def setupUi(self):
        self.labels = {}
        self.widgets = {}
        self.checkBoxes = {}
        self.showAdvanced = False
        self.valueItems = {}
        self.dependentItems = {}
        self.resize(650, 450)
        self.buttonBox = QDialogButtonBox()
        self.buttonBox.setOrientation(Qt.Horizontal)
        self.buttonBox.setStandardButtons(QDialogButtonBox.Cancel
                                          | QDialogButtonBox.Ok)
        tooltips = self._alg.getParameterDescriptions()
        self.setSizePolicy(QSizePolicy.Expanding, QSizePolicy.Expanding)
        self.verticalLayout = QVBoxLayout()
        self.verticalLayout.setSpacing(5)
        self.verticalLayout.setMargin(20)

        hLayout = QHBoxLayout()
        hLayout.setSpacing(5)
        hLayout.setMargin(0)
        descriptionLabel = QLabel(self.tr("Description"))
        self.descriptionBox = QLineEdit()
        self.descriptionBox.setText(self._alg.name)
        hLayout.addWidget(descriptionLabel)
        hLayout.addWidget(self.descriptionBox)
        self.verticalLayout.addLayout(hLayout)
        line = QFrame()
        line.setFrameShape(QFrame.HLine)
        line.setFrameShadow(QFrame.Sunken)
        self.verticalLayout.addWidget(line)

        for param in self._alg.parameters:
            if param.isAdvanced:
                self.advancedButton = QPushButton()
                self.advancedButton.setText(
                    self.tr('Show advanced parameters'))
                self.advancedButton.clicked.connect(
                    self.showAdvancedParametersClicked)
                advancedButtonHLayout = QHBoxLayout()
                advancedButtonHLayout.addWidget(self.advancedButton)
                advancedButtonHLayout.addStretch()
                self.verticalLayout.addLayout(advancedButtonHLayout)
                break
        for param in self._alg.parameters:
            if param.hidden:
                continue
            desc = param.description
            if isinstance(param, ParameterExtent):
                desc += self.tr('(xmin, xmax, ymin, ymax)')
            if isinstance(param, ParameterPoint):
                desc += self.tr('(x, y)')
            label = QLabel(desc)
            self.labels[param.name] = label
            widget = self.getWidgetFromParameter(param)
            self.valueItems[param.name] = widget
            if param.name in tooltips.keys():
                tooltip = tooltips[param.name]
            else:
                tooltip = param.description
            label.setToolTip(tooltip)
            widget.setToolTip(tooltip)
            if param.isAdvanced:
                label.setVisible(self.showAdvanced)
                widget.setVisible(self.showAdvanced)
                self.widgets[param.name] = widget
            self.verticalLayout.addWidget(label)
            self.verticalLayout.addWidget(widget)

        for output in self._alg.outputs:
            if output.hidden:
                continue
            if isinstance(output, (OutputRaster, OutputVector, OutputTable,
                                   OutputHTML, OutputFile, OutputDirectory)):
                label = QLabel(output.description + '<' +
                               output.__class__.__name__ + '>')
                item = QLineEdit()
                if hasattr(item, 'setPlaceholderText'):
                    item.setPlaceholderText(ModelerParametersDialog.ENTER_NAME)
                self.verticalLayout.addWidget(label)
                self.verticalLayout.addWidget(item)
                self.valueItems[output.name] = item

        label = QLabel(' ')
        self.verticalLayout.addWidget(label)
        label = QLabel(self.tr('Parent algorithms'))
        self.dependenciesPanel = self.getDependenciesPanel()
        self.verticalLayout.addWidget(label)
        self.verticalLayout.addWidget(self.dependenciesPanel)

        self.verticalLayout.addStretch(1000)
        self.setLayout(self.verticalLayout)

        self.setPreviousValues()
        self.setWindowTitle(self._alg.name)
        self.verticalLayout2 = QVBoxLayout()
        self.verticalLayout2.setSpacing(2)
        self.verticalLayout2.setMargin(0)
        self.tabWidget = QTabWidget()
        self.tabWidget.setMinimumWidth(300)
        self.paramPanel = QWidget()
        self.paramPanel.setLayout(self.verticalLayout)
        self.scrollArea = QScrollArea()
        self.scrollArea.setWidget(self.paramPanel)
        self.scrollArea.setWidgetResizable(True)
        self.tabWidget.addTab(self.scrollArea, self.tr('Parameters'))
        self.webView = QWebView()

        html = None
        url = None
        isText, help = self._alg.help()
        if help is not None:
            if isText:
                html = help
            else:
                url = QUrl(help)
        else:
            html = self.tr('<h2>Sorry, no help is available for this '
                           'algorithm.</h2>')
        try:
            if html:
                self.webView.setHtml(html)
            elif url:
                self.webView.load(url)
        except:
            self.webView.setHtml(
                self.tr('<h2>Could not open help file :-( </h2>'))
        self.tabWidget.addTab(self.webView, 'Help')
        self.verticalLayout2.addWidget(self.tabWidget)
        self.verticalLayout2.addWidget(self.buttonBox)
        self.setLayout(self.verticalLayout2)
        self.buttonBox.accepted.connect(self.okPressed)
        self.buttonBox.rejected.connect(self.cancelPressed)
        QMetaObject.connectSlotsByName(self)
    def setupUi(self):
        self.labels = {}
        self.widgets = {}
        self.checkBoxes = {}
        self.showAdvanced = False
        self.valueItems = {}
        self.dependentItems = {}
        self.resize(650, 450)
        self.buttonBox = QDialogButtonBox()
        self.buttonBox.setOrientation(Qt.Horizontal)
        self.buttonBox.setStandardButtons(QDialogButtonBox.Cancel
                                          | QDialogButtonBox.Ok)
        tooltips = self._alg.getParameterDescriptions()
        self.setSizePolicy(QSizePolicy.Expanding,
                           QSizePolicy.Expanding)
        self.verticalLayout = QVBoxLayout()
        self.verticalLayout.setSpacing(5)
        self.verticalLayout.setMargin(20)

        hLayout = QHBoxLayout()
        hLayout.setSpacing(5)
        hLayout.setMargin(0)
        descriptionLabel = QLabel(self.tr("Description"))
        self.descriptionBox = QLineEdit()
        self.descriptionBox.setText(self._alg.name)
        hLayout.addWidget(descriptionLabel)
        hLayout.addWidget(self.descriptionBox)
        self.verticalLayout.addLayout(hLayout)
        line = QFrame()
        line.setFrameShape(QFrame.HLine)
        line.setFrameShadow(QFrame.Sunken)
        self.verticalLayout.addWidget(line)

