Struct CachedWidget

pub struct CachedWidget { /* private fields */ }

A Singleton wrapper widget that caches and reuses its child widget across multiple instances.

CachedWidget is designed to optimize performance and memory usage by ensuring that only one instance of a child widget is created and shared across multiple uses in the UI. This is particularly useful for complex widgets that are used in different parts of the UI but should maintain a single state.

Usage

In the DSL, you can use CachedWidget as follows:

<CachedWidget> {
    my_widget = <MyWidget> {}
}

The child widget will be created once and cached. Subsequent uses of this CachedWidget with the same child id (mid_widget) will reuse the cached instance. Note that only one child is supported per CachedWidget.

CachedWidget supports Makepad’s widget finding mechanism, allowing child widgets to be located as expected.

Implementation Details

• Uses a global WidgetWrapperCache to store cached widgets
• Handles widget creation and caching in the after_apply hook
• Delegates most widget operations (like event handling and drawing) to the cached child widget

Note

While CachedWidget can significantly improve performance for complex, frequently used widgets, it should be used judiciously. Overuse of caching can lead to unexpected behavior if not managed properly.

Trait Implementations

impl LiveApply for CachedWidget

fn apply( &mut self, cx: &mut Cx, apply: &mut Apply<'_, '_, '_>, start_index: usize, nodes: &[LiveNode], ) -> usize

fn apply_over(&mut self, cx: &mut Cx, nodes: &[LiveNode])

impl LiveApplyReset for CachedWidget

fn apply_reset( &mut self, cx: &mut Cx, apply: &mut Apply<'_, '_, '_>, start_index: usize, nodes: &[LiveNode], )

impl LiveApplyValue for CachedWidget

fn apply_value( &mut self, cx: &mut Cx, apply: &mut Apply<'_, '_, '_>, index: usize, nodes: &[LiveNode], ) -> usize

impl LiveHook for CachedWidget

fn apply_value_instance( &mut self, cx: &mut Cx, apply: &mut Apply<'_, '_, '_>, index: usize, nodes: &[LiveNode], ) -> usize

Handles the application of instance properties to this CachedWidget.

In the case of CachedWidget This method is responsible for setting up the template for the child widget, and applying any changes to an existing widget instance.

fn after_apply( &mut self, cx: &mut Cx, _apply: &mut Apply<'_, '_, '_>, _index: usize, _nodes: &[LiveNode], )

Handles the creation or retrieval of the cached widget after applying changes.

This method is called after all properties have been applied to the widget. It ensures that the child widget is properly cached and retrieved from the global cache.

fn before_apply( &mut self, _cx: &mut Cx, apply: &mut Apply<'_, '_, '_>, _index: usize, _nodes: &[LiveNode], )

fn apply_value_unknown( &mut self, cx: &mut Cx, _apply: &mut Apply<'_, '_, '_>, index: usize, nodes: &[LiveNode], ) -> usize

fn skip_apply_animator( &mut self, _cx: &mut Cx, _apply: &mut Apply<'_, '_, '_>, _index: usize, _nodes: &[LiveNode], ) -> bool

fn skip_apply( &mut self, _cx: &mut Cx, _apply: &mut Apply<'_, '_, '_>, _index: usize, _nodes: &[LiveNode], ) -> Option<usize>

fn after_apply_from(&mut self, cx: &mut Cx, apply: &mut Apply<'_, '_, '_>)

fn after_new_from_doc(&mut self, _cx: &mut Cx)

fn after_update_from_doc(&mut self, _cx: &mut Cx)

fn after_apply_from_doc(&mut self, _cx: &mut Cx)

fn after_new_before_apply(&mut self, _cx: &mut Cx)

impl LiveHookDeref for CachedWidget

fn deref_before_apply( &mut self, cx: &mut Cx, apply: &mut Apply<'_, '_, '_>, index: usize, nodes: &[LiveNode], )

fn deref_after_apply( &mut self, cx: &mut Cx, apply: &mut Apply<'_, '_, '_>, index: usize, nodes: &[LiveNode], )

impl LiveNew for CachedWidget

fn live_type_info(cx: &mut Cx) -> LiveTypeInfo

fn live_design_with(cx: &mut Cx)

fn new(cx: &mut Cx) -> Self

fn new_apply( cx: &mut Cx, apply: &mut Apply<'_, '_, '_>, index: usize, nodes: &[LiveNode], ) -> Self

