Struct Shell 

pub struct Shell { /* private fields */ }

Host-facing isolate: the AppCell plus the methods the embedder pushes.

Every push is one call into the app: the App is borrowed for the binding call and released before the cell’s checkpoint, where the microtasks and futures the event queued run.

Implementations

impl Shell

pub fn new(platform: PlatformRef, setup: impl FnOnce(&mut App)) -> Shell

Builds the heap from platform, then runs application setup.

Setup (later widgets run_app) requests the first frame when it installs work that needs one.

pub fn app(&self) -> RefMut<'_, App>

The App, borrowed until the guard drops. A host that needs the whole thing, a borrow and then the checkpoint, takes cell.

pub fn cell(&self) -> &Rc<AppCell>

Trait Implementations

impl EmbedderClient for Shell

fn view_added(&mut self, id: ViewId)

The framework hears which view came, then “metrics changed”, as _addView invokes it.

fn view_removed(&mut self, id: ViewId)

The framework hears which view went, then “metrics changed”, as _removeView invokes it.

fn screens_changed(&mut self)

“Metrics changed”, as _updateDisplays invokes it.

fn request_app_exit(&mut self, reply: AppExitReply)

The binding’s answer goes to reply at the checkpoint of the call in which the observers decide: this push’s own when they answer at once.

fn app_lifecycle_state_changed(&mut self, state: AppLifecycleState)

On resumed or inactive, every view is marked to present and asked for a frame before the bindings hear the state: a view that did not change while the app was away would otherwise present nothing.

fn frame(&mut self, views: &[ViewId], frame: Frame)

A screen refreshed at frame.elapsed: views are the views on it, in sight, that asked for a frame (Platform::request_frame) before the refresh began; one that asks during it is in the next.

fn view_metrics_changed(&mut self, _id: ViewId)

Flutter’s window metrics event: something of id’s metrics changed, the screen it is on included.

fn view_focus_changed(&mut self, event: ViewFocusEvent)

Flutter PlatformDispatcher.onViewFocusChange.

fn drop_data(&mut self, data: DropData)

Files dragged from outside the application entered, moved over, were dropped on or left a view. No dart:ui hook; the default drops it.

fn pointer_data_packet(&mut self, packet: PointerDataPacket)

Flutter PlatformDispatcher.onPointerDataPacket.

fn key_data(&mut self, data: KeyData) -> bool

Flutter PlatformDispatcher.onKeyData.

fn pop_route(&mut self) -> bool

The user asked to go back: Android’s back button or back gesture, and whatever a later host maps onto the same idea.

fn view_close_requested(&mut self, view: ViewId)

The user asked to close view: its window’s close button, or the system’s Close command. The host closes nothing itself; the application closes the window, through HostWindow::close, or keeps it open, such as until its user has chosen whether to save. Nothing waits for an answer.

fn window_changed(&mut self, view: ViewId)

The window of view was minimized or restored, became occluded or shown, or moved, and its HostWindow already answers how it is now: as Flutter’s window controllers notify their listeners at the platform’s word. A resize is reported as a metrics change alone (view_metrics_changed). The default drops it.

fn view_request_failed(&mut self, request: RequestId, error: ViewError)

A request for a view (crate::Platform::request_view) got no view: the host could not make its window. The default drops it.

fn platform_brightness_changed(&mut self)

Flutter PlatformDispatcher.onPlatformBrightnessChanged: the host’s light or dark preference changed, and Platform::platform_brightness already answers the new one.

fn locales_changed(&mut self)

Flutter PlatformDispatcher.onLocaleChanged: the host’s locale list changed, and Platform::locales already answers the new one.

fn system_fonts_changed(&mut self)

Flutter PlatformDispatcher.onSystemFontsChanged: the host registered faces the framework did not have when text last laid out.

fn wake(&mut self, elapsed: Duration)

The wake asked for through Dispatcher::wake_at or Dispatcher::wake_now.

fn text_input_editing_value(&mut self, _view: ViewId, value: TextEditingValue)

Flutter TextInputClient.updateEditingValue. The default drops it.

fn text_input_action(&mut self, _view: ViewId, action: TextInputAction)

Flutter TextInputClient.performAction. The default drops it.

fn text_input_closed(&mut self, _view: ViewId)

Flutter TextInputClient.connectionClosed. The default drops it.

fn system_context_menu_hidden(&mut self)

Flutter SystemContextMenuClient.handleSystemHide. The default drops it.

fn custom_context_menu_action(&mut self, callback_id: &str)

Flutter SystemContextMenuClient.handleCustomContextMenuAction. The default drops it.