def helpFile(self):
     folder = GrassUtils.grassHelpPath()
     helpfile = str(folder) + os.sep + self.grassName + ".html"
     if os.path.exists(helpfile):
         return helpfile
     else:
         raise WrongHelpFileException("Grass help folder is not correctly configured.\nPlease configure it")

 def checkBeforeOpeningParametersDialog(self):
     msg = GrassUtils.checkGrassIsInstalled()
     if msg is not None:
         html = ("<p>This algorithm requires GRASS to be run."
         "Unfortunately, it seems that GRASS is not installed in your system, or it is not correctly configured to be used from QGIS</p>")
         html += '<p><a href= "http://docs.qgis.org/html/en/docs/user_manual/sextante/3rdParty.html">Click here</a> to know more about how to install and configure GRASS to be used with SEXTANTE</p>'
         return html

    def getPostProcessingErrorMessage(self, wrongLayers):
        html = AlgorithmProvider.getPostProcessingErrorMessage(self, wrongLayers)
        msg = GrassUtils.checkGrassIsInstalled(True)
        html += ("<p>This algorithm requires GRASS to be run. A test to check if GRASS is correctly installed "
                "and configured in your system has been performed, with the following result:</p><ul><i>")
        if msg is None:
            html += "GRASS seems to be correctly installed and configured</li></ul>"
        else:
            html += msg + "</i></li></ul>"
            html += '<p><a href= "http://docs.qgis.org/2.0/html/en/docs/user_manual/sextante/3rdParty.html">Click here</a> to know more about how to install and configure GRASS to be used with SEXTANTE</p>'

        return html

 def createAlgsList(self):
     self.preloadedAlgs = []
     folder = GrassUtils.grassDescriptionPath()
     for descriptionFile in os.listdir(folder):
         if descriptionFile.endswith("txt"):
             try:
                 alg = GrassAlgorithm(os.path.join(folder, descriptionFile))
                 if alg.name.strip() != "":
                     self.preloadedAlgs.append(alg)
                 else:
                     SextanteLog.addToLog(SextanteLog.LOG_ERROR, "Could not open GRASS algorithm: " + descriptionFile)
             except Exception,e:
                 SextanteLog.addToLog(SextanteLog.LOG_ERROR, "Could not open GRASS algorithm: " + descriptionFile)

 def processAlgorithm(self, progress):
     commands = []
     command = "nviz"
     vector = self.getParameterValue(self.VECTOR);
     elevation = self.getParameterValue(self.ELEVATION);
     if vector:
         layers = vector.split(";")
         for layer in layers:
             newfilename = self.exportVectorLayer(layer)
             vector = vector.replace(layer, newfilename)
         command += (" vector=" + vector.replace(";", ","))
     if elevation:
         layers = elevation.split(";")
         for layer in layers:
             newfilename = self.exportRasterLayer(layer)
             elevation = elevation.replace(layer, newfilename)
         command += (" elevation=" + elevation.replace(";", ","))
     if elevation is None and vector is None:
         command += " -q"
     commands.append(command)
     GrassUtils.createTempMapset();
     GrassUtils.executeGrass(commands, progress)

    def processAlgorithm(self, progress):
        commands = []
        vector = self.getParameterValue(self.VECTOR);
        elevation = self.getParameterValue(self.ELEVATION);

        region = str(self.getParameterValue(self.GRASS_REGION_EXTENT_PARAMETER))
        regionCoords = region.split(",")
        command = "g.region "
        command += "n=" + str(regionCoords[3])
        command +=" s=" + str(regionCoords[2])
        command +=" e=" + str(regionCoords[1])
        command +=" w=" + str(regionCoords[0])
        cellsize = self.getParameterValue(self.GRASS_REGION_CELLSIZE_PARAMETER)
        if cellsize:
            command +=" res=" + str(cellsize);
        else:
            command +=" res=" + str(self.getDefaultCellsize())
        commands.append(command)

        command = "nviz"
        if vector:
            layers = vector.split(";")
            for layer in layers:
                cmd, newfilename = self.exportVectorLayer(layer)
                commands.append(cmd)
                vector = vector.replace(layer, newfilename)
            command += (" vector=" + vector.replace(";", ","))
        if elevation:
            layers = elevation.split(";")
            for layer in layers:
                cmd, newfilename = self.exportRasterLayer(layer)
                commands.append(cmd)
                elevation = elevation.replace(layer, newfilename)
            command += (" elevation=" + elevation.replace(";", ","))
        if elevation is None and vector is None:
            command += " -q"
        commands.append(command)
        GrassUtils.createTempMapset();
        GrassUtils.executeGrass(commands, progress)

    def processAlgorithm(self, progress):
        if SextanteUtils.isWindows():
            path = GrassUtils.grassPath()
            if path == "":
                raise GeoAlgorithmExecutionException("GRASS folder is not configured.\nPlease configure it before running GRASS algorithms.")

