<style> · Hyperview

The <style> element defines specific style rules that can be used by elements of a screen.

<doc xmlns="https://hyperview.org/hyperview">
  <screen id="main">
    <styles>
      <style id="Main" flex="1" backgroundColor="red" />
    </styles>
    <body>
      <view style="Main" />
    </body>
  </screen>
</doc>

The <styles> element above contains one <style> with id "Main". The view in the body of the screen uses that style.

Structure

A <style> element should only appear as a direct child of a <styles> element or <modifier> element.

`id`

Type	Required
string	No

A global attribute uniquely identifying the element in the whole document. This id is used by elements in the <screen> to apply styles.

id is required when <style> is a direct child of a <styles> element. id will be ignored if the <style> is a direct child of a <modifier> element.

Layout rules

<style> attributes support the following layout props from React Native.

Layout rules can only be applied to most elements with a few exceptions (such as <spinner>).

`aspectRatio`

Aspect ratio controls the size of the undefined dimension of a node. See https://developer.mozilla.org/en-US/docs/Web/CSS/aspect-ratio for more details.

On a node with a set width/height, aspect ratio controls the size of the unset dimension
On a node with a set flex basis, aspect ratio controls the size of the node in the cross axis if unset
On a node with a measure function, aspect ratio works as though the measure function measures the flex basis
On a node with flex grow/shrink, aspect ratio controls the size of the node in the cross axis if unset
Aspect ratio takes min/max dimensions into account

Type	Required
number, string	No

`alignContent`

alignContent controls how rows align in the cross direction, overriding the alignContent of the parent. See https://developer.mozilla.org/en-US/docs/Web/CSS/align-content for more details.

Type	Required
'flex-start', 'flex-end', 'center', 'stretch', 'space-between', 'space-around'	No

`alignItems`

alignItems aligns children in the cross direction. For example, if children are flowing vertically, alignItems controls how they align horizontally. It works like align-items in CSS (default: stretch). See https://developer.mozilla.org/en-US/docs/Web/CSS/align-items for more details.

Type	Required
'flex-start', 'flex-end', 'center', 'stretch', 'baseline'	No

`alignSelf`

alignSelf controls how a child aligns in the cross direction, overriding the alignItems of the parent. It works like align-self in CSS (default: auto). See https://developer.mozilla.org/en-US/docs/Web/CSS/align-self for more details.

Type	Required
'auto', 'flex-start', 'flex-end', 'center', 'stretch', 'baseline'	No

`borderBottomWidth`

borderBottomWidth works like border-bottom-width in CSS. See https://developer.mozilla.org/en-US/docs/Web/CSS/border-bottom-width for more details.

Type	Required
number	No

`borderLeftWidth`

borderLeftWidth works like border-left-width in CSS. See https://developer.mozilla.org/en-US/docs/Web/CSS/border-left-width for more details.

Type	Required
number	No

`borderRightWidth`

borderRightWidth works like border-right-width in CSS. See https://developer.mozilla.org/en-US/docs/Web/CSS/border-right-width for more details.

Type	Required
number	No

`borderTopWidth`

borderTopWidth works like border-top-width in CSS. See https://developer.mozilla.org/en-US/docs/Web/CSS/border-top-width for more details.

Type	Required
number	No

`borderWidth`

borderWidth works like border-width in CSS. See https://developer.mozilla.org/en-US/docs/Web/CSS/border-width for more details.

Type	Required
number	No

`bottom`

bottom is the number of logical pixels to offset the bottom edge of this component.

It works similarly to bottom in CSS, but in Hyperview you must use points or percentages. Ems and other units are not supported.

See https://developer.mozilla.org/en-US/docs/Web/CSS/bottom for more details of how bottom affects layout.

Type	Required
number, string	No

`display`

display sets the display type of this component.

It works similarly to display in CSS, but only support 'flex' and 'none'. 'flex' is the default.

Type	Required
'none', 'flex'	No

`flex`

When flex is a positive number, it makes the component flexible and it will be sized proportional to its flex value. So a component with flex set to 2 will take twice the space as a component with flex set to 1.

When flex is 0, the component is sized according to width and height and it is inflexible.

When flex is -1, the component is normally sized according width and height. However, if there's not enough space, the component will shrink to its minWidth and minHeight.

flexGrow, flexShrink, and flexBasis work the same as in CSS.

