Unify the task source and task canceller API

I moved away from the `Window` struct all the logic to handle task
sources, into a new struct called `TaskManager`. In a happy world, I'd
be able to just have there two functions, of the types:

```rust
fn task_source<T: TaskSource>(&self, name: TaskSourceName) -> Box<T>
fn task_source_with_canceller<T: TaskSource>(&self, name: TaskSourceName)
  -> (Box<T>, TaskSourceCanceller)
```

And not so much duplicated code. However, because TaskSource can't be a
trait object (because it has generic type parameters), that's not
possible. Instead, I decided to reduce duplicated logic through macros.

For reasons[1], I have to pass both the name of the function with
canceller and the name of the function without, as I'm not able to
concatenate them in the macro itself. I could probably use
`concat_idents` to create both types already defined and reduce the
amount of arguments by one, but that macro is nightly only. At the same
time, not being able to declare macros inside `impl` forces me to pass
`self` as an argument.

All this makes this solution more verbose than it would be ideally. It
does reduce duplication, but it doesn't reduce the size of the file.

[1](https://github.com/rust-lang/rust/issues/29599)
This commit is contained in:
Agustin Chiappe Berrini 2018-09-24 19:31:59 -04:00
parent 14bc8ab754
commit 75eb94afca
26 changed files with 362 additions and 252 deletions

View file

@ -17,7 +17,7 @@ use crate::dom::bindings::refcounted::Trusted;
use crate::dom::bindings::reflector::reflect_dom_object;
use crate::dom::bindings::root::DomRoot;
use crate::dom::window::Window;
use crate::task_source::{TaskSource, TaskSourceName};
use crate::task_source::TaskSource;
use dom_struct::dom_struct;
use ipc_channel::ipc::{self, IpcReceiver};
use ipc_channel::router::ROUTER;
@ -97,8 +97,9 @@ impl AnalyserNode {
) -> Fallible<DomRoot<AnalyserNode>> {
let (node, recv) = AnalyserNode::new_inherited(window, context, options)?;
let object = reflect_dom_object(Box::new(node), window, AnalyserNodeBinding::Wrap);
let source = window.dom_manipulation_task_source();
let canceller = window.task_canceller(TaskSourceName::DOMManipulation);
let (source, canceller) = window
.task_manager()
.dom_manipulation_task_source_with_canceller();
let this = Trusted::new(&*object);
ROUTER.add_route(