[FEATURE] add support to SVG images from url.

Work done for Regione Toscana-SITA

python/core/symbology-ng/qgssvgcache.sip

@@ -34,7 +34,7 @@ class QgsSvgCacheEntry
 /**A cache for images / pictures derived from svg files. This class supports parameter replacement in svg files
 according to the svg params specification (http://www.w3.org/TR/2009/WD-SVGParamPrimer-20090616/). Supported are
 the parameters 'fill-color', 'pen-color', 'outline-width', 'stroke-width'. E.g. <circle fill="param(fill-color red)" stroke="param(pen-color black)" stroke-width="param(outline-width 1)"*/
-class QgsSvgCache
+class QgsSvgCache : QObject
 {
 %TypeHeaderCode
 #include <qgssvgcache.h>
@@ -56,7 +56,8 @@ class QgsSvgCache
                          double& defaultOutlineWidth ) const;
 
   protected:
-    QgsSvgCache();
+    //! protected constructor
+    QgsSvgCache( QObject* parent = 0 );
 
     /**Creates new cache entry and returns pointer to it*/
     QgsSvgCacheEntry* insertSVG( const QString& file, int size, const QColor& fill, const QColor& outline, double outlineWidth,

src/core/CMakeLists.txt

@@ -320,6 +320,7 @@ SET(QGIS_CORE_MOC_HDRS
   gps/qgsgpsdconnection.h
 
   symbology-ng/qgscptcityarchive.h
+  symbology-ng/qgssvgcache.h
 )
 
 IF (WITH_INTERNAL_QEXTSERIALPORT)

src/core/symbology-ng/qgsfillsymbollayerv2.cpp

@@ -309,13 +309,9 @@ QgsSVGFillSymbolLayer::~QgsSVGFillSymbolLayer()
 
 void QgsSVGFillSymbolLayer::setSvgFilePath( const QString& svgPath )
 {
-  QFile svgFile( svgPath );
-  if ( svgFile.open( QFile::ReadOnly ) )
-  {
-    mSvgData = svgFile.readAll();
+  mSvgData = QgsSvgCache::instance()->getImageData( svgPath );
+  storeViewBox();
 
-    storeViewBox();
-  }
   mSvgFilePath = svgPath;
   setDefaultSvgParams();
 }

src/core/symbology-ng/qgsmarkersymbollayerv2.cpp

@@ -674,7 +674,7 @@ void QgsSvgMarkerSymbolLayerV2::renderPoint( const QPointF& point, QgsSymbolV2Re
   }
   else
   {
-    p->setOpacity( context.alpha( ) );
+    p->setOpacity( context.alpha() );
     const QPicture& pct = QgsSvgCache::instance()->svgAsPicture( mPath, size, mFillColor, mOutlineColor, mOutlineWidth,
                           context.renderContext().scaleFactor(), context.renderContext().rasterScaleFactor() );
     p->drawPicture( 0, 0, pct );
@@ -842,6 +842,26 @@ QString QgsSvgMarkerSymbolLayerV2::symbolNameToPath( QString name )
   if ( QFile( name ).exists() )
     return QFileInfo( name ).canonicalFilePath();
 
+  // or it might be an url...
+  QUrl url( name );
+  if ( url.isValid() )
+  {
+    if ( url.isLocalFile() )
+    {
+      // it's a url to a local file
+      name = url.toLocalFile();
+      if ( QFile( name ).exists() )
+      {
+        return QFileInfo( name ).canonicalFilePath();
+      }
+    }
+    else
+    {
+      // it's a url pointing to a online resource
+      return name;
+    }
+  }
+
   // SVG symbol not found - probably a relative path was used
 
   QStringList svgPaths = QgsApplication::svgPaths();

src/core/symbology-ng/qgssvgcache.cpp

@@ -17,6 +17,11 @@
 
 #include "qgssvgcache.h"
 #include "qgslogger.h"
+#include "qgsnetworkaccessmanager.h"
+#include "qgsmessagelog.h"
+#include <QApplication>
+#include <QCoreApplication>
+#include <QCursor>
 #include <QDomDocument>
 #include <QDomElement>
 #include <QFile>
@@ -24,6 +29,9 @@
 #include <QPainter>
 #include <QPicture>
 #include <QSvgRenderer>
+#include <QFileInfo>
+#include <QNetworkReply>
+#include <QNetworkRequest>
 
 QgsSvgCacheEntry::QgsSvgCacheEntry(): file( QString() ), size( 0 ), outlineWidth( 0 ), widthScaleFactor( 1.0 ), rasterScaleFactor( 1.0 ), fill( Qt::black ),
     outline( Qt::black ), image( 0 ), picture( 0 )
@@ -81,7 +89,11 @@ QgsSvgCache* QgsSvgCache::instance()
   return mInstance;
 }
 