Type	Required
number	No

`flexBasis`

Type	Required
number, string	No

`flexDirection`

flexDirection controls which directions children of a container go. row goes left to right, column goes top to bottom, and you may be able to guess what the other two do. It works like flex-direction in CSS, except the default is column. See https://developer.mozilla.org/en-US/docs/Web/CSS/flex-direction for more details.

Type	Required
'row', 'row-reverse', 'column', 'column-reverse'	No

`flexGrow`

Type	Required
number	No

`flexShrink`

Type	Required
number	No

`flexWrap`

flexWrap controls whether children can wrap around after they hit the end of a flex container. It works like flex-wrap in CSS (default: nowrap). See https://developer.mozilla.org/en-US/docs/Web/CSS/flex-wrap for more details. Note it does not work anymore with alignItems: stretch (the default), so you may want to use alignItems: flex-start for example.

Type	Required
'wrap', 'nowrap'	No

`height`

height sets the height of this component.

It works similarly to height in CSS, but in Hyperview you must use points or percentages. Ems and other units are not supported. See https://developer.mozilla.org/en-US/docs/Web/CSS/height for more details.

Type	Required
number, string	No

`justifyContent`

justifyContent aligns children in the main direction. For example, if children are flowing vertically, justifyContent controls how they align vertically. It works like justify-content in CSS (default: flex-start). See https://developer.mozilla.org/en-US/docs/Web/CSS/justify-content for more details.

Type	Required
'flex-start', 'flex-end', 'center', 'space-between', 'space-around', 'space-evenly'	No

`left`

left is the number of logical pixels to offset the left edge of this component.

It works similarly to left in CSS, but in Hyperview you must use points or percentages. Ems and other units are not supported.

See https://developer.mozilla.org/en-US/docs/Web/CSS/left for more details of how left affects layout.

Type	Required
number, string	No

`margin`

Setting margin has the same effect as setting each of marginTop, marginLeft, marginBottom, and marginRight to the same value. You must use points or percentages. Ems and other units are not supported. See https://developer.mozilla.org/en-US/docs/Web/CSS/margin for more details.

Type	Required
number, string	No

`marginBottom`

marginBottom works like margin-bottom in CSS. You must use points or percentages. Ems and other units are not supported. See https://developer.mozilla.org/en-US/docs/Web/CSS/margin-bottom for more details.

Type	Required
number, string	No

`marginHorizontal`

Setting marginHorizontal has the same effect as setting both marginLeft and marginRight to the same value. You must use points or percentages. Ems and other units are not supported.

Type	Required
number, string	No

`marginLeft`

marginLeft works like margin-left in CSS. You must use points or percentages. Ems and other units are not supported. See https://developer.mozilla.org/en-US/docs/Web/CSS/margin-left for more details.

Type	Required
number, string	No

`marginRight`

marginRight works like margin-right in CSS. You must use points or percentages. Ems and other units are not supported. See https://developer.mozilla.org/en-US/docs/Web/CSS/margin-right for more details.

Type	Required
number, string	No

`marginTop`

marginTop works like margin-top in CSS. You must use points or percentages. Ems and other units are not supported. See https://developer.mozilla.org/en-US/docs/Web/CSS/margin-top for more details.

Type	Required
number, string	No

`marginVertical`

Setting marginVertical has the same effect as setting both marginTop and marginBottom to the same value. You must use points or percentages. Ems and other units are not supported.

Type	Required
number, string	No

`maxHeight`

maxHeight is the maximum height for this component, in logical pixels.

It works similarly to max-height in CSS, but in Hyperview you must use points or percentages. Ems and other units are not supported.

See https://developer.mozilla.org/en-US/docs/Web/CSS/max-height for more details.

Type	Required
number, string	No

`maxWidth`

maxWidth is the maximum width for this component, in logical pixels.

It works similarly to max-width in CSS, but in Hyperview you must use points or percentages. Ems and other units are not supported.

See https://developer.mozilla.org/en-US/docs/Web/CSS/max-width for more details.

Type	Required
number, string	No

`minHeight`

minHeight is the minimum height for this component, in logical pixels.

It works similarly to min-height in CSS, but in Hyperview you must use points or percentages. Ems and other units are not supported.

See https://developer.mozilla.org/en-US/docs/Web/CSS/min-height for more details.

Type	Required
number, string	No

`minWidth`

minWidth is the minimum width for this component, in logical pixels.

It works similarly to min-width in CSS, but in Hyperview you must use points or percentages. Ems and other units are not supported.

See https://developer.mozilla.org/en-US/docs/Web/CSS/min-width for more details.

