QGIS » ASGARD

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

"""

MenuBuilder - Create your own menus with your favorite layers

copyright            : (C) 2015 by Oslandia

email                : infos@oslandia.com

/***************************************************************************

 *                                                                         *

 *   This program is free software; you can redistribute it and/or modify  *

 *   it under the terms of the GNU General Public License as published by  *

 *   the Free Software Foundation; either version 2 of the License, or     *

 *   (at your option) any later version.                                   *

 *                                                                         *

 ***************************************************************************/

"""

import os

import re

import json

from contextlib import contextmanager

from collections import defaultdict

from functools import wraps, partial

import psycopg2

from PyQt5.QtCore import Qt, QRect, QSortFilterProxyModel

from PyQt5.QtWidgets import (

    QAction, QMessageBox, QDialog, QMenu, QTreeView,

    QAbstractItemView, QDockWidget, QWidget, QVBoxLayout,

    QSizePolicy, QLineEdit, QDialogButtonBox

)

from PyQt5.QtGui import (

    QIcon, QStandardItem,

    QStandardItemModel

)

from qgis.core import (

    QgsProject, QgsBrowserModel, QgsDataSourceUri, QgsSettings,

    QgsCredentials, QgsVectorLayer, QgsMimeDataUtils, QgsRasterLayer

)

from .menu_builder_dialog_base import Ui_Dialog

QGIS_MIMETYPE = 'application/x-vnd.qgis.qgis.uri'

ICON_MAPPER = {

    'postgres': ":/plugins/MenuBuilder/resources/postgis.svg",

    'WMS': ":/plugins/MenuBuilder/resources/wms.svg",

    'WFS': ":/plugins/MenuBuilder/resources/wfs.svg",

    'OWS': ":/plugins/MenuBuilder/resources/ows.svg",

    'spatialite': ":/plugins/MenuBuilder/resources/spatialite.svg",

    'mssql': ":/plugins/MenuBuilder/resources/mssql.svg",

    'gdal': ":/plugins/MenuBuilder/resources/gdal.svg",

    'ogr': ":/plugins/MenuBuilder/resources/ogr.svg",

}

class MenuBuilderDialog(QDialog, Ui_Dialog):

    def __init__(self, uiparent):

        super().__init__()

        self.setupUi(self)

        # reference to caller

        self.uiparent = uiparent

        self.combo_profile.lineEdit().setPlaceholderText(self.tr("Profile name"))

        # add icons

        self.button_add_menu.setIcon(QIcon(":/plugins/MenuBuilder/resources/plus.svg"))

        self.button_delete_profile.setIcon(QIcon(":/plugins/MenuBuilder/resources/delete.svg"))

        # custom qtreeview

        self.target = CustomQtTreeView(self)

        self.target.setGeometry(QRect(440, 150, 371, 451))

        self.target.setAcceptDrops(True)

        self.target.setDragEnabled(True)

        self.target.setDragDropMode(QAbstractItemView.DragDrop)

        self.target.setObjectName("target")

        self.target.setDropIndicatorShown(True)

        self.target.setSelectionMode(QAbstractItemView.ExtendedSelection)

        self.target.setHeaderHidden(True)

        sizePolicy = QSizePolicy(QSizePolicy.Expanding, QSizePolicy.Expanding)

        sizePolicy.setHorizontalStretch(0)

        sizePolicy.setVerticalStretch(0)

        sizePolicy.setHeightForWidth(self.target.sizePolicy().hasHeightForWidth())

        self.target.setSizePolicy(sizePolicy)

        self.target.setAutoFillBackground(True)

        self.verticalLayout_2.addWidget(self.target)

        self.menumodel = MenuTreeModel(self)

        self.target.setModel(self.menumodel)

        self.target.setAnimated(True)

        self.target.setDefaultDropAction(Qt.MoveAction)

        self.browser = QgsBrowserModel()

        self.browser.initialize()

        self.source.setModel(self.browser)

        self.source.setHeaderHidden(True)

        self.source.setDragEnabled(True)

        self.source.setSelectionMode(QAbstractItemView.ExtendedSelection)

