wheelwidget.h Example File

  /****************************************************************************
  **
  ** Copyright (C) 2015 The Qt Company Ltd.
  ** Contact: http://www.qt.io/licensing/
  **
  ** This file is part of the examples of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:BSD$
  ** 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 WHEELWIDGET_H
  #define WHEELWIDGET_H

  #include <QWidget>
  #include <QStringList>

  class QPainter;
  class QRect;

  class AbstractWheelWidget : public QWidget {
      Q_OBJECT

  public:
      AbstractWheelWidget(bool touch, QWidget *parent = 0);
      virtual ~AbstractWheelWidget();

      int currentIndex() const;
      void setCurrentIndex(int index);

      bool event(QEvent*);
      void paintEvent(QPaintEvent *e);
      virtual void paintItem(QPainter* painter, int index, const QRect &rect) = 0;

      virtual int itemHeight() const = 0;
      virtual int itemCount() const = 0;

  public slots:
      void scrollTo(int index);

  signals:
      void stopped(int index);

  protected:
      int m_currentItem;
      int m_itemOffset; // 0-itemHeight()
      qreal m_lastY;
  };

  class StringWheelWidget : public AbstractWheelWidget {
      Q_OBJECT

  public:
      StringWheelWidget(bool touch);

      QStringList items() const;
      void setItems( const QStringList &items );

      QSize sizeHint() const;
      QSize minimumSizeHint() const;

      void paintItem(QPainter* painter, int index, const QRect &rect);

      int itemHeight() const;
      int itemCount() const;

  private:
      QStringList m_items;
  };

  #endif // WHEELWIDGET_H