/******************************************************************************** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).** All rights reserved.** Contact: Nokia Corporation (qt-info@nokia.com)**** This file is part of the QtOpenVG module of the Qt Toolkit.**** $QT_BEGIN_LICENSE:LGPL$** No Commercial Usage** This file contains pre-release code and may not be distributed.** You may use this file in accordance with the terms and conditions** contained in the Technology Preview License Agreement accompanying** this package.**** GNU Lesser General Public License Usage** Alternatively, this file may be used under the terms of the GNU Lesser** General Public License version 2.1 as published by the Free Software** Foundation and appearing in the file LICENSE.LGPL included in the** packaging of this file. Please review the following information to** ensure the GNU Lesser General Public License version 2.1 requirements** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.**** In addition, as a special exception, Nokia gives you certain additional** rights. These rights are described in the Nokia Qt LGPL Exception** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.**** If you have questions regarding the use of this file, please contact** Nokia at qt-info@nokia.com.****************** $QT_END_LICENSE$******************************************************************************/#ifndef QVGIMAGEPOOL_P_H#define QVGIMAGEPOOL_P_H//// W A R N I N G// -------------//// This file is not part of the Qt API. It exists for the convenience// of other Qt classes. This header file may change from version to// version without notice, or even be removed.//// We mean it.//#include "qvg.h"#include <QtCore/qscopedpointer.h>QT_BEGIN_NAMESPACEclass QVGPixmapData;class QVGImagePoolPrivate;class Q_OPENVG_EXPORT QVGImagePool{public: QVGImagePool(); virtual ~QVGImagePool(); static QVGImagePool *instance(); // This function can be used from system-specific graphics system // plugins to alter the image allocation strategy. static void setImagePool(QVGImagePool *pool); // Create a new VGImage from the pool with the specified parameters // that is not associated with a pixmap. The VGImage is returned to // the pool when releaseImage() is called. // // This function will call reclaimSpace() when vgCreateImage() fails. // // This function is typically called when allocating temporary // VGImage's for pixmap filters. The "keepData" object will not // be reclaimed if reclaimSpace() needs to be called. virtual VGImage createTemporaryImage(VGImageFormat format, VGint width, VGint height, VGbitfield allowedQuality, QVGPixmapData *keepData = 0); // Create a new VGImage with the specified parameters and associate // it with "data". The QVGPixmapData will be notified when the // VGImage needs to be reclaimed by the pool. // // This function will call reclaimSpace() when vgCreateImage() fails. virtual VGImage createImageForPixmap(VGImageFormat format, VGint width, VGint height, VGbitfield allowedQuality, QVGPixmapData *data); // Create a permanent VGImage with the specified parameters. // If there is insufficient space for the vgCreateImage call, // then this function will call reclaimSpace() and try again. // // The caller is responsible for calling vgDestroyImage() // when it no longer needs the VGImage, as the image is not // recorded in the image pool. // // This function is typically used for pattern brushes where // the OpenVG engine is responsible for managing the lifetime // of the VGImage, destroying it automatically when the brush // is no longer in use. virtual VGImage createPermanentImage(VGImageFormat format, VGint width, VGint height, VGbitfield allowedQuality); // Release a VGImage that is no longer required. virtual void releaseImage(QVGPixmapData *data, VGImage image); // Notify the pool that a QVGPixmapData object is using // an image again. This allows the pool to move the image // within a least-recently-used list of QVGPixmapData objects. virtual void useImage(QVGPixmapData *data); // Notify the pool that the VGImage's associated with a // QVGPixmapData are being detached from the pool. The caller // will become responsible for calling vgDestroyImage(). virtual void detachImage(QVGPixmapData *data); // Reclaim space for an image allocation with the specified parameters. // Returns true if space was reclaimed, or false if there is no // further space that can be reclaimed. The "data" parameter // indicates the pixmap that is trying to obtain space which should // not itself be reclaimed. virtual bool reclaimSpace(VGImageFormat format, VGint width, VGint height, QVGPixmapData *data); // Hibernate the image pool because the context is about to be // destroyed. All VGImage's left in the pool should be released. virtual void hibernate();protected: // Helper functions for managing the LRU list of QVGPixmapData objects. void moveToHeadOfLRU(QVGPixmapData *data); void removeFromLRU(QVGPixmapData *data); QVGPixmapData *pixmapLRU();private: QScopedPointer<QVGImagePoolPrivate> d_ptr; Q_DECLARE_PRIVATE(QVGImagePool) Q_DISABLE_COPY(QVGImagePool)};QT_END_NAMESPACE#endif