Qt 5.8 | Qt Widgets | Code Editor Example | codeeditor.h Example File

Qt 5.8.0 Reference Documentation

# codeeditor.h Example File

widgets/codeeditor/codeeditor.h

      /****************************************************************************
      **
      ** Copyright (C) 2016 The Qt Company Ltd.
      ** Contact: https://www.qt.io/licensing/
      **
      ** This file is part of the examples of the Qt Toolkit.
      **
      ** $QT_BEGIN_LICENSE:BSD$
      ** Commercial License Usage
      ** Licensees holding valid commercial Qt licenses may use this file in
      ** accordance with the commercial license agreement provided with the
      ** Software or, alternatively, in accordance with the terms contained in
      ** a written agreement between you and The Qt Company. For licensing terms
      ** and conditions see https://www.qt.io/terms-conditions. For further
      ** information use the contact form at https://www.qt.io/contact-us.
      **
      ** BSD License Usage
      ** Alternatively, you may use this file under the terms of the BSD license
      ** as follows:
      **
      ** "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
      ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
      ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
      **
      ** $QT_END_LICENSE$
      **
      ****************************************************************************/

      #ifndef CODEEDITOR_H
      #define CODEEDITOR_H

      #include <QPlainTextEdit>
      #include <QObject>

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

      class LineNumberArea;

      class CodeEditor : public QPlainTextEdit
      {
          Q_OBJECT

      public:
          CodeEditor(QWidget *parent = 0);

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

      protected:
          void resizeEvent(QResizeEvent *event) override;

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

      private:
          QWidget *lineNumberArea;
      };

      class LineNumberArea : 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;
      };

      #endif