Flutter iOS Embedder
FlutterViewController Class Reference

#import <FlutterViewController.h>

Inheritance diagram for FlutterViewController:
<FlutterTextureRegistry> <FlutterPluginRegistry>

Instance Methods

(instancetype) - initWithEngine:nibName:bundle:
 
(instancetype) - initWithProject:nibName:bundle:
 
(instancetype) - initWithProject:initialRoute:nibName:bundle:
 
(instancetype) - initWithCoder:
 
(void) - setFlutterViewDidRenderCallback:
 
(NSString *) - lookupKeyForAsset:
 
(NSString *) - lookupKeyForAsset:fromPackage:
 
(void) - setInitialRoute:
 
(void) - popRoute
 
(void) - pushRoute:
 
(id< FlutterPluginRegistry >) - pluginRegistry
 
(BOOL) - loadDefaultSplashScreenView
 
- Instance Methods inherited from <FlutterTextureRegistry>
(int64_t) - registerTexture:
 
(void) - textureFrameAvailable:
 
(void) - unregisterTexture:
 
- Instance Methods inherited from <FlutterPluginRegistry>
(nullable NSObject< FlutterPluginRegistrar > *) - registrarForPlugin:
 
(BOOL) - hasPlugin:
 
(nullable NSObject *) - valuePublishedByPlugin:
 

Class Methods

(BOOL) + isUIAccessibilityIsVoiceOverRunning
 

Properties

BOOL displayingFlutterUI
 
UIView * splashScreenView
 
BOOL viewOpaque
 
FlutterEngineengine
 
NSObject< FlutterBinaryMessenger > * binaryMessenger
 
BOOL engineAllowHeadlessExecution
 

Detailed Description

A UIViewController implementation for Flutter views.

Dart execution, channel communication, texture registration, and plugin registration are all handled by FlutterEngine. Calls on this class to those members all proxy through to the FlutterEngine attached FlutterViewController.

A FlutterViewController can be initialized either with an already-running FlutterEngine via the initWithEngine: initializer, or it can be initialized with a FlutterDartProject that will be used to implicitly spin up a new FlutterEngine. Creating a FlutterEngine before showing a FlutterViewController can be used to pre-initialize the Dart VM and to prepare the isolate in order to reduce the latency to the first rendered frame. See https://flutter.cn/docs/development/add-to-app/performance for more details on loading latency.

Holding a FlutterEngine independently of FlutterViewControllers can also be used to not to lose Dart-related state and asynchronous tasks when navigating back and forth between a FlutterViewController and other UIViewControllers.

Definition at line 56 of file FlutterViewController.h.

Method Documentation

◆ initWithCoder:

- (instancetype) initWithCoder: (NSCoder*)  NS_DESIGNATED_INITIALIZER

Initializer that is called from loading a FlutterViewController from a XIB.

See also: https://developer.apple.com/documentation/foundation/nscoding/1416145-initwithcoder?language=objc

Definition at line 218 of file FlutterViewController.mm.

218  :(NSCoder*)aDecoder {
219  self = [super initWithCoder:aDecoder];
220  return self;
221 }

◆ initWithEngine:nibName:bundle:

- (instancetype) initWithEngine: (FlutterEngine*)  engine
nibName: (nullable NSString*)  nibName
bundle: (nullable NSBundle*)  NS_DESIGNATED_INITIALIZER 

Initializes this FlutterViewController with the specified FlutterEngine.

The initialized viewcontroller will attach itself to the engine as part of this process.

Parameters
engineThe FlutterEngine instance to attach to. Cannot be nil.
nibNameThe NIB name to initialize this UIViewController with.
nibBundleThe NIB bundle.

Definition at line 161 of file FlutterViewController.mm.

162  nibName:(nullable NSString*)nibName
163  bundle:(nullable NSBundle*)nibBundle {
164  NSAssert(engine != nil, @"Engine is required");
165  self = [super initWithNibName:nibName bundle:nibBundle];
166  if (self) {
167  _viewOpaque = YES;
168  if (engine.viewController) {
169  FML_LOG(ERROR) << "The supplied FlutterEngine " << [[engine description] UTF8String]
170  << " is already used with FlutterViewController instance "
171  << [[engine.viewController description] UTF8String]
172  << ". One instance of the FlutterEngine can only be attached to one "
173  "FlutterViewController at a time. Set FlutterEngine.viewController "
174  "to nil before attaching it to another FlutterViewController.";
175  }
176  _engine.reset([engine retain]);
177  _engineNeedsLaunch = NO;
178  _flutterView.reset([[FlutterView alloc] initWithDelegate:_engine
179  opaque:self.isViewOpaque
180  enableWideGamut:engine.project.isWideGamutEnabled]);
181  _weakFactory = std::make_unique<fml::WeakNSObjectFactory<FlutterViewController>>(self);
182  _ongoingTouches.reset([[NSMutableSet alloc] init]);
183 
184  [self performCommonViewControllerInitialization];
185  [engine setViewController:self];
186  }
187 
188  return self;
189 }

References _engine, _engineNeedsLaunch, _flutterView, _ongoingTouches, _viewOpaque, _weakFactory, and engine.

