flutter::PlatformViewIOS Class Reference

#include <platform_view_ios.h>

Inheritance diagram for flutter::PlatformViewIOS:

Public Member Functions
	PlatformViewIOS (PlatformView::Delegate &delegate, const std::shared_ptr< IOSContext > &context, const std::shared_ptr< FlutterPlatformViewsController > &platform_views_controller, const flutter::TaskRunners &task_runners)
	PlatformViewIOS (PlatformView::Delegate &delegate, IOSRenderingAPI rendering_api, const std::shared_ptr< FlutterPlatformViewsController > &platform_views_controller, const flutter::TaskRunners &task_runners, const std::shared_ptr< fml::ConcurrentTaskRunner > &worker_task_runner, const std::shared_ptr< const fml::SyncSwitch > &is_gpu_disabled_sync_switch)
	~PlatformViewIOS () override
fml::WeakNSObject< FlutterViewController >	GetOwnerViewController () const
void	SetOwnerViewController (const fml::WeakNSObject< FlutterViewController > &owner_controller)
void	attachView ()
void	RegisterExternalTexture (int64_t id, NSObject< FlutterTexture > *texture)
PointerDataDispatcherMaker	GetDispatcherMaker () override
	Returns a platform-specific PointerDataDispatcherMaker so the Engine can construct the PointerDataPacketDispatcher based on platforms. More...
void	SetSemanticsEnabled (bool enabled) override
	Used by embedder to notify the running isolate hosted by the engine on the UI thread that the accessibility tree needs to be generated. More...
const std::shared_ptr< IOSContext > &	GetIosContext ()
std::shared_ptr< PlatformMessageHandlerIos >	GetPlatformMessageHandlerIos () const
std::shared_ptr< PlatformMessageHandler >	GetPlatformMessageHandler () const override
	Specifies a delegate that will receive PlatformMessages from Flutter to the host platform. More...
Public Member Functions inherited from flutter::PlatformView
	PlatformView (Delegate &delegate, const TaskRunners &task_runners)
	Creates a platform view with the specified delegate and task runner. The base class by itself does not do much but is suitable for use in test environments where full platform integration may not be necessary. The platform view may only be created, accessed and destroyed on the platform task runner. More...
virtual	~PlatformView ()
	Destroys the platform view. The platform view is owned by the shell and will be destroyed by the same on the platform tasks runner. More...
virtual std::unique_ptr< VsyncWaiter >	CreateVSyncWaiter ()
	Invoked by the shell to obtain a platform specific vsync waiter. It is optional for platforms to override this method and provide a custom vsync waiter because a timer based fall-back waiter is used by default. However, it is highly recommended that platform provide their own Vsync waiter as the timer based fall-back will not render frames aligned with vsync boundaries. More...
void	DispatchPlatformMessage (std::unique_ptr< PlatformMessage > message)
	Used by embedders to dispatch a platform message to a running root isolate hosted by the engine. If an isolate is not running, the message is dropped. If there is no one on the other side listening on the channel, the message is dropped. When a platform message is dropped, any response handles associated with that message will be dropped as well. All users of platform messages must assume that message may not be delivered and/or their response handles may not be invoked. Platform messages are not buffered. More...
virtual void	HandlePlatformMessage (std::unique_ptr< PlatformMessage > message)
	Overridden by embedders to perform actions in response to platform messages sent from the framework to the embedder. Default implementation of this method simply returns an empty response. More...
void	DispatchSemanticsAction (int32_t node_id, SemanticsAction action, fml::MallocMapping args)
	Used by embedders to dispatch an accessibility action to a running isolate hosted by the engine. More...
virtual void	SetSemanticsEnabled (bool enabled)
	Used by embedder to notify the running isolate hosted by the engine on the UI thread that the accessibility tree needs to be generated. More...
virtual void	SetAccessibilityFeatures (int32_t flags)
	Used by the embedder to specify the features to enable in the accessibility tree generated by the isolate. This information is forwarded to the root isolate hosted by the engine on the UI thread. More...
virtual void	UpdateSemantics (SemanticsNodeUpdates updates, CustomAccessibilityActionUpdates actions)
	Used by the framework to tell the embedder to apply the specified semantics node updates. The default implementation of this method does nothing. More...
virtual void	SendChannelUpdate (const std::string &name, bool listening)
	Used by the framework to tell the embedder that it has registered a listener on a given channel. More...
void	SetViewportMetrics (int64_t view_id, const ViewportMetrics &metrics)
	Used by embedders to specify the updated viewport metrics for a view. In response to this call, on the raster thread, the rasterizer may need to be reconfigured to the updated viewport dimensions. On the UI thread, the framework may need to start generating a new frame for the updated viewport metrics as well. More...
void	NotifyCreated ()
	Used by embedders to notify the shell that a platform view has been created. This notification is used to create a rendering surface and pick the client rendering API to use to render into this surface. No frames will be scheduled or rendered before this call. The surface must remain valid till the corresponding call to NotifyDestroyed. More...
virtual void	NotifyDestroyed ()
	Used by embedders to notify the shell that the platform view has been destroyed. This notification used to collect the rendering surface and all associated resources. Frame scheduling is also suspended. More...
void	ScheduleFrame ()
	Used by embedders to schedule a frame. In response to this call, the framework may need to start generating a new frame. More...
void	AddView (int64_t view_id, const ViewportMetrics &viewport_metrics, AddViewCallback callback)
	Used by embedders to notify the shell of a new non-implicit view. More...
void	RemoveView (int64_t view_id, RemoveViewCallback callback)
	Used by embedders to notify the shell of a removed non-implicit view. More...
virtual sk_sp< GrDirectContext >	CreateResourceContext () const
