Commit Graph

5 Commits

Author SHA1 Message Date
Evan Welsh
a88e59c1a8 Adopt EventEmitter class instead of injecting Signal methods
Introduce a new class, EventEmitter, which implements signal
handling for pure JavaScript classes. EventEmitter still
utilizes GJS' addSignalMethods internally.

EventEmitter allows static typechecking to understand the
structure of event-emitting JS classes and makes creating
child classes simpler.

The name 'EventEmitter' mirrors a common name for this pattern
in Node and in JS libraries.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2043>
2022-07-04 18:30:49 -04:00
Florian Müllner
fc4f9f61fa signalTracker: Explicitly register destroyable types
We currently assume that any '::destroy' signal on a GObject type
has the semantics of the ClutterActor/GtkWidget signal, and should
therefore result in all signals being disconnected.

But we already have a case where the assumption doesn't hold: ShellWM
uses '::destroy' for the closing animation of windows, and the ShellWM
object itself remains very valid after the emission.

So rather than making assumptions about '::destroy', check objects
against a list of destroyable types that are explicitly registered
as such.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2226>
2022-03-06 00:10:03 +00:00
Florian Müllner
cf29ec2f22 signalTracker: Add TransientSignalHolder class
There are cases where we want to connect to a number of signals
for the lifetime of an object, but also other signals for a
limited period (say: between show and hide).

It is currently not possible to use disconnectObject() for the
latter, because it will disconnect all signals.

To address this use case, add a small class that can be used as
a transient signal holder, while still benefiting from autocleanup
by proxying the real owner.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2221>
2022-03-05 00:12:27 +00:00
Florian Müllner
7b0a94b246 signalTracker: Use connect_after to track 'destroy'
The 'destroy' signal currently doesn't work with connectObject(),
because the handler is only connected after the signal tracker's
own destroy handler, which disconnects all handlers.

Address this by using connect_after for the cleanup handler, so
that other destroy handlers run before it (unless they also use
ConnectFlags.AFTER, but well *shrug*).

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2221>
2022-03-05 00:12:27 +00:00
Florian Müllner
f45ccc9143 signalTracker: Provide monkey-patching for (dis)connectObject()
The module exports a `addObjectSignalMethods()` method that extends
the provided prototype with `connectObject()` and `disconnectObject()`
methods.

In its simplest form, `connectObject()` looks like the regular
`connect()` method, except for an additional parameter:

```js
    this._button.connectObject('clicked',
        () => this._onButtonClicked(), this);
```

The additional object can be used to disconnect all handlers on the
instance that were connected with that object, similar to
`g_signal_handlers_disconnect_by_data()` (which cannot be used
from introspection).

For objects that are subclasses of Clutter.Actor, that will happen
automatically when the actor is destroyed, similar to
`g_signal_connect_object()`.

Finally, `connectObject()` allows to conveniently connect multiple
signals at once, similar to `g_object_connect()`:

```js
    this._toggleButton.connect(
        'clicked', () => this._onClicked(),
        'notify::checked', () => this._onChecked(), this);
```

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1953>
2022-03-04 14:14:37 +00:00