Type	Required
number, string	No

`overflow`

overflow controls how children are measured and displayed. overflow: hidden causes views to be clipped while overflow: scroll causes views to be measured independently of their parents main axis. It works like overflow in CSS (default: visible). See https://developer.mozilla.org/en/docs/Web/CSS/overflow for more details. overflow: visible only works on iOS. On Android, all views will clip their children.

Type	Required
'visible', 'hidden', 'scroll'	No

`padding`

Setting padding has the same effect as setting each of paddingTop, paddingBottom, paddingLeft, and paddingRight to the same value. You must use points or percentages. Ems and other units are not supported.

See https://developer.mozilla.org/en-US/docs/Web/CSS/padding for more details.

Type	Required
number, string	No

`paddingBottom`

paddingBottom works like padding-bottom in CSS. You must use points or percentages. Ems and other units are not supported.

See https://developer.mozilla.org/en-US/docs/Web/CSS/padding-bottom for more details.

Type	Required
number, string	No

`paddingHorizontal`

Setting paddingHorizontal is like setting both of paddingLeft and paddingRight to the same value. You must use points or percentages. Ems and other units are not supported.

Type	Required
number, string	No

`paddingLeft`

paddingLeft works like padding-left in CSS. You must use points or percentages. Ems and other units are not supported.

See https://developer.mozilla.org/en-US/docs/Web/CSS/padding-left for more details.

Type	Required
number, string	No

`paddingRight`

paddingRight works like padding-right in CSS. You must use points or percentages. Ems and other units are not supported.

See https://developer.mozilla.org/en-US/docs/Web/CSS/padding-right for more details.

Type	Required
number, string	No

`paddingTop`

paddingTop works like padding-top in CSS. You must use points or percentages. Ems and other units are not supported.

See https://developer.mozilla.org/en-US/docs/Web/CSS/padding-top for more details.

Type	Required
number, string	No

`paddingVertical`

Setting paddingVertical is like setting both of paddingTop and paddingBottom to the same value. You must use points or percentages. Ems and other units are not supported.

Type	Required
number, string	No

`position`

position in Hyperview is similar to regular CSS, but everything is set to relative by default, so absolute positioning is always just relative to the parent.

If you want to position a child using specific numbers of logical pixels relative to its parent, set the child to have absolute position.

If you want to position a child relative to something that is not its parent, just don't use styles for that. Use the component tree.

Type	Required
'absolute', 'relative'	No

`right`

right is the number of logical pixels to offset the right edge of this component.

It works similarly to right in CSS, but in Hyperview you must use points or percentages. Ems and other units are not supported.

See https://developer.mozilla.org/en-US/docs/Web/CSS/right for more details of how right affects layout.

Type	Required
number, string	No

`top`

top is the number of logical pixels to offset the top edge of this component.

It works similarly to top in CSS, but in Hyperview you must use points or percentages. Ems and other units are not supported.

See https://developer.mozilla.org/en-US/docs/Web/CSS/top for more details of how top affects layout.

Type	Required
number, string	No

`width`

width sets the width of this component.

It works similarly to width in CSS, but in Hyperview you must use points or percentages. Ems and other units are not supported. See https://developer.mozilla.org/en-US/docs/Web/CSS/width for more details.

Type	Required
number, string	No

`zIndex`

zIndex sets the stack order of a positioned element and its descendents or flex items.

It works similarly to zIndex in CSS, but in Hyperview you must use only integers. See https://developer.mozilla.org/en-US/docs/Web/CSS/z-index for more details.

Type	Required
number	No

View & image rules

<style> elements support the following attributes for <view> and <image> as defined in React Native.

View rules will only be applied to <view> and <image> elements. Adding these rules to other elements will cause a warning in the client.

`borderRightColor`

Type	Required
color	No

`borderBottomColor`

Type	Required
color	No

`borderBottomLeftRadius`

Type	Required
number	No

`borderBottomRightRadius`

Type	Required
number	No

`borderColor`

Type	Required
color	No

`borderLeftColor`

Type	Required
color	No

`borderRadius`

Type	Required
number	No

`backgroundColor`

Type	Required
color	No

`borderStyle`

Type	Required
'solid', 'dotted', 'dashed'	No

`borderTopColor`

Type	Required
color	No

`borderTopLeftRadius`

Type	Required
number	No

`borderTopRightRadius`

Type	Required
number	No

`elevation`

NOTE: Elevation only works on Android. For iOS, use shadow style attributes.

Type	Required
number	No