole, an X terminal.
 
    SPDX-FileCopyrightText: 2006-2008 Robert Knight <robertknight@gmail.com>
    SPDX-License-Identifier: GPL-2.0-or-later
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU Lesser 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 Lesser General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
    02110-1301  USA.
*/
 
#ifndef TERMINAL_CHARACTER_DECODER_H
#define TERMINAL_CHARACTER_DECODER_H
 
#include "Character.h"
 
#include <QList>
 
class QTextStream;
 
namespace Konsole
{
 
/**
 * Base class for terminal character decoders
 *
 * The decoder converts lines of terminal characters which consist of a unicode character, foreground
 * and background colours and other appearance-related properties into text strings.
 *
 * Derived classes may produce either plain text with no other colour or appearance information, or
 * they may produce text which incorporates these additional properties.
 */
class TerminalCharacterDecoder
{
public:
    virtual ~TerminalCharacterDecoder()
    {
    }
 
    /** Begin decoding characters.  The resulting text is appended to @p output. */
    virtual void begin(QTextStream *output) = 0;
    /** End decoding. */
    virtual void end() = 0;
 
    /**
     * Converts a line of terminal characters with associated properties into a text string
     * and writes the string into an output QTextStream.
     *
     * @param characters An array of characters of length @p count.
     * @param count The number of characters
     * @param properties Additional properties which affect all characters in the line
     */
    virtual void decodeLine(std::span<const Character> characters, LineProperty properties) = 0;
};
 
/**
 * A terminal character decoder which produces plain text, ignoring colours and other appearance-related
 * properties of the original characters.
 */
class PlainTextDecoder : public TerminalCharacterDecoder
{
public:
    PlainTextDecoder();
 
    /**
     * Set whether trailing whitespace at the end of lines should be included
     * in the output.
     * Defaults to true.
     */
    void setTrailingWhitespace(bool enable);
    /**
     * Returns whether trailing whitespace at the end of lines is included
     * in the output.
     */
    bool trailingWhitespace() const;
    /**
     * Returns of character positions in the output stream
     * at which new lines where added.  Returns an empty if setTrackLinePositions() is false or if
     * the output device is not a string.
     */
    QList<int> linePositions() const;
    /** Enables recording of character positions at which new lines are added.  See linePositions() */
    void setRecordLinePositions(bool record);
 
    void begin(QTextStream *output) override;
    void end() override;
 
    void decodeLine(std::span<const Character> characters, LineProperty properties) override;
 
private:
    QTextStream *_output;
    bool _includeTrailingWhitespace;
 
    bool _recordLinePositions;
    QList<int> _linePositions;
};
 
}
 
#endif