Move minimum layer extent calculation to c++

python/core/processing/qgsprocessingutils.sip

@@ -152,6 +152,12 @@ class QgsProcessingUtils
    available in Python bindings as createFeatureSink()
 %End
 
+    static QgsRectangle combineLayerExtents( const QList< QgsMapLayer *> layers, const QgsCoordinateReferenceSystem &crs = QgsCoordinateReferenceSystem() );
+%Docstring
+ Combines the extent of several map ``layers``. If specified, the target ``crs``
+ will be used to transform the layer's extent to the desired output reference system.
+ :rtype: QgsRectangle
+%End
 
 };
 

python/plugins/processing/algs/gdal/ClipByExtent.py

@@ -88,6 +88,9 @@ def getConsoleCommands(self, parameters):
         noData = self.getParameterValue(self.NO_DATA)
         opts = self.getParameterValue(self.OPTIONS)
         projwin = self.getParameterValue(self.PROJWIN)
+        layer = self.getParameterValue(self.INPUT)
+        if not projwin:
+            projwin = QgsProcessingUtils.combineLayerExtents([layer])
 
         if noData is not None:
             noData = str(noData)

python/plugins/processing/algs/gdal/ogr2ogrclipextent.py

@@ -69,6 +69,8 @@ def getConsoleCommands(self, parameters):
         inLayer = self.getParameterValue(self.INPUT_LAYER)
         ogrLayer = ogrConnectionString(inLayer)[1:-1]
         clipExtent = self.getParameterValue(self.CLIP_EXTENT)
+        if not clipExtent:
+            clipExtent = QgsProcessingUtils.combineLayerExtents([inLayer])
 
         output = self.getOutputFromName(self.OUTPUT_LAYER)
         outFile = output.value

python/plugins/processing/algs/gdal/ogr2ogrtopostgis.py

@@ -203,6 +203,8 @@ def getConsoleCommands(self, parameters):
         simplify = str(self.getParameterValue(self.SIMPLIFY))
         segmentize = str(self.getParameterValue(self.SEGMENTIZE))
         spat = self.getParameterValue(self.SPAT)
+        if not spat:
+            spat = QgsProcessingUtils.combineLayerExtents([inLayer])
         clip = self.getParameterValue(self.CLIP)
         where = str(self.getParameterValue(self.WHERE))
         wherestring = '-where "' + where + '"'

python/plugins/processing/algs/gdal/ogr2ogrtopostgislist.py

@@ -205,6 +205,8 @@ def getConsoleCommands(self, parameters):
         simplify = self.getParameterValue(self.SIMPLIFY)
         segmentize = self.getParameterValue(self.SEGMENTIZE)
         spat = self.getParameterValue(self.SPAT)
+        if not spat:
+            spat = QgsProcessingUtils.combineLayerExtents([inLayer])
         clip = self.getParameterValue(self.CLIP)
         where = self.getParameterValue(self.WHERE)
         gt = self.getParameterValue(self.GT)

python/plugins/processing/algs/gdal/rasterize.py

@@ -106,6 +106,8 @@ def getConsoleCommands(self, parameters):
         inLayer = self.getParameterValue(self.INPUT)
         noData = self.getParameterValue(self.NO_DATA)
         rastext = str(self.getParameterValue(self.RAST_EXT))
+        if not rastext:
+            rastext = QgsProcessingUtils.combineLayerExtents([inLayer])
         opts = self.getParameterValue(self.OPTIONS)
         out = self.getOutputValue(self.OUTPUT)
 

python/plugins/processing/algs/gdal/translate.py

@@ -104,12 +104,15 @@ def group(self):
         return self.tr('Raster conversion')
 
     def getConsoleCommands(self, parameters):
+        inLayer = self.getParameterValue(self.INPUT)
         out = self.getOutputValue(translate.OUTPUT)
         outsize = str(self.getParameterValue(self.OUTSIZE))
         outsizePerc = str(self.getParameterValue(self.OUTSIZE_PERC))
         noData = self.getParameterValue(self.NO_DATA)
         expand = self.getParameterFromName(self.EXPAND).options[self.getParameterValue(self.EXPAND)][1]
         projwin = str(self.getParameterValue(self.PROJWIN))
+        if not projwin:
+            projwin = QgsProcessingUtils.combineLayerExtents([inLayer])
         crsId = self.getParameterValue(self.SRS)
         sds = self.getParameterValue(self.SDS)
         opts = self.getParameterValue(self.OPTIONS)

python/plugins/processing/algs/gdal/warp.py

@@ -122,10 +122,13 @@ def group(self):
         return self.tr('Raster projections')
 
     def getConsoleCommands(self, parameters):
+        inLayer = self.getParameterValue(self.INPUT)
         srccrs = self.getParameterValue(self.SOURCE_SRS)
         dstcrs = self.getParameterValue(self.DEST_SRS)
         useRasterExtent = self.getParameterValue(self.USE_RASTER_EXTENT)
         rasterExtent = self.getParameterValue(self.RASTER_EXTENT)
+        if not rasterExtent:
+            rasterExtent = QgsProcessingUtils.combineLayerExtents([inLayer])
         extentCrs = self.getParameterValue(self.EXTENT_CRS)
         opts = self.getParameterValue(self.OPTIONS)
         noData = self.getParameterValue(self.NO_DATA)

