File indexing completed on 2024-04-28 04:31:55

 /*
  * Copyright (C) 2010-2015 by Stephen Allewell
  * steve.allewell@gmail.com
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  */
 
 /** @file
  * This file defines a collection of background images to be used as overlays on
  * a canvas for the purpose of tracing.
  */
 
 #ifndef BackgroundImages_H
 #define BackgroundImages_H
 
 // Qt includes
 #include <QList>
 #include <QRect>
 #include <QSharedPointer>
 
 // Forward declaration of Qt classes
 class QDataStream;
 
 // Forward declaration of application classes
 class BackgroundImage;
 
 /**
  * This class defines a collection of background images allowing the addition
  * and removal of background images, setting the area occupied by an image and
  * changing the visibility status.
  *
  * The collection is stored in a QList of QSharedPointer objects. Generally the
  * BackgroundImage pointers would be owned by the collection and deleted in the
  * destructor. However if a background image is created and added to the list and
  * then undo is used it will be removed from the list but still referenced by the
  * AddBackgroundImageCommand which then becomes the owner. Using a QSharedPointer
  * to the BackgroundImage will ensure the BackgroundImage will be deleted
  * regardless of which object owns it or how many references there are to it.
  */
 class BackgroundImages
 {
 public:
     /**
      * Constructor to create an empty list of background images. Use the default
      * implementation for this.
      */
     BackgroundImages() = default;
 
     /**
      * Clear the contents of the collection.
      */
     void clear();
 
     /**
      * Get an iterator for the list of QSharedPointer to the background images.
      *
      * @return a QListIterator for BackgroundImage
      */
     QListIterator<QSharedPointer<BackgroundImage>> backgroundImages();
 
     /**
      * Add a background image to the list.
      *
      * @param backgroundImage is a QSharedPointer to the BackgroundImage to add
      */
     void addBackgroundImage(QSharedPointer<BackgroundImage> backgroundImage);
 
     /**
      * Remove a background image from the list.
      *
      * @param backgroundImage is a QSharedPointer to the BackgroundImage to remove
      *
      * @return @c true if the pointer was in the list, @c false otherwise
      */
     bool removeBackgroundImage(QSharedPointer<BackgroundImage> backgroundImage);
 
     /**
      * Fit a background image to a new location.
      *
      * @param backgroundImage is a QSharedPointer to the BackgroundImage to change
      * @param location is a const reference to a QRect defining the new location
      *
      * @return a QRect representing the previous location
      */
     QRect fitBackgroundImage(QSharedPointer<BackgroundImage> backgroundImage, const QRect &location);
 
     /**
      * Show or hide a background image.
      *
      * @param backgroundImage is a QSharedPointer to the BackgroundImage to change
      * @param show is @c true if the image is to be shown, @c false to hide
      *
      * @return the previous visibility state, @c true if shown, @c false if hidden
      */
     bool showBackgroundImage(QSharedPointer<BackgroundImage> backgroundImage, bool show);
 
     /**
      * Operator to stream out the class instance to a QDataStream. This will
      * stream the instance of the BackgroundImage contained in the list.
      *
      * @param stream a reference to the QDataStream to write to
      * @param backgroundImages a const reference to the class instance to write
      *
      * @return a reference to the QDataStream allowing chaining
      */
     friend QDataStream &operator<<(QDataStream &stream, const BackgroundImages &backgroundImages);
 
     /**
      * Operator to stream in the class instance from a QDataStream. The class
      * instance will have been created previously as an empty instance. This will
      * create instances of BackgroundImage and read those from the stream adding
      * them to the list.
      *
      * @param stream a reference to the QDataStream to read from
      * @param backgroundImages a reference to the class instance to read into
      *
      * @return a reference to the QDataStream allowing chaining
      */
     friend QDataStream &operator>>(QDataStream &stream, BackgroundImages &backgroundImages);
 
 private:
     static const int version = 100; /**< The version of the streamed object */
 
     QList<QSharedPointer<BackgroundImage>> m_backgroundImages; /**< A list of BackgroundImage shared pointers */
 };
 
 QDataStream &operator<<(QDataStream &, const BackgroundImages &);
 QDataStream &operator>>(QDataStream &, BackgroundImages &);
 
 #endif // BackgroundImages_H