        for param in self._alg.parameters:
            if param.isAdvanced:
                self.advancedButton = QPushButton()
                self.advancedButton.setText(self.tr('Show advanced parameters'))
                self.advancedButton.clicked.connect(
                    self.showAdvancedParametersClicked)
                advancedButtonHLayout = QHBoxLayout()
                advancedButtonHLayout.addWidget(self.advancedButton)
                advancedButtonHLayout.addStretch()
                self.verticalLayout.addLayout(advancedButtonHLayout)
                break
        for param in self._alg.parameters:
            if param.hidden:
                continue
            desc = param.description
            if isinstance(param, ParameterExtent):
                desc += self.tr('(xmin, xmax, ymin, ymax)')
            if isinstance(param, ParameterPoint):
                desc += self.tr('(x, y)')
            label = QLabel(desc)
            self.labels[param.name] = label
            widget = self.getWidgetFromParameter(param)
            self.valueItems[param.name] = widget
            if param.name in tooltips.keys():
                tooltip = tooltips[param.name]
            else:
                tooltip = param.description
            label.setToolTip(tooltip)
            widget.setToolTip(tooltip)
            if param.isAdvanced:
                label.setVisible(self.showAdvanced)
                widget.setVisible(self.showAdvanced)
                self.widgets[param.name] = widget
            self.verticalLayout.addWidget(label)
            self.verticalLayout.addWidget(widget)

        for output in self._alg.outputs:
            if output.hidden:
                continue
            if isinstance(output, (OutputRaster, OutputVector, OutputTable,
                                   OutputHTML, OutputFile, OutputDirectory)):
                label = QLabel(output.description + '<'
                               + output.__class__.__name__ + '>')
                item = QLineEdit()
                if hasattr(item, 'setPlaceholderText'):
                    item.setPlaceholderText(ModelerParametersDialog.ENTER_NAME)
                self.verticalLayout.addWidget(label)
                self.verticalLayout.addWidget(item)
                self.valueItems[output.name] = item

        label = QLabel(' ')
        self.verticalLayout.addWidget(label)
        label = QLabel(self.tr('Parent algorithms'))
        self.dependenciesPanel = self.getDependenciesPanel()
        self.verticalLayout.addWidget(label)
        self.verticalLayout.addWidget(self.dependenciesPanel)

        self.verticalLayout.addStretch(1000)
        self.setLayout(self.verticalLayout)

        self.setPreviousValues()
        self.setWindowTitle(self._alg.name)
        self.verticalLayout2 = QVBoxLayout()
        self.verticalLayout2.setSpacing(2)
        self.verticalLayout2.setMargin(0)
        self.tabWidget = QTabWidget()
        self.tabWidget.setMinimumWidth(300)
        self.paramPanel = QWidget()
        self.paramPanel.setLayout(self.verticalLayout)
        self.scrollArea = QScrollArea()
        self.scrollArea.setWidget(self.paramPanel)
        self.scrollArea.setWidgetResizable(True)
        self.tabWidget.addTab(self.scrollArea, self.tr('Parameters'))
        self.webView = QWebView()

        html = None
        url = None
        isText, help = self._alg.help()
        if help is not None:
            if isText:
                html = help
            else:
                url = QUrl(help)
        else:
            html = self.tr('<h2>Sorry, no help is available for this '
                           'algorithm.</h2>')
        try:
            if html:
                self.webView.setHtml(html)
            elif url:
                self.webView.load(url)
        except:
            self.webView.setHtml(self.tr('<h2>Could not open help file :-( </h2>'))
        self.tabWidget.addTab(self.webView, 'Help')
        self.verticalLayout2.addWidget(self.tabWidget)
        self.verticalLayout2.addWidget(self.buttonBox)
        self.setLayout(self.verticalLayout2)
        self.buttonBox.accepted.connect(self.okPressed)
        self.buttonBox.rejected.connect(self.cancelPressed)
        QMetaObject.connectSlotsByName(self)
class ModelerParametersDialog(QDialog):

    ENTER_NAME = '[Enter name if this is a final result]'
    NOT_SELECTED = '[Not selected]'
    USE_MIN_COVERING_EXTENT = '[Use min covering extent]'

    def __init__(self, alg, model, algName=None):
        QDialog.__init__(self)
        self.setModal(True)
        #The algorithm to define in this dialog. It is an instance of GeoAlgorithm
        self._alg = alg
        #The resulting algorithm after the user clicks on OK. it is an instance of the container Algorithm class
        self.alg = None
        #The model this algorithm is going to be added to
        self.model = model
        #The name of the algorithm in the model, in case we are editing it and not defining it for the first time
        self._algName = algName
        self.setupUi()
        self.params = None

    def setupUi(self):
        self.labels = {}
        self.widgets = {}
        self.checkBoxes = {}
        self.showAdvanced = False
        self.valueItems = {}
        self.dependentItems = {}
        self.resize(650, 450)
        self.buttonBox = QDialogButtonBox()
        self.buttonBox.setOrientation(Qt.Horizontal)
        self.buttonBox.setStandardButtons(QDialogButtonBox.Cancel
                                          | QDialogButtonBox.Ok)
        tooltips = self._alg.getParameterDescriptions()
        self.setSizePolicy(QSizePolicy.Expanding, QSizePolicy.Expanding)
        self.verticalLayout = QVBoxLayout()
        self.verticalLayout.setSpacing(5)
        self.verticalLayout.setMargin(20)

        hLayout = QHBoxLayout()
        hLayout.setSpacing(5)
        hLayout.setMargin(0)
        descriptionLabel = QLabel(self.tr("Description"))
        self.descriptionBox = QLineEdit()
        self.descriptionBox.setText(self._alg.name)
        hLayout.addWidget(descriptionLabel)
        hLayout.addWidget(self.descriptionBox)
        self.verticalLayout.addLayout(hLayout)
        line = QFrame()
        line.setFrameShape(QFrame.HLine)
        line.setFrameShadow(QFrame.Sunken)
        self.verticalLayout.addWidget(line)

        for param in self._alg.parameters:
            if param.isAdvanced:
                self.advancedButton = QPushButton()
                self.advancedButton.setText(
                    self.tr('Show advanced parameters'))
                self.advancedButton.clicked.connect(
                    self.showAdvancedParametersClicked)
                advancedButtonHLayout = QHBoxLayout()
                advancedButtonHLayout.addWidget(self.advancedButton)
                advancedButtonHLayout.addStretch()
                self.verticalLayout.addLayout(advancedButtonHLayout)
                break
        for param in self._alg.parameters:
            if param.hidden:
                continue
            desc = param.description
            if isinstance(param, ParameterExtent):
                desc += self.tr('(xmin, xmax, ymin, ymax)')
            if isinstance(param, ParameterPoint):
                desc += self.tr('(x, y)')
            label = QLabel(desc)
            self.labels[param.name] = label
            widget = self.getWidgetFromParameter(param)
            self.valueItems[param.name] = widget
            if param.name in tooltips.keys():
                tooltip = tooltips[param.name]
            else:
                tooltip = param.description
            label.setToolTip(tooltip)
            widget.setToolTip(tooltip)
            if param.isAdvanced:
                label.setVisible(self.showAdvanced)
                widget.setVisible(self.showAdvanced)
                self.widgets[param.name] = widget
            self.verticalLayout.addWidget(label)
            self.verticalLayout.addWidget(widget)

