def main():
    """Main function to run the example."""
    app = QApplication([])

    default_value_parameter = DefaultValueParameter()
    default_value_parameter.name = 'Value parameter'
    default_value_parameter.help_text = 'Help text'
    default_value_parameter.description = 'Description'
    default_value_parameter.labels = [
        'Setting', 'Do not use', 'Custom']
    default_value_parameter.options = [0, 1, None]

    parameters = [
        default_value_parameter
    ]

    extra_parameters = [
        (DefaultValueParameter, DefaultValueParameterWidget)
    ]

    parameter_container = ParameterContainer(
        parameters, extra_parameters=extra_parameters)
    parameter_container.setup_ui()

    widget = QWidget()
    layout = QGridLayout()
    layout.addWidget(parameter_container)

    widget.setLayout(layout)
    widget.setGeometry(0, 0, 500, 500)

    widget.show()

    sys.exit(app.exec_())

 def clear(self):
     """Clear current state."""
     # Adapted from http://stackoverflow.com/a/13103617/1198772
     for i in reversed(range(self.default_values_grid.count())):
         self.default_values_grid.itemAt(i).widget().setParent(None)
     self.parameters = []
     self.parameter_container = ParameterContainer()

 def clear(self):
     """Clear current state."""
     # Adapted from http://stackoverflow.com/a/13103617/1198772
     for i in reversed(range(self.kwExtraKeywordsGridLayout.count())):
         self.kwExtraKeywordsGridLayout.itemAt(i).widget().setParent(None)
     self.parameters = []
     self.parameter_container = ParameterContainer()

    def raster_changed(self, index):
        """Executed when raster is changed

        :param index: index of the selected raster
        :return:
        """
        registry = QgsMapLayerRegistry.instance()
        layer_id = self.cbo_raster_input.itemData(
            index, QtCore.Qt.UserRole)
        layer = registry.mapLayer(layer_id)
        layer_purpose = self.keyword_io.read_keywords(layer, 'layer_purpose')
        if layer_purpose == 'hazard':
            impact_function = self.if_registry.filter_by_hazard(
                self.if_registry.impact_functions,
                self.keyword_io.read_keywords(layer)
            )
        elif layer_purpose == 'exposure':
            impact_function = self.if_registry.filter_by_exposure(
                self.if_registry.impact_functions,
                self.keyword_io.read_keywords(layer)
            )
        else:
            impact_function = []

        if impact_function:
            parameters_dict = impact_function[0].parameters
            threshold_list = []
            for param_key, param_value in parameters_dict.iteritems():
                if 'threshold' in param_key:
                    threshold_list.append(param_value)

            if threshold_list:
                param_container = ParameterContainer(threshold_list)
                param_container.setup_ui(must_scroll=False)

                self.threshold_editor.layout().addWidget(param_container)
            else:
                empty_threshold_label = QLabel(
                    self.tr('No threshold configuration available '
                            'for this layer'))
                self.threshold_editor.layout().addWidget(
                    empty_threshold_label)

    def __init__(self, parent=None):
        """Constructor for the tab.

        :param parent: parent - widget to use as parent (Wizard Dialog).
        :type parent: QWidget

        """
        WizardStep.__init__(self, parent)

        self.parameters = []
        self.parameter_container = ParameterContainer()
        self.kwExtraKeywordsGridLayout.addWidget(self.parameter_container)

    def set_widgets(self):
        """Set widgets on the Extra Keywords tab."""
        existing_inasafe_default_values = self.parent.get_existing_keyword(
            'inasafe_default_values')
        # Remove old container and parameter
        if self.parameter_container:
            self.default_values_grid.removeWidget(
                self.parameter_container)
        if self.parameters:
            self.parameters = []

