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 57 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 236 of file FlutterViewController.mm.

236  :(NSCoder*)aDecoder {
237  self = [super initWithCoder:aDecoder];
238  return self;
239 }

◆ 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 174 of file FlutterViewController.mm.

175  nibName:(nullable NSString*)nibName
176  bundle:(nullable NSBundle*)nibBundle {
177  NSAssert(engine != nil, @"Engine is required");
178  self = [super initWithNibName:nibName bundle:nibBundle];
179  if (self) {
180  _viewOpaque = YES;
181  if (engine.viewController) {
182  FML_LOG(ERROR) << "The supplied FlutterEngine " << [[engine description] UTF8String]
183  << " is already used with FlutterViewController instance "
184  << [[engine.viewController description] UTF8String]
185  << ". One instance of the FlutterEngine can only be attached to one "
186  "FlutterViewController at a time. Set FlutterEngine.viewController "
187  "to nil before attaching it to another FlutterViewController.";
188  }
189  _engine = engine;
190  _engineNeedsLaunch = NO;
191  _flutterView = [[FlutterView alloc] initWithDelegate:_engine
192  opaque:self.isViewOpaque
193  enableWideGamut:engine.project.isWideGamutEnabled];
194  _ongoingTouches = [[NSMutableSet alloc] init];
195 
196  // TODO(cbracken): https://github.com/flutter/flutter/issues/157140
197  // Eliminate method calls in initializers and dealloc.
198  [self performCommonViewControllerInitialization];
199  [engine setViewController:self];
200  }
201 
202  return self;
203 }

References 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 2383 of file FlutterViewController.mm.

2383  {
2384  return UIAccessibilityIsVoiceOverRunning();
2385 }

◆ 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 659 of file FlutterViewController.mm.

659  {
660  NSString* launchscreenName =
661  [[[NSBundle mainBundle] infoDictionary] objectForKey:@"UILaunchStoryboardName"];
662  if (launchscreenName == nil) {
663  return NO;
664  }
665  UIView* splashView = [self splashScreenFromStoryboard:launchscreenName];
666  if (!splashView) {
667  splashView = [self splashScreenFromXib:launchscreenName];
668  }
669  if (!splashView) {
670  return NO;
671  }
672  self.splashScreenView = splashView;
673  return YES;
674 }

References splashScreenView.

◆ 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 2371 of file FlutterViewController.mm.

2371  :(NSString*)asset {
2372  return [FlutterDartProject lookupKeyForAsset:asset];
2373 }

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 2375 of file FlutterViewController.mm.

2375  :(NSString*)asset fromPackage:(NSString*)package {
2376  return [FlutterDartProject lookupKeyForAsset:asset fromPackage:package];
2377 }

References FlutterDartProject::lookupKeyForAsset:fromPackage:.

◆ pluginRegistry

- (id< FlutterPluginRegistry >) pluginRegistry

The FlutterPluginRegistry used by this FlutterViewController.

Definition at line 2379 of file FlutterViewController.mm.

2379  {
2380  return self.engine;
2381 }

◆ popRoute

- (void) popRoute

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

Definition at line 464 of file FlutterViewController.mm.

464  {
465  [self.engine.navigationChannel invokeMethod:@"popRoute" arguments:nil];
466 }

◆ 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 468 of file FlutterViewController.mm.

468  :(NSString*)route {
469  [self.engine.navigationChannel invokeMethod:@"pushRoute" arguments:route];
470 }

◆ 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 722 of file FlutterViewController.mm.

722  :(void (^)(void))callback {
723  _flutterViewRenderedCallback = callback;
724 }

◆ 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 244 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 198 of file FlutterViewController.h.

◆ engine

- (FlutterEngine*) engine
readnonatomicassign

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 236 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 255 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 211 of file FlutterViewController.h.

Referenced by loadDefaultSplashScreenView.

◆ 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 229 of file FlutterViewController.h.


The documentation for this class was generated from the following files:
FlutterEngine
Definition: FlutterEngine.h:61
+[FlutterDartProject lookupKeyForAsset:]
NSString * lookupKeyForAsset:(NSString *asset)
Definition: FlutterDartProject.mm:378
FlutterViewController::engine
FlutterEngine * engine
Definition: FlutterViewController.h:236
FlutterView
Definition: FlutterView.h:33
FlutterEngine::viewController
FlutterViewController * viewController
Definition: FlutterEngine.h:327
FlutterDartProject
Definition: FlutterDartProject.mm:252