QGIS/python/plugins/processing/parameters/ParameterMultipleInput.py

# -*- coding: utf-8 -*-

"""
***************************************************************************
    ParameterMultipleInput.py
    ---------------------
    Date                 : August 2012
    Copyright            : (C) 2012 by Victor Olaya
    Email                : volayaf at gmail 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__ = 'Victor Olaya'
__date__ = 'August 2012'
__copyright__ = '(C) 2012, Victor Olaya'

# This will get replaced with a git SHA1 when you do a git archive

__revision__ = '$Format:%H$'

from qgis.core import *
from processing.parameters.ParameterDataObject import ParameterDataObject
from processing.tools import dataobjects


class ParameterMultipleInput(ParameterDataObject):
    """A parameter representing several data objects.

    Its value is a string with substrings separated by semicolons,
    each of which represents the data source location of each element.
    """

    exported = None

    TYPE_VECTOR_ANY = -1
    TYPE_VECTOR_POINT = 0
    TYPE_VECTOR_LINE = 1
    TYPE_VECTOR_POLYGON = 2
    TYPE_RASTER = 3

    def __init__(self, name='', description='', datatype=-1, optional=False):
        ParameterDataObject.__init__(self, name, description)
        self.datatype = datatype
        self.optional = optional
        self.value = None
        self.exported = None

    def setValue(self, obj):
        self.exported = None
        if obj is None:
            if self.optional:
                self.value = None
                return True
            else:
                return False

        if isinstance(obj, list):
            if len(obj) == 0:
                if self.optional:
                    return True
                else:
                    return False
            s = ''
            idx = 0
            for layer in obj:
                s += self.getAsString(layer)
                if idx < len(obj) - 1:
                    s += ';'
                    idx = idx + 1
            self.value = s
            return True
        else:
            self.value = unicode(obj)
            return True

    def getSafeExportedLayers(self):
        """Returns not the value entered by the user, but a string with
        semicolon-separated filenames which contains the data of the
        selected layers, but saved in a standard format (currently
        shapefiles for vector layers and GeoTiff for raster) so that
        they can be opened by most external applications.

        If there is a selection and QGIS is configured to use just the
        selection, if exports the layer even if it is already in a
        suitable format.

        Works only if the layer represented by the parameter value is
        currently loaded in QGIS. Otherwise, it will not perform any
        export and return the current value string.

        If the current value represents a layer in a suitable format,
        it does no export at all and returns that value.

        Currently, it works just for vector layer. In the case of
        raster layers, it returns the parameter value.

        The layers are exported just the first time the method is
        called. The method can be called several times and it will
        always return the same string, performing the export only the
        first time.
        """

        if self.exported:
            return self.exported
        self.exported = self.value
        layers = self.value.split(';')
        if layers is None or len(layers) == 0:
            return self.value
        if self.datatype == ParameterMultipleInput.TYPE_RASTER:
            for layerfile in layers:
                layer = dataobjects.getObjectFromUri(layerfile, False)
                if layer:
                    filename = dataobjects.exportRasterLayer(layer)
                    self.exported = self.exported.replace(layerfile, filename)
            return self.exported
        else:
            for layerfile in layers:
                layer = dataobjects.getObjectFromUri(layerfile, False)
                if layer:
                    filename = dataobjects.exportVectorLayer(layer)
                    self.exported = self.exported.replace(layerfile, filename)
            return self.exported

    def getAsString(self, value):
        if self.datatype == ParameterMultipleInput.TYPE_RASTER:
            if isinstance(value, QgsRasterLayer):
                return unicode(value.dataProvider().dataSourceUri())
            else:
                s = unicode(value)
                layers = dataobjects.getRasterLayers()
                for layer in layers:
                    if layer.name() == s:
                        return unicode(layer.dataProvider().dataSourceUri())
                return s
        else:
            if isinstance(value, QgsVectorLayer):
                return unicode(value.source())
            else:
                s = unicode(value)
                layers = dataobjects.getVectorLayers(self.datatype)
                for layer in layers:
                    if layer.name() == s:
                        return unicode(layer.source())
                return s

    def getFileFilter(self):
        if self.datatype == ParameterMultipleInput.TYPE_RASTER:
            exts = dataobjects.getSupportedOutputRasterLayerExtensions()
        else:
            exts = dataobjects.getSupportedOutputVectorLayerExtensions()
        for i in range(len(exts)):
            exts[i] = exts[i].upper() + ' files(*.' + exts[i].lower() + ')'
        return ';;'.join(exts)

    def serialize(self):
        return self.__module__.split('.')[-1] + '|' + self.name + '|' \
            + self.description + '|' + str(self.datatype) + '|' \
            + str(self.optional)

    def deserialize(self, s):
        tokens = s.split('|')
        return ParameterMultipleInput(tokens[1], tokens[2], float(tokens[3]),
                                      tokens[4] == str(True))

    def getAsScriptCode(self):
        if self.datatype == ParameterMultipleInput.TYPE_RASTER:
            return '##' + self.name + '=multiple raster'
        else:
            return '##' + self.name + '=multiple vector'