        # Iterate through all inasafe fields
        # existing_inasafe_default_values

        for inasafe_field in self.inasafe_fields_for_the_layer():
            # Create DefaultSelectParameter
            parameter = DefaultValueParameter()
            parameter.guid = inasafe_field['key']
            parameter.name = inasafe_field['name']
            parameter.is_required = False
            parameter.help_text = inasafe_field['default_value']['description']
            # parameter.description = inasafe_field['default_value']
            parameter.element_type = unicode
            parameter.labels = get_inasafe_default_value_fields(
                self.parent.setting, inasafe_field['key'])[0]
            parameter.options = get_inasafe_default_value_fields(
                self.parent.setting, inasafe_field['key'])[1]

            if existing_inasafe_default_values:
                existing_default_value = existing_inasafe_default_values.get(
                    inasafe_field['key'])
                if existing_default_value:
                    parameter.default = existing_default_value

            self.parameters.append(parameter)

        # Create the parameter container and add to the wizard.
        self.parameter_container = ParameterContainer(
            self.parameters, extra_parameters=self.extra_parameters)
        self.parameter_container.setup_ui()
        self.default_values_grid.addWidget(self.parameter_container)

        # Set default value to None
        for parameter_widget in self.parameter_container.\
                get_parameter_widgets():
            parameter_widget.widget().set_value(None)
        # Set default value from existing keywords
        if existing_inasafe_default_values:
            for guid, default in existing_inasafe_default_values.items():
                parameter_widget = self.parameter_container.\
                    get_parameter_widget_by_guid(guid)
                if isinstance(parameter_widget, DefaultValueParameterWidget):
                    parameter_widget.set_value(default)

    def __init__(self, parent=None):
        """Constructor for the tab.

        :param parent: parent - widget to use as parent (Wizard Dialog).
        :type parent: QWidget
        """
        WizardStep.__init__(self, parent)

        self.extra_parameters = [
            (DefaultValueParameter, DefaultValueParameterWidget)
        ]
        self.parameters = []
        self.parameter_container = ParameterContainer(
            extra_parameters=self.extra_parameters)
        self.default_values_grid.addWidget(self.parameter_container)

    def __init__(self, parent=None):
        """Constructor for the tab.

        :param parent: parent - widget to use as parent (Wizard Dialog).
        :type parent: QWidget

        """
        WizardStep.__init__(self, parent)

        self.extra_parameters = [
            (DefaultSelectParameter, DefaultSelectParameterWidget)
        ]
        self.parameters = []
        self.parameter_container = ParameterContainer(
            extra_parameters=self.extra_parameters)
        self.kwExtraKeywordsGridLayout.addWidget(self.parameter_container)
        self.message_label = QLabel()

class StepKwInaSAFERasterDefaultValues(WizardStep, FORM_CLASS):

    """Keyword Wizard Step: InaSAFE Raster Default Values."""

    def __init__(self, parent=None):
        """Constructor for the tab.

        :param parent: parent - widget to use as parent (Wizard Dialog).
        :type parent: QWidget
        """
        WizardStep.__init__(self, parent)

        self.extra_parameters = [
            (DefaultValueParameter, DefaultValueParameterWidget)
        ]
        self.parameters = []
        self.parameter_container = ParameterContainer(
            extra_parameters=self.extra_parameters)
        self.default_values_grid.addWidget(self.parameter_container)

    def is_ready_to_next_step(self):
        """Check if the step is complete.

        If so, there is no reason to block the Next button.

        :returns: True if new step may be enabled.
        :rtype: bool
        """
        return True

    def get_next_step(self):
        """Find the proper step when user clicks the Next button.

        :returns: The step to be switched to
        :rtype: WizardStep instance or None
        """
        new_step = self.parent.step_kw_source
        return new_step

    def inasafe_fields_for_the_layer(self):
        """Return a list of inasafe fields the current layer.

