react-native/Libraries/Components/View/View.js

237 lines
8.9 KiB
JavaScript

/**
* Copyright (c) 2015-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*
* @providesModule View
* @flow
*/
'use strict';
const NativeMethodsMixin = require('NativeMethodsMixin');
const NativeModules = require('NativeModules');
const Platform = require('Platform');
const PropTypes = require('prop-types');
const React = require('React');
const ReactNativeFeatureFlags = require('ReactNativeFeatureFlags');
const ReactNativeStyleAttributes = require('ReactNativeStyleAttributes');
const ReactNativeViewAttributes = require('ReactNativeViewAttributes');
const ViewPropTypes = require('ViewPropTypes');
const invariant = require('fbjs/lib/invariant');
const requireNativeComponent = require('requireNativeComponent');
const warning = require('fbjs/lib/warning');
const {
AccessibilityComponentTypes,
AccessibilityTraits,
} = require('ViewAccessibility');
const forceTouchAvailable = (NativeModules.PlatformConstants &&
NativeModules.PlatformConstants.forceTouchAvailable) || false;
import type {ViewProps} from 'ViewPropTypes';
export type Props = ViewProps;
/**
* The most fundamental component for building a UI, `View` is a container that supports layout with
* [flexbox](docs/flexbox.html), [style](docs/style.html),
* [some touch handling](docs/handling-touches.html), and
* [accessibility](docs/accessibility.html) controls. `View` maps directly to the
* native view equivalent on whatever platform React Native is running on, whether that is a
* `UIView`, `<div>`, `android.view`, etc.
*
* `View` is designed to be nested inside other views and can have 0 to many children of any type.
*
* This example creates a `View` that wraps two colored boxes and a text component in a row with
* padding.
*
* ```javascript
* class ViewColoredBoxesWithText extends Component {
* render() {
* return (
* <View style={{flexDirection: 'row', height: 100, padding: 20}}>
* <View style={{backgroundColor: 'blue', flex: 0.3}} />
* <View style={{backgroundColor: 'red', flex: 0.5}} />
* <Text>Hello World!</Text>
* </View>
* );
* }
* }
* ```
*
* > `View`s are designed to be used with [`StyleSheet`](docs/style.html) for clarity
* > and performance, although inline styles are also supported.
*
* ### Synthetic Touch Events
*
* For `View` responder props (e.g., `onResponderMove`), the synthetic touch event passed to them
* are of the following form:
*
* - `nativeEvent`
* - `changedTouches` - Array of all touch events that have changed since the last event.
* - `identifier` - The ID of the touch.
* - `locationX` - The X position of the touch, relative to the element.
* - `locationY` - The Y position of the touch, relative to the element.
* - `pageX` - The X position of the touch, relative to the root element.
* - `pageY` - The Y position of the touch, relative to the root element.
* - `target` - The node id of the element receiving the touch event.
* - `timestamp` - A time identifier for the touch, useful for velocity calculation.
* - `touches` - Array of all current touches on the screen.
*/
// $FlowFixMe(>=0.41.0)
const View = React.createClass({
// TODO: We should probably expose the mixins, viewConfig, and statics publicly. For example,
// one of the props is of type AccessibilityComponentType. That is defined as a const[] above,
// but it is not rendered by the docs, since `statics` below is not rendered. So its Possible
// values had to be hardcoded.
mixins: [NativeMethodsMixin],
// `propTypes` should not be accessed directly on View since this wrapper only
// exists for DEV mode. However it's important for them to be declared.
// If the object passed to `createClass` specifies `propTypes`, Flow will
// create a static type from it. This property will be over-written below with
// a warn-on-use getter though.
// TODO (bvaughn) Remove the warn-on-use comment after April 1.
propTypes: ViewPropTypes,
// ReactElementValidator will (temporarily) use this private accessor when
// detected to avoid triggering the warning message.
// TODO (bvaughn) Remove this after April 1 ReactNative RC is tagged.
statics: {
__propTypesSecretDontUseThesePlease: ViewPropTypes
},
/**
* `NativeMethodsMixin` will look for this when invoking `setNativeProps`. We
* make `this` look like an actual native component class.
