This used to conflict with the util crate from the standard library, which
has long since been removed.
The import in layout has not been changed because of a conflict with the
util mod there.
The set_ids name is a holdover from a previous design and no longer
reflects what this method does. Instead move the content into
grant_paint_permission and rename it to
send_frame_tree_and_grant_paint_permission. Also move out the handling of
evicted iframes into its own method.
When the constellation change a FrameTree pipeline, it should send a
notification to the compositor, so that it can negotiate buffers from
the correct render task. This commit also migrates away from the
generalized FrameTreeUpdateMsg to ones specific to the situation at
hand. That turned out to be an unnecessary abstraction.
Instead of simply creating a new FrameTree when an iframe starts a
load, update the existing FrameTree's pipeline. This prevents the
FrameTree from accumulating many extra children.
Instead of cloning pipelines and storing them once per layer, store
them globally in the compositor and access them via id. This trades
lots of unnecessary duplication for a HashMap lookup.
It is possible for messages for defunct pipelines to arrive in the
compositor. If the compositor believes that the pipelines are in the
process of shutting down, simply ignore the messages. We still panic in
the case that the pipeline is totally unknown.
Fixes#3733.
Notes:
* This adds `#![allow(missing_copy_implementations)]` to components/*/lib.rs. I'm not sure how to approach the missing Copy warnings (are there things for which Copy should NOT be implemented, and how can I tell?) so I stuck this in to make life easier when looking through the warnings. I can easily remove this if necessary.
* This leaves the following type of warnings, which I couldn't figure out how to approach (I'll investigate it later if no one else wants to).
```
css/matching.rs:72:23: 72:35 warning: use of deprecated item: Use overloaded core::cmp::PartialEq, #[warn(deprecated)] on by default
css/matching.rs:72 this_as_query.equiv(other)
^~~~~~~~~~~~
css/matching.rs:95:10: 95:49 warning: use of deprecated item: Use overloaded core::cmp::PartialEq, #[warn(deprecated)] on by default
css/matching.rs:95 impl<'a> Equiv<ApplicableDeclarationsCacheEntry> for ApplicableDeclarationsCacheQuery<'a> {
```
The term "root layer" is used in the compositor to refer to both the
pipeline root layer and the page background layer. This can be quite
confusing. Instead, call the page background layer the "base layer,"
which is always the first child of the pipeline root layer.
It is possible for a PaintTask to start exiting soon after sending new
buffers to the compositor. In that case, the compositor should return
the now unnecessary buffers to the PaintTask so that it can properly
free them.
To accomplish this, the compositor now keeps a hash map of paint task
channels per pipeline id. When a PaintTask exists, the constellation
informs the compositor that it can forget about it. Additionally, the
PaintTask should not wait for any buffers when the engine is doing a
complete shutdown. In that case, the compositor is already halted and
has simply let all buffers leak. We pipe through the shutdown type when
destroying the pipeline to make this decision.
Fixes#2641.
When finding the layer under a point, take into account clipping
rectangles defined by layers that mask to bounds. This prevents clicks
from being hijacked by masked layers.