        :returns: A list where each value represents inasafe field.
        :rtype: list
        """
        # Get hazard or exposure value
        layer_purpose_key = self.parent.step_kw_purpose.selected_purpose()[
            'key']
        if layer_purpose_key != layer_purpose_aggregation['key']:
            subcategory_key = self.parent.step_kw_subcategory.\
                selected_subcategory()['key']
        else:
            subcategory_key = None
        # Get all fields with replace_null = True
        inasafe_fields = get_fields(
            layer_purpose_key,
            subcategory_key,
            replace_null=True,
            in_group=False)
        # remove compulsory field since it has been set in previous step
        try:
            inasafe_fields.remove(get_compulsory_fields(
                layer_purpose_key, subcategory_key))
        except ValueError:
            pass
        return inasafe_fields

    # noinspection PyTypeChecker
    def set_widgets(self):
        """Set widgets on the Extra Keywords tab."""
        existing_inasafe_default_values = self.parent.get_existing_keyword(
            'inasafe_default_values')
        # Remove old container and parameter
        if self.parameter_container:
            self.default_values_grid.removeWidget(
                self.parameter_container)
        if self.parameters:
            self.parameters = []

        # Iterate through all inasafe fields
        # existing_inasafe_default_values

        for inasafe_field in self.inasafe_fields_for_the_layer():
            # Create DefaultSelectParameter
            parameter = DefaultValueParameter()
            parameter.guid = inasafe_field['key']
            parameter.name = inasafe_field['name']
            parameter.is_required = False
            parameter.help_text = inasafe_field['default_value']['description']
            # parameter.description = inasafe_field['default_value']
            parameter.element_type = unicode
            parameter.labels = get_inasafe_default_value_fields(
                self.parent.setting, inasafe_field['key'])[0]
            parameter.options = get_inasafe_default_value_fields(
                self.parent.setting, inasafe_field['key'])[1]

            if existing_inasafe_default_values:
                existing_default_value = existing_inasafe_default_values.get(
                    inasafe_field['key'])
                if existing_default_value:
#.........这里部分代码省略.........

#.........这里部分代码省略.........
            "shortened. For example when planning water rations "
            "the units would be l.")
        unit_abbreviation_parameter.is_required = True
        unit_abbreviation_parameter.value = ''

        minimum_parameter = FloatParameter('UUID-6')
        minimum_parameter.name = tr('Minimum allowed')
        minimum_parameter.is_required = True
        minimum_parameter.precision = 2
        minimum_parameter.minimum_allowed_value = -99999.0
        minimum_parameter.maximum_allowed_value = 99999.0
        minimum_parameter.help_text = tr(
            'The minimum allowable quantity per person. ')
        minimum_parameter.description = tr(
            'The <b>minimum</b> is the minimum allowed quantity of the '
            'resource per person. For example you may dictate that the water '
            'ration per person per day should never be allowed to be less '
            'than 0.5l. This is enforced when tweaking a minimum needs set '
            'before an impact evaluation')
        minimum_parameter.value = 0.00

        maximum_parameter = FloatParameter('UUID-7')
        maximum_parameter.name = tr('Maximum allowed')
        maximum_parameter.is_required = True
        maximum_parameter.precision = 2
        maximum_parameter.minimum_allowed_value = -99999.0
        maximum_parameter.maximum_allowed_value = 99999.0
        maximum_parameter.help_text = tr(
            'The maximum allowable quantity per person. ')
        maximum_parameter.description = tr(
            'The <b>maximum</b> is the maximum allowed quantity of the '
            'resource per person. For example you may dictate that the water '
            'ration per person per day should never be allowed to be more '
            'than 50l. This is enforced when tweaking a minimum needs set '
            'before an impact evaluation.')
        maximum_parameter.value = 100.0

        default_parameter = FloatParameter('UUID-8')
        default_parameter.name = tr('Default')
        default_parameter.is_required = True
        default_parameter.precision = 2
        default_parameter.minimum_allowed_value = -99999.0
        default_parameter.maximum_allowed_value = 99999.0
        default_parameter.help_text = tr(
            'The default allowable quantity per person. ')
        default_parameter.description = tr(
            "The <b>default</b> is the default allowed quantity of the "
            "resource per person. For example you may indicate that the water "
            "ration per person weekly should be 67l.")
        default_parameter.value = 10.0

        frequency_parameter = StringParameter('UUID-9')
        frequency_parameter.name = tr('Frequency')
        frequency_parameter.help_text = tr(
            "The frequency that this resource needs to be provided to a "
            "displaced person. e.g. weekly, daily, once etc.")
        frequency_parameter.description = tr(
            "The <b>frequency</b> informs the aid worker how regularly this "
            "resource needs to be provided to the displaced person.")
        frequency_parameter.is_required = True
        frequency_parameter.value = tr('weekly')

