[−][src]Struct conrod_core::widget::scroll::State
Scroll state calculated for a single axis.
Fields
offset: Scalar
The distance that has been scrolled from the origin.
A positive offset pushes the scrollable range that is under the kid_area upwards.
A negative offset pushes the scrollable range that is under the kid_area downwards.
offset_bounds: Range
The start and end bounds for the offset along the axis.
scrollable_range_len: Scalar
The total range which may be "offset" from the "root" range (aka the kid_area
).
The scrollable_range
is determined as the bounding range around both the kid_area
and
all un-scrolled visible children widgets.
is_scrolling: bool
Whether or not the this axis is currently scrolling.
Methods
impl<A> State<A> where
A: Axis,
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A: Axis,
pub fn update(
ui: &Ui,
idx: Id,
kid_area: &KidArea,
maybe_prev_scroll_state: Option<Self>,
additional_offset: Scalar
) -> Self
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ui: &Ui,
idx: Id,
kid_area: &KidArea,
maybe_prev_scroll_state: Option<Self>,
additional_offset: Scalar
) -> Self
Calculate the new scroll state for the single axis of a Widget
.
> +---+
| | |
| =========================
| | | a | scroll root |
| | +---+ aka `kid_area` |
| | +--------+ |
| | | | |
| =========================
| | b |
| +--------+
scrollable| +--------+
range y| | |
| | | +------+
| | c | | |
| +--------+ | d |
| | |
> +------+
^--------------------^
scrollable
range x
kid_area
is the cropped area of the container widget in which kid widgets may be viewed.a
,b
,c
andd
are widgets that are kids of the "scroll root" widget in their original, un-scrolled positions.scrollable_range
is the total range occuppied by all children widgets in their original, un-scrolled positions.
Everything above and below the set of ==== bars of the parent widget is hidden, i.e:
=========================
| | a | scroll root |
| +---+ aka `kid_area` |
| +--------+ |
| | b | |
=========================
The scrollable_range
on each axis only becomes scrollable if its length exceeds the
length of the kid_area
on the same axis. Thus, in the above example, only the y
scrollable_range is scrollable.
The offset_bounds
are calculated as the amount which the original, un-scrolled,
scrollable_range
may be offset from its origin.
offset + >
bounds v |
.start > | =========================
| | |
| | kid_area |
| | |
| | |
> scrollable | =========================
^ range y |
^ |
^ |
offset ^ |
bounds ^ |
.end ^ |
^ |
^ |
+ >
Trait Implementations
impl<A: PartialEq> PartialEq<State<A>> for State<A>
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impl<A: Clone> Clone for State<A>
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fn clone(&self) -> State<A>
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fn clone_from(&mut self, source: &Self)
1.0.0[src]
Performs copy-assignment from source
. Read more
impl<A: Copy> Copy for State<A>
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impl<A: Debug> Debug for State<A>
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Auto Trait Implementations
Blanket Implementations
impl<T> Style for T where
T: Any + Debug + PartialEq<T>,
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T: Any + Debug + PartialEq<T>,
impl<T> From<T> for T
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impl<T> ToOwned for T where
T: Clone,
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T: Clone,
type Owned = T
The resulting type after obtaining ownership.
fn to_owned(&self) -> T
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fn clone_into(&self, target: &mut T)
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impl<T, U> Into<U> for T where
U: From<T>,
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U: From<T>,
impl<T, U> TryFrom<U> for T where
U: Into<T>,
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U: Into<T>,
type Error = Infallible
The type returned in the event of a conversion error.
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
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impl<T, U> TryInto<U> for T where
U: TryFrom<T>,
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U: TryFrom<T>,
type Error = <U as TryFrom<T>>::Error
The type returned in the event of a conversion error.
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>
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impl<T> Borrow<T> for T where
T: ?Sized,
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T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
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T: ?Sized,
fn borrow_mut(&mut self) -> &mut T
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impl<T> Any for T where
T: 'static + ?Sized,
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T: 'static + ?Sized,