	Used by the shell to obtain a Skia GPU context that is capable of operating on the IO thread. The context must be in the same share-group as the Skia GPU context used on the render thread. This context will always be used on the IO thread. Because it is in the same share-group as the separate render thread context, any GPU resources uploaded in this context will be visible to the render thread context (synchronization of GPU resources is managed by Skia). More...
virtual std::shared_ptr< impeller::Context >	GetImpellerContext () const
virtual void	ReleaseResourceContext () const
	Used by the shell to notify the embedder that the resource context previously obtained via a call to CreateResourceContext() is being collected. The embedder is free to collect an platform specific resources associated with this context. More...
virtual PointerDataDispatcherMaker	GetDispatcherMaker ()
	Returns a platform-specific PointerDataDispatcherMaker so the Engine can construct the PointerDataPacketDispatcher based on platforms. More...
fml::WeakPtr< PlatformView >	GetWeakPtr () const
	Returns a weak pointer to the platform view. Since the platform view may only be created, accessed and destroyed on the platform thread, any access to the platform view from a non-platform task runner needs a weak pointer to the platform view along with a reference to the platform task runner. A task must be posted to the platform task runner with the weak pointer captured in the same. The platform view method may only be called in the posted task once the weak pointer validity has been checked. This method is used by callers to obtain that weak pointer. More...
virtual void	OnPreEngineRestart () const
	Gives embedders a chance to react to a "cold restart" of the running isolate. The default implementation of this method does nothing. More...
void	SetNextFrameCallback (const fml::closure &closure)
	Sets a callback that gets executed when the rasterizer renders the next frame. Due to the asynchronous nature of rendering in Flutter, embedders usually add a placeholder over the contents in which Flutter is going to render when Flutter is first initialized. This callback may be used as a signal to remove that placeholder. The callback is executed on the render task runner and not the platform task runner. It is the embedder's responsibility to re-thread as necessary. More...
void	DispatchPointerDataPacket (std::unique_ptr< PointerDataPacket > packet)
	Dispatches pointer events from the embedder to the framework. Each pointer data packet may contain multiple pointer input events. Each call to this method wakes up the UI thread. More...
void	RegisterTexture (std::shared_ptr< flutter::Texture > texture)
	Used by the embedder to specify a texture that it wants the rasterizer to composite within the Flutter layer tree. All textures must have a unique identifier. When the rasterizer encounters an external texture within its hierarchy, it gives the embedder a chance to update that texture on the raster thread before it composites the same on-screen. More...
void	UnregisterTexture (int64_t texture_id)
	Used by the embedder to notify the rasterizer that it will no longer attempt to composite the specified texture within the layer tree. This allows the rasterizer to collect associated resources. More...
void	MarkTextureFrameAvailable (int64_t texture_id)
	Used by the embedder to notify the rasterizer that the context of the previously registered texture have been updated. Typically, Flutter will only render a frame if there is an updated layer tree. However, in cases where the layer tree is static but one of the externally composited textures has been updated by the embedder, the embedder needs to notify the rasterizer to render a new frame. In such cases, the existing layer tree may be reused with the frame re-composited with all updated external textures. Unlike the calls to register and unregister the texture, this call must be made each time a new texture frame is available. More...
virtual std::unique_ptr< std::vector< std::string > >	ComputePlatformResolvedLocales (const std::vector< std::string > &supported_locale_data)
	Directly invokes platform-specific APIs to compute the locale the platform would have natively resolved to. More...
virtual std::shared_ptr< ExternalViewEmbedder >	CreateExternalViewEmbedder ()
virtual void	RequestDartDeferredLibrary (intptr_t loading_unit_id)
	Invoked when the dart VM requests that a deferred library be loaded. Notifies the engine that the deferred library identified by the specified loading unit id should be downloaded and loaded into the Dart VM via LoadDartDeferredLibrary More...
virtual void	LoadDartDeferredLibrary (intptr_t loading_unit_id, std::unique_ptr< const fml::Mapping > snapshot_data, std::unique_ptr< const fml::Mapping > snapshot_instructions)
	Loads the Dart shared library into the Dart VM. When the Dart library is loaded successfully, the Dart future returned by the originating loadLibrary() call completes. More...
virtual void	LoadDartDeferredLibraryError (intptr_t loading_unit_id, const std::string error_message, bool transient)
	Indicates to the dart VM that the request to load a deferred library with the specified loading unit id has failed. More...
virtual void	UpdateAssetResolverByType (std::unique_ptr< AssetResolver > updated_asset_resolver, AssetResolver::AssetResolverType type)
	Replaces the asset resolver handled by the engine's AssetManager of the specified type with updated_asset_resolver. The matching AssetResolver is removed and replaced with updated_asset_resolvers. More...
virtual std::unique_ptr< SnapshotSurfaceProducer >	CreateSnapshotSurfaceProducer ()
	Creates an object that produces surfaces suitable for raster snapshotting. The rasterizer will request this surface if no on screen surface is currently available when an application requests a snapshot, e.g. if Scene.toImage or Picture.toImage are called while the application is in the background. More...
virtual std::shared_ptr< PlatformMessageHandler >	GetPlatformMessageHandler () const
	Specifies a delegate that will receive PlatformMessages from Flutter to the host platform. More...
const Settings &	GetSettings () const
	Get the settings for this platform view instance. More...
virtual double	GetScaledFontSize (double unscaled_font_size, int configuration_id) const
	Synchronously invokes platform-specific APIs to apply the system text scaling on the given unscaled font size. More...