        # add a dock widget

        self.dock_widget = QDockWidget("Menus")

        self.dock_widget.resize(400, 300)

        self.dock_widget.setFloating(True)

        self.dock_widget.setObjectName(self.tr("Menu Tree"))

        self.dock_widget_content = QWidget()

        self.dock_widget.setWidget(self.dock_widget_content)

        dock_layout = QVBoxLayout()

        self.dock_widget_content.setLayout(dock_layout)

        self.dock_view = DockQtTreeView(self.dock_widget_content)

        self.dock_view.setDragDropMode(QAbstractItemView.DragOnly)

        self.dock_menu_filter = QLineEdit()

        self.dock_menu_filter.setPlaceholderText(self.tr("Filter by table description (postgis only)"))

        dock_layout.addWidget(self.dock_menu_filter)

        dock_layout.addWidget(self.dock_view)

        self.dock_view.setHeaderHidden(True)

        self.dock_view.setDragEnabled(True)

        self.dock_view.setSelectionMode(QAbstractItemView.ExtendedSelection)

        self.dock_view.setAnimated(True)

        self.dock_view.setObjectName("treeView")

        self.proxy_model = LeafFilterProxyModel(self)

        self.proxy_model.setFilterRole(Qt.ToolTipRole)

        self.proxy_model.setFilterCaseSensitivity(Qt.CaseInsensitive)

        self.profile_list = []

        self.table = 'qgis_menubuilder_metadata'

        self.layer_handler = {

            'vector': self.load_vector,

            'raster': self.load_raster

        }

        # connect signals and handlers

        self.combo_database.activated.connect(partial(self.set_connection, dbname=None))

        self.combo_schema.activated.connect(self.update_profile_list)

        self.combo_profile.activated.connect(partial(self.update_model_idx, self.menumodel))

        self.button_add_menu.released.connect(self.add_menu)

        self.button_delete_profile.released.connect(self.delete_profile)

        self.dock_menu_filter.textEdited.connect(self.filter_update)

        self.dock_view.doubleClicked.connect(self.load_from_index)

        self.buttonBox.rejected.connect(self.reject)

        self.buttonBox.accepted.connect(self.accept)

        self.buttonBox.button(QDialogButtonBox.Apply).clicked.connect(self.apply)

    def filter_update(self):

        text = self.dock_menu_filter.displayText()

        self.proxy_model.setFilterRegExp(text)

    def show_dock(self, state, profile=None, schema=None):

        if not state:

            # just hide widget

            self.dock_widget.setVisible(state)

            return

        # dock must be read only and deepcopy of model is not supported (c++ inside!)

        self.dock_model = MenuTreeModel(self)

        if profile:

            # bypass combobox

            self.update_model(self.dock_model, schema, profile)

        else:

            self.update_model_idx(self.dock_model, self.combo_profile.currentIndex())

        self.dock_model.setHorizontalHeaderLabels(["Menus"])

        self.dock_view.setEditTriggers(QAbstractItemView.NoEditTriggers)

        self.proxy_model.setSourceModel(self.dock_model)

        self.dock_view.setModel(self.proxy_model)

        self.dock_widget.setVisible(state)

    def show_menus(self, state, profile=None, schema=None):

        if state:

            self.load_menus(profile=profile, schema=schema)

            return

        # remove menus

        for menu in self.uiparent.menus:

            self.uiparent.iface.mainWindow().menuBar().removeAction(menu.menuAction())

    def add_menu(self):

        """

        Add a menu inside qtreeview

        """

        item = QStandardItem('NewMenu')

        item.setIcon(QIcon(':/plugins/MenuBuilder/resources/menu.svg'))

        # select current index selected and insert as a sibling

        brother = self.target.selectedIndexes()

        if not brother or not brother[0].parent():

            # no selection, add menu at the top level

            self.menumodel.insertRow(self.menumodel.rowCount(), item)

            return

        parent = self.menumodel.itemFromIndex(brother[0].parent())

        if not parent:

            self.menumodel.insertRow(self.menumodel.rowCount(), item)

            return

        parent.appendRow(item)

    def update_database_list(self):

        """update list of defined postgres connections"""

        settings = QgsSettings()

        settings.beginGroup("/PostgreSQL/connections")

        keys = settings.childGroups()

        self.combo_database.clear()

        self.combo_schema.clear()

        self.menumodel.clear()

        self.combo_database.addItems(keys)

        self.combo_database.setCurrentIndex(-1)

        settings.endGroup()

        # clear profile list

        self.combo_profile.clear()

        self.combo_profile.setCurrentIndex(-1)

    def set_connection(self, databaseidx, dbname=None):

        """

