FlutterKeyboardManager Class Reference

#import <FlutterKeyboardManager.h>

Inheritance diagram for FlutterKeyboardManager:

Instance Methods
(nonnull instancetype)	- initWithViewDelegate:
(void)	- handleEvent:
(BOOL)	- isDispatchingKeyEvent:
(void)	- syncModifiersIfNeeded:timestamp:
(nonnull NSDictionary *)	- getPressedState

Detailed Description

Processes keyboard events and cooperate with |TextInputPlugin|.

A keyboard event goes through a few sections, each can choose to handled the event, and only unhandled events can move to the next section:

• Pre-filtering: Events during IME are sent to the system immediately.
• Keyboard: Dispatch to the embedder responder and the channel responder simultaneously. After both responders have responded (asynchronously), the event is considered handled if either responder handles.
• Text input: Events are sent to |TextInputPlugin| and are handled synchronously.
• Next responder: Events are sent to the next responder as specified by |viewDelegate|.

Definition at line 27 of file FlutterKeyboardManager.h.

Method Documentation

getPressedState

- (nonnull NSDictionary *) getPressedState

Returns the keyboard pressed state.

Returns the keyboard pressed state. The dictionary contains one entry per pressed keys, mapping from the logical key to the physical key.

Definition at line 73 of file FlutterKeyboardManager.mm.

                                         {
  // The embedder responder is the first element in _primaryResponders.
  FlutterEmbedderKeyResponder* embedderResponder =
      (FlutterEmbedderKeyResponder*)_primaryResponders[0];
  return [embedderResponder getPressedState];
}

handleEvent:

- (void) handleEvent:

(nonnull NSEvent*)

event

Processes a key event.

Unhandled events will be dispatched to the text input system, and possibly the next responder afterwards.

Definition at line 73 of file FlutterKeyboardManager.mm.

                   :(nonnull NSEvent*)event {
  // The `handleEvent` does not process the event immediately, but instead put
  // events into a queue. Events are processed one by one by `processNextEvent`.
 
  // Be sure to add a handling method in propagateKeyEvent when allowing more
  // event types here.
  if (event.type != NSEventTypeKeyDown && event.type != NSEventTypeKeyUp &&
      event.type != NSEventTypeFlagsChanged) {
    return;
  }
 
  [_pendingEvents addObject:event];
  [self processNextEvent];
}

initWithViewDelegate:

- (nonnull instancetype) initWithViewDelegate:

(nonnull id<FlutterKeyboardViewDelegate>)

viewDelegate

Initial value:

{
  NextResponderProvider _getNextResponder

Create a keyboard manager.

The |viewDelegate| is a weak reference, typically implemented by |FlutterViewController|.

Definition at line 73 of file FlutterKeyboardManager.mm.

                                            :(nonnull id<FlutterKeyboardViewDelegate>)viewDelegate {
  self = [super init];
  if (self != nil) {
    _processingEvent = FALSE;
    _viewDelegate = viewDelegate;
 
    FlutterMethodChannel* keyboardChannel =
        [FlutterMethodChannel methodChannelWithName:@"flutter/keyboard"
                                    binaryMessenger:[_viewDelegate getBinaryMessenger]
                                              codec:[FlutterStandardMethodCodec sharedInstance]];
 
    [keyboardChannel setMethodCallHandler:^(FlutterMethodCall* call, FlutterResult result) {
      [self handleKeyboardMethodCall:call result:result];
    }];
 
    _primaryResponders = [[NSMutableArray alloc] init];
 
    __weak __typeof__(self) weakSelf = self;
    [self addPrimaryResponder:[[FlutterEmbedderKeyResponder alloc]
                                  initWithSendEvent:^(const FlutterKeyEvent& event,
                                                      FlutterKeyEventCallback callback,
                                                      void* userData) {
                                    __strong __typeof__(weakSelf) strongSelf = weakSelf;
                                    [strongSelf.viewDelegate sendKeyEvent:event
                                                                 callback:callback
                                                                 userData:userData];
                                  }]];
 
    [self
        addPrimaryResponder:[[FlutterChannelKeyResponder alloc]
                                initWithChannel:[FlutterBasicMessageChannel
                                                    messageChannelWithName:@"flutter/keyevent"
                                                           binaryMessenger:[_viewDelegate
                                                                               getBinaryMessenger]
                                                                     codec:[FlutterJSONMessageCodec
                                                                               sharedInstance]]]];
 
    _pendingEvents = [[NSMutableArray alloc] init];
    _layoutMap = [NSMutableDictionary<NSNumber*, NSNumber*> dictionary];
    [self buildLayout];
    for (id<FlutterKeyPrimaryResponder> responder in _primaryResponders) {
      responder.layoutMap = _layoutMap;
    }
 
    [_viewDelegate subscribeToKeyboardLayoutChange:^() {
      [weakSelf buildLayout];
    }];
  }
  return self;
}

isDispatchingKeyEvent:

- (BOOL) isDispatchingKeyEvent:

(nonnull NSEvent *)

event

Returns yes if is event currently being redispatched.

In some instances (i.e. emoji shortcut) the event may be redelivered by cocoa as key equivalent to FlutterTextInput, in which case it shouldn't be processed again.

syncModifiersIfNeeded:timestamp:

- (void) syncModifiersIfNeeded:		(NSEventModifierFlags)	modifierFlags
timestamp:		(NSTimeInterval)	timestamp

Synthesize modifier keys events.

If needed, synthesize modifier keys up and down events by comparing their current pressing states with the given modifier flags.

Definition at line 73 of file FlutterKeyboardManager.mm.

                             :(NSEventModifierFlags)modifierFlags
                    timestamp:(NSTimeInterval)timestamp {
  for (id<FlutterKeyPrimaryResponder> responder in _primaryResponders) {
    [responder syncModifiersIfNeeded:modifierFlags timestamp:timestamp];
  }
}

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The documentation for this class was generated from the following files:

• shell/platform/darwin/macos/framework/Source/FlutterKeyboardManager.h
• shell/platform/darwin/macos/framework/Source/FlutterKeyboardManager.mm