react-native/ReactCommon/fabric/events/EventEmitter.cpp

84 lines
2.0 KiB
C++

/**
* Copyright (c) 2015-present, Facebook, Inc.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
#include "EventEmitter.h"
#include <folly/dynamic.h>
#include "RawEvent.h"
namespace facebook {
namespace react {
// TODO(T29874519): Get rid of "top" prefix once and for all.
/*
* Capitalizes the first letter of the event type and adds "top" prefix
* (e.g. "layout" becames "topLayout").
*/
static std::string normalizeEventType(const std::string &type) {
std::string prefixedType = type;
prefixedType[0] = toupper(prefixedType[0]);
prefixedType.insert(0, "top");
return prefixedType;
}
std::recursive_mutex &EventEmitter::DispatchMutex() {
static std::recursive_mutex mutex;
return mutex;
}
EventEmitter::EventEmitter(const EventTarget &eventTarget, const Tag &tag, const std::shared_ptr<const EventDispatcher> &eventDispatcher):
eventTarget_(eventTarget),
tag_(tag),
eventDispatcher_(eventDispatcher) {}
void EventEmitter::dispatchEvent(
const std::string &type,
const folly::dynamic &payload,
const EventPriority &priority
) const {
const auto &eventDispatcher = eventDispatcher_.lock();
if (!eventDispatcher) {
return;
}
// Mixing `target` into `payload`.
assert(payload.isObject());
folly::dynamic extendedPayload = folly::dynamic::object("target", tag_);
extendedPayload.merge_patch(payload);
std::weak_ptr<const EventEmitter> weakEventEmitter = shared_from_this();
eventDispatcher->dispatchEvent(
RawEvent(
normalizeEventType(type),
extendedPayload,
eventTarget_,
[weakEventEmitter]() {
auto eventEmitter = weakEventEmitter.lock();
if (!eventEmitter) {
return false;
}
return eventEmitter->getEnabled();
}
),
priority
);
}
void EventEmitter::setEnabled(bool enabled) const {
enabled_ = enabled;
}
bool EventEmitter::getEnabled() const {
return enabled_;
}
} // namespace react
} // namespace facebook