QgsNetworkContentFetcherRegistry: a registry for temporary downloaded…

… files
qgis · May 7, 2018 · 25108e5 · 25108e5
1 parent ba04dea
commit 25108e5
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diff --git a/python/core/qgsapplication.sip.in b/python/core/qgsapplication.sip.in
@@ -641,6 +641,14 @@ Returns the application's SVG cache, used for caching SVG images and handling pa
 within SVG files.
 
 .. versionadded:: 3.0
+%End
+
+    static QgsNetworkContentFetcherRegistry *networkContentFetcherRegistry();
+%Docstring
+Returns the application's SVG cache, used for caching SVG images and handling parameter replacement
+within SVG files.
+
+.. versionadded:: 3.2
 %End
 
     static QgsSymbolLayerRegistry *symbolLayerRegistry();

diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
@@ -238,6 +238,7 @@ SET(QGIS_CORE_SRCS
   qgsnetworkaccessmanager.cpp
   qgsnetworkdiskcache.cpp
   qgsnetworkcontentfetcher.cpp
+  qgsnetworkcontentfetcherregistry.cpp
   qgsnetworkcontentfetchertask.cpp
   qgsnetworkreplyparser.cpp
   qgsobjectcustomproperties.cpp
@@ -625,6 +626,7 @@ SET(QGIS_CORE_MOC_HDRS
   qgsnetworkaccessmanager.h
   qgsnetworkdiskcache.h
   qgsnetworkcontentfetcher.h
+  qgsnetworkcontentfetcherregistry.h
   qgsnetworkcontentfetchertask.h
   qgsnetworkreplyparser.h
   qgsofflineediting.h

diff --git a/src/core/qgsapplication.cpp b/src/core/qgsapplication.cpp
@@ -22,6 +22,7 @@
 #include "qgslogger.h"
 #include "qgsproject.h"
 #include "qgsnetworkaccessmanager.h"
+#include "qgsnetworkcontentfetcherregistry.h"
 #include "qgsproviderregistry.h"
 #include "qgsexpression.h"
 #include "qgsactionscoperegistry.h"
@@ -1664,6 +1665,11 @@ QgsSvgCache *QgsApplication::svgCache()
   return members()->mSvgCache;
 }
 
+QgsNetworkContentFetcherRegistry *QgsApplication::networkContentFetcherRegistry()
+{
+  return members()->mNetworkContentFertcherRegistry;
+}
+
 QgsSymbolLayerRegistry *QgsApplication::symbolLayerRegistry()
 {
   return members()->mSymbolLayerRegistry;
@@ -1743,6 +1749,7 @@ QgsApplication::ApplicationMembers::ApplicationMembers()
   mAnnotationRegistry = new QgsAnnotationRegistry();
   m3DRendererRegistry = new Qgs3DRendererRegistry();
   mProjectStorageRegistry = new QgsProjectStorageRegistry();
+  mNetworkContentFertcherRegistry = new QgsNetworkContentFetcherRegistry();
 }
 
 QgsApplication::ApplicationMembers::~ApplicationMembers()
@@ -1766,6 +1773,7 @@ QgsApplication::ApplicationMembers::~ApplicationMembers()
   delete mSvgCache;
   delete mSymbolLayerRegistry;
   delete mTaskManager;
+  delete mNetworkContentFertcherRegistry;
 }
 
 QgsApplication::ApplicationMembers *QgsApplication::members()

diff --git a/src/core/qgsapplication.h b/src/core/qgsapplication.h
@@ -46,6 +46,7 @@ class QgsUserProfileManager;
 class QgsPageSizeRegistry;
 class QgsLayoutItemRegistry;
 class QgsAuthManager;
+class QgsNetworkContentFetcherRegistry;
 
 /**
  * \ingroup core
@@ -586,6 +587,13 @@ class CORE_EXPORT QgsApplication : public QApplication
      */
     static QgsSvgCache *svgCache();
 
+    /**
+     * Returns the application's SVG cache, used for caching SVG images and handling parameter replacement
+     * within SVG files.
+     * \since QGIS 3.2
+     */
+    static QgsNetworkContentFetcherRegistry *networkContentFetcherRegistry();
+
     /**
      * Returns the application's symbol layer registry, used for managing symbol layers.
      * \since QGIS 3.0
@@ -802,6 +810,7 @@ class CORE_EXPORT QgsApplication : public QApplication
       QgsColorSchemeRegistry *mColorSchemeRegistry = nullptr;
       QgsFieldFormatterRegistry *mFieldFormatterRegistry = nullptr;
       QgsGpsConnectionRegistry *mGpsConnectionRegistry = nullptr;
+      QgsNetworkContentFetcherRegistry *mNetworkContentFertcherRegistry = nullptr;
       QgsMessageLog *mMessageLog = nullptr;
       QgsPaintEffectRegistry *mPaintEffectRegistry = nullptr;
       QgsPluginLayerRegistry *mPluginLayerRegistry = nullptr;

