add supportedFiltersAndFormats() method to QgsRasterFileWriter

qgis · Dec 11, 2017 · 52b5864 · 52b5864
1 parent 7037c29
commit 52b5864
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diff --git a/python/core/raster/qgsrasterfilewriter.sip b/python/core/raster/qgsrasterfilewriter.sip
@@ -35,6 +35,13 @@ class QgsRasterFileWriter
       WriteCanceled,
     };
 
+    enum RasterFormatOption
+    {
+      SortRecommended,
+    };
+    typedef QFlags<QgsRasterFileWriter::RasterFormatOption> RasterFormatOptions;
+
+
     QgsRasterFileWriter( const QString &outputUrl );
 
     QgsRasterDataProvider *createOneBandRaster( Qgis::DataType dataType,
@@ -156,6 +163,37 @@ class QgsRasterFileWriter
  :rtype: list of str
 %End
 
+    static QString filterForDriver( const QString &driverName );
+%Docstring
+Creates a filter for an GDAL driver key
+ :rtype: str
+%End
+
+    struct FilterFormatDetails
+    {
+      QString driverName;
+%Docstring
+Unique driver name
+%End
+
+      QString filterString;
+%Docstring
+Filter string for file picker dialogs
+%End
+    };
+
+    static QList< QgsRasterFileWriter::FilterFormatDetails > supportedFiltersAndFormats( RasterFormatOptions options = SortRecommended );
+%Docstring
+ Returns a list or pairs, with format filter string as first element and GDAL format key as second element.
+ Relies on GDAL_DMD_EXTENSIONS metadata, if it is empty corresponding driver will be skipped even if supported.
+
+ The ``options`` argument can be used to control the sorting and filtering of
+ returned formats.
+
+.. seealso:: :py:func:`supportedOutputRasterLayerExtensions()`
+ :rtype: list of QgsRasterFileWriter.FilterFormatDetails
+%End
+
     static QString driverForExtension( const QString &extension );
 %Docstring
  Returns the GDAL driver name for a specified file ``extension``. E.g. the

diff --git a/src/core/raster/qgsrasterfilewriter.cpp b/src/core/raster/qgsrasterfilewriter.cpp
@@ -1023,3 +1023,83 @@ QStringList QgsRasterFileWriter::extensionsForFormat( const QString &format )
   }
   return QStringList();
 }
+
+QString QgsRasterFileWriter::filterForDriver( const QString &driverName )
+{
+  GDALDriverH drv = GDALGetDriverByName( driverName.toLocal8Bit().data() );
+  if ( drv )
+  {
+    QString drvName = GDALGetDriverLongName( drv );
+    QString extensionsString = QString( GDALGetMetadataItem( drv, GDAL_DMD_EXTENSIONS, nullptr ) );
+    if ( extensionsString.isEmpty() )
+    {
+      return QString();
+    }
+    QStringList extensions = extensionsString.split( ' ' );
+    QString filter = drvName + " (";
+    for ( const QString &ext : extensions )
+    {
+      filter.append( QStringLiteral( "*.%1 *.%2" ).arg( ext.toLower(), ext.toUpper() ) );
+    }
+    filter.append( QStringLiteral( ")" ) );
+    return filter;
+  }
+
+  return QString();
+}
+
+QList< QgsRasterFileWriter::FilterFormatDetails > QgsRasterFileWriter::supportedFiltersAndFormats( RasterFormatOptions options )
+{
+  QList< FilterFormatDetails > results;
+
+  GDALAllRegister();
+  int const drvCount = GDALGetDriverCount();
+
+  FilterFormatDetails tifFormat;
+
+  for ( int i = 0; i < drvCount; ++i )
+  {
+    GDALDriverH drv = GDALGetDriver( i );
+    if ( drv )
+    {
+      QString drvName = GDALGetDriverShortName( drv );
+      char **driverMetadata = GDALGetMetadata( drv, nullptr );
+      if ( CSLFetchBoolean( driverMetadata, GDAL_DCAP_CREATE, false ) && CSLFetchBoolean( driverMetadata, GDAL_DCAP_RASTER, false ) )
+      {
+        QString filterString = filterForDriver( drvName );
+        if ( filterString.isEmpty() )
+          continue;
+
+        FilterFormatDetails details;
+        details.driverName = drvName;
+        details.filterString = filterString;
+
+        if ( options & SortRecommended )
+        {
+          if ( drvName == QLatin1String( "GTiff" ) )
+          {
+            tifFormat = details;
+            continue;
+          }
+        }
+
+        results << details;
+      }
+    }
+  }
+
+  std::sort( results.begin(), results.end(), []( const FilterFormatDetails & a, const FilterFormatDetails & b ) -> bool
+  {
+    return a.driverName < b.driverName;
+  } );
+
+  if ( options & SortRecommended )
+  {
+    if ( !tifFormat.filterString.isEmpty() )
+    {
+      results.insert( 0, tifFormat );
+    }
+  }
+
+  return results;
+}
diff --git a/src/core/raster/qgsrasterfilewriter.h b/src/core/raster/qgsrasterfilewriter.h
@@ -54,6 +54,16 @@ class CORE_EXPORT QgsRasterFileWriter
       WriteCanceled = 6, //!< Writing was manually canceled
     };
 
+    /**
+     * Options for sorting and filtering raster formats.
+     * \since QGIS 3.0
+     */
+    enum RasterFormatOption
+    {
+      SortRecommended = 1 << 1, //!< Use recommended sort order, with extremely commonly used formats listed first
+    };
+    Q_DECLARE_FLAGS( RasterFormatOptions, RasterFormatOption )
+
     QgsRasterFileWriter( const QString &outputUrl );
 
     /**
@@ -134,6 +144,33 @@ class CORE_EXPORT QgsRasterFileWriter
     void setPyramidsConfigOptions( const QStringList &list ) { mPyramidsConfigOptions = list; }
     QStringList pyramidsConfigOptions() const { return mPyramidsConfigOptions; }
 
+    //! Creates a filter for an GDAL driver key
+    static QString filterForDriver( const QString &driverName );
+
+    /**
+     * Details of available filters and formats.
+     * \since QGIS 3.0
+     */
+    struct FilterFormatDetails
+    {
+      //! Unique driver name
+      QString driverName;
+
+      //! Filter string for file picker dialogs
+      QString filterString;
+    };
+
+    /**
+     * Returns a list or pairs, with format filter string as first element and GDAL format key as second element.
+     * Relies on GDAL_DMD_EXTENSIONS metadata, if it is empty corresponding driver will be skipped even if supported.
+     *
+     * The \a options argument can be used to control the sorting and filtering of
+     * returned formats.
+     *
+     * \see supportedOutputRasterLayerExtensions()
+     */
+    static QList< QgsRasterFileWriter::FilterFormatDetails > supportedFiltersAndFormats( RasterFormatOptions options = SortRecommended );
+
     /**
      * Returns the GDAL driver name for a specified file \a extension. E.g. the
      * driver name for the ".tif" extension is "GTiff".