#Box.Scroll

Wrapper around React Native's ScrollView.

#Import

import { Box } from 'bumbag-native';

#Usage

Editable example

#Box.Scroll Props

Inherits React Native's ScrollView props

contentContainerStyle

false
  | ViewStyle
  | RegisteredStyle<ViewStyle>
  | RecursiveArray<false
  | ViewStyle
  | RegisteredStyle<ViewStyle>>

These styles will be applied to the scroll view content container which wraps all of the child views. Example:

return (

<ScrollView contentContainerStyle={styles.contentContainer}>
</ScrollView>

); ... const styles = StyleSheet.create({ contentContainer: { paddingVertical: 20 } });

decelerationRate number | "fast" | "normal"

A floating-point number that determines how quickly the scroll view decelerates after the user lifts their finger. You may also use string shortcuts "normal" and "fast" which match the underlying iOS settings for UIScrollViewDecelerationRateNormal and UIScrollViewDecelerationRateFast respectively.

  • 'normal': 0.998 on iOS, 0.985 on Android (the default)
  • 'fast': 0.99 on iOS, 0.9 on Android

horizontal boolean

When true the scroll view's children are arranged horizontally in a row instead of vertically in a column. The default value is false.

invertStickyHeaders boolean

If sticky headers should stick at the bottom instead of the top of the ScrollView. This is usually used with inverted ScrollViews.

keyboardDismissMode "none" | "interactive" | "on-drag"

Determines whether the keyboard gets dismissed in response to a drag.

  • 'none' (the default) drags do not dismiss the keyboard.
  • 'onDrag' the keyboard is dismissed when a drag begins.
  • 'interactive' the keyboard is dismissed interactively with the drag and moves in synchrony with the touch; dragging upwards cancels the dismissal.

keyboardShouldPersistTaps boolean | "always" | "never" | "handled"

Determines when the keyboard should stay visible after a tap.

  • 'never' (the default), tapping outside of the focused text input when the keyboard is up dismisses the keyboard. When this happens, children won't receive the tap.
  • 'always', the keyboard will not dismiss automatically, and the scroll view will not catch taps, but children of the scroll view can catch taps.
  • 'handled', the keyboard will not dismiss automatically when the tap was handled by a children, (or captured by an ancestor).
  • false, deprecated, use 'never' instead
  • true, deprecated, use 'always' instead

onContentSizeChange (w: number, h: number) => void

Called when scrollable content view of the ScrollView changes. Handler function is passed the content width and content height as parameters: (contentWidth, contentHeight) It's implemented using onLayout handler attached to the content container which this ScrollView renders.

onScroll

(event: NativeSyntheticEvent<NativeScrollEvent>) => void

Fires at most once per frame during scrolling. The frequency of the events can be contolled using the scrollEventThrottle prop.

onScrollBeginDrag

(event: NativeSyntheticEvent<NativeScrollEvent>) => void

Fires if a user initiates a scroll gesture.

onScrollEndDrag

(event: NativeSyntheticEvent<NativeScrollEvent>) => void

Fires when a user has finished scrolling.

onMomentumScrollEnd

(event: NativeSyntheticEvent<NativeScrollEvent>) => void

Fires when scroll view has finished moving

onMomentumScrollBegin

(event: NativeSyntheticEvent<NativeScrollEvent>) => void

Fires when scroll view has begun moving

pagingEnabled boolean

When true the scroll view stops on multiples of the scroll view's size when scrolling. This can be used for horizontal pagination. The default value is false.

scrollEnabled boolean

When false, the content does not scroll. The default value is true

removeClippedSubviews boolean

Experimental: When true offscreen child views (whose overflow value is hidden) are removed from their native backing superview when offscreen. This canimprove scrolling performance on long lists. The default value is false.

showsHorizontalScrollIndicator boolean

When true, shows a horizontal scroll indicator.

showsVerticalScrollIndicator boolean

When true, shows a vertical scroll indicator.