        Connect to selected postgresql database

        """

        selected = self.combo_database.itemText(databaseidx) or dbname

        if not selected:

            return

        settings = QgsSettings()

        settings.beginGroup("/PostgreSQL/connections/{}".format(selected))

        if not settings.contains("database"):

            # no entry?

            QMessageBox.critical(self, "Error", "There is no defined database connection")

            return

        uri = QgsDataSourceUri()

        settingsList = ["service", "host", "port", "database", "username", "password"]

        service, host, port, database, username, password = map(

            lambda x: settings.value(x, "", type=str), settingsList)

        useEstimatedMetadata = settings.value("estimatedMetadata", False, type=bool)

        sslmode = settings.enumValue("sslmode", uri.SslPrefer)

        settings.endGroup()

        if service:

            uri.setConnection(service, database, username, password, sslmode)

        else:

            uri.setConnection(host, port, database, username, password, sslmode)

        uri.setUseEstimatedMetadata(useEstimatedMetadata)

        # connect to db

        try:

            self.connect_to_uri(uri)

        except self.pg_error_types():

            QMessageBox.warning(

                self,

                "Plugin MenuBuilder: Message",

                self.tr("The database containing Menu's configuration is unavailable"),

                QMessageBox.Ok,

            )

            # connection not available

            return False

        # update schema list

        self.update_schema_list()

        return True

    @contextmanager

    def transaction(self):

        try:

            yield

            self.connection.commit()

        except self.pg_error_types() as e:

            self.connection.rollback()

            raise e

    def check_connected(func):

        """

        Decorator that checks if a database connection is active before executing function

        """

        @wraps(func)

        def wrapped(inst, *args, **kwargs):

            if not getattr(inst, 'connection', False):

                QMessageBox(

                    QMessageBox.Warning,

                    "Menu Builder",

                    inst.tr("Not connected to any database, please select one"),

                    QMessageBox.Ok,

                    inst

                )

                return

            if inst.connection.closed:

                QMessageBox(

                    QMessageBox.Warning,

                    "Menu Builder",

                    inst.tr("Not connected to any database, please select one"),

                    QMessageBox.Ok,

                    inst

                )

                return

            return func(inst, *args, **kwargs)

        return wrapped

    def connect_to_uri(self, uri):

        self.close_connection()

        self.host = uri.host() or os.environ.get('PGHOST')

        self.port = uri.port() or os.environ.get('PGPORT')

        username = uri.username() or os.environ.get('PGUSER') or os.environ.get('USER')

        password = uri.password() or os.environ.get('PGPASSWORD')

        conninfo = uri.connectionInfo()

        while True:

            try:

                self.connection = psycopg2.connect(uri.connectionInfo(), application_name="QGIS:MenuBuilder")

                break

            except self.pg_error_types() as e:

                err = str(e) or "Erreur d'authentification. Vérifiez les informations saisies."

                ok, username, password = QgsCredentials.instance().get(

                    conninfo, username, password, err)

                if not ok:

                    raise e

                if username:

                    uri.setUsername(username)

                if password:

                    uri.setPassword(password)

        QgsCredentials.instance().put(conninfo, username, password) 

        self.pgencoding = self.connection.encoding

        return True

    def pg_error_types(self):

        return (

            psycopg2.InterfaceError,

            psycopg2.OperationalError,

            psycopg2.ProgrammingError

        )

    @check_connected

    def update_schema_list(self):

        self.combo_schema.clear()

        with self.transaction():

            cur = self.connection.cursor()

            cur.execute("""

                select nspname

                from pg_namespace

                where nspname not ilike 'pg_%'

                and nspname not in ('pg_catalog', 'information_schema')

                """)

            schemas = [row[0] for row in cur.fetchall()]

            self.combo_schema.addItems(schemas)

    @check_connected

    def update_profile_list(self, schemaidx):

        """

        update profile list from database

        """

        schema = self.combo_schema.itemText(schemaidx)

        with self.transaction():

            cur = self.connection.cursor()

            cur.execute("""

                select 1

                from pg_tables

                    where schemaname = '{0}'

                    and tablename = '{1}'

                union

                select 1

                from pg_matviews

                    where schemaname = '{0}'

                    and matviewname = '{1}'

                union

                select 1

                from pg_views

                    where schemaname = '{0}'

                    and viewname = '{1}'

                """.format(schema, self.table))

            tables = cur.fetchone()

            if not tables:

                box = QMessageBox(

                    QMessageBox.Warning,

                    "Menu Builder",

                    self.tr("Table '{}.{}' not found in this database, "

                            "would you like to create it now ?")