        sentence_parameter = TextParameter('UUID-10')
        sentence_parameter.name = tr('Readable sentence')
        sentence_parameter.help_text = tr(
            'A readable presentation of the resource.')
        sentence_parameter.description = tr(
            "A <b>readable sentence</b> is a presentation of the resource "
            "that displays all pertinent information. If you are unsure then "
            "use the default. Properties should be included using double "
            "curly brackets '{{' '}}'. Including the resource name would be "
            "achieved by including e.g. {{ Resource name }}")
        sentence_parameter.is_required = True
        sentence_parameter.value = tr(
            "A displaced person should be provided with "
            "{{ Default }} {{ Unit }}/{{ Units }}/{{ Unit abbreviation }} of "
            "{{ Resource name }}. Though no less than {{ Minimum allowed }} "
            "and no more than {{ Maximum allowed }}. This should be provided "
            "{{ Frequency }}.")

        parameters = [
            name_parameter,
            description_parameter,
            unit_parameter,
            units_parameter,
            unit_abbreviation_parameter,
            default_parameter,
            minimum_parameter,
            maximum_parameter,
            frequency_parameter,
            sentence_parameter
        ]
        parameter_container = ParameterContainer(parameters)
        parameter_container.setup_ui()

        layout = QGridLayout()
        layout.setContentsMargins(0, 0, 0, 0)
        layout.setSpacing(0)
        layout.addWidget(parameter_container)
        self.parameters_scrollarea.setLayout(layout)

    def restore_default_values_page(self):
        """Setup UI for default values setting."""
        # Clear parameters so it doesn't add parameters when
        # restore from changes.
        if self.default_value_parameters:
            self.default_value_parameters = []
        if self.default_value_parameter_containers:
            self.default_value_parameter_containers = []

        default_fields = all_default_fields()

        for field_group in all_field_groups:
            settable_fields = []
            for field in field_group['fields']:
                if field not in default_fields:
                    continue
                else:
                    settable_fields.append(field)
                    default_fields.remove(field)

            if not settable_fields:
                continue
            # Create group box for each field group
            group_box = QGroupBox(self)
            group_box.setTitle(field_group['name'])
            self.container_layout.addWidget(group_box)
            parameters = []
            for settable_field in settable_fields:
                parameter = self.default_field_to_parameter(settable_field)
                if parameter:
                    parameters.append(parameter)
            parameter_container = ParameterContainer(
                parameters, description_text=field_group['description']
            )
            parameter_container.setup_ui(must_scroll=False)
            group_box_inner_layout = QVBoxLayout()
            group_box_inner_layout.addWidget(parameter_container)
            group_box.setLayout(group_box_inner_layout)

            # Add to attribute
            self.default_value_parameter_containers.append(parameter_container)

        # Only show non-groups default fields if there is one
        if len(default_fields) > 0:
            for default_field in default_fields:
                parameter = self.default_field_to_parameter(default_field)
                if parameter:
                    self.default_value_parameters.append(parameter)

            description_text = tr(
                'In this options you can change the global default values for '
                'these variables.')
            parameter_container = ParameterContainer(
                self.default_value_parameters,
                description_text=description_text)
            parameter_container.setup_ui(must_scroll=False)
            self.other_group_box = QGroupBox(tr('Non-group fields'))
            other_group_inner_layout = QVBoxLayout()
            other_group_inner_layout.addWidget(parameter_container)
            self.other_group_box.setLayout(other_group_inner_layout)
            self.container_layout.addWidget(self.other_group_box)