        for output in self._alg.outputs:
            if output.hidden:
                continue
            if isinstance(output, (OutputRaster, OutputVector, OutputTable,
                                   OutputHTML, OutputFile, OutputDirectory)):
                label = QLabel(output.description + '<' +
                               output.__class__.__name__ + '>')
                item = QLineEdit()
                if hasattr(item, 'setPlaceholderText'):
                    item.setPlaceholderText(ModelerParametersDialog.ENTER_NAME)
                self.verticalLayout.addWidget(label)
                self.verticalLayout.addWidget(item)
                self.valueItems[output.name] = item

        label = QLabel(' ')
        self.verticalLayout.addWidget(label)
        label = QLabel(self.tr('Parent algorithms'))
        self.dependenciesPanel = self.getDependenciesPanel()
        self.verticalLayout.addWidget(label)
        self.verticalLayout.addWidget(self.dependenciesPanel)

        self.verticalLayout.addStretch(1000)
        self.setLayout(self.verticalLayout)

        self.setPreviousValues()
        self.setWindowTitle(self._alg.name)
        self.verticalLayout2 = QVBoxLayout()
        self.verticalLayout2.setSpacing(2)
        self.verticalLayout2.setMargin(0)
        self.tabWidget = QTabWidget()
        self.tabWidget.setMinimumWidth(300)
        self.paramPanel = QWidget()
        self.paramPanel.setLayout(self.verticalLayout)
        self.scrollArea = QScrollArea()
        self.scrollArea.setWidget(self.paramPanel)
        self.scrollArea.setWidgetResizable(True)
        self.tabWidget.addTab(self.scrollArea, self.tr('Parameters'))
        self.webView = QWebView()

        html = None
        url = None
        isText, help = self._alg.help()
        if help is not None:
            if isText:
                html = help
            else:
                url = QUrl(help)
        else:
            html = self.tr('<h2>Sorry, no help is available for this '
                           'algorithm.</h2>')
        try:
            if html:
                self.webView.setHtml(html)
            elif url:
                self.webView.load(url)
        except:
            self.webView.setHtml(
                self.tr('<h2>Could not open help file :-( </h2>'))
        self.tabWidget.addTab(self.webView, 'Help')
        self.verticalLayout2.addWidget(self.tabWidget)
        self.verticalLayout2.addWidget(self.buttonBox)
        self.setLayout(self.verticalLayout2)
        self.buttonBox.accepted.connect(self.okPressed)
        self.buttonBox.rejected.connect(self.cancelPressed)
        QMetaObject.connectSlotsByName(self)

    def getAvailableDependencies(self):
        if self._algName is None:
            dependent = []
        else:
            dependent = self.model.getDependentAlgorithms(self._algName)
        opts = []
        for alg in self.model.algs.values():
            if alg.name not in dependent:
                opts.append(alg)
        return opts

    def getDependenciesPanel(self):
        return MultipleInputPanel(
            [alg.algorithm.name for alg in self.getAvailableDependencies()])

    def showAdvancedParametersClicked(self):
        self.showAdvanced = not self.showAdvanced
        if self.showAdvanced:
            self.advancedButton.setText(self.tr('Hide advanced parameters'))
        else:
            self.advancedButton.setText(self.tr('Show advanced parameters'))
        for param in self._alg.parameters:
            if param.isAdvanced:
                self.labels[param.name].setVisible(self.showAdvanced)
                self.widgets[param.name].setVisible(self.showAdvanced)

    def getAvailableValuesOfType(self, paramType, outType=None):
        values = []
        inputs = self.model.inputs
        for i in inputs.values():
            param = i.param
            if isinstance(param, paramType):
                values.append(ValueFromInput(param.name))
        if outType is None:
            return values
        if self._algName is None:
            dependent = []
        else:
            dependent = self.model.getDependentAlgorithms(self._algName)
        for alg in self.model.algs.values():
            if alg.name not in dependent:
                for out in alg.algorithm.outputs:
                    if isinstance(out, outType):
                        values.append(ValueFromOutput(alg.name, out.name))

        return values

    def resolveValueDescription(self, value):
        if isinstance(value, ValueFromInput):
            return self.model.inputs[value.name].param.description
        else:
            alg = self.model.algs[value.alg]
            return self.tr("'%s' from algorithm '%s'") % (
                alg.algorithm.getOutputFromName(
                    value.output).description, alg.description)

    def getWidgetFromParameter(self, param):
        if isinstance(param, ParameterRaster):
            item = QComboBox()
            layers = self.getAvailableValuesOfType(ParameterRaster,
                                                   OutputRaster)
            if param.optional:
                item.addItem(self.NOT_SELECTED, None)
            for layer in layers:
                item.addItem(self.resolveValueDescription(layer), layer)
        elif isinstance(param, ParameterVector):
            item = QComboBox()
            layers = self.getAvailableValuesOfType(ParameterVector,
                                                   OutputVector)
            if param.optional:
                item.addItem(self.NOT_SELECTED, None)
            for layer in layers:
                item.addItem(self.resolveValueDescription(layer), layer)
        elif isinstance(param, ParameterTable):
            item = QComboBox()
            tables = self.getAvailableValuesOfType(ParameterTable, OutputTable)
            layers = self.getAvailableValuesOfType(ParameterVector,
                                                   OutputVector)
            if param.optional:
                item.addItem(self.NOT_SELECTED, None)
            for table in tables:
                item.addItem(self.resolveValueDescription(table), table)
            for layer in layers:
                item.addItem(self.resolveValueDescription(layer), layer)
        elif isinstance(param, ParameterBoolean):
            item = QComboBox()
            item.addItem('Yes')
            item.addItem('No')
            bools = self.getAvailableValuesOfType(ParameterBoolean, None)
            for b in bools:
                item.addItem(self.resolveValueDescription(b), b)
            if param.default:
                item.setCurrentIndex(0)
            else:
                item.setCurrentIndex(1)
        elif isinstance(param, ParameterSelection):
            item = QComboBox()
            item.addItems(param.options)
            item.setCurrentIndex(param.default or 1)
        elif isinstance(param, ParameterFixedTable):
            item = FixedTablePanel(param)
        elif isinstance(param, ParameterRange):
            item = RangePanel(param)
        elif isinstance(param, ParameterMultipleInput):
            if param.datatype == ParameterMultipleInput.TYPE_VECTOR_ANY:
                options = self.getAvailableValuesOfType(
                    ParameterVector, OutputVector)
            else:
                options = self.getAvailableValuesOfType(
                    ParameterRaster, OutputRaster)
            opts = []
            for opt in options:
                opts.append(self.resolveValueDescription(opt))
            item = MultipleInputPanel(opts)
        elif isinstance(param, ParameterString):
            strings = self.getAvailableValuesOfType(ParameterString,
                                                    OutputString)
            options = [(self.resolveValueDescription(s), s) for s in strings]
            if param.multiline:
                item = MultilineTextPanel(options)
                item.setText(unicode(param.default or ""))
            else:
                item = QComboBox()
                item.setEditable(True)
                for desc, val in options:
                    item.addItem(desc, val)
                item.setEditText(unicode(param.default or ""))
        elif isinstance(param, ParameterTableField):
            item = QComboBox()
            item.setEditable(True)
            fields = self.getAvailableValuesOfType(ParameterTableField, None)
            for f in fields:
                item.addItem(self.resolveValueDescription(f), f)
        elif isinstance(param, ParameterNumber):
            item = QComboBox()
            item.setEditable(True)
            numbers = self.getAvailableValuesOfType(ParameterNumber,
                                                    OutputNumber)
            for n in numbers:
                item.addItem(self.resolveValueDescription(n), n)
            item.setEditText(unicode(param.default))
        elif isinstance(param, ParameterCrs):
            item = CrsSelectionPanel(param.default)
        elif isinstance(param, ParameterExtent):
            item = QComboBox()
            item.setEditable(True)
            extents = self.getAvailableValuesOfType(ParameterExtent,
                                                    OutputExtent)
            if self.canUseAutoExtent():
                item.addItem(self.USE_MIN_COVERING_EXTENT, None)
            for ex in extents:
                item.addItem(self.resolveValueDescription(ex), ex)
            if not self.canUseAutoExtent():
                item.setEditText(unicode(param.default))
        elif isinstance(param, ParameterPoint):
            item = QComboBox()
            item.setEditable(True)
            points = self.getAvailableValuesOfType(ParameterPoint)
            for p in points:
                item.addItem(self.resolveValueDescription(p), p)
            item.setEditText(unicode(param.default))
        elif isinstance(param, ParameterFile):
            item = QComboBox()
            item.setEditable(True)
            files = self.getAvailableValuesOfType(ParameterFile, OutputFile)
            for f in files:
                item.addItem(self.resolveValueDescription(f), f)
        elif isinstance(param, ParameterGeometryPredicate):
            item = GeometryPredicateSelectionPanel(param.enabledPredicates)
        else:
            item = QLineEdit()
            try:
                item.setText(unicode(param.default))
            except:
                pass
        return item