python/plugins/processing/algs/grass7/Grass7Algorithm.py

@@ -371,6 +371,9 @@ def processInputs(self):
 
         region = \
             str(self.getParameterValue(self.GRASS_REGION_EXTENT_PARAMETER))
+        if not region:
+            region = QgsProcessingUtils.combineLayerExtents(layers)
+
         regionCoords = region.split(',')
         command = 'g.region'
         command += ' n=' + str(regionCoords[3])

python/plugins/processing/algs/grass7/nviz7.py

@@ -102,6 +102,9 @@ def processAlgorithm(self, parameters, context, feedback):
 
         region = \
             str(self.getParameterValue(self.GRASS_REGION_EXTENT_PARAMETER))
+        if not region:
+            region = QgsProcessingUtils.combineLayerExtents(layers)
+
         regionCoords = region.split(',')
         command = 'g.region '
         command += 'n=' + str(regionCoords[3])

python/plugins/processing/algs/qgis/FindProjection.py

@@ -87,6 +87,8 @@ def processAlgorithm(self, parameters, context, feedback):
         layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT_LAYER), context)
 
         extent = self.getParameterValue(self.TARGET_AREA).split(',')
+        if not extent:
+            extent = QgsProcessingUtils.combineLayerExtents([layer])
         target_crs = QgsCoordinateReferenceSystem(self.getParameterValue(self.TARGET_AREA_CRS))
 
         target_geom = QgsGeometry.fromRect(QgsRectangle(float(extent[0]), float(extent[2]),

python/plugins/processing/algs/qgis/RasterCalculator.py

@@ -127,6 +127,8 @@ def processAlgorithm(self, parameters, context, feedback):
 
         output = self.getOutputValue(self.OUTPUT)
         extentValue = self.getParameterValue(self.EXTENT)
+        if not extentValue:
+            extentValue = QgsProcessingUtils.combineLayerExtents(layersValue)
 
         if extentValue:
             extent = extentValue.split(',')

python/plugins/processing/algs/saga/SagaAlgorithm.py

@@ -204,6 +204,10 @@ def processAlgorithm(self, parameters, context, feedback):
                             raise GeoAlgorithmExecutionException(
                                 self.tr('Unsupported file format'))
 
+        # TODO - set minimum extent
+        if not extent:
+            extent = QgsProcessingUtils.combineLayerExtents([layer])
+
         # 2: Set parameters and outputs
         command = self.undecoratedGroup + ' "' + self.cmdname + '"'
         command += ' ' + ' '.join(self.hardcodedStrings)

python/plugins/processing/core/parameters.py

@@ -42,6 +42,7 @@
 from qgis.core import (QgsRasterLayer, QgsVectorLayer, QgsMapLayer, QgsCoordinateReferenceSystem,
                        QgsExpressionContext, QgsExpressionContextUtils, QgsExpression, QgsExpressionContextScope,
                        QgsProject,
+                       QgsRectangle,
                        QgsVectorFileWriter,
                        QgsProcessingParameterDefinition)
 
@@ -356,52 +357,6 @@ def fromScriptCode(self, line):
             default = definition.strip()[len('extent') + 1:] or None
             return ParameterExtent(name, descName, default, isOptional)
 
-    def evaluate(self, alg):
-        if self.flags() & QgsProcessingParameterDefinition.FlagOptional and not bool(self.value):
-            self.value = self.getMinCoveringExtent(alg)
-
-    def getMinCoveringExtent(self, alg):
-        first = True
-        found = False
-        context = dataobjects.createContext()
-        for param in alg.parameters:
-            if param.value:
-                if isinstance(param, (ParameterRaster, ParameterVector)):
-                    if isinstance(param.value, (QgsRasterLayer,
-                                                QgsVectorLayer)):
-                        layer = param.value
-                    else:
-                        layer = QgsProcessingUtils.mapLayerFromString(param.value, context)
-                    if layer:
-                        found = True
-                        self.addToRegion(layer, first)
-                        first = False
-                elif isinstance(param, ParameterMultipleInput):
-                    layers = param.value.split(';')
-                    for layername in layers:
-                        layer = QgsProcessingUtils.mapLayerFromString(layername, context)
-                        if layer:
-                            found = True
-                            self.addToRegion(layer, first)
-                            first = False
-        if found:
-            return '{},{},{},{}'.format(
-                self.xmin, self.xmax, self.ymin, self.ymax)
-        else:
-            return None
-
-    def addToRegion(self, layer, first):
-        if first:
-            self.xmin = layer.extent().xMinimum()
-            self.xmax = layer.extent().xMaximum()
-            self.ymin = layer.extent().yMinimum()
-            self.ymax = layer.extent().yMaximum()
-        else:
-            self.xmin = min(self.xmin, layer.extent().xMinimum())
-            self.xmax = max(self.xmax, layer.extent().xMaximum())
-            self.ymin = min(self.ymin, layer.extent().yMinimum())
-            self.ymax = max(self.ymax, layer.extent().yMaximum())
-
 
 class ParameterPoint(Parameter):
 

src/core/processing/qgsprocessingutils.cpp

@@ -18,6 +18,7 @@
 #include "qgsprocessingutils.h"
 #include "qgsproject.h"
 #include "qgssettings.h"
+#include "qgscsexception.h"
 #include "qgsprocessingcontext.h"
 #include "qgsvectorlayerexporter.h"
 #include "qgsvectorfilewriter.h"
@@ -400,3 +401,37 @@ void QgsProcessingUtils::createFeatureSinkPython( QgsFeatureSink **sink, QString
 }
 