diff --git a/src/core/qgsnetworkcontentfetcherregistry.cpp b/src/core/qgsnetworkcontentfetcherregistry.cpp
@@ -0,0 +1,93 @@
+/***************************************************************************
+                       qgsnetworkcontentfetcherregistry.cpp
+                             -------------------
+    begin                : April, 2018
+    copyright            : (C) 2018 by Denis Rouzaud
+    email                : denis.rouzaud@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.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#include "qgsnetworkcontentfetcherregistry.h"
+
+#include "qgsapplication.h"
+#include "qgsnetworkcontentfetchertask.h"
+
+QgsNetworkContentFetcherRegistry::QgsNetworkContentFetcherRegistry()
+  : QObject()
+{
+}
+
+QgsNetworkContentFetcherRegistry::~QgsNetworkContentFetcherRegistry()
+{
+  QMap<QUrl, FetchedContent>::const_iterator it = mFileRegistry.constBegin();
+  for ( ; it != mFileRegistry.constEnd(); ++it )
+  {
+    it.value().mFile->deleteLater();
+  }
+}
+
+const QgsNetworkContentFetcherTask *QgsNetworkContentFetcherRegistry::fetch( const QUrl &url, const bool reload )
+{
+  if ( mFileRegistry.contains( url ) )
+  {
+    if ( !reload )
+    {
+      return mFileRegistry.value( url ).mFetchingTask;
+    }
+    else
+    {
+      FetchedContent content = mFileRegistry.take( url );
+      if ( content.mFetchingTask )
+      {
+        content.mFetchingTask->cancel();
+      }
+      if ( content.mFile )
+      {
+        content.mFile->deleteLater();
+      }
+    }
+  }
+
+  QgsNetworkContentFetcherTask *fetcher = new QgsNetworkContentFetcherTask( url );
+  QgsApplication::instance()->taskManager()->addTask( fetcher );
+  mFileRegistry.insert( url,
+                        FetchedContent( nullptr,
+                                        QgsNetworkContentFetcherRegistry::Downloading ) );
+
+  QObject::connect( fetcher, &QgsNetworkContentFetcherTask::fetched, this, [ = ]()
+  {
+    QNetworkReply *reply = fetcher->reply();
+    FetchedContent content = mFileRegistry.take( url );
+    if ( reply->error() == QNetworkReply::NoError )
+    {
+      content.setFile( new QTemporaryFile( QStringLiteral( "XXXXXX" ) ) );
+      content.mFile->write( reply->readAll() );
+      content.setStatus( Finished );
+    }
+    else
+    {
+      content.setStatus( Failed );
+      content.setError( reply->error() );
+    }
+    mFileRegistry.insert( url, content );
+  } );
+
+
+  return fetcher;
+}
+
+
+
+QgsNetworkContentFetcherRegistry::FetchedContent QgsNetworkContentFetcherRegistry::file( const QUrl &url )
+{
+  return mFileRegistry.value( url );
+}
diff --git a/src/core/qgsnetworkcontentfetcherregistry.h b/src/core/qgsnetworkcontentfetcherregistry.h
@@ -0,0 +1,110 @@
+/***************************************************************************
+                       qgsnetworkcontentfetcherregistry.h
+                             -------------------
+    begin                : April, 2018
+    copyright            : (C) 2018 by Denis Rouzaud
+    email                : denis.rouzaud@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.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#ifndef QGSNETWORKCONTENTFETCHERREGISTRY_H
+#define QGSNETWORKCONTENTFETCHERREGISTRY_H
+
+#include <QObject>
+#include <QMap>
+#include <QNetworkReply>
+#include <QTemporaryFile>
+
+class QTemporaryFile;
+
+class QgsNetworkContentFetcherTask;
+
+
+/**
+ * \class QgsNetworkContentFetcherRegistry
+ * \ingroup core
+ * \brief Registry for temporary fetched files
+ *
+ * This provides a simple way of downloading and accessing
+ * remote files during QGIS application running.
+ *
+ * \see QgsNetworkContentFetcher
+ * \see QgsNetworkContentFetcherTask
+ *
+ * \since QGIS 3.2
+*/
+class QgsNetworkContentFetcherRegistry : public QObject
+{
+    Q_OBJECT
+  public:
+    //! Status of fetched content
+    enum ContentStatus
+    {
+      UnknownUrl, //!< No download started for such URL
+      Downloading, //!< Currently downloading
+      Finished, //!< Download finished and successful
+      Failed //!< Download failed
+    };
+
+    /**
+     * FetchedContent contains a pointer to the file and the status of the download
+     */
+    class FetchedContent
+    {
+      public:
+        //! Constructs a FetchedContent with pointer to the downloaded file and status of the download
+        explicit FetchedContent( QTemporaryFile *file = nullptr, ContentStatus status = UnknownUrl )
+          : mFile( file ), mStatus( status ) {}
+
+        //! Return a pointer to the local file, a null pointer if the file is not accessible yet.
+        const QFile *file() const {return mFile;}
+
+        //! Return the status of the download
+        ContentStatus status() const {return mStatus;}
+
+        //! Return the potential error of the download
+        QNetworkReply::NetworkError reply() const {return mError;}
+
+      private:
+        void setFile( QTemporaryFile *file ) {mFile = file;}
+        void setStatus( ContentStatus status ) {mStatus = status;}
+        void setError( QNetworkReply::NetworkError error ) {mError = error;}
+        QTemporaryFile *mFile;
+        QgsNetworkContentFetcherTask *mFetchingTask;
+        ContentStatus mStatus;
+        QNetworkReply::NetworkError mError = QNetworkReply::NoError;
+
+        // allow modification of task and file from main class
+        friend class QgsNetworkContentFetcherRegistry;
+    };
+
+    //! Create the registry for temporary downloaded files
+    explicit QgsNetworkContentFetcherRegistry();
+
+    ~QgsNetworkContentFetcherRegistry();
+
+    /**
+     * @brief fetch
+     * @param url
+     * @param reload
+     * @return
+     */
+    const QgsNetworkContentFetcherTask *fetch( const QUrl &url, const bool reload = false );
+
+    FetchedContent file( const QUrl &url );
+
+  private:
+    QMap<QUrl, FetchedContent> mFileRegistry;
+
+};
+
+#endif // QGSNETWORKCONTENTFETCHERREGISTRY_H