Additional Inherited Members
Public Types inherited from flutter::PlatformView
using	AddViewCallback = std::function< void(bool added)>
using	RemoveViewCallback = std::function< void(bool removed)>
virtual std::unique_ptr< Surface >	CreateRenderingSurface ()
Protected Attributes inherited from flutter::PlatformView
PlatformView::Delegate &	delegate_
const TaskRunners	task_runners_
fml::WeakPtrFactory< PlatformView >	weak_factory_

Detailed Description

A bridge connecting the platform agnostic shell and the iOS embedding.

The shell provides and requests for UI related data and this PlatformView subclass fulfills it with iOS specific capabilities. As an example, the iOS embedding (the FlutterEngine and the FlutterViewController) sends pointer data to the shell and receives the shell's request for a Skia GrDirectContext and supplies it.

Despite the name "view", this class is unrelated to UIViews on iOS and doesn't have the same lifecycle. It's a long lived bridge owned by the FlutterEngine and can be attached and detached sequentially to multiple FlutterViewControllers and FlutterViews.

Definition at line 41 of file platform_view_ios.h.

Constructor & Destructor Documentation

PlatformViewIOS() [1/2]

flutter::PlatformViewIOS::PlatformViewIOS	(	PlatformView::Delegate &	delegate,
		const std::shared_ptr< IOSContext > &	context,
		const std::shared_ptr< FlutterPlatformViewsController > &	platform_views_controller,
		const flutter::TaskRunners &	task_runners
	)

Definition at line 42 of file platform_view_ios.mm.

