Support SVG relative paths in SVG cache to enable relative data defin…

…ed paths. Fixes #8883

src/core/symbology-ng/qgssvgcache.cpp

@@ -20,6 +20,8 @@
 #include "qgslogger.h"
 #include "qgsnetworkaccessmanager.h"
 #include "qgsmessagelog.h"
+#include "qgssymbollayerv2utils.h"
+
 #include <QApplication>
 #include <QCoreApplication>
 #include <QCursor>
@@ -165,7 +167,10 @@ const QPicture& QgsSvgCache::svgAsPicture( const QString& file, double size, con
 QgsSvgCacheEntry* QgsSvgCache::insertSVG( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth,
     double widthScaleFactor, double rasterScaleFactor )
 {
-  QgsSvgCacheEntry* entry = new QgsSvgCacheEntry( file, size, outlineWidth, widthScaleFactor, rasterScaleFactor, fill, outline );
+  // The file may be relative path (e.g. if path is data defined)
+  QString path = QgsSymbolLayerV2Utils::symbolNameToPath( file );
+
+  QgsSvgCacheEntry* entry = new QgsSvgCacheEntry( path, size, outlineWidth, widthScaleFactor, rasterScaleFactor, fill, outline );
 
   replaceParamsAndCacheSvg( entry );
 

src/core/symbology-ng/qgssvgcache.h

@@ -32,6 +32,9 @@ class CORE_EXPORT QgsSvgCacheEntry
 {
   public:
     QgsSvgCacheEntry();
+    /** Constructor.
+     * @param file Absolute path to SVG file (relative paths are not resolved).
+     */
     QgsSvgCacheEntry( const QString& file, double size, double outlineWidth, double widthScaleFactor, double rasterScaleFctor, const QColor& fill, const QColor& outline );
     ~QgsSvgCacheEntry();
 
@@ -69,8 +72,14 @@ class CORE_EXPORT QgsSvgCache : public QObject
     static QgsSvgCache* instance();
     ~QgsSvgCache();
 
+    /** Get SVG  as QImage.
+     * @param file Absolute or relative path to SVG file.
+     */
     const QImage& svgAsImage( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth,
                               double widthScaleFactor, double rasterScaleFactor, bool& fitsInCache );
+    /** Get SVG  as QPicture&.
+     * @param file Absolute or relative path to SVG file.
+     */
     const QPicture& svgAsPicture( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth,
                                   double widthScaleFactor, double rasterScaleFactor, bool forceVectorOutput = false );
 
@@ -90,7 +99,10 @@ class CORE_EXPORT QgsSvgCache : public QObject
     //! protected constructor
     QgsSvgCache( QObject * parent = 0 );
 
-    /**Creates new cache entry and returns pointer to it*/
+    /**Creates new cache entry and returns pointer to it
+     * @param file Absolute or relative path to SVG file. If the path is relative the file is searched by QgsSymbolLayerV2Utils::symbolNameToPath() in SVG paths.
+    in settings svg/searchPathsForSVG
+     */
     QgsSvgCacheEntry* insertSVG( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth,
                                  double widthScaleFactor, double rasterScaleFactor );
 

src/core/symbology-ng/qgssymbollayerv2utils.h

@@ -249,7 +249,10 @@ class CORE_EXPORT QgsSymbolLayerV2Utils
     //! Return a list of svg files at the specified directory
     static QStringList listSvgFilesAt( QString directory );
 
-    //! Get symbol's path from its name
+    /** Get symbol's path from its name.
+     *  If the name is not absolute path the file is searched in SVG paths specified
+     *  in settings svg/searchPathsForSVG.
+     */
     static QString symbolNameToPath( QString name );
 
     //! Get symbols's name from its path