This code is ugly and terrible but it works™. Previsously when a download
would finish it would refresh all the views. Now the if the widget get's
into the Donwloading state, it will setup a callback that will check
periodicly if it's still downloading and update the widget state when
the episode stops downloading.
Since gtk Widgets are not Send, and the callbacks all run in the gtk
main loop, it *should* not be possible that 2 things try to access the
same widget at the same time.
When iteration of data is finished, None will be returned and
the or_else() block will be executed. Now a callback can be
passed that will be executd when the iteration/loading finishes.
Previously we would refresh all the views when download/cancel
button was clicked. This was done mainly to avoid zombie widget bugs
that would arise from shared state.
Now we still refresh all the background views but not the visible one.
Instead the widget has the reponsibility of recalculating it's state.
make the data: Vec<T> mutable, then reverse the vector
so it can be used as a stack, and then use the ::pop()
method to retrieve the item.
This also avoid the constrain for Clone on T.
The state machines are not send and the code is sequnecial.
We only need `&mut machine` refference to pass to `take_mut::take`
to change the state of the machine. In 2/3 cases we can even use
`.get_mut()` method and even avoid the dynamic borrow checks at
runtime. For the `TitleMachine` The only thing that will hold
a refference to it after initialization will be the play_button
callback. So it's justifiable to use `RefCell` insetead of a `Mutex`.
`DateMachine` and `DurationMachine` are only mutated during initialization
and thus do not need shared ownership.
`TitleMachine` is only mutated during initialization and after that only
the callback will keep holding a referrence to it. The `EpisodeWidget`s
get dropped after initialization. So it's justifiable to use `Rc<Mutex<T>>`
instead of `Arc`.
Add a ButtonState Machine which represents the state of total_size
label, play button, and download button. Also implemented the
update/determine_state function for ButtonState.
Also implemented required generic functions for MediaMachine<X,Y,Z>
that convert it to the desired state.
Currently it's required that you take mut self in order to manipulate
the internal state machines. This would not allow passing an Arc/Rc to
a callback since A/Rc<T> only derefs to &T and not T.
The take_mut crate allows the retrieval of ownership if you have a &mut refference
and as long you return T again. So Arc<Mutex<Machine> could work with
callbacks and embed Nested state machies without copying.
Before we were avoiding reloading the widget in view by
directly dimming the title label. Now instead we reload
the whole widget since I can't figure out a way to have
multiple Owneded refferences of the same state machine.