    : PlatformView(delegate, task_runners),
      ios_context_(context),
      platform_views_controller_(platform_views_controller),
      accessibility_bridge_([this](bool enabled) { PlatformView::SetSemanticsEnabled(enabled); }),
      platform_message_handler_(
          new PlatformMessageHandlerIos(task_runners.GetPlatformTaskRunner())) {}

PlatformViewIOS() [2/2]

flutter::PlatformViewIOS::PlatformViewIOS ( PlatformView::Delegate &  delegate, IOSRenderingAPI  rendering_api, const std::shared_ptr< FlutterPlatformViewsController > &  platform_views_controller, const flutter::TaskRunners &  task_runners, const std::shared_ptr< fml::ConcurrentTaskRunner > &  worker_task_runner, const std::shared_ptr< const fml::SyncSwitch > &  is_gpu_disabled_sync_switch  )

explicit

Definition at line 54 of file platform_view_ios.mm.

    : PlatformViewIOS(delegate,
                      IOSContext::Create(rendering_api,
                                         delegate.OnPlatformViewGetSettings().enable_impeller
                                             ? IOSRenderingBackend::kImpeller
                                             : IOSRenderingBackend::kSkia,
                                         is_gpu_disabled_sync_switch),
                      platform_views_controller,
                      task_runners) {}

~PlatformViewIOS()

flutter::PlatformViewIOS::~PlatformViewIOS ( )

overridedefault

Member Function Documentation

attachView()

void flutter::PlatformViewIOS::attachView

(

)

Called one time per FlutterViewController when the FlutterViewController's UIView is first loaded.

Can be used to perform late initialization after FlutterViewController's init.

Definition at line 113 of file platform_view_ios.mm.

                                 {
  FML_DCHECK(owner_controller_);
  FML_DCHECK(owner_controller_.get().isViewLoaded)
      << "FlutterViewController's view should be loaded "
         "before attaching to PlatformViewIOS.";
  auto flutter_view = static_cast<FlutterView*>(owner_controller_.get().view);
  auto ca_layer = fml::scoped_nsobject<CALayer>{[[flutter_view layer] retain]};
  ios_surface_ = IOSSurface::Create(ios_context_, ca_layer);
  FML_DCHECK(ios_surface_ != nullptr);
 
  if (accessibility_bridge_) {
    accessibility_bridge_.Set(std::make_unique<AccessibilityBridge>(
        owner_controller_.get(), this, [owner_controller_.get() platformViewsController]));
  }
}

GetDispatcherMaker()

PointerDataDispatcherMaker flutter::PlatformViewIOS::GetDispatcherMaker ( )

overridevirtual

Returns a platform-specific PointerDataDispatcherMaker so the Engine can construct the PointerDataPacketDispatcher based on platforms.

Reimplemented from flutter::PlatformView.

Definition at line 129 of file platform_view_ios.mm.

                                                               {
  return [](DefaultPointerDataDispatcher::Delegate& delegate) {
    return std::make_unique<SmoothPointerDataDispatcher>(delegate);
  };
}

GetIosContext()

const std::shared_ptr< IOSContext > & flutter::PlatformViewIOS::GetIosContext ( )

inline

Accessor for the IOSContext associated with the platform view.

Definition at line 93 of file platform_view_ios.h.

{ return ios_context_; }

GetOwnerViewController()

fml::WeakNSObject< FlutterViewController > flutter::PlatformViewIOS::GetOwnerViewController

(

)

const

Returns the FlutterViewController currently attached to the FlutterEngine owning this PlatformViewIOS.

Definition at line 77 of file platform_view_ios.mm.

                                                                                     {
  return owner_controller_;
}

GetPlatformMessageHandler()

std::shared_ptr< PlatformMessageHandler > flutter::PlatformViewIOS::GetPlatformMessageHandler ( ) const

inlineoverridevirtual

Specifies a delegate that will receive PlatformMessages from Flutter to the host platform.

