Struct masonry::WidgetId

pub struct WidgetId(/* private fields */);

A unique identifier for a single Widget.

WidgetIds are generated automatically for all widgets in the widget tree. More specifically, each WidgetPod has a unique WidgetId.

These ids are used internally to route events, and can be used to communicate between widgets, by submitting a command (as with [EventCtx::submit_command]) and passing a WidgetId as the Target.

A widget can retrieve its id via methods on the various contexts, such as LifeCycleCtx::widget_id.

Explicit WidgetIds.

Sometimes, you may want to construct a widget, in a way that lets you know its id, so you can refer to the widget later. You can use WidgetPod::new_with_id to pass an id to the WidgetPod you’re creating; various widgets which have methods to create children may have variants taking ids as parameters.

If you set a WidgetId directly, you are responsible for ensuring that it is unique. Two widgets must not be created with the same id.

Implementations

impl WidgetId

pub fn next() -> WidgetId

Allocate a new, unique WidgetId.

All widgets are assigned ids automatically; you should only create an explicit id if you need to know it ahead of time, for instance if you want two sibling widgets to know each others’ ids.

You must ensure that a given WidgetId is only ever used for one widget at a time.

pub const fn reserved(raw: u16) -> WidgetId

Create a reserved WidgetId, suitable for reuse.

The caller is responsible for ensuring that this ID is in fact assigned to a single widget at any time, or your code may become haunted.

The actual inner representation of the returned WidgetId will not be the same as the raw value that is passed in; it will be u64::max_value() - raw.

pub fn to_raw(self) -> u64

Trait Implementations

impl Clone for WidgetId

fn clone(&self) -> WidgetId

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for WidgetId

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<WidgetId> for NodeId

fn from(id: WidgetId) -> NodeId

Converts to this type from the input type.

impl Hash for WidgetId

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for WidgetId

fn eq(&self, other: &WidgetId) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for WidgetId

impl Eq for WidgetId

impl StructuralPartialEq for WidgetId