qgsimagecache.h

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/***************************************************************************
                         qgsimagecache.h
                         ---------------
    begin                : December 2018
    copyright            : (C) 2018 by Nyall Dawson
    email                : nyall dot dawson at gmail dot 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.                                   *
 *                                                                         *
 ***************************************************************************/
 
#ifndef QGSIMAGECACHE_H
#define QGSIMAGECACHE_H
 
#include "qgis_core.h"
#include "qgis_sip.h"
#include "qgsabstractcontentcache.h"
 
#include <QElapsedTimer>
#include <QImage>
#include <QSize>
 
class QgsSettingsEntryInteger;
class QTemporaryDir;
 
#ifndef SIP_RUN


class CORE_EXPORT QgsImageSizeCacheEntry : public QgsAbstractContentCacheEntry
{
  public:
    QgsImageSizeCacheEntry( const QString &path );

    QSize size;
 
    int dataSize() const override;
    void dump() const override;
    bool isEqual( const QgsAbstractContentCacheEntry *other ) const override;
};

class CORE_EXPORT QgsImageSizeCache : public QgsAbstractContentCache< QgsImageSizeCacheEntry >
{
    Q_OBJECT
 
  public:
    QgsImageSizeCache( QObject *parent SIP_TRANSFERTHIS = nullptr );
    ~QgsImageSizeCache() override;
    long maximumSize() const { return mMaxCacheSize; }
    QSize originalSize( const QString &path, bool blocking = false );
};

class CORE_EXPORT QgsImageCacheEntry : public QgsAbstractContentCacheEntry
{
  public:
    QgsImageCacheEntry( const QString &path, QSize size, bool keepAspectRatio, double opacity, double targetDpi, int frameNumber );

    QSize size;

    bool keepAspectRatio = true;

    double opacity = 1.0;

    QImage image;

    bool isMissingImage = false;

    double targetDpi = 96;

    int frameNumber = -1;

    int totalFrameCount = -1;

    int nextFrameDelay = -1;
 
    int dataSize() const override;
    void dump() const override;
    bool isEqual( const QgsAbstractContentCacheEntry *other ) const override;
};

#endif

#ifdef SIP_RUN
class CORE_EXPORT QgsImageCache : public QgsAbstractContentCacheBase // for sip we skip to the base class and avoid the template difficulty
{
#else
class CORE_EXPORT QgsImageCache : public QgsAbstractContentCache< QgsImageCacheEntry >
{
#endif
    Q_OBJECT
 
  public:
    QgsImageCache( QObject *parent SIP_TRANSFERTHIS = nullptr );
 
    ~QgsImageCache() override;
 
    static const QgsSettingsEntryInteger *settingsMaxImageCacheSize SIP_SKIP;

    long maximumSize() const { return mMaxCacheSize; }

    QImage pathAsImage(
      const QString &path,
      const QSize size,
      const bool keepAspectRatio,
      const double opacity,
      bool &fitsInCache SIP_OUT,
      bool blocking = false,
      double targetDpi = 96,
      int frameNumber = -1,
      bool *isMissing SIP_PYARGREMOVE = nullptr
    );

    QSize originalSize( const QString &path, bool blocking = false ) const;

    int totalFrameCount( const QString &path, bool blocking = false );

    int nextFrameDelay( const QString &path, int currentFrame = 0, bool blocking = false );

    void prepareAnimation( const QString &path );
 
  signals:

    void remoteImageFetched( const QString &url );
 
  private:
    QImage pathAsImagePrivate(
      const QString &path, const QSize size, const bool keepAspectRatio, const double opacity, bool &fitsInCache, bool blocking, double targetDpi, int frameNumber, bool *isMissing, int &totalFrameCount, int &nextFrameDelayMs
    );
 
    QImage renderImage(
      const QString &path, QSize size, const bool keepAspectRatio, const double opacity, double targetDpi, int frameNumber, bool &isBroken, int &totalFrameCount, int &nextFrameDelayMs, bool blocking = false
    ) const;
 
    static QImage getFrameFromReader( QImageReader &reader, int frameNumber );
 
    QSize originalSizePrivate( const QString &path, bool blocking = false ) const;

    QByteArray mMissingSvg;
 
    QByteArray mFetchingSvg;
 
    QMap< QString, QString > mExtractedAnimationPaths;
    std::unique_ptr< QTemporaryDir > mTemporaryDir;
    QMap< QString, int > mTotalFrameCounts;
    QMap< QString, QVector< int > > mImageDelays;
 
    mutable QgsImageSizeCache mImageSizeCache;
 
    friend class QgsImageSizeCache;
    friend class TestQgsImageCache;
};
 
#endif // QGSIMAGECACHE_H