renderarea.cpp Example File

  /****************************************************************************
  **
  ** 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."
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/

  #include "renderarea.h"

  #include <QPainter>

  RenderArea::RenderArea(const QPainterPath &path, QWidget *parent)
      : QWidget(parent), path(path)
  {
      penWidth = 1;
      rotationAngle = 0;
      setBackgroundRole(QPalette::Base);
  }

  QSize RenderArea::minimumSizeHint() const
  {
      return QSize(50, 50);
  }

  QSize RenderArea::sizeHint() const
  {
      return QSize(100, 100);
  }

  void RenderArea::setFillRule(Qt::FillRule rule)
  {
      path.setFillRule(rule);
      update();
  }

  void RenderArea::setFillGradient(const QColor &color1, const QColor &color2)
  {
      fillColor1 = color1;
      fillColor2 = color2;
      update();
  }

  void RenderArea::setPenWidth(int width)
  {
      penWidth = width;
      update();
  }

  void RenderArea::setPenColor(const QColor &color)
  {
      penColor = color;
      update();
  }

  void RenderArea::setRotationAngle(int degrees)
  {
      rotationAngle = degrees;
      update();
  }

  void RenderArea::paintEvent(QPaintEvent *)
  {
      QPainter painter(this);
      painter.setRenderHint(QPainter::Antialiasing);
      painter.scale(width() / 100.0, height() / 100.0);
      painter.translate(50.0, 50.0);
      painter.rotate(-rotationAngle);
      painter.translate(-50.0, -50.0);

      painter.setPen(QPen(penColor, penWidth, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
      QLinearGradient gradient(0, 0, 0, 100);
      gradient.setColorAt(0.0, fillColor1);
      gradient.setColorAt(1.0, fillColor2);
      painter.setBrush(gradient);
      painter.drawPath(path);
  }