View

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.

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

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

Invoked on mount and layout changes with

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

This event is fired immediately once the layout has been calculated, but the new layout may not yet be reflected on the screen at the time the event is received, especially if a layout animation is in progress.

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

For most touch interactions, you'll simply want to wrap your component in TouchableHighlight or TouchableOpacity. Check out Touchable.js, ScrollResponder.js and ResponderEventPlugin.js for more discussion.

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-only is the equivalent of

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.

This is a special performance property exposed by RCTView and is useful for scrolling content when there are many subviews, most of which are offscreen. For this property to be effective, it must be applied to a view that contains many subviews that extend outside its bound. The subviews must also have overflow: hidden, as should the containing view (or one of its superviews).

Used to locate this view in end-to-end tests. NB: disables the 'layout-only view removal' optimization for this view!

Indicates to accessibility services to treat UI component like a native one. Works for Android only.

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.

Provides additional traits to screen reader. By default no traits are provided unless specified otherwise in element

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.

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.

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.

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.

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.