Qt 5.9 | Qt Widgets | Plug & Paint Example | paintarea.h Example File

Qt 5.9.9 Reference Documentation

# paintarea.h Example File

tools/plugandpaint/app/paintarea.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 PAINTAREA_H
      #define PAINTAREA_H

      #include <QColor>
      #include <QImage>
      #include <QPainterPath>
      #include <QWidget>

      class BrushInterface;

      class PaintArea : public QWidget
      {
          Q_OBJECT

      public:
          PaintArea(QWidget *parent = 0);

          bool openImage(const QString &fileName);
          bool saveImage(const QString &fileName, const char *fileFormat);
          void setImage(const QImage &image);
          void insertShape(const QPainterPath &path);
          void setBrushColor(const QColor &color);
          void setBrushWidth(int width);
          void setBrush(BrushInterface *brushInterface, const QString &brush);

          QImage image() const { return theImage; }
          QColor brushColor() const { return color; }
          int brushWidth() const { return thickness; }
          QSize sizeHint() const override;

      protected:
          void paintEvent(QPaintEvent *event) override;
          void mousePressEvent(QMouseEvent *event) override;
          void mouseMoveEvent(QMouseEvent *event) override;
          void mouseReleaseEvent(QMouseEvent *event) override;

      private:
          void setupPainter(QPainter &painter);

          QImage theImage;
          QColor color;
          int thickness;

          BrushInterface *brushInterface;
          QString brush;
          QPoint lastPos;

          QPainterPath pendingPath;
      };

      #endif