Flutter macOS Embedder
FlutterTextField Class Reference

#import <FlutterTextInputSemanticsObject.h>

Inheritance diagram for FlutterTextField:
FlutterTextFieldMock

Instance Methods

(instancetype) - initWithPlatformNode:fieldEditor:
 
(void) - updateString:withSelection:
 
(void) - startEditing
 

Detailed Description

An NSTextField implementation that represents the NativeViewAccessible for the FlutterTextPlatformNode

The NSAccessibility protocol does not provide full support for text editing. This appkit text field is used to get around this problem. The FlutterTextPlatformNode creates a hidden FlutterTextField, since VoiceOver only provides text editing announcements for NSTextField subclasses.

All of the text editing events in this native text field are redirected to the FlutterTextInputPlugin.

Definition at line 78 of file FlutterTextInputSemanticsObject.h.

Method Documentation

◆ initWithPlatformNode:fieldEditor:

- (instancetype) initWithPlatformNode: (flutter::FlutterTextPlatformNode*)  node
fieldEditor: (FlutterTextInputPlugin*)  plugin 

Initializes a FlutterTextField that uses the FlutterTextInputPlugin as its field editor. The text field redirects all of the text editing events to the FlutterTextInputPlugin.

Definition at line 69 of file FlutterTextInputSemanticsObject.mm.

70  fieldEditor:(FlutterTextInputPlugin*)plugin {
71  self = [super initWithFrame:NSZeroRect];
72  if (self) {
73  _node = node;
74  _plugin = plugin;
75  [self setCell:[[FlutterTextFieldCell alloc] initWithTextField:self fieldEditor:plugin]];
76  }
77  return self;
78 }

References _plugin.

◆ startEditing

- (void) startEditing

Makes the field editor (plugin) current editor for this TextField, meaning that the text field will start getting editing events.

Definition at line 112 of file FlutterTextInputSemanticsObject.mm.

112  {
113  if (!_plugin) {
114  return;
115  }
116  if (self.currentEditor == _plugin) {
117  return;
118  }
119  if (!_node) {
120  return;
121  }
122  // Selecting text seems to be the only way to make the field editor
123  // current editor.
124  [self selectText:self];
125  NSAssert(self.currentEditor == _plugin, @"Failed to set current editor");
126 
127  _plugin.client = self;
128 
129  // Restore previous selection.
130  NSString* textValue = @(_node->GetStringAttribute(ax::mojom::StringAttribute::kValue).data());
131  int start = _node->GetIntAttribute(ax::mojom::IntAttribute::kTextSelStart);
132  int end = _node->GetIntAttribute(ax::mojom::IntAttribute::kTextSelEnd);
133  NSAssert((start >= 0 && end >= 0) || (start == -1 && end == -1), @"selection is invalid");
134  NSRange selection;
135  if (start >= 0 && end >= 0) {
136  selection = NSMakeRange(MIN(start, end), ABS(end - start));
137  } else {
138  // The native behavior is to place the cursor at the end of the string if
139  // there is no selection.
140  selection = NSMakeRange([self stringValue].length, 0);
141  }
142  [self updateString:textValue withSelection:selection];
143 }

References _plugin, FlutterTextInputPlugin::client, and updateString:withSelection:.

Referenced by flutter::testing::TEST().

◆ updateString:withSelection:

- (void) updateString: (NSString*)  string
withSelection: (NSRange)  selection 

Updates the string value and the selection of this text field.

Calling this method is necessary for macOS to get notified about string and selection changes.

Definition at line 80 of file FlutterTextInputSemanticsObject.mm.

80  :(NSString*)string withSelection:(NSRange)selection {
81  NSAssert(_plugin.client == self,
82  @"Can't update FlutterTextField when it is not the first responder");
83  if (![[self stringValue] isEqualToString:string]) {
84  [self setStringValue:string];
85  }
86  if (!NSEqualRanges(_plugin.selectedRange, selection)) {
87  [_plugin setSelectedRange:selection];
88  }
89 }

References _plugin, and FlutterTextInputPlugin::client.

Referenced by startEditing.


The documentation for this class was generated from the following files:
flutter::FlutterTextPlatformNode
The ax platform node for a text field.
Definition: FlutterTextInputSemanticsObject.h:19
FlutterTextInputPlugin::client
FlutterTextField * client
Definition: FlutterTextInputPlugin.h:31
FlutterTextInputPlugin
Definition: FlutterTextInputPlugin.h:24
_plugin
FlutterTextInputPlugin * _plugin
Definition: FlutterTextInputSemanticsObject.mm:62
FlutterTextFieldCell
Definition: FlutterTextInputSemanticsObject.mm:23