*/
viewConfig: {
uiViewClassName: 'RCTView',
validAttributes: ReactNativeViewAttributes.RCTView
},
contextTypes: {
isInAParentText: PropTypes.bool,
},
render: function() {
invariant(
!(this.context.isInAParentText && Platform.OS === 'android'),
'Nesting of <View> within <Text> is not supported on Android.');
// WARNING: This method will not be used in production mode as in that mode we
// replace wrapper component View with generated native wrapper RCTView. Avoid
// adding functionality this component that you'd want to be available in both
// dev and prod modes.
return <RCTView {...this.props} />;
},
});
// Warn about unsupported use of View static properties as these will no longer
// be supported with React fiber. This warning message will go away in the next
// ReactNative release. Use defineProperty() rather than createClass() statics
// because the mixin process auto-triggers the 1-time warning message.
// TODO (bvaughn) Remove this after April 1 ReactNative RC is tagged.
function mixinStatics (target) {
let warnedAboutAccessibilityTraits = false;
let warnedAboutAccessibilityComponentType = false;
let warnedAboutForceTouchAvailable = false;
let warnedAboutPropTypes = false;
// $FlowFixMe https://github.com/facebook/flow/issues/285
Object.defineProperty(target, 'AccessibilityTraits', {
get: function() {
warning(
warnedAboutAccessibilityTraits,
'View.AccessibilityTraits has been deprecated and will be ' +
'removed in a future version of ReactNative. Use ' +
'ViewAccessibility.AccessibilityTraits instead.'
);
warnedAboutAccessibilityTraits = true;
return AccessibilityTraits;
}
});
// $FlowFixMe https://github.com/facebook/flow/issues/285
Object.defineProperty(target, 'AccessibilityComponentType', {
get: function() {
warning(
warnedAboutAccessibilityComponentType,
'View.AccessibilityComponentType has been deprecated and will be ' +
'removed in a future version of ReactNative. Use ' +
'ViewAccessibility.AccessibilityComponentTypes instead.'
);
warnedAboutAccessibilityComponentType = true;
return AccessibilityComponentTypes;
}
});
// $FlowFixMe https://github.com/facebook/flow/issues/285
Object.defineProperty(target, 'forceTouchAvailable', {
get: function() {
warning(
warnedAboutForceTouchAvailable,
'View.forceTouchAvailable has been deprecated and will be removed ' +
'in a future version of ReactNative. Use ' +
'NativeModules.PlatformConstants.forceTouchAvailable instead.'
);
warnedAboutForceTouchAvailable = true;
return forceTouchAvailable;
}
});
// $FlowFixMe https://github.com/facebook/flow/issues/285
Object.defineProperty(target, 'propTypes', {
get: function() {
warning(
warnedAboutPropTypes,
'View.propTypes has been deprecated and will be removed in a future ' +
'version of ReactNative. Use ViewPropTypes instead.'
);
warnedAboutPropTypes = true;
return ViewPropTypes;
}
});
}
const RCTView = requireNativeComponent('RCTView', View, {
nativeOnly: {
nativeBackgroundAndroid: true,
nativeForegroundAndroid: true,
}
});
if (__DEV__) {
const UIManager = require('UIManager');
const viewConfig = UIManager.viewConfigs && UIManager.viewConfigs.RCTView || {};
for (const prop in viewConfig.nativeProps) {
const viewAny: any = View; // Appease flow
if (!viewAny.propTypes[prop] && !ReactNativeStyleAttributes[prop]) {
throw new Error(
'View is missing propType for native prop `' + prop + '`'
);
}
}
}
// TODO (bvaughn) Remove feature flags once all static View accessors are gone.
// We temporarily wrap fiber native views with the create-class View above,
// Because external code sometimes accesses static properties of this view.
let ViewToExport = RCTView;
if (
__DEV__ ||
ReactNativeFeatureFlags.useFiber
) {
mixinStatics(View);
ViewToExport = View;
} else {
// TODO (bvaughn) Remove this mixin once all static View accessors are gone.
mixinStatics((RCTView : any));
}
// TODO (bvaughn) Temporarily mask Flow warnings for View property accesses.
// We're wrapping the string type (Fiber) for now to avoid any actual problems.
module.exports = ((ViewToExport : any) : typeof View);