sugar4.activity

Core activity classes and functionality for Sugar activities.

Submodules

• sugar4.activity.activity
• sugar4.activity.activityhandle
• sugar4.activity.activityinstance
• sugar4.activity.bundlebuilder
• sugar4.activity.widgets

Classes

Activity	Initialise an Activity.
SimpleActivity	A simple activity implementation for quick prototyping.

Package Contents

class sugar4.activity.Activity(handle, create_jobject=True, application=None)

Bases: sugar4.graphics.window.Window

Initialise an Activity.

Parameters:

• handle (ActivityHandle) – instance providing the activity id and access to the presence service which may provide sharing for this application

• create_jobject (boolean) – DEPRECATED: define if it should create a journal object if we are not resuming. The parameter is ignored, and always will be created a object in the Journal.

Signals:

• shared - the activity has been shared on a network in

  order that other users may join,

• joined - the activity has joined with other instances of

  the activity to create a shared network activity.

• closing - the activity is about to close

Side effects:

• sets the display DPI setting (resolution) to the Sugar screen resolution.

• connects our “close-request” signal to our close handling.

• creates a base Gtk.ApplicationWindow within this window.

• creates activity service handling for this application.

When your activity implements __init__(), it must call the Activity class __init__() before any Activity specific code.

__gtype_name__ = 'SugarActivity'

__gsignals__

shared_activity = None

sugar_accel_group = None

add_stop_button(button)

Register an extra stop button. Normally not required. Use only when an activity has more than the default stop button.

Parameters:

button (Gtk.Button) – a stop button

iconify()

Iconify the activity window.

show()

Show the activity window.

In GTK4, ApplicationWindow uses present() instead of show(). This method provides compatibility with the activityinstance API.

run_main_loop()

Run the main loop for the activity.

Note: In modern applications, this is typically handled by the application framework, but we keep this for compatibility with legacy code.

get_active()

Get whether the activity is active. An activity may be made inactive by the shell as a result of another activity being active. An active activity accumulates usage metrics.

Returns:

if the activity is active.

Return type:

boolean

set_active(active)

Set whether the activity is active. An activity may declare itself active or inactive, as can the shell. An active activity accumulates usage metrics.

Parameters:

active (boolean) – if the activity is active.

active

Whether an activity is active.

get_max_participants()

Get the maximum number of users that can share a instance of this activity. Should be configured in the activity.info file. When not configured, it will be zero.

Returns:

the maximum number of participants

Return type:

int

See also get_max_participants() in ActivityBundle.

set_max_participants(participants)

Set the maximum number of users that can share a instance of this activity. An activity may use this method instead of or as well as configuring the activity.info file. When both are used, this method takes precedence over the activity.info file.

Parameters:

participants (int) – the maximum number of participants

max_participants

get_id()

Get the activity id, a likely-unique identifier for the instance of an activity, randomly assigned when a new instance is started, or read from the journal object metadata when a saved instance is resumed.

Returns:

the activity id

Return type:

str

See also create_activity_id() and unique_id().

get_bundle_id()

Returns:

the bundle_id from the activity.info file

Return type:

str

get_canvas()

Get the canvas.

Returns:

the widget used as canvas

Return type:

Gtk.Widget

set_canvas(canvas)

Set the canvas.

Parameters:

canvas (Gtk.Widget) – the widget used as canvas

canvas

The Gtk.Widget used as canvas, or work area of your activity. A common canvas is Gtk.ScrolledWindow.

get_activity_root()

Deprecated. This part of the API has been moved out of this class to the module itself

abstractmethod read_file(file_path)

Subclasses implement this method if they support resuming objects from the journal. ‘file_path’ is the file to read from.

You should immediately open the file from the file_path, because the file_name will be deleted immediately after returning from read_file().

Once the file has been opened, you do not have to read it immediately: After you have opened it, the file will only be really gone when you close it.

Although not required, this is also a good time to read all meta-data: the file itself cannot be changed externally, but the title, description and other metadata[‘tags’] may change. So if it is important for you to notice changes, this is the time to record the originals.

