flutter::PlatformViewEmbedder Class Reference

#include <platform_view_embedder.h>

Inheritance diagram for flutter::PlatformViewEmbedder:

Classes
class	EmbedderPlatformMessageHandler
struct	PlatformDispatchTable

Public Types
using	UpdateSemanticsCallback = std::function< void(int64_t view_id, flutter::SemanticsNodeUpdates update, flutter::CustomAccessibilityActionUpdates actions)>
using	PlatformMessageResponseCallback = std::function< void(std::unique_ptr< PlatformMessage >)>
using	ComputePlatformResolvedLocaleCallback = std::function< std::unique_ptr< std::vector< std::string > >(const std::vector< std::string > &supported_locale_data)>
using	OnPreEngineRestartCallback = std::function< void()>
using	ChanneUpdateCallback = std::function< void(const std::string &, bool)>
using	ViewFocusChangeRequestCallback = std::function< void(const ViewFocusChangeRequest &)>
Public Types inherited from flutter::PlatformView
using	AddViewCallback = std::function< void(bool added)>
using	RemoveViewCallback = std::function< void(bool removed)>

Public Member Functions
	PlatformViewEmbedder (PlatformView::Delegate &delegate, const flutter::TaskRunners &task_runners, const EmbedderSurfaceSoftware::SoftwareDispatchTable &software_dispatch_table, PlatformDispatchTable platform_dispatch_table, std::shared_ptr< EmbedderExternalViewEmbedder > external_view_embedder)
	~PlatformViewEmbedder () override
void	UpdateSemantics (int64_t view_id, flutter::SemanticsNodeUpdates update, flutter::CustomAccessibilityActionUpdates actions) override
	Used by the framework to tell the embedder to apply the specified semantics node updates. The default implementation of this method does nothing.
void	HandlePlatformMessage (std::unique_ptr< PlatformMessage > message) override
	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.
std::shared_ptr< PlatformMessageHandler >	GetPlatformMessageHandler () const override
	Specifies a delegate that will receive PlatformMessages from Flutter to the host platform.
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.
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.
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.
void	DispatchSemanticsAction (int64_t view_id, 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.
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.
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.
virtual void	SetApplicationLocale (std::string locale)
	Used by the framework to set application locale in the embedding.
virtual void	SetSemanticsTreeEnabled (bool enabled)
	Used by the framework to tell the embedder to prepare or clear resoruce for accepting semantics tree.
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.
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.
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.
void	ScheduleFrame ()
	Used by embedders to schedule a frame. In response to this call, the framework may need to start generating a new frame.
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.
void	RemoveView (int64_t view_id, RemoveViewCallback callback)
	Used by embedders to notify the shell of a removed non-implicit view.
void	SendViewFocusEvent (const ViewFocusEvent &event)
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.
virtual PointerDataDispatcherMaker	GetDispatcherMaker ()
	Returns a platform-specific PointerDataDispatcherMaker so the Engine can construct the PointerDataPacketDispatcher based on platforms.
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.
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.
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.
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.
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.
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.
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
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.
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.
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.
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.
const Settings &	GetSettings () const
	Get the settings for this platform view instance.
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.
virtual void	SetupImpellerContext ()
	Performs any deferred setup of the Impeller context.

Additional Inherited Members
Protected Attributes inherited from flutter::PlatformView
PlatformView::Delegate &	delegate_
const TaskRunners	task_runners_
fml::WeakPtrFactory< PlatformView >	weak_factory_

Detailed Description

Definition at line 36 of file platform_view_embedder.h.

Member Typedef Documentation

ChanneUpdateCallback

using flutter::PlatformViewEmbedder::ChanneUpdateCallback = std::function<void(const std::string&, bool)>

Definition at line 48 of file platform_view_embedder.h.

ComputePlatformResolvedLocaleCallback

using flutter::PlatformViewEmbedder::ComputePlatformResolvedLocaleCallback = std::function<std::unique_ptr<std::vector<std::string> >( const std::vector<std::string>& supported_locale_data)>

Definition at line 44 of file platform_view_embedder.h.

OnPreEngineRestartCallback

using flutter::PlatformViewEmbedder::OnPreEngineRestartCallback = std::function<void()>

Definition at line 47 of file platform_view_embedder.h.