        commands = []
        self.exportedLayers = {}

        #self.calculateRegion()
        region = str(self.getParameterValue(self.GRASS_REGION_EXTENT_PARAMETER))
        regionCoords = region.split(",")
        GrassUtils.createTempMapset();

        command = "g.region"
        command += " n=" + str(regionCoords[3])
        command +=" s=" + str(regionCoords[2])
        command +=" e=" + str(regionCoords[1])
        command +=" w=" + str(regionCoords[0])
        command +=" res=" + str(self.getParameterValue(self.GRASS_REGION_CELLSIZE_PARAMETER));
        commands.append(command)

        #1: Export layer to grass mapset
        for param in self.parameters:
            if isinstance(param, ParameterRaster):
                if param.value == None:
                    continue
                value = param.value
                commands.append(self.exportRasterLayer(value))
            if isinstance(param, ParameterVector):
                if param.value == None:
                    continue
                value = param.value
                commands.append(self.exportVectorLayer(value))
            if isinstance(param, ParameterTable):
                pass
            if isinstance(param, ParameterMultipleInput):
                if param.value == None:
                    continue
                layers = param.value.split(";")
                if layers == None or len(layers) == 0:
                    continue
                if param.datatype == ParameterMultipleInput.TYPE_RASTER:
                    for layer in layers:
                        commands.append(self.exportRasterLayer(layer))
                elif param.datatype == ParameterMultipleInput.TYPE_VECTOR_ANY:
                    for layer in layers:
                        commands.append(self.exportVectorLayer(layer))

        #2: set parameters and outputs
        command = self.grassName
        for param in self.parameters:
            if param.value == None:
                continue
            if param.name == self.GRASS_REGION_CELLSIZE_PARAMETER or param.name == self.GRASS_REGION_EXTENT_PARAMETER:
                continue
            if isinstance(param, (ParameterRaster, ParameterVector)):
                value = param.value
                if value in self.exportedLayers.keys():
                    command+=(" " + param.name + "=" + self.exportedLayers[value])
                else:
                    command+=(" " + param.name + "=" + value)
            elif isinstance(param, ParameterMultipleInput):
                s = param.value
                for layer in self.exportedLayers.keys():
                    s = s.replace(layer, self.exportedLayers[layer])
                s = s.replace(";",",")
                command+=(" " + param.name + "=" + s);
            elif isinstance(param, ParameterBoolean):
                if param.value:
                    command += (" " + param.name)
            elif isinstance(param, ParameterSelection):
                idx = int(param.value)
                command+=(" " + param.name + "=" + str(param.options[idx]));
            else:
                command+=(" " + param.name + "=" + str(param.value));

        for out in self.outputs:
            if isinstance(out, OutputFile):
                command+=(" " + out.name + "=\"" + out.value + "\"");
            else:
                command+=(" " + out.name + "=" + out.name);

        command += " --overwrite"
        commands.append(command)

        #3:Export resulting layers to a format that qgis can read
        for out in self.outputs:
            if isinstance(out, OutputRaster):
                filename = out.value
                #Raster layer output: adjust region to layer before exporting
                commands.append("g.region rast=" + out.name)
                command = "r.out.gdal -c createopt=\"TFW=YES,COMPRESS=LZW\""
                command += " input="
                command += out.name
                command += " output=\"" + filename + "\""
                commands.append(command)
            if isinstance(out, OutputVector):
                command = "v.out.ogr -ce input=" + out.name
                command += " dsn=\"" + os.path.dirname(out.value) + "\""
#.........这里部分代码省略.........