◆ initWithProject:initialRoute:nibName:bundle:

- (instancetype) initWithProject: (nullable FlutterDartProject *)  project
initialRoute: (nullable NSString *)  initialRoute
nibName: (nullable NSString *)  nibName
bundle: (nullable NSBundle *)  NS_DESIGNATED_INITIALIZER 

Initializes a new FlutterViewController and FlutterEngine with the specified FlutterDartProject and initialRoute.

This will implicitly create a new FlutterEngine which is retrievable via the engine property after initialization.

Parameters
projectThe FlutterDartProject to initialize the FlutterEngine with.
initialRouteThe initial Navigator route to load.
nibNameThe NIB name to initialize this UIViewController with.
nibBundleThe NIB bundle.

◆ initWithProject:nibName:bundle:

- (instancetype) initWithProject: (nullable FlutterDartProject *)  project
nibName: (nullable NSString *)  nibName
bundle: (nullable NSBundle *)  NS_DESIGNATED_INITIALIZER 

Initializes a new FlutterViewController and FlutterEngine with the specified FlutterDartProject.

This will implicitly create a new FlutterEngine which is retrievable via the engine property after initialization.

Parameters
projectThe FlutterDartProject to initialize the FlutterEngine with.
nibNameThe NIB name to initialize this UIViewController with.
nibBundleThe NIB bundle.

◆ isUIAccessibilityIsVoiceOverRunning

+ (BOOL) isUIAccessibilityIsVoiceOverRunning

A wrapper around UIAccessibilityIsVoiceOverRunning().

As a C function, UIAccessibilityIsVoiceOverRunning() cannot be mocked in testing. Mock this class method to testing features depends on UIAccessibilityIsVoiceOverRunning().

Definition at line 2397 of file FlutterViewController.mm.

2397  {
2398  return UIAccessibilityIsVoiceOverRunning();
2399 }

◆ loadDefaultSplashScreenView

- (BOOL) loadDefaultSplashScreenView

Attempts to set the splashScreenView property from the UILaunchStoryboardName from the main bundle's Info.plist file. This method will not change the value of splashScreenView if it cannot find a default one from a storyboard or nib.

Returns
YES if successful, NO otherwise.

Definition at line 673 of file FlutterViewController.mm.

673  {
674  NSString* launchscreenName =
675  [[[NSBundle mainBundle] infoDictionary] objectForKey:@"UILaunchStoryboardName"];
676  if (launchscreenName == nil) {
677  return NO;
678  }
679  UIView* splashView = [self splashScreenFromStoryboard:launchscreenName];
680  if (!splashView) {
681  splashView = [self splashScreenFromXib:launchscreenName];
682  }
683  if (!splashView) {
684  return NO;
685  }
686  self.splashScreenView = splashView;
687  return YES;
688 }

◆ lookupKeyForAsset:

- (NSString *) lookupKeyForAsset: (NSString*)  asset

Returns the file name for the given asset. The returned file name can be used to access the asset in the application's main bundle.

Parameters
assetThe name of the asset. The name can be hierarchical.
Returns
The file name to be used for lookup in the main bundle.

Definition at line 2385 of file FlutterViewController.mm.

2385  :(NSString*)asset {
2386  return [FlutterDartProject lookupKeyForAsset:asset];
2387 }

References FlutterDartProject::lookupKeyForAsset:.

◆ lookupKeyForAsset:fromPackage:

- (NSString *) lookupKeyForAsset: (NSString*)  asset
fromPackage: (NSString*)  package 

Returns the file name for the given asset which originates from the specified package. The returned file name can be used to access the asset in the application's main bundle.

Parameters
assetThe name of the asset. The name can be hierarchical.
packageThe name of the package from which the asset originates.
Returns
The file name to be used for lookup in the main bundle.

Definition at line 2389 of file FlutterViewController.mm.

2389  :(NSString*)asset fromPackage:(NSString*)package {
2390  return [FlutterDartProject lookupKeyForAsset:asset fromPackage:package];
2391 }

References FlutterDartProject::lookupKeyForAsset:fromPackage:.

◆ pluginRegistry

- (id< FlutterPluginRegistry >) pluginRegistry

The FlutterPluginRegistry used by this FlutterViewController.

Definition at line 2393 of file FlutterViewController.mm.

2393  {
2394  return _engine;
2395 }

References _engine.

◆ popRoute

- (void) popRoute

Instructs the Flutter Navigator (if any) to go back.

Definition at line 453 of file FlutterViewController.mm.

453  {
454  [[_engine.get() navigationChannel] invokeMethod:@"popRoute" arguments:nil];
455 }

◆ pushRoute:

- (void) pushRoute: (NSString*)  route

Instructs the Flutter Navigator (if any) to push a route on to the navigation stack.

Parameters
routeThe name of the route to push to the navigation stack.

Definition at line 457 of file FlutterViewController.mm.