                    .format(schema, self.table),

                    QMessageBox.Cancel | QMessageBox.Yes,

                    self

                )

                ret = box.exec_()

                if ret == QMessageBox.Cancel:

                    return False

                elif ret == QMessageBox.Yes:

                    cur.execute("""

                        create table {}.{} (

                            id serial,

                            name varchar,

                            profile varchar,

                            model_index varchar,

                            datasource_uri text

                        )

                        """.format(schema, self.table))

                    self.connection.commit()

                    return False

            cur.execute("""

                select distinct(profile) from {}.{}

                """.format(schema, self.table))

            profiles = [row[0] for row in cur.fetchall()]

            saved_profile = self.combo_profile.currentText()

            self.combo_profile.clear()

            self.combo_profile.addItems(profiles)

            self.combo_profile.setCurrentIndex(self.combo_profile.findText(saved_profile))

    @check_connected

    def delete_profile(self):

        """

        Delete profile currently selected

        """

        idx = self.combo_profile.currentIndex()

        schema = self.combo_schema.currentText()

        profile = self.combo_profile.itemText(idx)

        box = QMessageBox(

            QMessageBox.Warning,

            "Menu Builder",

            self.tr("Delete '{}' profile ?").format(profile),

            QMessageBox.Cancel | QMessageBox.Yes,

            self

        )

        ret = box.exec_()

        if ret == QMessageBox.Cancel:

            return False

        elif ret == QMessageBox.Yes:

            self.combo_profile.removeItem(idx)

            with self.transaction():

                cur = self.connection.cursor()

                cur.execute("""

                    delete from {}.{}

                    where profile = '{}'

                    """.format(schema, self.table, profile))

        self.menumodel.clear()

        self.combo_profile.setCurrentIndex(-1)

    def update_model_idx(self, model, profile_index):

        """

        wrapper that checks combobox

        """

        profile = self.combo_profile.itemText(profile_index)

        schema = self.combo_schema.currentText()

        self.update_model(model, schema, profile)

    def sortby_modelindex(self, rows):

        return sorted(

            rows,

            key=lambda line: '/'.join(

                ['{:04}'.format(elem[0]) for elem in json.loads(line[2])]

            ))

    @check_connected

    def update_model(self, model, schema, profile):

        """

        Update the model by retrieving the profile given in database

        """

        menudict = {}

        with self.transaction():

            cur = self.connection.cursor()

            select = """

                select name, profile, model_index, table_comment, datasource_uri

                from {}.{}

                where profile = '{}'

                """.format(schema, self.table, profile)

            cur.execute(select)

            rows = cur.fetchall()

            model.clear()

            for name, profile, model_index, comment, datasource_uri in self.sortby_modelindex(rows):

                menu = model.invisibleRootItem()

                indexes = json.loads(model_index)

                parent = ''

                for idx, subname in indexes[:-1]:

                    parent += '{}-{}/'.format(idx, subname)

                    if parent in menudict:

                        # already created entry

                        menu = menudict[parent]

                        continue

                    # create menu

                    item = QStandardItem(subname)

                    uri_struct = QgsMimeDataUtils.Uri(datasource_uri)

                    item.setData(uri_struct)

                    item.setIcon(QIcon(':/plugins/MenuBuilder/resources/menu.svg'))

                    item.setFlags(Qt.ItemIsSelectable | Qt.ItemIsUserCheckable |

                                  Qt.ItemIsEnabled | Qt.ItemIsDropEnabled |

                                  Qt.ItemIsEditable)

                    item.setWhatsThis("menu")

                    menu.appendRow(item)

                    menudict[parent] = item

                    # set current menu to the new created item

                    menu = item

                # add leaf (layer item)

                item = QStandardItem(name)

                uri_struct = QgsMimeDataUtils.Uri(datasource_uri)

                # fix layer name instead of table name

                # usefull when the layer has been renamed in menu

                uri_struct.name = name

                if uri_struct.providerKey in ICON_MAPPER:

                    item.setIcon(QIcon(ICON_MAPPER[uri_struct.providerKey]))

                item.setData(uri_struct)

                # avoid placing dragged layers on it

                item.setDropEnabled(False)

                if uri_struct.providerKey == 'postgres':

