Struct egui::Id [−][src]
pub struct Id(_);
egui tracks widgets frame-to-frame using Id
s.
For instance, if you start dragging a slider one frame, egui stores
the sliders Id
as the current active id so that next frame when
you move the mouse the same slider changes, even if the mouse has
moved outside the slider.
For some widgets Id
s are also used to persist some state about the
widgets, such as Window position or wether not a collapsing header region is open.
This implies that the Id
s must be unique.
For simple things like sliders and buttons that don’t have any memory and doesn’t move we can use the location of the widget as a source of identity. For instance, a slider only needs a unique and persistent ID while you are dragging the slider. As long as it is still while moving, that is fine.
For things that need to persist state even after moving (windows, collapsing headers) the location of the widgets is obviously not good enough. For instance, a collapsing region needs to remember wether or not it is open even if the layout next frame is different and the collapsing is not lower down on the screen.
Then there are widgets that need no identifiers at all, like labels, because they have no state nor are interacted with.
Implementations
Trait Implementations
impl Copy for Id
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impl Eq for Id
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impl StructuralEq for Id
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impl StructuralPartialEq for Id
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Auto Trait Implementations
Blanket Implementations
impl<T> BorrowMut<T> for T where
T: ?Sized,
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impl<T> BorrowMut<T> for T where
T: ?Sized,
[src]pub fn borrow_mut(&mut self) -> &mut T
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pub fn borrow_mut(&mut self) -> &mut T
[src]Mutably borrows from an owned value. Read more
impl<T> ToOwned for T where
T: Clone,
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impl<T> ToOwned for T where
T: Clone,
[src]type Owned = T
type Owned = T
The resulting type after obtaining ownership.
pub fn to_owned(&self) -> T
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pub fn to_owned(&self) -> T
[src]Creates owned data from borrowed data, usually by cloning. Read more
pub fn clone_into(&self, target: &mut T)
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pub fn clone_into(&self, target: &mut T)
[src]🔬 This is a nightly-only experimental API. (toowned_clone_into
)
recently added
Uses borrowed data to replace owned data, usually by cloning. Read more