test_select_nodes_tree.py

import toga

class StartApp(toga.App):
    def startup(self):
        # Main window
        self.main_window = toga.MainWindow(self.name)
        self.main_window.app = self

        # Tree data source
        tree_data = {
                    'root1' : {},
                    'root2': {
                        'sub1_root2' : {},
                        'sub2_root2' : 'sub2_sub1_root2'
                        },
                    'root3': 'sub1_root3',
                    }

        # Tree widget from Toga with data source and a function to call
        #   when any node is selected
        self.tree = toga.Tree(['Navigate'], data=tree_data,
                            on_selection=self.selection_test)

        # Text Input to show the text of the selected nodes
        self.input = toga.TextInput(initial='No node was selected')
        self.input_box = toga.Box(children=[self.input])

        # Main widget of the application, show both the Tree data and the
        #   buttons to control thee application
        frame = toga.SplitContainer()
        frame.content = [self.tree, self.input_box]

        # Add the main widget inside of the main application
        self.main_window.content = frame
        # Show the application
        self.main_window.show()

    def selection_test(self, nodes):
        # Add the nodes texts selected by the user inside of the text input box
        self.input.value = ', '.join(node.text for node in nodes)

def main():
    # Start the application with the title and the name of the organization
    app = StartApp('Test Tree multiple selection', 'org.pybee.test')
    app.main_loop()

if __name__ == '__main__':
    main()