Application

The app is the main entry point and container for the Toga GUI.

Usage

The app class is used by instantiating with a name, namespace and callback to a startup delegate which takes 1 argument of the app instance.

To start a UI loop, call app.main_loop()

import toga


def build(app):
    # build UI
    pass


if __name__ == '__main__':
    app = toga.App('First App', 'org.pybee.helloworld', startup=build)
    app.main_loop()

Alternatively, you can subclass App and implement the startup method

import toga


class MyApp(toga.App):
    def startup(self):
        # build UI
        pass


if __name__ == '__main__':
    app = MyApp('First App', 'org.pybee.helloworld', startup=build)
    app.main_loop()

Supported Platforms

Component	iOS	win32	web	django	cocoa	gtk	android
App

Reference

class toga.interface.app.App(name, app_id, icon=None, id=None, startup=None, document_types=None)

The App is the top level of any GUI program. It is the manager of all the other bits of the GUI app: the main window and events that window generates like user input.

When you create an App you need to provide it a name, an id for uniqueness (by convention, the identifier is a “reversed domain name”.) and an optional startup function which should run once the App has initialised. The startup function typically constructs some initial user interface.

Once the app is created you should invoke the main_loop() method, which will hand over execution of your program to Toga to make the App interface do its thing.

Here is the absolute minimum App:

app = toga.App('Empty App', 'org.pybee.empty')
app.main_loop()

Instantiate a new application

Parameters:

• name (str) – The name of the application
• app_id (str) – The unique application identifier, the reversed domain name, e.g. ‘org.pybee.me’
• icon (str) – Icon for the application
• id (str) – The DOM identifier for the app (optional)
• startup (callable that expects a single argument of toga.App) – The callback method before starting the app, typically to add the components
• document_types (list of str) – Document types

add_document(doc)

Add a new document to this app.

Parameters:doc – The document to add

app = None

app_id

The identifier for the app.

This is the reversed domain name, often used for targetting resources, etc.

Return type:str

commands

The commands registered with this application.

Return type:CommandSet

documents

Return the list of documents associated with this app.

Return type:list of str

exit()

Shut down the application

id

The DOM identifier for the app.

This id can be used to target CSS directives

Return type:str

main_loop()

Invoke the application to handle user input.

This method typically only returns once the application is exiting.

open_document(fileURL)

Add a new document to this app.

Parameters:fileURL (str) – The URL/path to the file to add as a document

startup()

Create and show the main window for the application