style

false
  | ViewStyle
  | RegisteredStyle<ViewStyle>
  | RecursiveArray<false
  | ViewStyle
  | RegisteredStyle<ViewStyle>>

Style

refreshControl

ReactElement<RefreshControlProps, string
  | ((props: any) => ReactElement<any, any>)
  | (new (props: any) => Component<any, any, any>)>

A RefreshControl component, used to provide pull-to-refresh functionality for the ScrollView.

snapToInterval number

When set, causes the scroll view to stop at multiples of the value of snapToInterval. This can be used for paginating through children that have lengths smaller than the scroll view. Used in combination with snapToAlignment and decelerationRate="fast". Overrides less configurable pagingEnabled prop.

snapToOffsets number[]

When set, causes the scroll view to stop at the defined offsets. This can be used for paginating through variously sized children that have lengths smaller than the scroll view. Typically used in combination with decelerationRate="fast". Overrides less configurable pagingEnabled and snapToInterval props.

snapToStart boolean

Use in conjunction with snapToOffsets. By default, the beginning of the list counts as a snap offset. Set snapToStart to false to disable this behavior and allow the list to scroll freely between its start and the first snapToOffsets offset. The default value is true.

snapToEnd boolean

Use in conjunction with snapToOffsets. By default, the end of the list counts as a snap offset. Set snapToEnd to false to disable this behavior and allow the list to scroll freely between its end and the last snapToOffsets offset. The default value is true.

stickyHeaderIndices number[]

An array of child indices determining which children get docked to the top of the screen when scrolling. For example passing stickyHeaderIndices={[0]} will cause the first child to be fixed to the top of the scroll view. This property is not supported in conjunction with horizontal={true}.

disableIntervalMomentum boolean

When true, the scroll view stops on the next index (in relation to scroll position at release) regardless of how fast the gesture is. This can be used for horizontal pagination when the page is less than the width of the ScrollView. The default value is false.

disableScrollViewPanResponder boolean

When true, the default JS pan responder on the ScrollView is disabled, and full control over touches inside the ScrollView is left to its child components. This is particularly useful if snapToInterval is enabled, since it does not follow typical touch patterns. Do not use this on regular ScrollView use cases without snapToInterval as it may cause unexpected touches to occur while scrolling. The default value is false.

hitSlop Insets

This defines how far a touch event can start away from the view. Typical interface guidelines recommend touch targets that are at least 30 - 40 points/density-independent pixels. If a Touchable view has a height of 20 the touchable height can be extended to 40 with hitSlop={{top: 10, bottom: 10, left: 0, right: 0}} NOTE The touch area never extends past the parent view bounds and the Z-index of sibling views always takes precedence if a touch hits two overlapping views.

onLayout (event: LayoutChangeEvent) => void

Invoked on mount and layout changes with

{nativeEvent: { layout: {x, y, width, height}}}.

pointerEvents "auto" | "none" | "box-none" | "box-only"

In the absence of auto property, none is much like CSS's none value. box-none is as if you had applied the CSS class:

.box-none { pointer-events: none; } .box-none * { pointer-events: all; }

box-only is the equivalent of

.box-only { pointer-events: all; } .box-only * { pointer-events: none; }

But since pointerEvents does not affect layout/appearance, and we are already deviating from the spec by adding additional modes, we opt to not include pointerEvents on style. On some platforms, we would need to implement it as a className anyways. Using style or not is an implementation detail of the platform.

testID string

Used to locate this view in end-to-end tests.

nativeID string

Used to reference react managed views from native code.

collapsable boolean

Views that are only used to layout their children or otherwise don't draw anything may be automatically removed from the native hierarchy as an optimization. Set this property to false to disable this optimization and ensure that this View exists in the native view hierarchy.

needsOffscreenAlphaCompositing boolean

Whether this view needs to rendered offscreen and composited with an alpha in order to preserve 100% correct colors and blending behavior. The default (false) falls back to drawing the component and its children with an alpha applied to the paint used to draw each element instead of rendering the full component offscreen and compositing it back with an alpha value. This default may be noticeable and undesired in the case where the View you are setting an opacity on has multiple overlapping elements (e.g. multiple overlapping Views, or text and a background).

