Files
react-native/ReactCommon/utils/RunLoopObserver.cpp
T
Valentin Shergin d76e03f85a Fabric: Introducing RunLoopObserver
Summary:
`RunLoopObserver` is one of the core interfaces that bridge intrinsically platform-specific functionality to cross-platform React Native core. `RunLoopObserver` allows subscribing for notifications about changes in a run loop life cycle. Primarily it supposed to be used for observing UI (aka main) and JavaScript execution thread/run-loop.
Having a `RunLoopObserver` implemented in a platform-specific manner allows building these components in a cross-platform manner:
* Sync and async UI event delivery pipeline;
* Timing for some animation engine;
* Timers (probably additional features are required).

Changelog: [Internal] Fabric-specific internal change.

Reviewed By: sammy-SC

Differential Revision: D21341997

fbshipit-source-id: 7ef61fb51f550dd0f2e89c64af657e0f0de029aa
2020-05-06 18:28:52 -07:00

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1.4 KiB
C++

/*
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
#include "RunLoopObserver.h"
#include <cassert>
namespace facebook {
namespace react {
RunLoopObserver::RunLoopObserver(
Activity activities,
WeakOwner const &owner) noexcept
: activities_(activities), owner_(owner) {}
void RunLoopObserver::setDelegate(Delegate const *delegate) const noexcept {
// We need these constraints to ensure basic thread-safety.
assert(delegate && "A delegate must not be `nullptr`.");
assert(!delegate_ && "`RunLoopObserver::setDelegate` must be called once.");
delegate_ = delegate;
}
void RunLoopObserver::enable() const noexcept {
if (enabled_) {
return;
}
enabled_ = true;
startObserving();
}
void RunLoopObserver::disable() const noexcept {
if (!enabled_) {
return;
}
enabled_ = false;
stopObserving();
}
void RunLoopObserver::activityDidChange(Activity activity) const noexcept {
if (!enabled_) {
return;
}
assert(
!owner_.expired() &&
"`owner_` is null. The caller must `lock` the owner and check it for being not null.");
delegate_->activityDidChange(delegate_, activity);
}
RunLoopObserver::WeakOwner RunLoopObserver::getOwner() const noexcept {
return owner_;
}
} // namespace react
} // namespace facebook