    def canUseAutoExtent(self):
        for param in self._alg.parameters:
            if isinstance(
                    param,
                (ParameterRaster, ParameterVector, ParameterMultipleInput)):
                return True
        return False

    def setTableContent(self):
        params = self._alg.parameters
        outputs = self._alg.outputs
        visibleParams = [p for p in params if not p.hidden]
        visibleOutputs = [p for o in outputs if not o.hidden]
        self.tableWidget.setRowCount(len(visibleParams) + len(visibleOutputs))

        for i, param in visibleParams:
            item = QTableWidgetItem(param.description)
            item.setFlags(Qt.ItemIsEnabled)
            self.tableWidget.setItem(i, 0, item)
            item = self.getWidgetFromParameter(param)
            self.valueItems[param.name] = item
            self.tableWidget.setCellWidget(i, 1, item)
            self.tableWidget.setRowHeight(i, 22)

        for i, output in visibleOutputs:
            item = QTableWidgetItem(output.description + '<' +
                                    output.__module__.split('.')[-1] + '>')
            item.setFlags(Qt.ItemIsEnabled)
            self.tableWidget.setItem(i, 0, item)
            item = QLineEdit()
            if hasattr(item, 'setPlaceholderText'):
                item.setPlaceholderText(ModelerParametersDialog.ENTER_NAME)
            self.valueItems[output.name] = item
            self.tableWidget.setCellWidget(i, 1, item)
            self.tableWidget.setRowHeight(i, 22)

    def setComboBoxValue(self, combo, value, param):
        if isinstance(value, list):
            value = value[0]
        items = [combo.itemData(i) for i in range(combo.count())]
        try:
            idx = items.index(value)
            combo.setCurrentIndex(idx)
            return
        except ValueError:
            pass
        if combo.isEditable():
            if value is not None:
                combo.setEditText(unicode(value))
        elif isinstance(param, ParameterSelection):
            combo.setCurrentIndex(int(value))
        elif isinstance(param, ParameterBoolean):
            if value:
                combo.setCurrentIndex(0)
            else:
                combo.setCurrentIndex(1)

    def setPreviousValues(self):
        if self._algName is not None:
            alg = self.model.algs[self._algName]
            self.descriptionBox.setText(alg.description)
            for param in alg.algorithm.parameters:
                if param.hidden:
                    continue
                widget = self.valueItems[param.name]
                if param.name in alg.params:
                    value = alg.params[param.name]
                else:
                    value = None
                if isinstance(
                        param,
                    (ParameterRaster, ParameterVector, ParameterTable,
                     ParameterTableField, ParameterSelection, ParameterNumber,
                     ParameterBoolean, ParameterExtent, ParameterFile,
                     ParameterPoint)):
                    self.setComboBoxValue(widget, value, param)
                elif isinstance(param, ParameterString):
                    if param.multiline:
                        widget.setValue(value)
                    else:
                        self.setComboBoxValue(widget, value, param)
                elif isinstance(param, ParameterCrs):
                    widget.setAuthId(value)
                elif isinstance(param, ParameterFixedTable):
                    pass  # TODO!
                elif isinstance(param, ParameterMultipleInput):
                    if param.datatype == ParameterMultipleInput.TYPE_VECTOR_ANY:
                        options = self.getAvailableValuesOfType(
                            ParameterVector, OutputVector)
                    else:
                        options = self.getAvailableValuesOfType(
                            ParameterRaster, OutputRaster)
                    selected = []
                    for i, opt in enumerate(options):
                        if opt in value:
                            selected.append(i)
                    widget.setSelectedItems(selected)
                elif isinstance(param, ParameterGeometryPredicate):
                    widget.setValue(value)

            for name, out in alg.outputs.iteritems():
                widget = self.valueItems[name].setText(out.description)

            selected = []
            dependencies = self.getAvailableDependencies()
            for idx, dependency in enumerate(dependencies):
                if dependency.name in alg.dependencies:
                    selected.append(idx)

            self.dependenciesPanel.setSelectedItems(selected)

    def createAlgorithm(self):
        alg = Algorithm(self._alg.commandLineName())
        alg.setName(self.model)
        alg.description = self.descriptionBox.text()
        params = self._alg.parameters
        outputs = self._alg.outputs
        for param in params:
            if param.hidden:
                continue
            if not self.setParamValue(alg, param, self.valueItems[param.name]):
                return None
        for output in outputs:
            if not output.hidden:
                name = unicode(self.valueItems[output.name].text())
                if name.strip(
                ) != '' and name != ModelerParametersDialog.ENTER_NAME:
                    alg.outputs[output.name] = ModelerOutput(name)

        selectedOptions = self.dependenciesPanel.selectedoptions
        availableDependencies = self.getAvailableDependencies()
        for selected in selectedOptions:
            alg.dependencies.append(availableDependencies[selected].name)

        return alg

    def setParamValueLayerOrTable(self, alg, param, widget):
        idx = widget.currentIndex()
        if idx < 0:
            return False
        else:
            value = widget.itemData(widget.currentIndex())
            alg.params[param.name] = value
            return True