Rendering offscreen to preserve correct alpha behavior is extremely expensive and hard to debug for non-native developers, which is why it is not turned on by default. If you do need to enable this property for an animation, consider combining it with renderToHardwareTextureAndroid if the view contents are static (i.e. it doesn't need to be redrawn each frame). If that property is enabled, this View will be rendered off-screen once, saved in a hardware texture, and then composited onto the screen with an alpha each frame without having to switch rendering targets on the GPU.

renderToHardwareTextureAndroid boolean

Whether this view should render itself (and all of its children) into a single hardware texture on the GPU.

On Android, this is useful for animations and interactions that only modify opacity, rotation, translation, and/or scale: in those cases, the view doesn't have to be redrawn and display lists don't need to be re-executed. The texture can just be re-used and re-composited with different parameters. The downside is that this can use up limited video memory, so this prop should be set back to false at the end of the interaction/animation.

focusable boolean

Whether this View should be focusable with a non-touch input device, eg. receive focus with a hardware keyboard.

shouldRasterizeIOS boolean

Whether this view should be rendered as a bitmap before compositing.

On iOS, this is useful for animations and interactions that do not modify this component's dimensions nor its children; for example, when translating the position of a static view, rasterization allows the renderer to reuse a cached bitmap of a static view and quickly composite it during each frame.

Rasterization incurs an off-screen drawing pass and the bitmap consumes memory. Test and measure when using this property.

isTVSelectable boolean

(Apple TV only) When set to true, this view will be focusable and navigable using the Apple TV remote.

hasTVPreferredFocus boolean

(Apple TV only) May be set to true to force the Apple TV focus engine to move focus to this view.

tvParallaxProperties

{
  enabled?: boolean;
  shiftDistanceX?: number;
  shiftDistanceY?: number;
  tiltAngle?: number;
  magnification?: number;
  pressMagnification?: number;
  pressDuration?: number;
  pressDelay?: number;
}

(Apple TV only) Object with properties to control Apple TV parallax effects.

tvParallaxShiftDistanceX number

(Apple TV only) May be used to change the appearance of the Apple TV parallax effect when this view goes in or out of focus. Defaults to 2.0.

tvParallaxShiftDistanceY number

(Apple TV only) May be used to change the appearance of the Apple TV parallax effect when this view goes in or out of focus. Defaults to 2.0.

tvParallaxTiltAngle number

(Apple TV only) May be used to change the appearance of the Apple TV parallax effect when this view goes in or out of focus. Defaults to 0.05.

tvParallaxMagnification number

(Apple TV only) May be used to change the appearance of the Apple TV parallax effect when this view goes in or out of focus. Defaults to 1.0.

onStartShouldSetResponder (event: GestureResponderEvent) => boolean

Does this view want to become responder on the start of a touch?

onMoveShouldSetResponder (event: GestureResponderEvent) => boolean

Called for every touch move on the View when it is not the responder: does this view want to "claim" touch responsiveness?

onResponderEnd (event: GestureResponderEvent) => void

If the View returns true and attempts to become the responder, one of the following will happen:

onResponderGrant (event: GestureResponderEvent) => void

The View is now responding for touch events. This is the time to highlight and show the user what is happening

onResponderReject (event: GestureResponderEvent) => void

Something else is the responder right now and will not release it

onResponderMove (event: GestureResponderEvent) => void

The user is moving their finger

onResponderRelease (event: GestureResponderEvent) => void

Fired at the end of the touch, ie "touchUp"

onResponderStart (event: GestureResponderEvent) => void

onResponderTerminationRequest (event: GestureResponderEvent) => boolean

Something else wants to become responder. Should this view release the responder? Returning true allows release

onResponderTerminate (event: GestureResponderEvent) => void

The responder has been taken from the View. Might be taken by other views after a call to onResponderTerminationRequest, or might be taken by the OS without asking (happens with control center/ notification center on iOS)

onStartShouldSetResponderCapture (event: GestureResponderEvent) => boolean

onStartShouldSetResponder and onMoveShouldSetResponder are called with a bubbling pattern, where the deepest node is called first. That means that the deepest component will become responder when multiple Views return true for *ShouldSetResponder handlers. This is desirable in most cases, because it makes sure all controls and buttons are usable.