-QgsSvgCache::QgsSvgCache(): mTotalSize( 0 ), mLeastRecentEntry( 0 ), mMostRecentEntry( 0 )
+QgsSvgCache::QgsSvgCache( QObject *parent )
+    : QObject( parent )
+    , mTotalSize( 0 )
+    , mLeastRecentEntry( 0 )
+    , mMostRecentEntry( 0 )
 {
 }
 
@@ -163,14 +175,8 @@ void QgsSvgCache::containsParams( const QString& path, bool& hasFillParam, QColo
   defaultOutlineColor = QColor( Qt::black );
   defaultOutlineWidth = 1.0;
 
-  QFile svgFile( path );
-  if ( !svgFile.open( QIODevice::ReadOnly ) )
-  {
-    return;
-  }
-
   QDomDocument svgDoc;
-  if ( !svgDoc.setContent( &svgFile ) )
+  if ( !svgDoc.setContent( getImageData( path ) ) )
   {
     return;
   }
@@ -186,14 +192,8 @@ void QgsSvgCache::replaceParamsAndCacheSvg( QgsSvgCacheEntry* entry )
     return;
   }
 
-  QFile svgFile( entry->file );
-  if ( !svgFile.open( QIODevice::ReadOnly ) )
-  {
-    return;
-  }
-
   QDomDocument svgDoc;
-  if ( !svgDoc.setContent( &svgFile ) )
+  if ( !svgDoc.setContent( getImageData( entry->file ) ) )
   {
     return;
   }
@@ -206,6 +206,118 @@ void QgsSvgCache::replaceParamsAndCacheSvg( QgsSvgCacheEntry* entry )
   mTotalSize += entry->svgContent.size();
 }
 
+QByteArray QgsSvgCache::getImageData( const QString &path ) const
+{
+  // is it a path to local file?
+  QFile svgFile( path );
+  if ( svgFile.exists() )
+  {
+    if ( svgFile.open( QIODevice::ReadOnly ) )
+    {
+      return svgFile.readAll();
+    }
+    else
+    {
+      return QByteArray();
+    }
+  }
+
+  // maybe it's a url...
+  QUrl svgUrl( path );
+  if ( !svgUrl.isValid() )
+  {
+    return QByteArray();
+  }
+
+  // check whether it's a url pointing to a local file
+  if ( svgUrl.isLocalFile() )
+  {
+    svgFile.setFileName( svgUrl.toLocalFile() );
+    if ( svgFile.exists() )
+    {
+      if ( svgFile.open( QIODevice::ReadOnly ) )
+      {
+        return svgFile.readAll();
+      }
+    }
+
+    // not found...
+    return QByteArray();
+  }
+
+  // the url points to a remote resource, download it!
+  QNetworkReply *reply = 0;
+
+  // The following code blocks until the file is downloaded...
+  // TODO: use signals to get reply finished notification, in this moment
+  // it's executed while rendering.
+  while ( 1 )
+  {
+    QgsDebugMsg( QString( "get svg: %1" ).arg( svgUrl.toString() ) );
+    QNetworkRequest request( svgUrl );
+    request.setAttribute( QNetworkRequest::CacheLoadControlAttribute, QNetworkRequest::PreferCache );
+    request.setAttribute( QNetworkRequest::CacheSaveControlAttribute, true );
+
+    reply = QgsNetworkAccessManager::instance()->get( request );
+    connect( reply, SIGNAL( downloadProgress( qint64, qint64 ) ), this, SLOT( downloadProgress( qint64, qint64 ) ) );
+
+    //emit statusChanged( tr( "Downloading svg." ) );
+
+    // wait until the image download finished
+    // TODO: connect to the reply->finished() signal
+    QApplication::setOverrideCursor( QCursor( Qt::WaitCursor ) );
+    while ( !reply->isFinished() )
+    {
+      QCoreApplication::processEvents( QEventLoop::ExcludeUserInputEvents, 500 );
+    }
+    QApplication::restoreOverrideCursor();
+
+    if ( reply->error() != QNetworkReply::NoError )
+    {
+      QgsMessageLog::logMessage( tr( "SVG request failed [error: %1 - url: %2]" ).arg( reply->errorString() ).arg( reply->url().toString() ), tr( "SVG" ) );
+
+      reply->deleteLater();
+      return QByteArray();
+    }
+
+    QVariant redirect = reply->attribute( QNetworkRequest::RedirectionTargetAttribute );
+    if ( redirect.isNull() )
+    {
+      // neither network error nor redirection
+      // TODO: cache the image
+      break;
+    }
+
+    // do a new request to the redirect url
+    svgUrl = redirect.toUrl();
+    reply->deleteLater();
+  }
+
+  QVariant status = reply->attribute( QNetworkRequest::HttpStatusCodeAttribute );
+  if ( !status.isNull() && status.toInt() >= 400 )
+  {
+    QVariant phrase = reply->attribute( QNetworkRequest::HttpReasonPhraseAttribute );
+    QgsMessageLog::logMessage( tr( "SVG request error [status: %1 - reason phrase: %2]" ).arg( status.toInt() ).arg( phrase.toString() ), tr( "SVG" ) );
+
+    reply->deleteLater();
+    return QByteArray();
+  }
+
+  QString contentType = reply->header( QNetworkRequest::ContentTypeHeader ).toString();
+  QgsDebugMsg( "contentType: " + contentType );
+  if ( !contentType.startsWith( "image/svg+xml", Qt::CaseInsensitive ) )
+  {
+    reply->deleteLater();
+    return QByteArray();
+  }
+
+  // read the image data
+  QByteArray ba = reply->readAll();
+  reply->deleteLater();
+
+  return ba;
+}
+
 void QgsSvgCache::cacheImage( QgsSvgCacheEntry* entry )
 {
   if ( !entry )
@@ -553,3 +665,9 @@ void QgsSvgCache::takeEntryFromList( QgsSvgCacheEntry* entry )
   }
 }
 