 def initializeSettings(self):
     AlgorithmProvider.initializeSettings(self)
     if SextanteUtils.isWindows() or SextanteUtils.isMac():
         SextanteConfig.addSetting(Setting(self.getDescription(), GrassUtils.GRASS_FOLDER, "GRASS folder", GrassUtils.grassPath()))
         SextanteConfig.addSetting(Setting(self.getDescription(), GrassUtils.GRASS_WIN_SHELL, "Msys folder", GrassUtils.grassWinShell()))
     SextanteConfig.addSetting(Setting(self.getDescription(), GrassUtils.GRASS_LOG_COMMANDS, "Log execution commands", False))
     SextanteConfig.addSetting(Setting(self.getDescription(), GrassUtils.GRASS_LOG_CONSOLE, "Log console output", False))
     SextanteConfig.addSetting(Setting(self.getDescription(), GrassUtils.GRASS_LATLON, "Coordinates are lat/lon", False))
     SextanteConfig.addSetting(Setting(self.getDescription(), GrassUtils.GRASS_HELP_FOLDER, "GRASS help folder", GrassUtils.grassHelpPath()))

    def processAlgorithm(self, progress):
        if SextanteUtils.isWindows():
            path = GrassUtils.grassPath()
            if path == "":
                raise GeoAlgorithmExecutionException("GRASS folder is not configured.\nPlease configure it before running GRASS algorithms.")

        commands = []
        self.exportedLayers = {}
        outputCommands = []

        # if GRASS session has been created outside of this algorithm then get the list of layers loaded in GRASS
        # otherwise start a new session
        existingSession = GrassUtils.sessionRunning
        if existingSession:
            self.exportedLayers = GrassUtils.getSessionLayers()
        else:
            GrassUtils.startGrassSession()


        #1: Export layer to grass mapset
        for param in self.parameters:
            if isinstance(param, ParameterRaster):
                if param.value == None:
                    continue
                value = param.value
                # check if the layer hasn't already been exported in, for example, previous GRASS calls in this session
                if value in self.exportedLayers.keys():
                    continue
                else:
                    self.setSessionProjectionFromLayer(value, commands)
                    commands.append(self.exportRasterLayer(value))
            if isinstance(param, ParameterVector):
                if param.value == None:
                    continue
                value = param.value
                if value in self.exportedLayers.keys():
                    continue
                else:
                    self.setSessionProjectionFromLayer(value, commands)
                    commands.append(self.exportVectorLayer(value))
            if isinstance(param, ParameterTable):
                pass
            if isinstance(param, ParameterMultipleInput):
                if param.value == None:
                    continue
                layers = param.value.split(";")
                if layers == None or len(layers) == 0:
                    continue
                if param.datatype == ParameterMultipleInput.TYPE_RASTER:
                    for layer in layers:
                        if layer in self.exportedLayers.keys():
                            continue
                        else:
                            self.setSessionProjectionFromLayer(layer, commands)
                            commands.append(self.exportRasterLayer(layer))
                elif param.datatype == ParameterMultipleInput.TYPE_VECTOR_ANY:
                    for layer in layers:
                        if layer in self.exportedLayers.keys():
                            continue
                        else:
                            self.setSessionProjectionFromLayer(layer, commands)
                            commands.append(self.exportVectorLayer(layer))

        self.setSessionProjectionFromProject(commands)

        region = str(self.getParameterValue(self.GRASS_REGION_EXTENT_PARAMETER))
        regionCoords = region.split(",")
        command = "g.region"
        command += " n=" + str(regionCoords[3])
        command +=" s=" + str(regionCoords[2])
        command +=" e=" + str(regionCoords[1])
        command +=" w=" + str(regionCoords[0])
        cellsize = self.getParameterValue(self.GRASS_REGION_CELLSIZE_PARAMETER)
        if cellsize:
            command +=" res=" + str(cellsize);
        else:
            command +=" res=" + str(self.getDefaultCellsize())

        commands.append(command)

        #2: set parameters and outputs
        command = self.grassName
        for param in self.parameters:
            if param.value == None or param.value == "":
                continue
            if (param.name == self.GRASS_REGION_CELLSIZE_PARAMETER or param.name == self.GRASS_REGION_EXTENT_PARAMETER 
                    or param.name == self.GRASS_MIN_AREA_PARAMETER or param.name == self.GRASS_SNAP_TOLERANCE_PARAMETER):
                continue
            if isinstance(param, (ParameterRaster, ParameterVector)):
                value = param.value
                if value in self.exportedLayers.keys():
                    command+=(" " + param.name + "=" + self.exportedLayers[value])
                else:
                    command+=(" " + param.name + "=" + value)
            elif isinstance(param, ParameterMultipleInput):
                s = param.value
                for layer in self.exportedLayers.keys():
                    s = s.replace(layer, self.exportedLayers[layer])
                s = s.replace(";",",")
                command+=(" " + param.name + "=" + s);
#.........这里部分代码省略.........