However, sometimes a parent will want to make sure that it becomes responder. This can be handled by using the capture phase. Before the responder system bubbles up from the deepest component, it will do a capture phase, firing on*ShouldSetResponderCapture. So if a parent View wants to prevent the child from becoming responder on a touch start, it should have a onStartShouldSetResponderCapture handler which returns true.

onMoveShouldSetResponderCapture (event: GestureResponderEvent) => boolean

onStartShouldSetResponder and onMoveShouldSetResponder are called with a bubbling pattern, where the deepest node is called first. That means that the deepest component will become responder when multiple Views return true for *ShouldSetResponder handlers. This is desirable in most cases, because it makes sure all controls and buttons are usable.

However, sometimes a parent will want to make sure that it becomes responder. This can be handled by using the capture phase. Before the responder system bubbles up from the deepest component, it will do a capture phase, firing on*ShouldSetResponderCapture. So if a parent View wants to prevent the child from becoming responder on a touch start, it should have a onStartShouldSetResponderCapture handler which returns true.

onTouchStart (event: GestureResponderEvent) => void

onTouchMove (event: GestureResponderEvent) => void

onTouchEnd (event: GestureResponderEvent) => void

onTouchCancel (event: GestureResponderEvent) => void

onTouchEndCapture (event: GestureResponderEvent) => void

accessible boolean

When true, indicates that the view is an accessibility element. By default, all the touchable elements are accessible.

accessibilityActions

readonly Readonly<{ name: string; label?: string; }>[]

Provides an array of custom actions available for accessibility.

accessibilityLabel string

Overrides the text that's read by the screen reader when the user interacts with the element. By default, the label is constructed by traversing all the children and accumulating all the Text nodes separated by space.

accessibilityRole

"none"
  | "text"
  | "search"
  | "button"
  | "link"
  | "menu"
  | "alert"
  | "checkbox"
  | "radio"
  | "image"
  | "keyboardkey"
  | "adjustable"
  | "imagebutton"
  | "header"
  | "summary"
  | "combobox"
  | ... 10 more ...
  | "toolbar"

Accessibility Role tells a person using either VoiceOver on iOS or TalkBack on Android the type of element that is focused on.

accessibilityState AccessibilityState

Accessibility State tells a person using either VoiceOver on iOS or TalkBack on Android the state of the element currently focused on.

accessibilityHint string

An accessibility hint helps users understand what will happen when they perform an action on the accessibility element when that result is not obvious from the accessibility label.

accessibilityValue AccessibilityValue

Represents the current value of a component. It can be a textual description of a component's value, or for range-based components, such as sliders and progress bars, it contains range information (minimum, current, and maximum).

onAccessibilityAction (event: AccessibilityActionEvent) => void

When accessible is true, the system will try to invoke this function when the user performs an accessibility custom action.

accessibilityLiveRegion "none" | "assertive" | "polite"

Indicates to accessibility services whether the user should be notified when this view changes. Works for Android API >= 19 only. See http://developer.android.com/reference/android/view/View.html#attr_android:accessibilityLiveRegion for references.

importantForAccessibility "auto" | "yes" | "no" | "no-hide-descendants"

Controls how view is important for accessibility which is if it fires accessibility events and if it is reported to accessibility services that query the screen. Works for Android only. See http://developer.android.com/reference/android/R.attr.html#importantForAccessibility for references.

