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 clipboard_event(&mut self, view: ViewId, event: ClipboardEvent)

The user copied, cut or pasted in view through the platform’s own command: the browser’s, or a desktop’s Edit menu, which a key reaches only once the framework has left it unhandled. No dart:ui hook; the default drops it.

fn edit_command(&mut self, view: ViewId, command: EditCommand)

The user chose an edit command for view from the system’s own Edit menu, which a key reaches only once the framework has left it unhandled: undo, redo, select all or delete. No dart:ui hook; the default drops it.

fn menu_selected(&mut self, id: MenuId)

The user chose the item id of the app’s menu bar (MenuBar::set_menus). Flutter’s Menu.selectedCallback on the flutter/menu channel. The default drops it.

fn dock_menu_selected(&mut self, id: MenuId)

The user chose the item id of the Dock icon’s menu (DockMenu::set_menu). No dart:ui hook; the default drops it.

fn tray_icon_event(&mut self, icon: TrayIconId, event: TrayIconEvent)

Something happened to the tray icon icon, as its system reports it. No dart:ui hook; the default drops it.

fn open_requested(&mut self, request: OpenRequest)

The system asks the app to open files and links: from the file manager, another app or the command line, at launch or while it runs. A launch’s request comes once the client exists. No dart:ui hook: Flutter’s embedders hand these to their plugins. The default drops it.

fn notification_activated(&mut self, activation: NotificationActivation)

The user clicked a notification the app posted, or one of its actions, or replied: while the app runs, or to start it, when the activation comes once the client exists. No dart:ui hook: Flutter’s apps hear these through plugins. The default drops it.

fn pointer_reports(&mut self, reports: Vec<PointerReport>)

What pointing devices did, as the system reported it, in the order it happened: the embedder API’s FlutterEngineSendPointerEvent. The client adds what the framework also needs (PointerDataPacketConverter) and hands the result to 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 clipboard_changed(&mut self)

Another app changed what is on the clipboard, or the host cleared a copy of this app’s that expired, as far as the host can tell: at the moments its system says so, or lets it check. The app’s own writes are not reported, as it made them, but where the system tells them apart from no other change, as a browser does not. No dart:ui hook; the default drops it.

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.