            # Add to attribute
            self.default_value_parameter_containers.append(parameter_container)

#.........这里部分代码省略.........
                    'value': custom_value,
                    'type': SINGLE_DYNAMIC,
                    'constraint': {
                        'min': min_value,
                        'max': max_value,
                        'step': step
                    }
                }

            custom_fields = self.metadata.get('inasafe_fields', {}).get(
                field['key'], [])
            if field['key'] in self.metadata.get('inasafe_fields', {}):
                selected_option = FIELDS
            if isinstance(custom_fields, basestring):
                custom_fields = [custom_fields]
            options[FIELDS] = {
                'label': field_label,
                'value': custom_fields,
                'type': MULTIPLE_DYNAMIC,
                'constraint': {}
            }
            used_fields.extend(custom_fields)

            parameter = GroupSelectParameter()
            parameter.guid = field['key']
            parameter.name = field['name']
            parameter.options = options
            parameter.selected = selected_option
            parameter.help_text = field['help_text']
            parameter.description = field['description']

            self.parameters.append(parameter)

        self.parameter_container = ParameterContainer(
            parameters=self.parameters,
            extra_parameters=self.extra_parameters,
            vertical=False
        )
        self.parameter_container.setup_ui()

        constraints = self.field_group.get('constraints', {})

        for key, value in constraints.items():
            self.parameter_container.add_validator(
                validators[key],
                kwargs=value['kwargs'],
                validation_message=value['message'])

        self.parameter_layout.addWidget(self.parameter_container)

        # Set move or copy
        if self.field_group.get('exclusive', False):
            # If exclusive, do not add used field.
            self.populate_field_list(excluded_fields=used_fields)
            # Use move action since it's exclusive
            self.field_list.setDefaultDropAction(Qt.MoveAction)
            # Just make sure that the signal is disconnected
            try:
                # noinspection PyUnresolvedReferences
                self.field_list.itemChanged.disconnect(self.drop_remove)
            except TypeError:
                pass
            # Set header
            header_text = self.field_group['description']
            header_text += '\n\n' + tr(
                'You can only map one field to one concept.')

    def populate_parameter(self):
        """Helper to setup the parameter widget."""
        used_fields = []
        self.parameters = []
        for field in self.field_group.get('fields', []):
            selected_option = DO_NOT_USE
            options = OrderedDict([
                (DO_NOT_USE,
                 {
                     'label': tr('Do not use'),
                     'value': None,
                     'type': STATIC,
                     'constraint': {}
                 }),
            ])

            # Example: count
            if field['absolute']:
                # Used in field options
                field_label = tr('Count fields')
            else:  # Example: ratio
                # Used in field options
                field_label = tr('Ratio fields')
                global_default_value = get_inasafe_default_value_qsetting(
                    self.setting, GLOBAL, field['key'])
                options[GLOBAL_DEFAULT] = {
                    'label': tr('Global default'),
                    'value': global_default_value,
                    'type': STATIC,
                    'constraint': {}
                }
                default_custom_value = get_inasafe_default_value_qsetting(
                    self.setting, RECENT, field['key'])
                custom_value = self.metadata.get(
                    'inasafe_default_values', {}).get(
                    field['key'], default_custom_value)
                if field['key'] in self.metadata.get(
                        'inasafe_default_values', {}):
                    if custom_value == global_default_value:
                        selected_option = GLOBAL_DEFAULT
                    else:
                        selected_option = CUSTOM_VALUE
                min_value = field['default_value'].get('min_value', 0)
                max_value = field['default_value'].get('max_value', 100)
                default_step = (max_value - min_value) / 100.0
                step = field['default_value'].get('increment', default_step)
                options[CUSTOM_VALUE] = {
                    'label': tr('Custom'),
                    'value': custom_value,
                    'type': SINGLE_DYNAMIC,
                    'constraint': {
                        'min': min_value,
                        'max': max_value,
                        'step': step
                    }
                }

            custom_fields = self.metadata.get('inasafe_fields', {}).get(
                field['key'], [])
            if field['key'] in self.metadata.get('inasafe_fields', {}):
                selected_option = FIELDS
            if isinstance(custom_fields, basestring):
                custom_fields = [custom_fields]
            options[FIELDS] = {
                'label': field_label,
                'value': custom_fields,
                'type': MULTIPLE_DYNAMIC,
                'constraint': {}
            }
            used_fields.extend(custom_fields)