+void QgsSvgCache::downloadProgress( qint64 bytesReceived, qint64 bytesTotal )
+{
+  QString msg = tr( "%1 of %2 bytes of svg image downloaded." ).arg( bytesReceived ).arg( bytesTotal < 0 ? QString( "unknown number of" ) : QString::number( bytesTotal ) );
+  QgsDebugMsg( msg );
+  emit statusChanged( msg );
+}

src/core/symbology-ng/qgssvgcache.h

@@ -22,6 +22,7 @@
 #include <QMap>
 #include <QMultiHash>
 #include <QString>
+#include <QUrl>
 
 class QDomElement;
 class QImage;
@@ -59,8 +60,10 @@ class CORE_EXPORT QgsSvgCacheEntry
 /**A cache for images / pictures derived from svg files. This class supports parameter replacement in svg files
 according to the svg params specification (http://www.w3.org/TR/2009/WD-SVGParamPrimer-20090616/). Supported are
 the parameters 'fill-color', 'pen-color', 'outline-width', 'stroke-width'. E.g. <circle fill="param(fill-color red)" stroke="param(pen-color black)" stroke-width="param(outline-width 1)"*/
-class CORE_EXPORT QgsSvgCache
+class CORE_EXPORT QgsSvgCache : public QObject
 {
+    Q_OBJECT
+
   public:
 
     static QgsSvgCache* instance();
@@ -76,8 +79,16 @@ class CORE_EXPORT QgsSvgCache
     void containsParams( const QString& path, bool& hasFillParam, QColor& defaultFillColor, bool& hasOutlineParam, QColor& defaultOutlineColor, bool& hasOutlineWidthParam,
                          double& defaultOutlineWidth ) const;
 
+    /**Get image data*/
+    QByteArray getImageData( const QString &path ) const;
+
+  signals:
+    /** Emit a signal to be caught by qgisapp and display a msg on status bar */
+    void statusChanged( QString const &  theStatusQString );
+
   protected:
-    QgsSvgCache();
+    //! protected constructor
+    QgsSvgCache( QObject * parent = 0 );
 
     /**Creates new cache entry and returns pointer to it*/
     QgsSvgCacheEntry* insertSVG( const QString& file, int size, const QColor& fill, const QColor& outline, double outlineWidth,
@@ -96,6 +107,9 @@ class CORE_EXPORT QgsSvgCache
     //Removes entry from the ordered list (but does not delete the entry itself)
     void takeEntryFromList( QgsSvgCacheEntry* entry );
 
+  private slots:
+    void downloadProgress( qint64, qint64 );
+
   private:
     static QgsSvgCache* mInstance;
 

src/gui/symbology-ng/qgssymbollayerv2widget.cpp

@@ -683,12 +683,16 @@ void QgsSvgMarkerSymbolLayerV2Widget::setGuiForSvg( const QgsSvgMarkerSymbolLaye
   mBorderWidthSpinBox->blockSignals( true );
   mBorderWidthSpinBox->setValue( layer->outlineWidth() );
   mBorderWidthSpinBox->blockSignals( false );
-
 }
 
 
 void QgsSvgMarkerSymbolLayerV2Widget::setSymbolLayer( QgsSymbolLayerV2* layer )
 {
+  if ( !layer )
+  {
+    return;
+  }
+
   if ( layer->layerType() != "SvgMarker" )
     return;
 