    def setParamTableFieldValue(self, alg, param, widget):
        idx = widget.findText(widget.currentText())
        if idx < 0:
            s = unicode(widget.currentText()).strip()
            if s == '':
                if param.optional:
                    alg.params[param.name] = None
                    return True
                else:
                    return False
            else:
                alg.params[param.name] = s
                return True
        else:
            alg.params[param.name] = widget.itemData(widget.currentIndex())
        return True

    def setParamStringValue(self, alg, param, widget):
        if param.multiline:
            value = widget.getValue()
            option = widget.getOption()
            if option == MultilineTextPanel.USE_TEXT:
                if value == '':
                    if param.optional:
                        alg.params[param.name] = None
                        return True
                    else:
                        return False
                else:
                    alg.params[param.name] = value
            else:
                alg.params[param.name] = value
        else:
            idx = widget.findText(widget.currentText())
            if idx < 0:
                value = widget.currentText().strip()
                if value == '':
                    if param.optional:
                        alg.params[param.name] = None
                        return True
                    else:
                        return False
                else:
                    alg.params[param.name] = value
            else:
                alg.params[param.name] = widget.itemData(widget.currentIndex())
        return True

    def setParamFileValue(self, alg, param, widget):
        idx = widget.findText(widget.currentText())
        if idx < 0:
            value = widget.currentText()
        else:
            value = widget.itemData(widget.currentIndex())
        alg.params[param.name] = value
        return True

    def setParamNumberValue(self, alg, param, widget):
        idx = widget.findText(widget.currentText())
        if idx < 0:
            s = widget.currentText().strip()
            if s:
                try:
                    value = float(s)
                except:
                    return False
            elif param.optional:
                value = None
            else:
                return False
        else:
            value = widget.itemData(widget.currentIndex())
        alg.params[param.name] = value
        return True

    def setParamExtentValue(self, alg, param, widget):
        idx = widget.findText(widget.currentText())
        if idx < 0:
            s = unicode(widget.currentText()).strip()
            if s:
                try:
                    tokens = s.split(',')
                    if len(tokens) != 4:
                        return False
                    for token in tokens:
                        float(token)
                except:
                    return False
            elif param.optional:
                s = None
            else:
                return False
            alg.params[param.name] = [s]
        else:
            value = widget.itemData(widget.currentIndex())
            alg.params[param.name] = value
        return True

    def setParamPointValue(self, alg, param, widget):
        idx = widget.findText(widget.currentText())
        if idx < 0:
            s = unicode(widget.currentText()).strip()
            if s:
                try:
                    tokens = s.split(',')
                    if len(tokens) != 2:
                        return False
                    for token in tokens:
                        float(token)
                except:
                    return False
            elif param.optional:
                s = None
            else:
                return False
            alg.params[param.name] = [s]
        else:
            value = widget.itemData(widget.currentIndex())
            alg.params[param.name] = value
        return True

    def setParamValue(self, alg, param, widget):
        if isinstance(param,
                      (ParameterRaster, ParameterVector, ParameterTable)):
            return self.setParamValueLayerOrTable(alg, param, widget)
        elif isinstance(param, ParameterBoolean):
            if widget.currentIndex() < 2:
                value = widget.currentIndex() == 0
            else:
                value = widget.itemData(widget.currentIndex())
            alg.params[param.name] = value
            return True
        elif isinstance(param, ParameterString):
            return self.setParamStringValue(alg, param, widget)
        elif isinstance(param, ParameterNumber):
            return self.setParamNumberValue(alg, param, widget)
        elif isinstance(param, ParameterExtent):
            return self.setParamExtentValue(alg, param, widget)
        elif isinstance(param, ParameterPoint):
            return self.setParamPointValue(alg, param, widget)
        elif isinstance(param, ParameterFile):
            return self.setParamFileValue(alg, param, widget)
        elif isinstance(param, ParameterSelection):
            alg.params[param.name] = widget.currentIndex()
            return True
        elif isinstance(param, ParameterRange):
            alg.params[param.name] = widget.getValue()
            return True
        elif isinstance(param, ParameterCrs):
            authid = widget.getValue()
            if authid is None and not param.optional:
                return False
            alg.params[param.name] = authid
            return True
        elif isinstance(param, ParameterFixedTable):
            table = widget.table
            if not bool(table) and not param.optional:
                return False
            alg.params[param.name] = ParameterFixedTable.tableToString(table)
            return True
        elif isinstance(param, ParameterTableField):
            return self.setParamTableFieldValue(alg, param, widget)
        elif isinstance(param, ParameterMultipleInput):
            if param.datatype == ParameterMultipleInput.TYPE_VECTOR_ANY:
                options = self.getAvailableValuesOfType(
                    ParameterVector, OutputVector)
            else:
                options = self.getAvailableValuesOfType(
                    ParameterRaster, OutputRaster)
            values = [options[i] for i in widget.selectedoptions]
            if len(values) == 0 and not param.optional:
                return False
            alg.params[param.name] = values
            return True
        elif isinstance(param, ParameterGeometryPredicate):
            alg.params[param.name] = widget.value()
            return True
        else:
            alg.params[param.name] = unicode(widget.text())
            return True

    def okPressed(self):
        self.alg = self.createAlgorithm()
        if self.alg is not None:
            self.close()
        else:
            QMessageBox.warning(self, self.tr('Unable to add algorithm'),
                                self.tr('Wrong or missing parameter values'))

    def cancelPressed(self):
        self.alg = None
        self.close()
class ModelerParametersDialog(QDialog):

    ENTER_NAME = '[Enter name if this is a final result]'
    NOT_SELECTED = '[Not selected]'
    USE_MIN_COVERING_EXTENT = '[Use min covering extent]'

    def __init__(self, alg, model, algName=None):
        QDialog.__init__(self)
        self.setModal(True)
        #The algorithm to define in this dialog. It is an instance of GeoAlgorithm
        self._alg = alg
        #The resulting algorithm after the user clicks on OK. it is an instance of the container Algorithm class
        self.alg = None
        #The model this algorithm is going to be added to
        self.model = model
        #The name of the algorithm in the model, in case we are editing it and not defining it for the first time
        self._algName = algName
        self.setupUi()
        self.params = None

    def setupUi(self):
        self.labels = {}
        self.widgets = {}
        self.checkBoxes = {}
        self.showAdvanced = False
        self.valueItems = {}
        self.dependentItems = {}
        self.resize(650, 450)
        self.buttonBox = QDialogButtonBox()
        self.buttonBox.setOrientation(Qt.Horizontal)
        self.buttonBox.setStandardButtons(QDialogButtonBox.Cancel
                                          | QDialogButtonBox.Ok)
        tooltips = self._alg.getParameterDescriptions()
        self.setSizePolicy(QSizePolicy.Expanding,
                           QSizePolicy.Expanding)
        self.verticalLayout = QVBoxLayout()
        self.verticalLayout.setSpacing(5)
        self.verticalLayout.setMargin(20)