            parameter = GroupSelectParameter()
            parameter.guid = field['key']
            parameter.name = field['name']
            parameter.options = options
            parameter.selected = selected_option
            parameter.help_text = field['help_text']
            parameter.description = field['description']

            self.parameters.append(parameter)

        self.parameter_container = ParameterContainer(
            parameters=self.parameters,
            extra_parameters=self.extra_parameters,
            vertical=False
        )
        self.parameter_container.setup_ui()

        constraints = self.field_group.get('constraints', {})

        for key, value in constraints.items():
            self.parameter_container.add_validator(
                validators[key],
                kwargs=value['kwargs'],
                validation_message=value['message'])

        self.parameter_layout.addWidget(self.parameter_container)

        # Set move or copy
        if self.field_group.get('exclusive', False):
#.........这里部分代码省略.........

class StepKwInaSAFEFields(WizardStep, FORM_CLASS):
    """Keyword Wizard Step: InaSAFE Fields"""

    def __init__(self, parent=None):
        """Constructor for the tab.

        :param parent: parent - widget to use as parent (Wizard Dialog).
        :type parent: QWidget

        """
        WizardStep.__init__(self, parent)

        self.parameters = []
        self.parameter_container = ParameterContainer()
        self.kwExtraKeywordsGridLayout.addWidget(self.parameter_container)

    def is_ready_to_next_step(self):
        """Check if the step is complete. If so, there is
            no reason to block the Next button.

        :returns: True if new step may be enabled.
        :rtype: bool
        """
        return True

    def get_next_step(self):
        """Find the proper step when user clicks the Next button.

        :returns: The step to be switched to
        :rtype: WizardStep instance or None
        """
        layer_purpose = self.parent.step_kw_purpose.selected_purpose()
        if layer_purpose['key'] != layer_purpose_aggregation['key']:
            subcategory = self.parent.step_kw_subcategory. \
                selected_subcategory()
        else:
            subcategory = {'key': None}

        # Check if it can go to inasafe default field step
        default_inasafe_fields = get_fields(
            layer_purpose['key'],
            subcategory['key'],
            replace_null=True,
            in_group=False)
        if default_inasafe_fields:
            return self.parent.step_kw_default_inasafe_fields

        # Any other case
        return self.parent.step_kw_source

    def inasafe_fields_for_the_layer(self):
        """Return a list of inasafe fields the current layer.

        :returns: A list where each value represents inasafe field.
        :rtype: list
        """
        if (self.parent.get_layer_geometry_key() ==
                layer_geometry_raster['key']):
            return []
        # Get hazard or exposure value
        layer_purpose_key = self.parent.step_kw_purpose.selected_purpose()[
            'key']
        if layer_purpose_key != layer_purpose_aggregation['key']:
            subcategory_key = self.parent.step_kw_subcategory.\
                selected_subcategory()['key']
        else:
            subcategory_key = None
        # Get all fields with replace_null = False
        inasafe_fields = get_fields(
            layer_purpose_key,
            subcategory_key,
            replace_null=False,
            in_group=False)
        # remove compulsory field since it has been set in previous step
        try:
            inasafe_fields.remove(get_compulsory_fields(
                layer_purpose_key, subcategory_key))
        except ValueError:
            pass
        return inasafe_fields

    # noinspection PyTypeChecker
    def set_widgets(self):
        """Set widgets on the Extra Keywords tab."""
        existing_inasafe_field = self.parent.get_existing_keyword(
            'inasafe_fields')
        # Remove old container and parameter
        if self.parameter_container:
            self.kwExtraKeywordsGridLayout.removeWidget(
                self.parameter_container)
        if self.parameters:
            self.parameters = []

        layer_data_provider = self.parent.layer.dataProvider()

        # Iterate through all inasafe fields
        for inasafe_field in self.inasafe_fields_for_the_layer():
            # Option for Not Available
            option_list = [no_field]
            for field in layer_data_provider.fields():
#.........这里部分代码省略.........