                    # set tooltip to postgres comment

                    item.setToolTip(comment)

                menudict[parent].appendRow(item)

    @check_connected

    def save_changes(self, save_to_db=True):

        """

        Save changes in the postgres table

        """

        schema = self.combo_schema.currentText()

        profile = self.combo_profile.currentText()

        if not profile:

            QMessageBox(

                QMessageBox.Warning,

                "Menu Builder",

                self.tr("Profile cannot be empty"),

                QMessageBox.Ok,

                self

            ).exec_()

            return False

        if save_to_db:

            try:

                with self.transaction():

                    cur = self.connection.cursor()

                    cur.execute("delete from {}.{} where profile = '{}'".format(

                        schema, self.table, profile))

                    for item, data in self.target.iteritems():

                        if not data:

                            continue

                        cur.execute("""

                        insert into {}.{} (name,profile,model_index,datasource_uri)

                        values (%s, %s, %s, %s)

                        """.format(schema, self.table), (

                            item[-1][1],

                            profile,

                            json.dumps(item),

                            data.data())

                        )

            except Exception as exc:

                QMessageBox(

                    QMessageBox.Warning,

                    "Menu Builder",

                    exc.message.decode(self.pgencoding),

                    QMessageBox.Ok,

                    self

                ).exec_()

                return False

        self.save_session(

            self.combo_database.currentText(),

            schema,

            profile,

            self.activate_dock.isChecked(),

            self.activate_menubar.isChecked()

        )

        self.update_profile_list(self.combo_schema.currentIndex())

        self.show_dock(self.activate_dock.isChecked())

        self.show_menus(self.activate_menubar.isChecked())

        return True

    @check_connected

    def load_menus(self, profile=None, schema=None):

        """

        Load menus in the main windows qgis bar

        """

        if not schema:

            schema = self.combo_schema.currentText()

        if not profile:

            profile = self.combo_profile.currentText()

        # remove previous menus

        for menu in self.uiparent.menus:

            self.uiparent.iface.mainWindow().menuBar().removeAction(menu.menuAction())

        with self.transaction():

            cur = self.connection.cursor()

            select = """

                select name, profile, model_index, table_comment, datasource_uri

                from {}.{}

                where profile = '{}'

                """.format(schema, self.table, profile)

            cur.execute(select)

            rows = cur.fetchall()

        # item accessor ex: '0-menu/0-submenu/1-item/'

        menudict = {}

        # reference to parent item

        parent = ''

        # reference to qgis main menu bar

        menubar = self.uiparent.iface.mainWindow().menuBar()

        for name, profile, model_index, comment, datasource_uri in self.sortby_modelindex(rows):

            uri_struct = QgsMimeDataUtils.Uri(datasource_uri)

            indexes = json.loads(model_index)

            # root menu

            parent = '{}-{}/'.format(indexes[0][0], indexes[0][1])

            if parent not in menudict:

                menu = QMenu(self.uiparent.iface.mainWindow())

                self.uiparent.menus.append(menu)

                menu.setObjectName(indexes[0][1])

                menu.setTitle(indexes[0][1])

                menubar.insertMenu(

                    self.uiparent.iface.firstRightStandardMenu().menuAction(),

                    menu)

                menudict[parent] = menu

            else:

                # menu already there

                menu = menudict[parent]

            for idx, subname in indexes[1:-1]:

                # intermediate submenus

                parent += '{}-{}/'.format(idx, subname)

                if parent not in menudict:

                    submenu = menu.addMenu(subname)

                    submenu.setObjectName(subname)

                    submenu.setTitle(subname)

                    menu = submenu

                    # store it for later use

                    menudict[parent] = menu

                    continue

                # already treated

                menu = menudict[parent]

            # last item = layer

            layer = QAction(name, self)

            if uri_struct.providerKey in ICON_MAPPER:

                layer.setIcon(QIcon(ICON_MAPPER[uri_struct.providerKey]))

            if uri_struct.providerKey == 'postgres':

                # set tooltip to postgres comment

                layer.setStatusTip(comment)

                layer.setToolTip(comment)

            layer.setData(uri_struct.uri)

            layer.setWhatsThis(uri_struct.providerKey)

            layer.triggered.connect(self.layer_handler[uri_struct.layerType])

            menu.addAction(layer)  

    def load_from_index(self, index):