Possible values: 'auto' - The system determines whether the view is important for accessibility - default (recommended). 'yes' - The view is important for accessibility. 'no' - The view is not important for accessibility. 'no-hide-descendants' - The view is not important for accessibility, nor are any of its descendant views.

accessibilityElementsHidden boolean

A Boolean value indicating whether the accessibility elements contained within this accessibility element are hidden to the screen reader.

accessibilityViewIsModal boolean

A Boolean value indicating whether VoiceOver should ignore the elements within views that are siblings of the receiver.

onAccessibilityEscape () => void

When accessibile is true, the system will invoke this function when the user performs the escape gesture (scrub with two fingers).

onAccessibilityTap () => void

When accessible is true, the system will try to invoke this function when the user performs accessibility tap gesture.

onMagicTap () => void

When accessible is true, the system will invoke this function when the user performs the magic tap gesture.

accessibilityIgnoresInvertColors boolean

https://reactnative.dev/docs/accessibility#accessibilityignoresinvertcolorsios

alwaysBounceHorizontal boolean

When true the scroll view bounces horizontally when it reaches the end even if the content is smaller than the scroll view itself. The default value is true when horizontal={true} and false otherwise.

alwaysBounceVertical boolean

When true the scroll view bounces vertically when it reaches the end even if the content is smaller than the scroll view itself. The default value is false when horizontal={true} and true otherwise.

automaticallyAdjustContentInsets boolean

Controls whether iOS should automatically adjust the content inset for scroll views that are placed behind a navigation bar or tab bar/ toolbar. The default value is true.

bounces boolean

When true the scroll view bounces when it reaches the end of the content if the content is larger then the scroll view along the axis of the scroll direction. When false it disables all bouncing even if the alwaysBounce* props are true. The default value is true.

bouncesZoom boolean

When true gestures can drive zoom past min/max and the zoom will animate to the min/max value at gesture end otherwise the zoom will not exceed the limits.

canCancelContentTouches boolean

When false once tracking starts won't try to drag if the touch moves. The default value is true.

centerContent boolean

When true the scroll view automatically centers the content when the content is smaller than the scroll view bounds; when the content is larger than the scroll view this property has no effect. The default value is false.

contentInset Insets

The amount by which the scroll view content is inset from the edges of the scroll view. Defaults to {0, 0, 0, 0}.

contentOffset PointPropType

Used to manually set the starting scroll offset. The default value is {x: 0, y: 0}

contentInsetAdjustmentBehavior

"always"
  | "never"
  | "automatic"
  | "scrollableAxes"

This property specifies how the safe area insets are used to modify the content area of the scroll view. The default value of this property must be 'automatic'. But the default value is 'never' until RN@0.51.

directionalLockEnabled boolean

When true the ScrollView will try to lock to only vertical or horizontal scrolling while dragging. The default value is false.

indicatorStyle "default" | "black" | "white"

The style of the scroll indicators.

  • default (the default), same as black.
  • black, scroll indicator is black. This style is good against a white content background.
  • white, scroll indicator is white. This style is good against a black content background.

maintainVisibleContentPosition

{
  autoscrollToTopThreshold?: number;
  minIndexForVisible: number;
}

When set, the scroll view will adjust the scroll position so that the first child that is currently visible and at or beyond minIndexForVisible will not change position. This is useful for lists that are loading content in both directions, e.g. a chat thread, where new messages coming in might otherwise cause the scroll position to jump. A value of 0 is common, but other values such as 1 can be used to skip loading spinners or other content that should not maintain position.

The optional autoscrollToTopThreshold can be used to make the content automatically scroll to the top after making the adjustment if the user was within the threshold of the top before the adjustment was made. This is also useful for chat-like applications where you want to see new messages scroll into place, but not if the user has scrolled up a ways and it would be disruptive to scroll a bunch.

Caveat 1: Reordering elements in the scrollview with this enabled will probably cause jumpiness and jank. It can be fixed, but there are currently no plans to do so. For now, don't re-order the content of any ScrollViews or Lists that use this feature.