    def set_widgets(self):
        """Set widgets on the Extra Keywords tab."""
        existing_inasafe_field = self.parent.get_existing_keyword(
            'inasafe_fields')
        # Remove old container and parameter
        if self.parameter_container:
            self.kwExtraKeywordsGridLayout.removeWidget(
                self.parameter_container)
        if self.parameters:
            self.parameters = []

        layer_data_provider = self.parent.layer.dataProvider()

        # Iterate through all inasafe fields
        for inasafe_field in self.inasafe_fields_for_the_layer():
            # Option for Not Available
            option_list = [no_field]
            for field in layer_data_provider.fields():
                # Check the field type
                if isinstance(inasafe_field['type'], list):
                    if field.type() in inasafe_field['type']:
                        field_name = field.name()
                        option_list.append('%s' % field_name)
                else:
                    if field.type() == inasafe_field['type']:
                        field_name = field.name()
                        option_list.append('%s' % field_name)

            # If there is no option, pass
            if option_list == [no_field]:
                continue

            # Create SelectParameter
            select_parameter = SelectParameter()
            select_parameter.guid = inasafe_field['key']
            select_parameter.name = inasafe_field['name']
            select_parameter.is_required = False
            select_parameter.description = inasafe_field['description']
            select_parameter.help_text = inasafe_field['help_text']
            select_parameter.element_type = unicode
            select_parameter.options_list = option_list
            select_parameter.value = no_field
            # Check if there is already value in the metadata.
            if existing_inasafe_field:
                existing_value = existing_inasafe_field.get(
                    inasafe_field['key'])
                if existing_value:
                    if existing_value in select_parameter.options_list:
                        select_parameter.value = existing_value

            self.parameters.append(select_parameter)

        # Create the parameter container and add to the wizard.
        self.parameter_container = ParameterContainer(self.parameters)
        self.parameter_container.setup_ui()
        self.kwExtraKeywordsGridLayout.addWidget(self.parameter_container)

        if not self.parameters:
            no_field_message = tr(
                'There is no available field that has match type for the '
                'InaSAFE fields. You can click next.')
            self.lblInaSAFEFields.setText(no_field_message)

class StepKwDefaultInaSAFEFields(WizardStep, FORM_CLASS):
    """Keyword Wizard Step: Default InaSAFE Fields"""

    def __init__(self, parent=None):
        """Constructor for the tab.

        :param parent: parent - widget to use as parent (Wizard Dialog).
        :type parent: QWidget

        """
        WizardStep.__init__(self, parent)

        self.extra_parameters = [
            (DefaultSelectParameter, DefaultSelectParameterWidget)
        ]
        self.parameters = []
        self.parameter_container = ParameterContainer(
            extra_parameters=self.extra_parameters)
        self.kwExtraKeywordsGridLayout.addWidget(self.parameter_container)
        self.message_label = QLabel()

    def is_ready_to_next_step(self):
        """Check if the step is complete. If so, there is
            no reason to block the Next button.

        :returns: True if new step may be enabled.
        :rtype: bool
        """
        return True

    def get_next_step(self):
        """Find the proper step when user clicks the Next button.

        :returns: The step to be switched to
        :rtype: WizardStep instance or None
        """
        new_step = self.parent.step_kw_source
        return new_step

    def inasafe_fields_for_the_layer(self):
        """Return a list of inasafe fields the current layer.

        :returns: A list where each value represents inasafe field.
        :rtype: list
        """
        if (self.parent.get_layer_geometry_key() ==
                layer_geometry_raster['key']):
            return []
        # Get hazard or exposure value
        layer_purpose_key = self.parent.step_kw_purpose.selected_purpose()[
            'key']
        if layer_purpose_key != layer_purpose_aggregation['key']:
            subcategory_key = self.parent.step_kw_subcategory.\
                selected_subcategory()['key']
        else:
            subcategory_key = None
        # Get all fields with replace_null = True
        inasafe_fields = get_fields(
            layer_purpose_key,
            subcategory_key,
            replace_null=True,
            in_group=False)
        # remove compulsory field since it has been set in previous step
        try:
            inasafe_fields.remove(get_compulsory_fields(
                layer_purpose_key, subcategory_key))
        except ValueError:
            pass
        return inasafe_fields

