/ 
Clay-UI-0.06
/ Clay::UI::Enum::Result

NAME

Clay::UI::Enum::Result - what an event listener returns: stop the event or let it continue

SYNOPSIS

use v5.22;
use warnings;
use feature 'signatures';
no warnings 'experimental::signatures';

use Object::Pad;
use Clay::UI::Box;
use Clay::UI::Events::OnPress;
use Clay::UI::Enum::Result;

class My::Panel :strict(params) :does(Clay::UI::Box) {}

my $card   = My::Panel->new(id => 'card');
my $button = My::Panel->new(id => 'button');
$card->add_child($button);

$card->on('OnPress', sub ($event) { say 'card saw the press'; return });
$button->on('OnPress', sub ($event) {
	say 'button pressed';
	return Clay::UI::Enum::Result->CONTINUE;   # let the card see it too
});

my $result = $button->fire_event(Clay::UI::Events::OnPress->new);
say 'stopped at ', $result == Clay::UI::Enum::Result->HANDLED ? 'the card' : 'nowhere';

DESCRIPTION

An event listener's return value decides whether the event stops at the listener's widget. Return CONTINUE to let it go on; anything else stops it. The bubble mode of the event decides what stopping means (Clay::UI::Enum::Bubble): with IF_CONTINUE the event does not move on to the parent, with ALWAYS and NEVER it travels as it would anyway, but the widget is still recorded as the event's handled_by.

"fire_event" in Clay::UI::Role::Events::Emitter and "result" in Clay::UI::Events::Event also report the outcome as one of these values.

The values are singleton objects (built with Object::PadX::Enum); compare them with == and !=.

VALUES

HANDLED

return Clay::UI::Enum::Result->HANDLED;

Stops the event at this widget. Returning undef, an empty return, or any other value has the same effect: only CONTINUE lets an event go on. As a result of fire_event: some listener stopped the event, and $event->handled_by names the widget.

CONTINUE

return Clay::UI::Enum::Result->CONTINUE;

Lets the event go on to the parent (with IF_CONTINUE). As a result of fire_event: no listener stopped the event.

METHODS

name, values and from_name work as described in "METHODS" in Clay::UI::Enum::Bubble.

SEE ALSO

Clay::UI::Enum::Bubble, Clay::UI::Role::Events::Emitter, Clay::UI::Role::Events::Listener.