[Processing] Add GDAL build virtual raster alg - part 2.

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

@@ -0,0 +1,82 @@
+# -*- coding: utf-8 -*-
+
+"""
+***************************************************************************
+    merge.py
+    ---------------------
+    Date                 : October 2014
+    Copyright            : (C) 2014 by Radoslaw Guzinski
+    Email                : rmgu at dhi-gras dot 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.                                   *
+*                                                                         *
+***************************************************************************
+"""
+
+__author__ = 'Radoslaw Guzinski'
+__date__ = 'October 2014'
+__copyright__ = '(C) 2014, Radoslaw Guzinski'
+
+# This will get replaced with a git SHA1 when you do a git archive
+
+__revision__ = '$Format:%H$'
+
+
+from processing.algs.gdal.GdalAlgorithm import GdalAlgorithm
+from processing.core.outputs import OutputRaster
+from processing.core.parameters import ParameterBoolean
+from processing.core.parameters import ParameterMultipleInput
+from processing.core.parameters import ParameterSelection
+from processing.tools.system import *
+from processing.algs.gdal.GdalUtils import GdalUtils
+import os
+
+class buildvrt(GdalAlgorithm):
+
+    INPUT = 'INPUT'
+    OUTPUT = 'OUTPUT'
+    RESOLUTION = 'RESOLUTION'
+    SEPARATE = 'SEPARATE'
+    PROJ_DIFFERENCE = 'PROJ_DIFFERENCE'
+
+    RESOLUTION_OPTIONS = ['average', 'highest', 'lowest']
+
+    def defineCharacteristics(self):
+        self.name = 'Build Virtual Raster'
+        self.group = '[GDAL] Miscellaneous'
+        self.addParameter(ParameterMultipleInput(buildvrt.INPUT, 'Input layers', ParameterMultipleInput.TYPE_RASTER))
+        self.addParameter(ParameterSelection(buildvrt.RESOLUTION, 'Resolution', buildvrt.RESOLUTION_OPTIONS, 0))
+        self.addParameter(ParameterBoolean(buildvrt.SEPARATE, 'Layer stack', True))
+        self.addParameter(ParameterBoolean(buildvrt.PROJ_DIFFERENCE, 'Allow projection difference', False))
+        self.addOutput(OutputRaster(buildvrt.OUTPUT, 'Output layer'))
+
+    def processAlgorithm(self, progress):
+        arguments = []
+        arguments.append('-resolution')
+        arguments.append(self.RESOLUTION_OPTIONS[self.getParameterValue(self.RESOLUTION)])
+        if self.getParameterValue(buildvrt.SEPARATE):
+            arguments.append('-separate')
+        if self.getParameterValue(buildvrt.PROJ_DIFFERENCE):
+            arguments.append('-allow_projection_difference')
+        # Always write input files to a text file in case there are many of them and the
+        # length of the command will be longer then allowed in command prompt
+        listFile = os.path.join(tempFolder(), 'buildvrtInputFiles.txt')
+        with open(listFile, 'w') as f:
+            f.write(self.getParameterValue(buildvrt.INPUT).replace(';', '\n'))
+        arguments.append('-input_file_list')
+        arguments.append(listFile)
+        out = self.getOutputValue(buildvrt.OUTPUT)
+        # Ideally the file extensions should be limited to just .vrt but I'm not sure how
+        # to do it simply so instead a check is performed.
+        _, ext = os.path.splitext(out)
+        if not ext.lower() == '.vrt':
+            out = out.replace(ext, '.vrt')
+            self.setOutputValue(self.OUTPUT, out)
+        arguments.append(out)
+
+
+        GdalUtils.runGdal(['gdalbuildvrt', GdalUtils.escapeAndJoin(arguments)], progress)