        hLayout = QHBoxLayout()
        hLayout.setSpacing(5)
        hLayout.setMargin(0)
        descriptionLabel = QLabel(self.tr("Description"))
        self.descriptionBox = QLineEdit()
        self.descriptionBox.setText(self._alg.name)
        hLayout.addWidget(descriptionLabel)
        hLayout.addWidget(self.descriptionBox)
        self.verticalLayout.addLayout(hLayout)
        line = QFrame()
        line.setFrameShape(QFrame.HLine)
        line.setFrameShadow(QFrame.Sunken)
        self.verticalLayout.addWidget(line)

        for param in self._alg.parameters:
            if param.isAdvanced:
                self.advancedButton = QPushButton()
                self.advancedButton.setText(self.tr('Show advanced parameters'))
                self.advancedButton.clicked.connect(
                    self.showAdvancedParametersClicked)
                advancedButtonHLayout = QHBoxLayout()
                advancedButtonHLayout.addWidget(self.advancedButton)
                advancedButtonHLayout.addStretch()
                self.verticalLayout.addLayout(advancedButtonHLayout)
                break
        for param in self._alg.parameters:
            if param.hidden:
                continue
            desc = param.description
            if isinstance(param, ParameterExtent):
                desc += self.tr('(xmin, xmax, ymin, ymax)')
            if isinstance(param, ParameterPoint):
                desc += self.tr('(x, y)')
            label = QLabel(desc)
            self.labels[param.name] = label
            widget = self.getWidgetFromParameter(param)
            self.valueItems[param.name] = widget
            if param.name in tooltips.keys():
                tooltip = tooltips[param.name]
            else:
                tooltip = param.description
            label.setToolTip(tooltip)
            widget.setToolTip(tooltip)
            if param.isAdvanced:
                label.setVisible(self.showAdvanced)
                widget.setVisible(self.showAdvanced)
                self.widgets[param.name] = widget
            self.verticalLayout.addWidget(label)
            self.verticalLayout.addWidget(widget)

        for output in self._alg.outputs:
            if output.hidden:
                continue
            if isinstance(output, (OutputRaster, OutputVector, OutputTable,
                                   OutputHTML, OutputFile, OutputDirectory)):
                label = QLabel(output.description + '<'
                               + output.__class__.__name__ + '>')
                item = QLineEdit()
                if hasattr(item, 'setPlaceholderText'):
                    item.setPlaceholderText(ModelerParametersDialog.ENTER_NAME)
                self.verticalLayout.addWidget(label)
                self.verticalLayout.addWidget(item)
                self.valueItems[output.name] = item

        label = QLabel(' ')
        self.verticalLayout.addWidget(label)
        label = QLabel(self.tr('Parent algorithms'))
        self.dependenciesPanel = self.getDependenciesPanel()
        self.verticalLayout.addWidget(label)
        self.verticalLayout.addWidget(self.dependenciesPanel)

        self.verticalLayout.addStretch(1000)
        self.setLayout(self.verticalLayout)

        self.setPreviousValues()
        self.setWindowTitle(self._alg.name)
        self.verticalLayout2 = QVBoxLayout()
        self.verticalLayout2.setSpacing(2)
        self.verticalLayout2.setMargin(0)
        self.tabWidget = QTabWidget()
        self.tabWidget.setMinimumWidth(300)
        self.paramPanel = QWidget()
        self.paramPanel.setLayout(self.verticalLayout)
        self.scrollArea = QScrollArea()
        self.scrollArea.setWidget(self.paramPanel)
        self.scrollArea.setWidgetResizable(True)
        self.tabWidget.addTab(self.scrollArea, self.tr('Parameters'))
        self.webView = QWebView()

        html = None
        url = None
        isText, help = self._alg.help()
        if help is not None:
            if isText:
                html = help
            else:
                url = QUrl(help)
        else:
            html = self.tr('<h2>Sorry, no help is available for this '
                           'algorithm.</h2>')
        try:
            if html:
                self.webView.setHtml(html)
            elif url:
                self.webView.load(url)
        except:
            self.webView.setHtml(self.tr('<h2>Could not open help file :-( </h2>'))
        self.tabWidget.addTab(self.webView, 'Help')
        self.verticalLayout2.addWidget(self.tabWidget)
        self.verticalLayout2.addWidget(self.buttonBox)
        self.setLayout(self.verticalLayout2)
        self.buttonBox.accepted.connect(self.okPressed)
        self.buttonBox.rejected.connect(self.cancelPressed)
        QMetaObject.connectSlotsByName(self)

    def getAvailableDependencies(self):
        if self._algName is None:
            dependent = []
        else:
            dependent = self.model.getDependentAlgorithms(self._algName)
        opts = []
        for alg in self.model.algs.values():
            if alg.name not in dependent:
                opts.append(alg)
        return opts

    def getDependenciesPanel(self):
        return MultipleInputPanel([alg.algorithm.name for alg in self.getAvailableDependencies()])

    def showAdvancedParametersClicked(self):
        self.showAdvanced = not self.showAdvanced
        if self.showAdvanced:
            self.advancedButton.setText(self.tr('Hide advanced parameters'))
        else:
            self.advancedButton.setText(self.tr('Show advanced parameters'))
        for param in self._alg.parameters:
            if param.isAdvanced:
                self.labels[param.name].setVisible(self.showAdvanced)
                self.widgets[param.name].setVisible(self.showAdvanced)

    def getAvailableValuesOfType(self, paramType, outType=None):
        values = []
        inputs = self.model.inputs
        for i in inputs.values():
            param = i.param
            if isinstance(param, paramType):
                values.append(ValueFromInput(param.name))
        if outType is None:
            return values
        if self._algName is None:
            dependent = []
        else:
            dependent = self.model.getDependentAlgorithms(self._algName)
        for alg in self.model.algs.values():
            if alg.name not in dependent:
                for out in alg.algorithm.outputs:
                    if isinstance(out, outType):
                        values.append(ValueFromOutput(alg.name, out.name))

        return values

    def resolveValueDescription(self, value):
        if isinstance(value, ValueFromInput):
            return self.model.inputs[value.name].param.description
        else:
            alg = self.model.algs[value.alg]
            return self.tr("'%s' from algorithm '%s'") % (alg.algorithm.getOutputFromName(value.output).description, alg.description)

