react-native/React/Base/RCTEventDispatcher.m

236 lines
6.3 KiB
Objective-C

/**
* Copyright (c) 2015-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*/
#import "RCTEventDispatcher.h"
#import "RCTAssert.h"
#import "RCTBridge.h"
#import "RCTBridge+Private.h"
#import "RCTUtils.h"
#import "RCTProfile.h"
const NSInteger RCTTextUpdateLagWarningThreshold = 3;
NSString *RCTNormalizeInputEventName(NSString *eventName)
{
if ([eventName hasPrefix:@"on"]) {
eventName = [eventName stringByReplacingCharactersInRange:(NSRange){0, 2} withString:@"top"];
} else if (![eventName hasPrefix:@"top"]) {
eventName = [[@"top" stringByAppendingString:[eventName substringToIndex:1].uppercaseString]
stringByAppendingString:[eventName substringFromIndex:1]];
}
return eventName;
}
static NSNumber *RCTGetEventID(id<RCTEvent> event)
{
return @(
event.viewTag.intValue |
(((uint64_t)event.eventName.hash & 0xFFFF) << 32) |
(((uint64_t)event.coalescingKey) << 48)
);
}
@implementation RCTEventDispatcher
{
// We need this lock to protect access to _events, _eventQueue and _eventsDispatchScheduled. It's filled in on main thread and consumed on js thread.
NSLock *_eventQueueLock;
// We have this id -> event mapping so we coalesce effectively.
NSMutableDictionary<NSNumber *, id<RCTEvent>> *_events;
// This array contains ids of events in order they come in, so we can emit them to JS in the exact same order.
NSMutableArray<NSNumber *> *_eventQueue;
BOOL _eventsDispatchScheduled;
NSHashTable<id<RCTEventDispatcherObserver>> *_observers;
NSLock *_observersLock;
}
@synthesize bridge = _bridge;
RCT_EXPORT_MODULE()
- (void)setBridge:(RCTBridge *)bridge
{
_bridge = bridge;
_events = [NSMutableDictionary new];
_eventQueue = [NSMutableArray new];
_eventQueueLock = [NSLock new];
_eventsDispatchScheduled = NO;
_observers = [NSHashTable weakObjectsHashTable];
_observersLock = [NSLock new];
}
- (void)sendAppEventWithName:(NSString *)name body:(id)body
{
[_bridge enqueueJSCall:@"RCTNativeAppEventEmitter"
method:@"emit"
args:body ? @[name, body] : @[name]
completion:NULL];
}
- (void)sendDeviceEventWithName:(NSString *)name body:(id)body
{
[_bridge enqueueJSCall:@"RCTDeviceEventEmitter"
method:@"emit"
args:body ? @[name, body] : @[name]
completion:NULL];
}
- (void)sendInputEventWithName:(NSString *)name body:(NSDictionary *)body
{
if (RCT_DEBUG) {
RCTAssert([body[@"target"] isKindOfClass:[NSNumber class]],
@"Event body dictionary must include a 'target' property containing a React tag");
}
name = RCTNormalizeInputEventName(name);
[_bridge enqueueJSCall:@"RCTEventEmitter"
method:@"receiveEvent"
args:body ? @[body[@"target"], name, body] : @[body[@"target"], name]
completion:NULL];
}
- (void)sendTextEventWithType:(RCTTextEventType)type
reactTag:(NSNumber *)reactTag
text:(NSString *)text
key:(NSString *)key
eventCount:(NSInteger)eventCount
{
static NSString *events[] = {
@"focus",
@"blur",
@"change",
@"submitEditing",
@"endEditing",
@"keyPress"
};
NSMutableDictionary *body = [[NSMutableDictionary alloc] initWithDictionary:@{
@"eventCount": @(eventCount),
@"target": reactTag
}];
if (text) {
body[@"text"] = text;
}
if (key) {
if (key.length == 0) {
key = @"Backspace"; // backspace
} else {
switch ([key characterAtIndex:0]) {
case '\t':
key = @"Tab";
break;
case '\n':
key = @"Enter";
default:
break;
}
}
body[@"key"] = key;
}
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
[self sendInputEventWithName:events[type] body:body];
#pragma clang diagnostic pop
}
- (void)sendEvent:(id<RCTEvent>)event
{
[_observersLock lock];
for (id<RCTEventDispatcherObserver> observer in _observers) {
[observer eventDispatcherWillDispatchEvent:event];
}
[_observersLock unlock];
[_eventQueueLock lock];
NSNumber *eventID = RCTGetEventID(event);
id<RCTEvent> previousEvent = _events[eventID];
if (previousEvent) {
RCTAssert([event canCoalesce], @"Got event %@ which cannot be coalesced, but has the same eventID %@ as the previous event %@", event, eventID, previousEvent);
event = [previousEvent coalesceWithEvent:event];
} else {
[_eventQueue addObject:eventID];
}
_events[eventID] = event;
BOOL scheduleEventsDispatch = NO;
if (!_eventsDispatchScheduled) {
_eventsDispatchScheduled = YES;
scheduleEventsDispatch = YES;
}
// We have to release the lock before dispatching block with events,
// since dispatchBlock: can be executed synchronously on the same queue.
// (This is happening when chrome debugging is turned on.)
[_eventQueueLock unlock];
if (scheduleEventsDispatch) {
[_bridge dispatchBlock:^{
[self flushEventsQueue];
} queue:RCTJSThread];
}
}
- (void)addDispatchObserver:(id<RCTEventDispatcherObserver>)observer
{
[_observersLock lock];
[_observers addObject:observer];
[_observersLock unlock];
}
- (void)removeDispatchObserver:(id<RCTEventDispatcherObserver>)observer
{
[_observersLock lock];
[_observers removeObject:observer];
[_observersLock unlock];
}
- (void)dispatchEvent:(id<RCTEvent>)event
{
[_bridge enqueueJSCall:[[event class] moduleDotMethod] args:[event arguments]];
}
- (dispatch_queue_t)methodQueue
{
return RCTJSThread;
}
// js thread only (which surprisingly can be the main thread, depends on used JS executor)
- (void)flushEventsQueue
{
[_eventQueueLock lock];
NSDictionary *events = _events;
_events = [NSMutableDictionary new];
NSMutableArray *eventQueue = _eventQueue;
_eventQueue = [NSMutableArray new];
_eventsDispatchScheduled = NO;
[_eventQueueLock unlock];
for (NSNumber *eventId in eventQueue) {
[self dispatchEvent:events[eventId]];
}
}
@end
@implementation RCTBridge (RCTEventDispatcher)
- (RCTEventDispatcher *)eventDispatcher
{
return [self moduleForClass:[RCTEventDispatcher class]];
}
@end