material.Clickable is useful for adding a click response to any widget
or area.
Rename widget.Button to widget.Clickable to reflect the wider use
spectrum.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Before this change, the widget.Button.Layout method assumed the caller had set
up the pointer hit area before. Further, the very common rectangular hit
areas needed both an AreaOp and a widget.Button.Layout call.
Make widget.Button less subtle and more useful by setting up a
pointer hit area given by the incoming minimum constraints.
Drop a pointer.AreaOp made redundant by the change.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
It was left over from a previous approach to enable the program
to decide the ordering between calls to Layout vs Clicked.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Determining the enabled state of a widget from whether its Clicked method has
been called only works for button-like widgets. For example, it's not clear a
Clicked method is appropriate for a CheckBox.
Remove the feature for now, and let's find a better design in the future.
As a nice side effect, we can now process events in Layout methods, so that
buttons react to user input even when Clicked is not called.
Signed-off-by: Elias Naur <mail@eliasnaur.com>