    def getWidgetFromParameter(self, param):
        if isinstance(param, ParameterRaster):
            item = QComboBox()
            layers = self.getAvailableValuesOfType(ParameterRaster, OutputRaster)
            if param.optional:
                item.addItem(self.NOT_SELECTED, None)
            for layer in layers:
                item.addItem(self.resolveValueDescription(layer), layer)
        elif isinstance(param, ParameterVector):
            item = QComboBox()
            layers = self.getAvailableValuesOfType(ParameterVector, OutputVector)
            if param.optional:
                item.addItem(self.NOT_SELECTED, None)
            for layer in layers:
                item.addItem(self.resolveValueDescription(layer), layer)
        elif isinstance(param, ParameterTable):
            item = QComboBox()
            tables = self.getAvailableValuesOfType(ParameterTable, OutputTable)
            layers = self.getAvailableValuesOfType(ParameterVector, OutputVector)
            if param.optional:
                item.addItem(self.NOT_SELECTED, None)
            for table in tables:
                item.addItem(self.resolveValueDescription(table), table)
            for layer in layers:
                item.addItem(self.resolveValueDescription(layer), layer)
        elif isinstance(param, ParameterBoolean):
            item = QComboBox()
            item.addItem('Yes')
            item.addItem('No')
            bools = self.getAvailableValuesOfType(ParameterBoolean, None)
            for b in bools:
                item.addItem(self.resolveValueDescription(b), b)
            if param.default:
                item.setCurrentIndex(0)
            else:
                item.setCurrentIndex(1)
        elif isinstance(param, ParameterSelection):
            item = QComboBox()
            item.addItems(param.options)
            item.setCurrentIndex(param.default or 1)
        elif isinstance(param, ParameterFixedTable):
            item = FixedTablePanel(param)
        elif isinstance(param, ParameterRange):
            item = RangePanel(param)
        elif isinstance(param, ParameterMultipleInput):
            if param.datatype == ParameterMultipleInput.TYPE_VECTOR_ANY:
                options = self.getAvailableValuesOfType(ParameterVector, OutputVector)
            else:
                options = self.getAvailableValuesOfType(ParameterRaster, OutputRaster)
            opts = []
            for opt in options:
                opts.append(self.resolveValueDescription(opt))
            item = MultipleInputPanel(opts)
        elif isinstance(param, ParameterString):
            strings = self.getAvailableValuesOfType(ParameterString, OutputString)
            options = [(self.resolveValueDescription(s), s) for s in strings]
            if param.multiline:
                item = MultilineTextPanel(options)
                item.setText(unicode(param.default or ""))
            else:
                item = QComboBox()
                item.setEditable(True)
                for desc, val in options:
                    item.addItem(desc, val)
                item.setEditText(unicode(param.default or ""))
        elif isinstance(param, ParameterTableField):
            item = QComboBox()
            item.setEditable(True)
            fields = self.getAvailableValuesOfType(ParameterTableField, None)
            for f in fields:
                item.addItem(self.resolveValueDescription(f), f)
        elif isinstance(param, ParameterNumber):
            item = QComboBox()
            item.setEditable(True)
            numbers = self.getAvailableValuesOfType(ParameterNumber, OutputNumber)
            for n in numbers:
                item.addItem(self.resolveValueDescription(n), n)
            item.setEditText(unicode(param.default))
        elif isinstance(param, ParameterCrs):
            item = CrsSelectionPanel(param.default)
        elif isinstance(param, ParameterExtent):
            item = QComboBox()
            item.setEditable(True)
            extents = self.getAvailableValuesOfType(ParameterExtent, OutputExtent)
            if self.canUseAutoExtent():
                item.addItem(self.USE_MIN_COVERING_EXTENT, None)
            for ex in extents:
                item.addItem(self.resolveValueDescription(ex), ex)
            if not self.canUseAutoExtent():
                item.setEditText(unicode(param.default))
        elif isinstance(param, ParameterPoint):
            item = QComboBox()
            item.setEditable(True)
            points = self.getAvailableValuesOfType(ParameterPoint)
            for p in points:
                item.addItem(self.resolveValueDescription(p), p)
            item.setEditText(unicode(param.default))
        elif isinstance(param, ParameterFile):
            item = QComboBox()
            item.setEditable(True)
            files = self.getAvailableValuesOfType(ParameterFile, OutputFile)
            for f in files:
                item.addItem(self.resolveValueDescription(f), f)
        elif isinstance(param, ParameterGeometryPredicate):
            item = GeometryPredicateSelectionPanel(param.enabledPredicates)
        else:
            item = QLineEdit()
            try:
                item.setText(unicode(param.default))
            except:
                pass
        return item

    def canUseAutoExtent(self):
        for param in self._alg.parameters:
            if isinstance(param, (ParameterRaster, ParameterVector, ParameterMultipleInput)):
                return True
        return False

    def setTableContent(self):
        params = self._alg.parameters
        outputs = self._alg.outputs
        visibleParams = [p for p in params if not p.hidden]
        visibleOutputs = [p for o in outputs if not o.hidden]
        self.tableWidget.setRowCount(len(visibleParams) + len(visibleOutputs))

        for i, param in visibleParams:
            item = QTableWidgetItem(param.description)
            item.setFlags(Qt.ItemIsEnabled)
            self.tableWidget.setItem(i, 0, item)
            item = self.getWidgetFromParameter(param)
            self.valueItems[param.name] = item
            self.tableWidget.setCellWidget(i, 1, item)
            self.tableWidget.setRowHeight(i, 22)

        for i, output in visibleOutputs:
            item = QTableWidgetItem(output.description + '<'
                                    + output.__module__.split('.')[-1] + '>')
            item.setFlags(Qt.ItemIsEnabled)
            self.tableWidget.setItem(i, 0, item)
            item = QLineEdit()
            if hasattr(item, 'setPlaceholderText'):
                item.setPlaceholderText(ModelerParametersDialog.ENTER_NAME)
            self.valueItems[output.name] = item
            self.tableWidget.setCellWidget(i, 1, item)
            self.tableWidget.setRowHeight(i, 22)

    def setComboBoxValue(self, combo, value, param):
        if isinstance(value, list):
            value = value[0]
        items = [combo.itemData(i) for i in range(combo.count())]
        try:
            idx = items.index(value)
            combo.setCurrentIndex(idx)
            return
        except ValueError:
            pass
        if combo.isEditable():
            if value is not None:
                combo.setEditText(unicode(value))
        elif isinstance(param, ParameterSelection):
            combo.setCurrentIndex(int(value))
        elif isinstance(param, ParameterBoolean):
            if value:
                combo.setCurrentIndex(0)
            else:
                combo.setCurrentIndex(1)

    def setPreviousValues(self):
        if self._algName is not None:
            alg = self.model.algs[self._algName]
            self.descriptionBox.setText(alg.description)
            for param in alg.algorithm.parameters:
                if param.hidden:
                    continue
                widget = self.valueItems[param.name]
                if param.name in alg.params:
                    value = alg.params[param.name]
                else:
                    value = None
                if isinstance(param, (
                        ParameterRaster,
                        ParameterVector,
                        ParameterTable,
                        ParameterTableField,
                        ParameterSelection,
                        ParameterNumber,
                        ParameterBoolean,
                        ParameterExtent,
                        ParameterFile,
                        ParameterPoint
                )):
                    self.setComboBoxValue(widget, value, param)
                elif isinstance(param, ParameterString):
                    if param.multiline:
                        widget.setValue(value)
                    else:
                        self.setComboBoxValue(widget, value, param)
                elif isinstance(param, ParameterCrs):
                    widget.setAuthId(value)
                elif isinstance(param, ParameterFixedTable):
                    pass  # TODO!
                elif isinstance(param, ParameterMultipleInput):
                    if param.datatype == ParameterMultipleInput.TYPE_VECTOR_ANY:
                        options = self.getAvailableValuesOfType(ParameterVector, OutputVector)
                    else:
                        options = self.getAvailableValuesOfType(ParameterRaster, OutputRaster)
                    selected = []
                    for i, opt in enumerate(options):
                        if opt in value:
                            selected.append(i)
                    widget.setSelectedItems(selected)
                elif isinstance(param, ParameterGeometryPredicate):
                    widget.setValue(value)

