OpenSlides/openslides/utils/projector.py
Norman Jäckel dc7d27a985 Added REST API for projector. Introduced new projector API.
Added custom slide projector element class.
Added welcome slide as custom slide.
Added user slide projector element class.
Added clock, countdown ans message projector elements.
Renamed SignalConnectMetaClass classmethod get_all_objects to get_all (private API).
Added migrations to core app.
Fixed and wrote tests.
Updated CHANGELOG.
2015-05-29 12:44:25 +02:00

67 lines
2.1 KiB
Python

from django.dispatch import Signal
from .dispatch import SignalConnectMetaClass
class ProjectorElement(object, metaclass=SignalConnectMetaClass):
"""
Base class for an element on the projector.
Every app which wants to add projector elements has to create classes
subclassing from this base class with different names. The name and
scripts attributes have to be set. The metaclass
(SignalConnectMetaClass) does the rest of the magic.
"""
signal = Signal()
name = None
scripts = None
def __init__(self, **kwargs):
"""
Initializes the projector element instance. This is done when the
signal is sent.
Because of Django's signal API, we have to take wildcard keyword
arguments. But they are not used here.
"""
pass
@classmethod
def get_dispatch_uid(cls):
"""
Returns the classname as a unique string for each class. Returns None
for the base class so it will not be connected to the signal.
"""
if not cls.__name__ == 'ProjectorElement':
return cls.__name__
def get_data(self, projector_object, config_entry):
"""
Returns all data to be sent to the client. The projector object and
the config entry have to be given.
"""
self.projector_object = projector_object
self.config_entry = config_entry
assert self.config_entry.get('name') == self.name, (
'To get data of a projector element, the correct config entry has to be given.')
return {
'scripts': self.get_scripts(),
'context': self.get_context()}
def get_scripts(self):
"""
Returns ...?
"""
# TODO: Write docstring
if self.scripts is None:
raise NotImplementedError(
'A projector element class must define either a '
'get_scripts method or have a scripts argument.')
return self.scripts
def get_context(self):
"""
Returns the context of the projector element.
"""
return None