File indexing completed on 2024-11-03 11:26:11
0001 /** 0002 * SPDX-FileCopyrightText: (C) 2003 by Sébastien Laoût <slaout@linux62.org> 0003 * SPDX-License-Identifier: GPL-2.0-or-later 0004 */ 0005 0006 #ifndef BACKGROUNDMANAGER_H 0007 #define BACKGROUNDMANAGER_H 0008 0009 #include <QtCore/QList> 0010 #include <QtCore/QObject> 0011 #include <QtCore/QTimer> 0012 #include <QtGui/QColor> 0013 0014 class QPixmap; 0015 class QString; 0016 0017 /** A node in the list of background images of BackgroundManager. 0018 * It can only be used by BackgroundManager because it is an internal structure of this manager. 0019 * @author Sébastien Laoût 0020 */ 0021 class BackgroundEntry 0022 { 0023 friend class BackgroundManager; 0024 0025 public: 0026 ~BackgroundEntry(); 0027 0028 protected: 0029 BackgroundEntry(const QString &location); 0030 0031 QString name; 0032 QString location; 0033 bool tiled; /// << Only valid after some object subscribed to this image! Because it's only read at this time. 0034 QPixmap *pixmap; /// << Only valid (non-null) after some object subscribed to this image! Because it's only read at this time. 0035 QPixmap *preview; /// << Only valid (non-null) after some object requested the preview. 0036 int customersCount; 0037 }; 0038 0039 /** A node in the list of opaque background images (with a background color applied to an image) of BackgroundManager. 0040 * It can only be used by BackgroundManager because it is an internal structure of this manager. 0041 * @author Sébastien Laoût 0042 */ 0043 class OpaqueBackgroundEntry 0044 { 0045 friend class BackgroundManager; 0046 0047 public: 0048 ~OpaqueBackgroundEntry(); 0049 0050 protected: 0051 OpaqueBackgroundEntry(const QString &name, const QColor &color); 0052 0053 QString name; 0054 QColor color; 0055 QPixmap *pixmap; 0056 int customersCount; 0057 }; 0058 0059 /** Manage the list of background images. 0060 * BASIC FUNCTIONNING OF A BACKGROUND CHOOSER: 0061 * It get all image names with imageNames() to put them in eg. a QComboBox and then, 0062 * when it's time to get the preview of an image it call preview() with the image name to get it. 0063 * Preview are only computed on demand and then cached to fast the next demands (only the pointer will have to be returned). 0064 * Previews are scaled to fit in a rectangle of 100 by 75 pixels, and with a white background color. 0065 * They are also saved to files, so that the scaling/opaquification has not to be done later (they will be directly loaded from file). 0066 * Previews are saved in Global::backgroundsFolder()+"previews/", so that emptying the folder is sufficient to remove them. 0067 * BASIC FUNCTIONING OF AN IMAGE REQUESTER: 0068 * When eg. a basket is assigned an image name, it register it with subscribe(). 0069 * The full pixmap is then loaded from file and cached (if it was not already loaded) and the "tiled" property is read from the image configuration file. 0070 * If this object want to have the pixmap applied on a background color (for no transparency => really faster drawing), 0071 * it should register for the couple (imageName,color) with subscribe(): the pixmap will be created in the cache. 0072 * Then, the object can get the subscribed images with pixmap() or opaquePixmap() and know if it's tiled with tiled(). 0073 * When the user removed the object background image (or when the object/basket/... is removed), the object should call unsubscribe() for 0074 * EVERY subscribed image and image couples. Usage count is decreased for those images and a garbage collector will remove the cached images 0075 * if nothing is subscribed to them (to free memory). 0076 * @author Sébastien Laoût 0077 */ 0078 class BackgroundManager : private QObject 0079 { 0080 Q_OBJECT 0081 private: 0082 /// LIST OF IMAGES: 0083 typedef QList<BackgroundEntry *> BackgroundsList; 0084 typedef QList<OpaqueBackgroundEntry *> OpaqueBackgroundsList; 0085 0086 public: 0087 /// CONTRUCTOR AND DESTRUCTOR: 0088 BackgroundManager(); 0089 ~BackgroundManager() override; 0090 /// SUBSCRIPTION TO IMAGES: 0091 bool subscribe(const QString &image); /// << @Return true if the loading is a success. In the counter-case, calling methods below is unsafe with this @p image name. 0092 bool subscribe(const QString &image, const QColor &color); /// << Idem. 0093 void unsubscribe(const QString &image); 0094 void unsubscribe(const QString &image, const QColor &color); 0095 /// GETTING THE IMAGES AND PROPERTIES: 0096 QPixmap *pixmap(const QString &image); 0097 QPixmap *opaquePixmap(const QString &image, const QColor &color); 0098 bool tiled(const QString &image); 0099 /// LIST OF IMAGES AND PREVIEWS: 0100 bool exists(const QString &image); 0101 QStringList imageNames(); 0102 QPixmap *preview(const QString &image); 0103 /// USED FOR EXPORTATION: 0104 QString pathForImageName(const QString &image); /// << It is STRONGLY advised to not use those two methods unless it's to copy (export) the images or something like that... 0105 QString previewPathForImageName(const QString &image); 0106 /// USED FOR IMPORTATION: 0107 void addImage(const QString &fullPath); 0108 0109 private: 0110 BackgroundEntry *backgroundEntryFor(const QString &image); 0111 OpaqueBackgroundEntry *opaqueBackgroundEntryFor(const QString &image, const QColor &color); 0112 0113 private: 0114 BackgroundsList m_backgroundsList; 0115 OpaqueBackgroundsList m_opaqueBackgroundsList; 0116 QTimer m_garbageTimer; 0117 private Q_SLOTS: 0118 void requestDelayedGarbage(); 0119 void doGarbage(); 0120 }; 0121 0122 #endif // BACKGROUNDMANAGER_H