            for name, out in alg.outputs.iteritems():
                widget = self.valueItems[name].setText(out.description)

            selected = []
            dependencies = self.getAvailableDependencies()
            for idx, dependency in enumerate(dependencies):
                if dependency.name in alg.dependencies:
                    selected.append(idx)

            self.dependenciesPanel.setSelectedItems(selected)

    def createAlgorithm(self):
        alg = Algorithm(self._alg.commandLineName())
        alg.setName(self.model)
        alg.description = self.descriptionBox.text()
        params = self._alg.parameters
        outputs = self._alg.outputs
        for param in params:
            if param.hidden:
                continue
            if not self.setParamValue(alg, param, self.valueItems[param.name]):
                return None
        for output in outputs:
            if not output.hidden:
                name = unicode(self.valueItems[output.name].text())
                if name.strip() != '' and name != ModelerParametersDialog.ENTER_NAME:
                    alg.outputs[output.name] = ModelerOutput(name)

        selectedOptions = self.dependenciesPanel.selectedoptions
        availableDependencies = self.getAvailableDependencies()
        for selected in selectedOptions:
            alg.dependencies.append(availableDependencies[selected].name)

        return alg

    def setParamValueLayerOrTable(self, alg, param, widget):
        idx = widget.currentIndex()
        if idx < 0:
            return False
        else:
            value = widget.itemData(widget.currentIndex())
            alg.params[param.name] = value
            return True

    def setParamTableFieldValue(self, alg, param, widget):
        idx = widget.findText(widget.currentText())
        if idx < 0:
            s = unicode(widget.currentText()).strip()
            if s == '':
                if param.optional:
                    alg.params[param.name] = None
                    return True
                else:
                    return False
            else:
                alg.params[param.name] = s
                return True
        else:
            alg.params[param.name] = widget.itemData(widget.currentIndex())
        return True

    def setParamStringValue(self, alg, param, widget):
        if param.multiline:
            value = widget.getValue()
            option = widget.getOption()
            if option == MultilineTextPanel.USE_TEXT:
                if value == '':
                    if param.optional:
                        alg.params[param.name] = None
                        return True
                    else:
                        return False
                else:
                    alg.params[param.name] = value
            else:
                alg.params[param.name] = value
        else:
            idx = widget.findText(widget.currentText())
            if idx < 0:
                value = widget.currentText().strip()
                if value == '':
                    if param.optional:
                        alg.params[param.name] = None
                        return True
                    else:
                        return False
                else:
                    alg.params[param.name] = value
            else:
                alg.params[param.name] = widget.itemData(widget.currentIndex())
        return True

    def setParamFileValue(self, alg, param, widget):
        idx = widget.findText(widget.currentText())
        if idx < 0:
            value = widget.currentText()
        else:
            value = widget.itemData(widget.currentIndex())
        alg.params[param.name] = value
        return True

    def setParamNumberValue(self, alg, param, widget):
        idx = widget.findText(widget.currentText())
        if idx < 0:
            s = widget.currentText().strip()
            if s:
                try:
                    value = float(s)
                except:
                    return False
            elif param.optional:
                value = None
            else:
                return False
        else:
            value = widget.itemData(widget.currentIndex())
        alg.params[param.name] = value
        return True

    def setParamExtentValue(self, alg, param, widget):
        idx = widget.findText(widget.currentText())
        if idx < 0:
            s = unicode(widget.currentText()).strip()
            if s:
                try:
                    tokens = s.split(',')
                    if len(tokens) != 4:
                        return False
                    for token in tokens:
                        float(token)
                except:
                    return False
            elif param.optional:
                s = None
            else:
                return False
            alg.params[param.name] = [s]
        else:
            value = widget.itemData(widget.currentIndex())
            alg.params[param.name] = value
        return True

    def setParamPointValue(self, alg, param, widget):
        idx = widget.findText(widget.currentText())
        if idx < 0:
            s = unicode(widget.currentText()).strip()
            if s:
                try:
                    tokens = s.split(',')
                    if len(tokens) != 2:
                        return False
                    for token in tokens:
                        float(token)
                except:
                    return False
            elif param.optional:
                s = None
            else:
                return False
            alg.params[param.name] = [s]
        else:
            value = widget.itemData(widget.currentIndex())
            alg.params[param.name] = value
        return True

    def setParamValue(self, alg, param, widget):
        if isinstance(param, (ParameterRaster, ParameterVector,
                              ParameterTable)):
            return self.setParamValueLayerOrTable(alg, param, widget)
        elif isinstance(param, ParameterBoolean):
            if widget.currentIndex() < 2:
                value = widget.currentIndex() == 0
            else:
                value = widget.itemData(widget.currentIndex())
            alg.params[param.name] = value
            return True
        elif isinstance(param, ParameterString):
            return self.setParamStringValue(alg, param, widget)
        elif isinstance(param, ParameterNumber):
            return self.setParamNumberValue(alg, param, widget)
        elif isinstance(param, ParameterExtent):
            return self.setParamExtentValue(alg, param, widget)
        elif isinstance(param, ParameterPoint):
            return self.setParamPointValue(alg, param, widget)
        elif isinstance(param, ParameterFile):
            return self.setParamFileValue(alg, param, widget)
        elif isinstance(param, ParameterSelection):
            alg.params[param.name] = widget.currentIndex()
            return True
        elif isinstance(param, ParameterRange):
            alg.params[param.name] = widget.getValue()
            return True
        elif isinstance(param, ParameterCrs):
            authid = widget.getValue()
            if authid is None and not param.optional:
                return False
            alg.params[param.name] = authid
            return True
        elif isinstance(param, ParameterFixedTable):
            table = widget.table
            if not bool(table) and not param.optional:
                return False
            alg.params[param.name] = ParameterFixedTable.tableToString(table)
            return True
        elif isinstance(param, ParameterTableField):
            return self.setParamTableFieldValue(alg, param, widget)
        elif isinstance(param, ParameterMultipleInput):
            if param.datatype == ParameterMultipleInput.TYPE_VECTOR_ANY:
                options = self.getAvailableValuesOfType(ParameterVector, OutputVector)
            else:
                options = self.getAvailableValuesOfType(ParameterRaster, OutputRaster)
            values = [options[i] for i in widget.selectedoptions]
            if len(values) == 0 and not param.optional:
                return False
            alg.params[param.name] = values
            return True
        elif isinstance(param, ParameterGeometryPredicate):
            alg.params[param.name] = widget.value()
            return True
        else:
            alg.params[param.name] = unicode(widget.text())
            return True

    def okPressed(self):
        self.alg = self.createAlgorithm()
        if self.alg is not None:
            self.close()
        else:
            QMessageBox.warning(self, self.tr('Unable to add algorithm'),
                                self.tr('Wrong or missing parameter values'))

    def cancelPressed(self):
        self.alg = None
        self.close()