        """Load layers from selected item index"""

        item = self.dock_model.itemFromIndex(self.proxy_model.mapToSource(index))

        if item.whatsThis() == 'menu':

            return

        if item.data().layerType == 'vector':

            layer = QgsVectorLayer(

                item.data().uri,  # uri

                item.text(),  # layer name

                item.data().providerKey  # provider name

            )

        elif item.data().layerType == 'raster':

            layer = QgsRasterLayer(

                item.data().uri,  # uri

                item.text(),  # layer name

                item.data().providerKey  # provider name

            )

        if not layer:

            return

        QgsProject.instance().addMapLayer(layer)

    def load_vector(self):

        action = self.sender()

        layer = QgsVectorLayer(

            action.data(),  # uri

            action.text(),  # layer name

            action.whatsThis()  # provider name

        )

        QgsProject.instance().addMapLayer(layer)

    def load_raster(self):

        action = self.sender()

        layer = QgsRasterLayer(

            action.data(),  # uri

            action.text(),  # layer name

            action.whatsThis()  # provider name

        )

        QgsProject.instance().addMapLayer(layer)

    def accept(self):

        if self.save_changes():

            QDialog.reject(self)

            self.close_connection()

    def apply(self):

        if self.save_changes(save_to_db=False):

            QDialog.reject(self)

            self.close_connection()

    def reject(self):

        self.close_connection()

        QDialog.reject(self)

    def close_connection(self):

        """close current pg connection if exists"""

        if getattr(self, 'connection', False):

            if self.connection.closed:

                return

            self.connection.close()

    def save_session(self, database, schema, profile, dock, menubar):

        """save current profile for next session"""

        settings = QgsSettings()

        settings.setValue("MenuBuilder/database", database)

        settings.setValue("MenuBuilder/schema", schema)

        settings.setValue("MenuBuilder/profile", profile)

        settings.setValue("MenuBuilder/dock", dock)

        settings.setValue("MenuBuilder/menubar", menubar)

    def restore_session(self):

        settings = QgsSettings()

        database = settings.value("MenuBuilder/database", False)

        schema = settings.value("MenuBuilder/schema", 'public')

        profile = settings.value("MenuBuilder/profile", False)

        dock = settings.value("MenuBuilder/dock", False)

        menubar = settings.value("MenuBuilder/menubar", False)

        if not any([database, profile]):

            return

        connected = self.set_connection(0, dbname=database)

        if not connected:

            # don't try to continue

            return

        self.show_dock(bool(dock), profile=profile, schema=schema)

        if bool(dock):

            self.uiparent.iface.addDockWidget(Qt.LeftDockWidgetArea, self.dock_widget)

        self.show_menus(bool(menubar), profile=profile, schema=schema)

        self.close_connection()  

class CustomQtTreeView(QTreeView):

    def dragEnterEvent(self, event):

        if not event.mimeData():

            # don't drag menu entry

            return False

        # refuse if it's not a qgis mimetype

        if event.mimeData().hasFormat(QGIS_MIMETYPE):

            event.acceptProposedAction()

    def keyPressEvent(self, event):

        if event.key() == Qt.Key_Delete:

            model = self.selectionModel().model()

            parents = defaultdict(list)

            for idx in self.selectedIndexes():

                parents[idx.parent()].append(idx)

            for parent, idx_list in parents.items():

                for diff, index in enumerate(idx_list):

                    model.removeRow(index.row() - diff, parent)

        elif event.key() == Qt.Key_Return:

            pass

        else:

            super().keyPressEvent(event)

    def iteritems(self, level=0):

        """

        Dump model to store in database.

        Generates each level recursively

        """

        rowcount = self.model().rowCount()

        for itemidx in range(rowcount):

            # iterate over parents

            parent = self.model().itemFromIndex(self.model().index(itemidx, 0))

            for item, uri in self.traverse_tree(parent, []):

                yield item, uri

    def traverse_tree(self, parent, identifier):

        """

        Iterate over childs, recursively

        """

        identifier.append([parent.row(), parent.text()])

        for row in range(parent.rowCount()):

            child = parent.child(row)

            if child.hasChildren():

                # child is a menu ?

                for item in self.traverse_tree(child, identifier):

                    yield item

                identifier.pop()

            else:

                # add leaf

                sibling = list(identifier)

                sibling.append([child.row(), child.text()])

                yield sibling, child.data()