 
+QgsRectangle QgsProcessingUtils::combineLayerExtents( const QList<QgsMapLayer *> layers, const QgsCoordinateReferenceSystem &crs )
+{
+  QgsRectangle extent;
+  Q_FOREACH ( QgsMapLayer *layer, layers )
+  {
+    if ( !layer )
+      continue;
+
+    if ( crs.isValid() )
+    {
+      //transform layer extent to target CRS
+      QgsCoordinateTransform ct( layer->crs(), crs );
+      try
+      {
+        QgsRectangle reprojExtent = ct.transformBoundingBox( layer->extent() );
+        extent.combineExtentWith( reprojExtent );
+      }
+      catch ( QgsCsException & )
+      {
+        // can't reproject... what to do here? hmmm?
+        // let's ignore this layer for now, but maybe we should just use the original extent?
+      }
+    }
+    else
+    {
+      extent.combineExtentWith( layer->extent() );
+    }
+
+  }
+  return extent;
+}
+
+
+

src/core/processing/qgsprocessingutils.h

@@ -180,6 +180,11 @@ class CORE_EXPORT QgsProcessingUtils
       const QgsCoordinateReferenceSystem &crs,
       QgsProcessingContext &context ) SIP_PYNAME( createFeatureSink );
 
+    /**
+     * Combines the extent of several map \a layers. If specified, the target \a crs
+     * will be used to transform the layer's extent to the desired output reference system.
+     */
+    static QgsRectangle combineLayerExtents( const QList< QgsMapLayer *> layers, const QgsCoordinateReferenceSystem &crs = QgsCoordinateReferenceSystem() );
 
   private:
 

tests/src/core/testqgsprocessing.cpp

@@ -216,6 +216,7 @@ class TestQgsProcessing: public QObject
     void parameterVectorLayer();
     void parameterOutputVectorLayer();
     void checkParamValues();
+    void combineLayerExtent();
 
   private:
 
@@ -2181,5 +2182,39 @@ void TestQgsProcessing::checkParamValues()
   a.checkParameterVals();
 }
 
+void TestQgsProcessing::combineLayerExtent()
+{
+  QgsRectangle ext = QgsProcessingUtils::combineLayerExtents( QList< QgsMapLayer *>() );
+  QVERIFY( ext.isNull() );
+
+  QString testDataDir = QStringLiteral( TEST_DATA_DIR ) + '/'; //defined in CmakeLists.txt
+
+  QString raster1 = testDataDir + "tenbytenraster.asc";
+  QString raster2 = testDataDir + "landsat.tif";
+  QFileInfo fi1( raster1 );
+  QgsRasterLayer *r1 = new QgsRasterLayer( fi1.filePath(), "R1" );
+  QFileInfo fi2( raster2 );
+  QgsRasterLayer *r2 = new QgsRasterLayer( fi2.filePath(), "R2" );
+
+  ext = QgsProcessingUtils::combineLayerExtents( QList< QgsMapLayer *>() << r1 );
+  QGSCOMPARENEAR( ext.xMinimum(), 1535375.000000, 10 );
+  QGSCOMPARENEAR( ext.xMaximum(), 1535475, 10 );
+  QGSCOMPARENEAR( ext.yMinimum(), 5083255, 10 );
+  QGSCOMPARENEAR( ext.yMaximum(), 5083355, 10 );
+
+  ext = QgsProcessingUtils::combineLayerExtents( QList< QgsMapLayer *>() << r1 << r2 );
+  QGSCOMPARENEAR( ext.xMinimum(), 781662, 10 );
+  QGSCOMPARENEAR( ext.xMaximum(), 1535475, 10 );
+  QGSCOMPARENEAR( ext.yMinimum(), 3339523, 10 );
+  QGSCOMPARENEAR( ext.yMaximum(), 5083355, 10 );
+
+  // with reprojection
+  ext = QgsProcessingUtils::combineLayerExtents( QList< QgsMapLayer *>() << r1 << r2, QgsCoordinateReferenceSystem::fromEpsgId( 3785 ) );
+  QGSCOMPARENEAR( ext.xMinimum(), 1995320, 10 );
+  QGSCOMPARENEAR( ext.xMaximum(), 2008833, 10 );
+  QGSCOMPARENEAR( ext.yMinimum(), 3523084, 10 );
+  QGSCOMPARENEAR( ext.yMaximum(), 3536664, 10 );
+}
+
 QGSTEST_MAIN( TestQgsProcessing )
 #include "testqgsprocessing.moc"