StackState
public final class StackState implements ScrollableState
The VerticalStack state that allows programmatic control and observation of the stack's state.
A StackState object can be created and remembered using rememberStackState.
Note: Properties of the state will only be correctly populated after the VerticalStack it is associated with has been composed for the first time.
Warning: A single StackState instance must not be shared across multiple VerticalStack composables.
| See also | |
|---|---|
rememberStackState |
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VerticalStack |
Summary
Nested types |
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public static class StackState.Companion |
Public constructors |
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StackState(@IntRange(from = 0) int initialTopItem) |
Public methods |
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final void |
animateScrollToItem(Scroll animate to a given |
float |
dispatchRawDelta(float delta) |
boolean |
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boolean |
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final @NonNull InteractionSource |
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boolean |
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boolean |
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final int |
The index of the item that's currently at the top of the stack, defaults to 0. |
final float |
The offset of the top item as a fraction of the stack item container size. |
boolean |
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void |
scroll( |
final void |
scrollToItem(int item)Scroll (jump immediately) to a given |
Inherited methods |
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Public constructors
StackState
public StackState(@IntRange(from = 0) int initialTopItem)
| Parameters | |
|---|---|
@IntRange(from = 0) int initialTopItem |
The index of the item to show at the top of the stack initially. Must be non-negative. Defaults to 0. |
Public methods
animateScrollToItem
public final void animateScrollToItem(
int item,
@NonNull AnimationSpec<@NonNull Float> animationSpec
)
Scroll animate to a given item's closest snap position. If the item is too far away from topItem, not all the items in the range will be composed. Instead, the stack will jump to a nearer item, then compose and animate the rest of the items until the destination item.
| Parameters | |
|---|---|
int item |
The index of the destination item |
@NonNull AnimationSpec<@NonNull Float> animationSpec |
An |
getInteractionSource
public final @NonNull InteractionSource getInteractionSource()
InteractionSource that's used to dispatch drag events when this stack is being dragged. To know whether a fling (or animated scroll) is in progress, use isScrollInProgress.
getTopItem
public final int getTopItem()
The index of the item that's currently at the top of the stack, defaults to 0.
getTopItemOffsetFraction
@FrequentlyChangingValue
public final float getTopItemOffsetFraction()
The offset of the top item as a fraction of the stack item container size. The value indicates how much the item is offset from the snapped position. This value ranges between 0.0 (snapped position) and 1.0 (lower bound of the top item is at the top of the viewport).
scroll
public void scroll(
@NonNull MutatePriority scrollPriority,
@NonNull SuspendFunction1<@NonNull ScrollScope, Unit> block
)
scrollToItem
public final void scrollToItem(int item)
Scroll (jump immediately) to a given item index.
| Parameters | |
|---|---|
int item |
The index of the destination item |