react-native/Libraries/Components/MaskedView/MaskedViewIOS.ios.js

94 lines
2.5 KiB
JavaScript

/**
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @format
* @flow
*/
const React = require('React');
const StyleSheet = require('StyleSheet');
const View = require('View');
const RCTMaskedViewNativeComponent = require('RCTMaskedViewNativeComponent');
import type {ViewProps} from 'ViewPropTypes';
type Props = $ReadOnly<{|
...ViewProps,
children: React.Node,
/**
* Should be a React element to be rendered and applied as the
* mask for the child element.
*/
maskElement: React.Element<any>,
|}>;
/**
* Renders the child view with a mask specified in the `maskElement` prop.
*
* ```
* import React from 'react';
* import { MaskedViewIOS, Text, View } from 'react-native';
*
* class MyMaskedView extends React.Component {
* render() {
* return (
* <MaskedViewIOS
* style={{ flex: 1 }}
* maskElement={
* <View style={styles.maskContainerStyle}>
* <Text style={styles.maskTextStyle}>
* Basic Mask
* </Text>
* </View>
* }
* >
* <View style={{ flex: 1, backgroundColor: 'blue' }} />
* </MaskedViewIOS>
* );
* }
* }
* ```
*
* The above example will render a view with a blue background that fills its
* parent, and then mask that view with text that says "Basic Mask".
*
* The alpha channel of the view rendered by the `maskElement` prop determines how
* much of the view's content and background shows through. Fully or partially
* opaque pixels allow the underlying content to show through but fully
* transparent pixels block that content.
*
*/
class MaskedViewIOS extends React.Component<Props> {
_hasWarnedInvalidRenderMask = false;
render() {
const {maskElement, children, ...otherViewProps} = this.props;
if (!React.isValidElement(maskElement)) {
if (!this._hasWarnedInvalidRenderMask) {
console.warn(
'MaskedView: Invalid `maskElement` prop was passed to MaskedView. ' +
'Expected a React Element. No mask will render.',
);
this._hasWarnedInvalidRenderMask = true;
}
return <View {...otherViewProps}>{children}</View>;
}
return (
<RCTMaskedViewNativeComponent {...otherViewProps}>
<View pointerEvents="none" style={StyleSheet.absoluteFill}>
{maskElement}
</View>
{children}
</RCTMaskedViewNativeComponent>
);
}
}
module.exports = MaskedViewIOS;