codeeditor.h

// Copyright Contributors to the Open Shading Language project.
// SPDX-License-Identifier: BSD-3-Clause
// https://github.com/AcademySoftwareFoundation/OpenShadingLanguage


/**************************************************************************
** This code ia partially based on an example found here:
** http://doc.qt.io/qt-5/qtwidgets-widgets-codeeditor-example.html
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
**   * Redistributions of source code must retain the above copyright
**     notice, this list of conditions and the following disclaimer.
**   * Redistributions in binary form must reproduce the above copyright
**     notice, this list of conditions and the following disclaimer in
**     the documentation and/or other materials provided with the
**     distribution.
**   * Neither the name of The Qt Company Ltd nor the names of its
**     contributors may be used to endorse or promote products derived
**     from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**************************************************************************/


#pragma once

#include <QObject>
#include <QPlainTextEdit>

class QFont;
class QPaintEvent;
class QResizeEvent;
class QSize;
class QWidget;

class LineNumberArea;


class CodeEditor final : public QPlainTextEdit {
    Q_OBJECT

public:
    CodeEditor(QWidget* parent             = nullptr,
               const std::string& filename = "untitled");

    void lineNumberAreaPaintEvent(QPaintEvent* event);
    int lineNumberAreaWidth();

    const std::string& full_filename() const { return m_full_filename; }
    const std::string& brief_filename() const { return m_brief_filename; }

    void set_filename(const std::string& filename);

    std::string text_string() const;

    int char_width_pixels() const;
    int line_spacing_pixels() const;

    static QFont fixedFont();

protected:
    void keyPressEvent(QKeyEvent* event) override;
    void resizeEvent(QResizeEvent* event) override;

private slots:
    void updateLineNumberAreaWidth(int newBlockCount);
    void highlightCurrentLine();
    void updateLineNumberArea(const QRect&, int);

private:
    QWidget* lineNumberArea;
    std::string m_full_filename;
    std::string m_brief_filename;
};



class LineNumberArea final : public QWidget {
public:
    LineNumberArea(CodeEditor* editor) : QWidget(editor)
    {
        codeEditor = editor;
    }

    QSize sizeHint() const override
    {
        return QSize(codeEditor->lineNumberAreaWidth(), 0);
    }

protected:
    void paintEvent(QPaintEvent* event) override
    {
        codeEditor->lineNumberAreaPaintEvent(event);
    }

private:
    CodeEditor* codeEditor;
};