    # noinspection PyTypeChecker
    def set_widgets(self):
        """Set widgets on the Extra Keywords tab."""
        self.clear()
        existing_inasafe_field = self.parent.get_existing_keyword(
            'inasafe_fields')
        existing_inasafe_default_values = self.parent.get_existing_keyword(
            'inasafe_default_values')
        # Remove old container and parameter
        if self.parameter_container:
            self.kwExtraKeywordsGridLayout.removeWidget(
                self.parameter_container)
        if self.parameters:
            self.parameters = []

        layer_data_provider = self.parent.layer.dataProvider()

        # Iterate through all inasafe fields
        # existing_inasafe_default_values

        for inasafe_field in self.inasafe_fields_for_the_layer():
            # Option for Not Available
            option_list = [no_field]
            for field in layer_data_provider.fields():
                # Check the field type
                if isinstance(inasafe_field['type'], list):
                    if field.type() in inasafe_field['type']:
                        field_name = field.name()
                        option_list.append('%s' % field_name)
                else:
#.........这里部分代码省略.........

    def set_widgets(self):
        """Set widgets on the Extra Keywords tab."""
        self.clear()
        existing_inasafe_field = self.parent.get_existing_keyword(
            'inasafe_fields')
        existing_inasafe_default_values = self.parent.get_existing_keyword(
            'inasafe_default_values')
        # Remove old container and parameter
        if self.parameter_container:
            self.kwExtraKeywordsGridLayout.removeWidget(
                self.parameter_container)
        if self.parameters:
            self.parameters = []

        layer_data_provider = self.parent.layer.dataProvider()

        # Iterate through all inasafe fields
        # existing_inasafe_default_values

        for inasafe_field in self.inasafe_fields_for_the_layer():
            # Option for Not Available
            option_list = [no_field]
            for field in layer_data_provider.fields():
                # Check the field type
                if isinstance(inasafe_field['type'], list):
                    if field.type() in inasafe_field['type']:
                        field_name = field.name()
                        option_list.append('%s' % field_name)
                else:
                    if field.type() == inasafe_field['type']:
                        field_name = field.name()
                        option_list.append('%s' % field_name)

            # Create DefaultSelectParameter
            parameter = DefaultSelectParameter()
            parameter.guid = inasafe_field['key']
            parameter.name = inasafe_field['name']
            parameter.is_required = False
            parameter.description = inasafe_field['description']
            parameter.help_text = inasafe_field['help_text']
            parameter.element_type = unicode
            parameter.options_list = option_list
            parameter.value = no_field
            parameter.default_labels = get_inasafe_default_value_fields(
                self.parent.setting, inasafe_field['key'])[0]
            parameter.default_values = get_inasafe_default_value_fields(
                self.parent.setting, inasafe_field['key'])[1]
            parameter.minimum = inasafe_field['default_value'].get(
                'min_value')
            parameter.maximum = inasafe_field['default_value'].get(
                'max_value')
            # Check if there is already value in the metadata.
            if existing_inasafe_field:
                existing_value = existing_inasafe_field.get(
                    inasafe_field['key'])
                if existing_value:
                    if existing_value in parameter.options_list:
                        parameter.value = existing_value

            if existing_inasafe_default_values:
                existing_default_value = existing_inasafe_default_values.get(
                    inasafe_field['key'])
                if existing_default_value:
                    parameter.default = existing_default_value

            self.parameters.append(parameter)

        # Create the parameter container and add to the wizard.
        self.parameter_container = ParameterContainer(
            self.parameters, extra_parameters=self.extra_parameters)
        self.parameter_container.setup_ui()
        self.kwExtraKeywordsGridLayout.addWidget(self.parameter_container)
        # Add Message label
        self.kwExtraKeywordsGridLayout.addWidget(self.message_label)

        # Set default value to None
        for parameter_widget in self.parameter_container.\
                get_parameter_widgets():
            parameter_widget.widget().set_default(None