457  :(NSString*)route {
458  [[_engine.get() navigationChannel] invokeMethod:@"pushRoute" arguments:route];
459 }

◆ setFlutterViewDidRenderCallback:

- (void) setFlutterViewDidRenderCallback: (void(^)(void))  callback

Registers a callback that will be invoked when the Flutter view has been rendered. The callback will be fired only once.

Replaces an existing callback. Use a nil callback to unregister the existing one.

Definition at line 732 of file FlutterViewController.mm.

732  :(void (^)(void))callback {
733  _flutterViewRenderedCallback.reset(callback, fml::scoped_policy::OwnershipPolicy::kRetain);
734 }

References _flutterViewRenderedCallback.

◆ setInitialRoute:

- (void) setInitialRoute: ("Use FlutterViewController initializer to specify initial route")  FLUTTER_DEPRECATED

Deprecated API to set initial route.

Attempts to set the first route that the Flutter app shows if the Flutter runtime hasn't yet started. The default is "/".

This method must be called immediately after initWithProject and has no effect when using initWithEngine if the FlutterEngine has already been run.

Setting this after the Flutter started running has no effect. See pushRoute and popRoute to change the route after Flutter started running.

This is deprecated because it needs to be called at the time of initialization and thus should just be in the initWithProject initializer. If using initWithEngine, the initial route should be set on the engine's initializer.

Parameters
routeThe name of the first route to show.

Property Documentation

◆ binaryMessenger

- (NSObject< FlutterBinaryMessenger > *) binaryMessenger
readnonatomicassign

The FlutterBinaryMessenger associated with this FlutterViewController (used for communicating with channels).

This is just a convenient way to get the |FlutterEngine|'s binary messenger.

Definition at line 243 of file FlutterViewController.h.

◆ displayingFlutterUI

- (BOOL) displayingFlutterUI
readnonatomicassign

True if at least one frame has rendered and the ViewController has appeared.

This property is reset to false when the ViewController disappears. It is guaranteed to only alternate between true and false for observers.

Definition at line 197 of file FlutterViewController.h.

◆ engine

- (FlutterEngine *) engine
readnonatomicweak

The FlutterEngine instance for this view controller. This could be the engine this FlutterViewController is initialized with or a new FlutterEngine implicitly created if no engine was supplied during initialization.

Definition at line 235 of file FlutterViewController.h.

◆ engineAllowHeadlessExecution

- (BOOL) engineAllowHeadlessExecution
readnonatomicassign

If the FlutterViewController creates a FlutterEngine, this property determines if that FlutterEngine has allowHeadlessExecution set.

The intention is that this is used with the XIB. Otherwise, a FlutterEngine can just be sent to the init methods.

See also: -[FlutterEngine initWithName:project:allowHeadlessExecution:]

Definition at line 254 of file FlutterViewController.h.

◆ splashScreenView

- (UIView *) splashScreenView
readwritenonatomicstrong

Specifies the view to use as a splash screen. Flutter's rendering is asynchronous, so the first frame rendered by the Flutter application might not immediately appear when the Flutter view is initially placed in the view hierarchy. The splash screen view will be used as a replacement until the first frame is rendered.

The view used should be appropriate for multiple sizes; an autoresizing mask to have a flexible width and height will be applied automatically.

Set to nil to remove the splash screen view.

Definition at line 210 of file FlutterViewController.h.

◆ viewOpaque

- (BOOL) viewOpaque
readwritenonatomicassign

Controls whether the created view will be opaque or not.

Default is YES. Note that setting this to NO may negatively impact performance when using hardware acceleration, and toggling this will trigger a re-layout of the view.

Definition at line 228 of file FlutterViewController.h.


The documentation for this class was generated from the following files:
_weakFactory
std::unique_ptr< fml::WeakNSObjectFactory< FlutterEngine > > _weakFactory
Definition: FlutterEngine.mm:120
_flutterViewRenderedCallback
fml::ScopedBlock< void(^)(void)> _flutterViewRenderedCallback
Definition: FlutterViewController.mm:128
FlutterEngine
Definition: FlutterEngine.h:61
FlutterViewController::engine
FlutterEngine * engine
Definition: FlutterViewController.h:235
_engine
fml::scoped_nsobject< FlutterEngine > _engine
Definition: FlutterViewController.mm:120
_viewOpaque
BOOL _viewOpaque
Definition: FlutterViewController.mm:133
_flutterView
fml::scoped_nsobject< FlutterView > _flutterView
Definition: FlutterViewController.mm:126
+[FlutterDartProject lookupKeyForAsset:]
NSString * lookupKeyForAsset:(NSString *asset)
Definition: FlutterDartProject.mm:388
FlutterEngine::viewController
FlutterViewController * viewController
Definition: FlutterEngine.h:327
_engineNeedsLaunch
BOOL _engineNeedsLaunch
Definition: FlutterViewController.mm:134
_ongoingTouches
fml::scoped_nsobject< NSMutableSet< NSNumber * > > _ongoingTouches
Definition: FlutterViewController.mm:135
FlutterView
Definition: FlutterView.h:34
FlutterDartProject
Definition: FlutterDartProject.mm:262