Flutter iOS Embedder
FlutterKeyboardManager.h
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1 // Copyright 2013 The Flutter Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef FLUTTER_SHELL_PLATFORM_DARWIN_IOS_FRAMEWORK_SOURCE_FLUTTERKEYBOARDMANAGER_H_
6 #define FLUTTER_SHELL_PLATFORM_DARWIN_IOS_FRAMEWORK_SOURCE_FLUTTERKEYBOARDMANAGER_H_
7 
9 
10 #import <Foundation/NSObject.h>
11 #import <UIKit/UIKit.h>
12 
16 
17 typedef void (^KeyEventCompleteCallback)(bool, FlutterUIPressProxy* _Nonnull)
18  API_AVAILABLE(ios(13.4));
19 
20 /**
21  * A hub that manages how key events are dispatched to various Flutter key
22  * responders, and propagates it to the superclass if the Flutter key responders
23  * do not handle it.
24  *
25  * This class manages one or more primary responders, as well as zero or more
26  * secondary responders.
27  *
28  * An event that is received by |handlePresses| is first dispatched to *all*
29  * primary responders. Each primary responder responds *asynchronously* with a
30  * boolean, indicating whether it handles the event.
31  *
32  * An event that is not handled by any primary responders is then passed to to
33  * the first secondary responder (in the chronological order of addition),
34  * which responds *synchronously* with a boolean, indicating whether it handles
35  * the event. If not, the event is passed to the next secondary responder, and
36  * so on.
37  *
38  * The event is then handed back to the |completeCallback| from the original
39  * call to |handlePresses| so that it can respond synchronously to the OS if the
40  * event was not handled by the responders. The |completeCallback| is called on
41  * the platform thread because the platform thread is blocked by a nested event
42  * loop while the response from the framework is being collected, and it needs
43  * to be called on the platform thread to unblock the thread by exiting the
44  * nested event loop.
45  *
46  * Preventing primary responders from receiving events is not supported, because
47  * in reality this class only supports two hardcoded responders
48  * (FlutterChannelKeyResponder and FlutterEmbedderKeyResponder), where the only purpose
49  * of supporting two is to maintain the legacy channel API during the
50  * deprecation window, after which the channel responder should be removed, and
51  * only one primary responder will exist.
52  */
53 @interface FlutterKeyboardManager : NSObject
54 /**
55  * Add a primary responder, which asynchronously decides whether to handle an
56  * event.
57  */
58 - (void)addPrimaryResponder:(nonnull id<FlutterKeyPrimaryResponder>)responder;
59 
60 /**
61  * Add a secondary responder, which synchronously decides whether to handle an
62  * event in order if no earlier responders handle.
63  */
64 - (void)addSecondaryResponder:(nonnull id<FlutterKeySecondaryResponder>)responder;
65 
66 /**
67  * Dispatches a key press event to all responders, gathering their responses,
68  * and then calls the |nextAction| if the event was not handled.
69  */
70 - (void)handlePress:(nonnull FlutterUIPressProxy*)press
71  nextAction:(nonnull void (^)())next API_AVAILABLE(ios(13.4));
72 @end
73 
74 #endif // FLUTTER_SHELL_PLATFORM_DARWIN_IOS_FRAMEWORK_SOURCE_FLUTTERKEYBOARDMANAGER_H_
FlutterKeyPrimaryResponder-p
Definition: FlutterKeyPrimaryResponder.h:19
API_AVAILABLE
UITextSmartQuotesType smartQuotesType API_AVAILABLE(ios(11.0))
FlutterKeyPrimaryResponder.h
FlutterKeySecondaryResponder-p
Definition: FlutterKeySecondaryResponder.h:17
KeyEventCompleteCallback
void(^ KeyEventCompleteCallback)(bool, FlutterUIPressProxy *_Nonnull) API_AVAILABLE(ios(13.4))
Definition: FlutterKeyboardManager.h:17
FlutterUIPressProxy
Definition: FlutterUIPressProxy.h:17
FlutterUIPressProxy.h
FlutterKeySecondaryResponder.h
FlutterKeyboardManager
Definition: FlutterKeyboardManager.h:53