Parameters:

file_path (str) – the file path to read

abstractmethod write_file(file_path)

Subclasses implement this method if they support saving data to objects in the journal. ‘file_path’ is the file to write to.

If the user did make changes, you should create the file_path and save all document data to it.

Additionally, you should also write any metadata needed to resume your activity. For example, the Read activity saves the current page and zoom level, so it can display the page.

Note: Currently, the file_path WILL be different from the one you received in read_file(). Even if you kept the file_path from read_file() open until now, you must still write the entire file to this file_path.

Parameters:

file_path (str) – complete path of the file to write

notify_user(summary, body)

Display a notification with the given summary and body. The notification will go under the activities icon in the frame.

Note: In GTK4/Flatpak, this uses the portal notification system.

get_preview()

Get a preview image from the canvas, for use as metadata for the journal object. This should be what the user is seeing at the time.

Returns:

image data in PNG format

Return type:

bytes

Activities may override this method, and return a string with image data in PNG format with a width and height of PREVIEW_SIZE pixels.

The method creates a Cairo surface for the canvas widget, draws on it, then resizes to a surface with the preview size.

save()

Save to the journal.

This may be called by the close() method.

Activities should not override this method. This method is part of the public API of an activity, and should behave in standard ways. Use your own implementation of write_file() to save your activity specific data.

copy()

Make a copy of the journal object.

Activities may use this to ‘Keep in Journal’ the current state of the activity. A new journal object will be created for the running activity.

Activities should not override this method. Instead, like save() do any copy work that needs to be done in write_file().

get_shared_activity()

Get the shared activity of type sugar4.presence.activity.Activity, or None if the activity is not shared, or is shared and not yet joined.

Returns:

instance of

the shared activity or None

Return type:

sugar4.presence.activity.Activity

get_shared()

Get whether the activity is shared.

Returns:

the activity is shared.

Return type:

bool

invite(account_path, contact_id)

Invite a buddy to join this activity.

Parameters:

• account_path – account path

• contact_id – contact ID

Side Effects:

Calls share() to privately share the activity if it wasn’t shared before.

abstractmethod share(private=False)

Request that the activity be shared on the network.

Parameters:

private (bool) – True to share by invitation only, False to advertise as shared to everyone.

Once the activity is shared, its privacy can be changed by setting the private property of the sugar4.presence.activity.Activity class.

can_close()

Return whether close() is permitted.

An activity may override this function to code extra checks before closing.

Returns:

whether close() is permitted by activity, default True.

Return type:

bool

close(skip_save=False)

Save to the journal and stop the activity.

Activities should not override this method, but should implement write_file() to do any state saving instead. If the activity wants to control whether it can close, it should override can_close().

Parameters:

skip_save (bool) – avoid last-chance save; but does not prevent a journal object, as an object is created when the activity starts. Use this when an activity calls save() just prior to close().

get_metadata()

Get the journal object metadata.

Returns:

the journal object metadata, or None if there is no object.

Return type:

dict

Activities can set metadata in write_file() using:

self.metadata['MyKey'] = 'Something'

and retrieve metadata in read_file() using:

self.metadata.get('MyKey', 'aDefaultValue')

Make sure your activity works properly if one or more of the metadata items is missing. Never assume they will all be present.

metadata

abstractmethod handle_view_source()

An activity may override this method to show additional information in the View Source window. Examples can be seen in Browse and TurtleArt.

Raises:

NotImplementedError –

get_document_path(async_cb, async_err_cb)

Not implemented.

busy()

Show that the activity is busy. If used, must be called once before a lengthy operation, and unbusy() must be called after the operation completes.

self.busy()
self.long_operation()
self.unbusy()

unbusy()

Show that the activity is not busy. An equal number of calls to unbusy() are required to balance the calls to busy().

Returns:

a count of further calls to unbusy() expected

Return type:

int

class sugar4.activity.SimpleActivity(handle=None, application=None)

Bases: Activity

A simple activity implementation for quick prototyping.

This provides a basic activity with a toolbar and content area.