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Currently eframe [calls
`prevent_default()`](962c7c7516/crates/eframe/src/web/events.rs (L307-L369))
for all copy / paste events on the
[*document*](962c7c7516/crates/eframe/src/web/events.rs (L88)),
making embedding an egui application in a page (e.g. an react
application) hard (as all copy & paste functionality for other elements
on the page is broken by this).
I'm not sure what the motivation for this is, if any.
This commit / PR adds a callback (`should_prevent_default`), similar to
`should_propgate_event`, that an egui application can use to overwrite
this behavior. It defaults to returning `true` for all events, to keep
the existing behavior.
I call `should_prevent_default` in every place that
`should_propagate_event` is called (which is not all places that
`prevent_default` is called!). I'm not sure for the motivation of not
calling `should_propagate_event` everywhere that `stop_propagation` is
called, but I kept that behavior for the `should_prevent_default`
callback too.
Please let me know if I'm missing some existing functionality that would
allow me to do this, or if there's a reason that we don't want
applications to be able to customize this (i.e. if there's a reason to
always `prevent_default` for all copy / paste events on the whole
document)
ab0f0b7b64