If this returns null that means PlatformMessages should be sent to the PlatformView. That is to protect legacy behavior, any embedder that wants to support executing Platform Channel handlers on background threads should be returning a thread-safe PlatformMessageHandler instead.

Reimplemented from flutter::PlatformView.

Definition at line 99 of file platform_view_ios.h.

                                                                                   {
    return platform_message_handler_;
  }

GetPlatformMessageHandlerIos()

std::shared_ptr< PlatformMessageHandlerIos > flutter::PlatformViewIOS::GetPlatformMessageHandlerIos ( ) const

inline

Definition at line 95 of file platform_view_ios.h.

                                                                                {
    return platform_message_handler_;
  }

RegisterExternalTexture()

void flutter::PlatformViewIOS::RegisterExternalTexture	(	int64_t	id,
		NSObject< FlutterTexture > *	texture
	)

Called through when an external texture such as video or camera is given to the FlutterEngine or FlutterViewController.

Definition at line 135 of file platform_view_ios.mm.

                                                                                 {
  RegisterTexture(ios_context_->CreateExternalTexture(
      texture_id, fml::scoped_nsobject<NSObject<FlutterTexture>>{[texture retain]}));
}

SetOwnerViewController()

void flutter::PlatformViewIOS::SetOwnerViewController

(

const fml::WeakNSObject< FlutterViewController > &

owner_controller

)

Updates the FlutterViewController currently attached to the FlutterEngine owning this PlatformViewIOS. This should be updated when the FlutterEngine is given a new FlutterViewController.

Definition at line 81 of file platform_view_ios.mm.

                                                                    {
  FML_DCHECK(task_runners_.GetPlatformTaskRunner()->RunsTasksOnCurrentThread());
  std::lock_guard<std::mutex> guard(ios_surface_mutex_);
  if (ios_surface_ || !owner_controller) {
    NotifyDestroyed();
    ios_surface_.reset();
    accessibility_bridge_.Clear();
  }
  owner_controller_ = owner_controller;
 
  // Add an observer that will clear out the owner_controller_ ivar and
  // the accessibility_bridge_ in case the view controller is deleted.
  dealloc_view_controller_observer_.reset(
      [[[NSNotificationCenter defaultCenter] addObserverForName:FlutterViewControllerWillDealloc
                                                         object:owner_controller_.get()
                                                          queue:[NSOperationQueue mainQueue]
                                                     usingBlock:^(NSNotification* note) {
                                                       // Implicit copy of 'this' is fine.
                                                       accessibility_bridge_.Clear();
                                                       owner_controller_.reset();
                                                     }] retain]);
 
  if (owner_controller_ && [owner_controller_.get() isViewLoaded]) {
    this->attachView();
  }
  // Do not call `NotifyCreated()` here - let FlutterViewController take care
  // of that when its Viewport is sized.  If `NotifyCreated()` is called here,
  // it can occasionally get invoked before the viewport is sized resulting in
  // a framebuffer that will not be able to completely attach.
}

SetSemanticsEnabled()

void flutter::PlatformViewIOS::SetSemanticsEnabled ( bool  enabled )

overridevirtual

Used by embedder to notify the running isolate hosted by the engine on the UI thread that the accessibility tree needs to be generated.

Attention

Subclasses may choose to override this method to perform platform specific functions. However, they must call the base class method at some point in their implementation.

Parameters

[in]

enabled

Whether the accessibility tree needs to be generated.

Reimplemented from flutter::PlatformView.

Definition at line 169 of file platform_view_ios.mm.

                                                      {
  if (!owner_controller_) {
    FML_LOG(WARNING) << "Could not set semantics to enabled, this "
                        "PlatformViewIOS has no ViewController.";
    return;
  }
  if (enabled && !accessibility_bridge_) {
    accessibility_bridge_.Set(std::make_unique<AccessibilityBridge>(
        owner_controller_.get(), this, [owner_controller_.get() platformViewsController]));
  } else if (!enabled && accessibility_bridge_) {
    accessibility_bridge_.Clear();
  } else {
    PlatformView::SetSemanticsEnabled(enabled);
  }
}

---

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

• shell/platform/darwin/ios/platform_view_ios.h
• shell/platform/darwin/ios/platform_view_ios.mm