Caveat 2: This uses contentOffset and frame.origin in native code to compute visibility. Occlusion, transforms, and other complexity won't be taken into account as to whether content is "visible" or not.

maximumZoomScale number

The maximum allowed zoom scale. The default value is 1.0.

minimumZoomScale number

The minimum allowed zoom scale. The default value is 1.0.

onScrollAnimationEnd () => void

Called when a scrolling animation ends.

pinchGestureEnabled boolean

When true, ScrollView allows use of pinch gestures to zoom in and out. The default value is true.

scrollEventThrottle number

This controls how often the scroll event will be fired while scrolling (in events per seconds). A higher number yields better accuracy for code that is tracking the scroll position, but can lead to scroll performance problems due to the volume of information being send over the bridge. The default value is zero, which means the scroll event will be sent only once each time the view is scrolled.

scrollIndicatorInsets Insets

The amount by which the scroll view indicators are inset from the edges of the scroll view. This should normally be set to the same value as the contentInset. Defaults to {0, 0, 0, 0}.

scrollToOverflowEnabled boolean

When true, the scroll view can be programmatically scrolled beyond its content size. The default value is false.

scrollsToTop boolean

When true the scroll view scrolls to top when the status bar is tapped. The default value is true.

snapToAlignment "center" | "start" | "end"

When snapToInterval is set, snapToAlignment will define the relationship of the the snapping to the scroll view. - start (the default) will align the snap at the left (horizontal) or top (vertical) - center will align the snap in the center - end will align the snap at the right (horizontal) or bottom (vertical)

onScrollToTop

(event: NativeSyntheticEvent<NativeScrollEvent>) => void

Fires when the scroll view scrolls to top after the status bar has been tapped

zoomScale number

The current scale of the scroll view content. The default value is 1.0.

endFillColor string | typeof OpaqueColorValue

Sometimes a scrollview takes up more space than its content fills. When this is the case, this prop will fill the rest of the scrollview with a color to avoid setting a background and creating unnecessary overdraw. This is an advanced optimization that is not needed in the general case.

scrollPerfTag string

Tag used to log scroll performance on this scroll view. Will force momentum events to be turned on (see sendMomentumEvents). This doesn't do anything out of the box and you need to implement a custom native FpsListener for it to be useful.

overScrollMode "auto" | "always" | "never"

Used to override default value of overScroll mode.

Possible values: - 'auto' - Default value, allow a user to over-scroll this view only if the content is large enough to meaningfully scroll. - 'always' - Always allow a user to over-scroll this view. - 'never' - Never allow a user to over-scroll this view.

nestedScrollEnabled boolean

Enables nested scrolling for Android API level 21+. Nested scrolling is supported by default on iOS.

fadingEdgeLength number

Fades out the edges of the the scroll content.

If the value is greater than 0, the fading edges will be set accordingly to the current scroll direction and position, indicating if there is more content to show.

The default value is 0.

persistentScrollbar boolean

Causes the scrollbars not to turn transparent when they are not in use. The default value is false.

Inherits Box props

animated boolean

children

string
  | number
  | boolean
  | {}
  | ReactElement<any, string
  | ((props: any) => ReactElement<any, string
  | ...
  | (new (props: any) => Component<any, any, any>)>)
  | (new (props: any) => Component<...>)>
  | ReactNodeArray
  | ReactPortal
  | ((props: BoxProps) => ReactNode)

alignX "right" | "left" | "center"

alignY "top" | "bottom" | "center"

altitude string

variant string

colorMode string

disabled boolean

overrides

{
  altitudes?: AltitudesThemeConfig;
  borders?: BordersThemeConfig;
  borderRadii?: BorderRadiiThemeConfig;
  breakpoints?: {
    ...
  }; ... 34 more ...;
  Text?: TextThemeConfig;
}

elementRef ((instance: any) => void) | RefObject<any>

themeKey string

Inherits React Native's View props

#Theming

Box.Scroll.styles.base
This is a box
On this page
Copyright © 2021 Jake Moxey