where Self: Sized,

fn new_apply_over(cx: &mut Cx, nodes: &[LiveNode]) -> Self

where Self: Sized,

fn new_apply_mut_index( cx: &mut Cx, apply: &mut Apply<'_, '_, '_>, index: &mut usize, nodes: &[LiveNode], ) -> Self

where Self: Sized,

fn new_from_ptr(cx: &mut Cx, live_ptr: Option<LivePtr>) -> Self

where Self: Sized,

fn update_from_ptr(&mut self, cx: &mut Cx, live_ptr: Option<LivePtr>)

fn update_from_ptr_with_scope( &mut self, cx: &mut Cx, live_ptr: Option<LivePtr>, scope: &mut Scope<'_, '_>, )

fn new_from_ptr_with_scope( cx: &mut Cx, live_ptr: Option<LivePtr>, scope: &mut Scope<'_, '_>, ) -> Self

where Self: Sized,

fn new_main(cx: &mut Cx) -> Option<Self>

where Self: Sized,

fn register_main_module(cx: &mut Cx)

fn update_main(&mut self, cx: &mut Cx)

fn new_local(cx: &mut Cx) -> Self

where Self: Sized,

fn new_from_module( cx: &mut Cx, module_id: LiveModuleId, id: LiveId, ) -> Option<Self>

where Self: Sized,

fn update_from_module( &mut self, cx: &mut Cx, module_id: LiveModuleId, id: LiveId, )

impl LiveRegister for CachedWidget

fn live_register(cx: &mut Cx)

impl Widget for CachedWidget

fn handle_event( &mut self, cx: &mut Cx, event: &Event, scope: &mut Scope<'_, '_>, )

fn draw_walk( &mut self, cx: &mut Cx2d<'_, '_>, scope: &mut Scope<'_, '_>, walk: Walk, ) -> DrawStep

fn handle_event_with( &mut self, cx: &mut Cx, event: &Event, scope: &mut Scope<'_, '_>, _sweep_area: Area, )

fn widget(&self, path: &[LiveId]) -> WidgetRef

fn widgets(&self, paths: &[&[LiveId]]) -> WidgetSet

fn widget_uid(&self) -> WidgetUid

fn widget_to_data( &self, _cx: &mut Cx, _actions: &Actions, _nodes: &mut LiveNodeVec, _path: &[LiveId], ) -> bool

fn data_to_widget( &mut self, _cx: &mut Cx, _nodes: &[LiveNode], _path: &[LiveId], )

fn draw_3d( &mut self, _cx: &mut Cx3d<'_, '_>, _scope: &mut Scope<'_, '_>, ) -> DrawStep

fn draw_3d_all(&mut self, cx: &mut Cx3d<'_, '_>, scope: &mut Scope<'_, '_>)

fn draw(&mut self, cx: &mut Cx2d<'_, '_>, scope: &mut Scope<'_, '_>) -> DrawStep

fn draw_walk_all( &mut self, cx: &mut Cx2d<'_, '_>, scope: &mut Scope<'_, '_>, walk: Walk, )

fn draw_all(&mut self, cx: &mut Cx2d<'_, '_>, scope: &mut Scope<'_, '_>)

fn draw_unscoped(&mut self, cx: &mut Cx2d<'_, '_>) -> DrawStep

fn draw_all_unscoped(&mut self, cx: &mut Cx2d<'_, '_>)

fn text(&self) -> String

fn set_text(&mut self, _cx: &mut Cx, _v: &str)

fn set_key_focus(&self, cx: &mut Cx)

fn key_focus(&self, cx: &Cx) -> bool

fn set_disabled(&mut self, _cx: &mut Cx, _disabled: bool)

fn disabled(&self, _cx: &Cx) -> bool

fn ref_cast_type_id(&self) -> LiveType

where Self: 'static,

fn ui_runner(&self) -> UiRunner<Self>

where Self: Sized + 'static,

impl WidgetNode for CachedWidget

fn walk(&mut self, cx: &mut Cx) -> Walk

fn area(&self) -> Area

fn redraw(&mut self, cx: &mut Cx)

fn find_widgets( &self, path: &[LiveId], cached: WidgetCache, results: &mut WidgetSet, )

fn uid_to_widget(&self, uid: WidgetUid) -> WidgetRef

fn widget_design(&mut self) -> Option<&mut dyn WidgetDesign>

fn set_action_data(&mut self, _data: Arc<dyn ActionTrait>)

fn action_data(&self) -> Option<Arc<dyn ActionTrait>>

fn set_visible(&mut self, _cx: &mut Cx, _visible: bool)

fn visible(&self) -> bool