@@ -711,8 +715,6 @@ void QgsSvgMarkerSymbolLayerV2Widget::setSymbolLayer( QgsSymbolLayerV2* layer )
     }
   }
 
-
-
   spinSize->setValue( mLayer->size() );
   spinAngle->setValue( mLayer->angle() );
 
@@ -725,7 +727,6 @@ void QgsSvgMarkerSymbolLayerV2Widget::setSymbolLayer( QgsSymbolLayerV2* layer )
   spinOffsetY->blockSignals( false );
 
   setGuiForSvg( mLayer );
-
 }
 
 QgsSymbolLayerV2* QgsSvgMarkerSymbolLayerV2Widget::symbolLayer()
@@ -790,6 +791,21 @@ void QgsSvgMarkerSymbolLayerV2Widget::on_mFileLineEdit_textEdited( const QString
   emit changed();
 }
 
+void QgsSvgMarkerSymbolLayerV2Widget::on_mFileLineEdit_editingFinished()
+{
+  if ( !QFileInfo( mFileLineEdit->text() ).exists() )
+  {
+    QUrl url( mFileLineEdit->text() );
+    if ( !url.isValid() )
+    {
+        return;
+    }
+  }
+  mLayer->setPath( mFileLineEdit->text() );
+  setGuiForSvg( mLayer );
+  emit changed();
+}
+
 void QgsSvgMarkerSymbolLayerV2Widget::on_mChangeColorButton_clicked()
 {
   if ( !mLayer )
@@ -945,7 +961,7 @@ void QgsSVGFillSymbolLayerWidget::on_mTextureWidthSpinBox_valueChanged( double d
   }
 }
 
-void QgsSVGFillSymbolLayerWidget::on_mSVGLineEdit_textChanged( const QString & text )
+void QgsSVGFillSymbolLayerWidget::on_mSVGLineEdit_textEdited( const QString & text )
 {
   if ( !mLayer )
   {
@@ -958,14 +974,39 @@ void QgsSVGFillSymbolLayerWidget::on_mSVGLineEdit_textChanged( const QString & t
     return;
   }
   mLayer->setSvgFilePath( text );
-  emit changed();
   updateParamGui();
+  emit changed();
+}
+
+void QgsSVGFillSymbolLayerWidget::on_mSVGLineEdit_editingFinished()
+{
+  if ( !mLayer )
+  {
+    return;
+  }
+
+  QFileInfo fi( mSVGLineEdit->text() );
+  if ( !fi.exists() )
+  {
+    QUrl url( mSVGLineEdit->text() );
+    if ( !url.isValid() )
+    {
+        return;
+    }
+  }
+  mLayer->setSvgFilePath( mSVGLineEdit->text() );
+  updateParamGui();
+  emit changed();
 }
 
 void QgsSVGFillSymbolLayerWidget::setFile( const QModelIndex& item )
 {
-  mSVGLineEdit->setText( item.data( Qt::UserRole ).toString() );
+  QString file = item.data( Qt::UserRole ).toString();
+  mLayer->setSvgFilePath( file );
+  mSVGLineEdit->setText( file );
+
   updateParamGui();
+  emit changed();
 }
 
 void QgsSVGFillSymbolLayerWidget::insertIcons()
@@ -1000,8 +1041,8 @@ void QgsSVGFillSymbolLayerWidget::on_mRotationSpinBox_valueChanged( double d )
   if ( mLayer )
   {
     mLayer->setAngle( d );
+    emit changed();
   }
-  emit changed();
 }
 
 void QgsSVGFillSymbolLayerWidget::updateParamGui()

src/gui/symbology-ng/qgssymbollayerv2widget.h

@@ -198,6 +198,7 @@ class GUI_EXPORT QgsSvgMarkerSymbolLayerV2Widget : public QgsSymbolLayerV2Widget
     void setOffset();
     void on_mFileToolButton_clicked();
     void on_mFileLineEdit_textEdited( const QString& text );
+    void on_mFileLineEdit_editingFinished();
     void on_mChangeColorButton_clicked();
     void on_mChangeBorderColorButton_clicked();
     void on_mBorderWidthSpinBox_valueChanged( double d );
@@ -266,7 +267,8 @@ class GUI_EXPORT QgsSVGFillSymbolLayerWidget : public QgsSymbolLayerV2Widget, pr
   private slots:
     void on_mBrowseToolButton_clicked();
     void on_mTextureWidthSpinBox_valueChanged( double d );
-    void on_mSVGLineEdit_textChanged( const QString & text );
+    void on_mSVGLineEdit_textEdited( const QString & text );
+    void on_mSVGLineEdit_editingFinished();
     void setFile( const QModelIndex& item );
     void populateIcons( const QModelIndex& item );
     void on_mRotationSpinBox_valueChanged( double d );