FlutterTextInputPlugin Class Reference

#import <FlutterTextInputPlugin.h>

Inheritance diagram for FlutterTextInputPlugin:

Instance Methods
(instancetype)	- initWithViewController:
(BOOL)	- isFirstResponder
(BOOL)	- handleKeyEvent:
(void)	- handleMethodCall:result:
(NSRect)	- firstRectForCharacterRange:actualRange:
(NSDictionary *)	- editingState

Properties
FlutterTextField *	client
NSTextInputContext *	textInputContext
NSString *	customRunLoopMode

Detailed Description

A plugin to handle text input.

Responsible for bridging the native macOS text input system with the Flutter framework text editing classes, via system channels.

This is not an FlutterPlugin since it needs access to FlutterViewController internals, so needs to be managed differently.

When accessibility is on, accessibility bridge creates a NSTextField, i.e. FlutterTextField, for every text field in the Flutter. This plugin acts as a field editor for those NSTextField[s].

Definition at line 27 of file FlutterTextInputPlugin.h.

Method Documentation

editingState

- (NSDictionary*) editingState

Provided by category FlutterTextInputPlugin(TestMethods).

Referenced by FlutterInputPluginTestObjc::testClearClientDuringComposing, and FlutterInputPluginTestObjc::testEmptyCompositionRange.

firstRectForCharacterRange:actualRange:

- (NSRect) firstRectForCharacterRange:		(NSRange)	range
actualRange:		(NSRangePointer)	actualRange

Provided by category FlutterTextInputPlugin(TestMethods).

handleKeyEvent:

- (BOOL) handleKeyEvent:

(NSEvent*)

event

Handles key down events received from the view controller, responding YES if the event was handled.

Note, the Apple docs suggest that clients should override essentially all the mouse and keyboard event-handling methods of NSResponder. However, experimentation indicates that only key events are processed by the native layer; Flutter processes mouse events. Additionally, processing both keyUp and keyDown results in duplicate processing of the same keys.

Definition at line 605 of file FlutterTextInputPlugin.mm.

                      :(NSEvent*)event {
  if (event.type == NSEventTypeKeyUp ||
      (event.type == NSEventTypeFlagsChanged && event.modifierFlags < _previouslyPressedFlags)) {
    return NO;
  }
  _previouslyPressedFlags = event.modifierFlags;
  if (!_shown) {
    return NO;
  }
 
  _eventProducedOutput = NO;
  BOOL res = [_textInputContext handleEvent:event];
  // NSTextInputContext#handleEvent returns YES if the context handles the event. One of the reasons
  // the event is handled is because it's a key equivalent. But a key equivalent might produce a
  // text command (indicated by calling doCommandBySelector) or might not (for example, Cmd+Q). In
  // the latter case, this command somehow has not been executed yet and Flutter must dispatch it to
  // the next responder. See https://github.com/flutter/flutter/issues/106354 .
  // The event is also not redispatched if there is IME composition active, because it might be
  // handled by the IME. See https://github.com/flutter/flutter/issues/134699
 
  // both NSEventModifierFlagNumericPad and NSEventModifierFlagFunction are set for arrow keys.
  bool is_navigation = event.modifierFlags & NSEventModifierFlagFunction &&
                       event.modifierFlags & NSEventModifierFlagNumericPad;
  bool is_navigation_in_ime = is_navigation && self.hasMarkedText;
 
  if (event.isKeyEquivalent && !is_navigation_in_ime && !_eventProducedOutput) {
    return NO;
  }
  return res;
}

handleMethodCall:result:

- (void) handleMethodCall:		(FlutterMethodCall *)	call
result:		(FlutterResult)	result

Provided by category FlutterTextInputPlugin(TestMethods).

Referenced by FlutterInputPluginTestObjc::testClearClientDuringComposing, and FlutterInputPluginTestObjc::testEmptyCompositionRange.

initWithViewController:

- (instancetype) initWithViewController:

(FlutterViewController*)

viewController

Initializes a text input plugin that coordinates key event handling with |viewController|.

Definition at line 342 of file FlutterTextInputPlugin.mm.

                                      :(FlutterViewController*)viewController {
  // The view needs an empty frame otherwise it is visible on dark background.
  // https://github.com/flutter/flutter/issues/118504
  self = [super initWithFrame:NSZeroRect];
  self.clipsToBounds = YES;
  if (self != nil) {
    _flutterViewController = viewController;
    _channel = [FlutterMethodChannel methodChannelWithName:kTextInputChannel
                                           binaryMessenger:viewController.engine.binaryMessenger
                                                     codec:[FlutterJSONMethodCodec sharedInstance]];
    _shown = FALSE;
    // NSTextView does not support _weak reference, so this class has to
    // use __unsafe_unretained and manage the reference by itself.
    //
    // Since the dealloc removes the handler, the pointer should
    // be valid if the handler is ever called.
    __unsafe_unretained FlutterTextInputPlugin* unsafeSelf = self;
    [_channel setMethodCallHandler:^(FlutterMethodCall* call, FlutterResult result) {
      [unsafeSelf handleMethodCall:call result:result];
    }];
    _textInputContext = [[NSTextInputContext alloc] initWithClient:unsafeSelf];
    _previouslyPressedFlags = 0;
 
    // Initialize with the zero matrix which is not
    // an affine transform.
    _editableTransform = CATransform3D();
    _caretRect = CGRectNull;
  }
  return self;
}

References _caretRect, _editableTransform, and FlutterMethodChannel::methodChannelWithName:binaryMessenger:codec:.

isFirstResponder

- (BOOL) isFirstResponder

Whether this plugin is the first responder of this NSWindow.

When accessibility is on, this plugin is set as the first responder to act as the field editor for FlutterTextFields.

Returns false if accessibility is off.

Definition at line 373 of file FlutterTextInputPlugin.mm.

                         {
  if (!self.flutterViewController.viewLoaded) {
    return false;
  }
  return [self.flutterViewController.view.window firstResponder] == self;
}

Property Documentation

client

- (FlutterTextField*) client

readwritenonatomicweak

The NSTextField that currently has this plugin as its field editor.

Must be nil if accessibility is off.

Definition at line 34 of file FlutterTextInputPlugin.h.

Referenced by FlutterTextField::startEditing, and FlutterTextField::updateString:withSelection:.

customRunLoopMode

- (NSString*) customRunLoopMode

readwritenonatomicassign

Provided by category FlutterTextInputPlugin(TestMethods).

Definition at line 71 of file FlutterTextInputPlugin.h.

textInputContext

- (NSTextInputContext*) textInputContext

readwritenonatomicassign

Provided by category FlutterTextInputPlugin(TestMethods).

Definition at line 70 of file FlutterTextInputPlugin.h.

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

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