PlatformMessageResponseCallback

using flutter::PlatformViewEmbedder::PlatformMessageResponseCallback = std::function<void(std::unique_ptr<PlatformMessage>)>

Definition at line 42 of file platform_view_embedder.h.

UpdateSemanticsCallback

using flutter::PlatformViewEmbedder::UpdateSemanticsCallback = std::function<void(int64_t view_id, flutter::SemanticsNodeUpdates update, flutter::CustomAccessibilityActionUpdates actions)>

Definition at line 38 of file platform_view_embedder.h.

ViewFocusChangeRequestCallback

using flutter::PlatformViewEmbedder::ViewFocusChangeRequestCallback = std::function<void(const ViewFocusChangeRequest&)>

Definition at line 49 of file platform_view_embedder.h.

Constructor & Destructor Documentation

PlatformViewEmbedder()

flutter::PlatformViewEmbedder::PlatformViewEmbedder	(	PlatformView::Delegate &	delegate,
		const flutter::TaskRunners &	task_runners,
		const EmbedderSurfaceSoftware::SoftwareDispatchTable &	software_dispatch_table,
		PlatformDispatchTable	platform_dispatch_table,
		std::shared_ptr< EmbedderExternalViewEmbedder >	external_view_embedder
	)

Definition at line 48 of file platform_view_embedder.cc.

    : PlatformView(delegate, task_runners),
      external_view_embedder_(std::move(external_view_embedder)),
      embedder_surface_(
          std::make_unique<EmbedderSurfaceSoftware>(software_dispatch_table,
                                                    external_view_embedder_)),
      platform_message_handler_(new EmbedderPlatformMessageHandler(
          GetWeakPtr(),
          task_runners.GetPlatformTaskRunner())),
      platform_dispatch_table_(std::move(platform_dispatch_table)) {}

~PlatformViewEmbedder()

flutter::PlatformViewEmbedder::~PlatformViewEmbedder ( )

overridedefault

Member Function Documentation

GetPlatformMessageHandler()

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

overridevirtual

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 219 of file platform_view_embedder.cc.

                                                      {
  return platform_message_handler_;
}

HandlePlatformMessage()

void flutter::PlatformViewEmbedder::HandlePlatformMessage ( std::unique_ptr< PlatformMessage >  message )

overridevirtual

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.

Embedders that wish to send platform messages to the framework may use the DispatchPlatformMessage method. This method is for messages that go the other way.

See also

DispatchPlatformMessage()

Parameters

[in]

message

The message

Reimplemented from flutter::PlatformView.

Definition at line 125 of file platform_view_embedder.cc.

                                                   {
  if (!message) {
    return;
  }
 
  if (platform_dispatch_table_.platform_message_response_callback == nullptr) {
    if (message->response()) {
      message->response()->CompleteEmpty();
    }
    return;
  }
 
  platform_dispatch_table_.platform_message_response_callback(
      std::move(message));
}

References message, and flutter::PlatformViewEmbedder::PlatformDispatchTable::platform_message_response_callback.

UpdateSemantics()

void flutter::PlatformViewEmbedder::UpdateSemantics ( int64_t  view_id, flutter::SemanticsNodeUpdates  updates, flutter::CustomAccessibilityActionUpdates  actions  )

overridevirtual

Used by the framework to tell the embedder to apply the specified semantics node updates. The default implementation of this method does nothing.

See also

SemanticsNode, SemticsNodeUpdates, CustomAccessibilityActionUpdates

Parameters

[in]	view_id	The ID of the view that this update is for
[in]	updates	A map with the stable semantics node identifier as key and the node properties as the value.
[in]	actions	A map with the stable semantics node identifier as key and the custom node action as the value.

Reimplemented from flutter::PlatformView.

Definition at line 115 of file platform_view_embedder.cc.

                                                     {
  if (platform_dispatch_table_.update_semantics_callback != nullptr) {
    platform_dispatch_table_.update_semantics_callback(
        view_id, std::move(update), std::move(actions));
  }
}

References flutter::PlatformViewEmbedder::PlatformDispatchTable::update_semantics_callback, and view_id.

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

• shell/platform/embedder/platform_view_embedder.h
• shell/platform/embedder/platform_view_embedder.cc