Until now, every event has had a particular target. We're about to simplify
key event delivery to match the first matching filter, so there is no
longer a global meaning to the tag argument to Source.Event.
Add fields to filters to specify their target tags.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
If the client asks for the focus to be set to a tag, allow it. There is a
check at the end of Router.Frame that clears the focus if the tag turns
out to fail the requirements (visible and has asked for FocusEvents).
The change simplifies the logic for determining whether a command can
be executed immediately.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Processing one event at a time allows a widget to execute commands after
the event that triggered it, instead of after all matching events.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Change the semantics of commands to execute immediately. In cases where
execution of a command introduces a inconsistency, freeze event routing
and defer the command as well as queued events to the next frame.
Rename Source.Queue to Source.Execute to better fit the new command
semantics.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
This change defers event routing from the time the event is queued until
the time Events is called. This allows a future change to execute
commands immediately and to react to event order changes during a frame.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Refactor delivery of reset events to be resolved and delivered as part of
Source.Events. This is a preparation for changing event handling to be
lazy.
Reset events are delivered to event handlers that are either new or
haven't been active in the previous frame for a particular event type
(pointer or key events), to ensure the handler state is reset.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Instead of having to supply the predicates for event filtering at the
time of layout, the new Filter type allows widgets to filter at the time
of calling Source.Events. There is then only the need for a single input
op type, in package event.
Filters most importantly allow the use of one tag for several event types,
and we can define that a widget w has &w as its primary tag, by convention.
This allows the replacement of per-widget Focus methods with direct uses
of FocusCmd{&w}, and the later addition of Source.Focused(&w) queries.
Note that the TestCursor test needed restructuring to avoid its use of
InputOps.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Modeling focus change as an operation is awkward, because focus changes
logically happen during event processing, not layout. In particular, you
want to apply focus changes even if a widget is subsequently never laid
out.
Now that input.Source is concrete, it's much more straightforward to
offer focus changes as a command which can be queued through the
Source. A future change may similarly offer a command for directional
focus changes.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Elias Naur