react-native/Libraries/Lists/VirtualizedSectionList.js

541 lines
16 KiB
JavaScript

/**
* Copyright (c) 2015-present, Facebook, Inc.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @flow
* @format
*/
'use strict';
const React = require('React');
const View = require('View');
const VirtualizedList = require('VirtualizedList');
const invariant = require('fbjs/lib/invariant');
import type {ViewToken} from 'ViewabilityHelper';
import type {Props as VirtualizedListProps} from 'VirtualizedList';
type Item = any;
type SectionItem = any;
type SectionBase = {
// Must be provided directly on each section.
data: $ReadOnlyArray<SectionItem>,
key?: string,
// Optional props will override list-wide props just for this section.
renderItem?: ?({
item: SectionItem,
index: number,
section: SectionBase,
separators: {
highlight: () => void,
unhighlight: () => void,
updateProps: (select: 'leading' | 'trailing', newProps: Object) => void,
},
}) => ?React.Element<any>,
ItemSeparatorComponent?: ?React.ComponentType<any>,
keyExtractor?: (item: SectionItem, index: ?number) => string,
// TODO: support more optional/override props
// FooterComponent?: ?ReactClass<any>,
// HeaderComponent?: ?ReactClass<any>,
// onViewableItemsChanged?: ({viewableItems: Array<ViewToken>, changed: Array<ViewToken>}) => void,
};
type RequiredProps<SectionT: SectionBase> = {
sections: $ReadOnlyArray<SectionT>,
};
type OptionalProps<SectionT: SectionBase> = {
/**
* Rendered after the last item in the last section.
*/
ListFooterComponent?: ?(React.ComponentType<any> | React.Element<any>),
/**
* Rendered at the very beginning of the list.
*/
ListHeaderComponent?: ?(React.ComponentType<any> | React.Element<any>),
/**
* Default renderer for every item in every section.
*/
renderItem?: (info: {
item: Item,
index: number,
section: SectionT,
separators: {
highlight: () => void,
unhighlight: () => void,
updateProps: (select: 'leading' | 'trailing', newProps: Object) => void,
},
}) => ?React.Element<any>,
/**
* Rendered at the top of each section.
*/
renderSectionHeader?: ?({section: SectionT}) => ?React.Element<any>,
/**
* Rendered at the bottom of each section.
*/
renderSectionFooter?: ?({section: SectionT}) => ?React.Element<any>,
/**
* Rendered at the bottom of every Section, except the very last one, in place of the normal
* ItemSeparatorComponent.
*/
SectionSeparatorComponent?: ?React.ComponentType<any>,
/**
* Rendered at the bottom of every Item except the very last one in the last section.
*/
ItemSeparatorComponent?: ?React.ComponentType<any>,
/**
* Warning: Virtualization can drastically improve memory consumption for long lists, but trashes
* the state of items when they scroll out of the render window, so make sure all relavent data is
* stored outside of the recursive `renderItem` instance tree.
*/
enableVirtualization?: ?boolean,
keyExtractor: (item: Item, index: number) => string,
onEndReached?: ?({distanceFromEnd: number}) => void,
/**
* If provided, a standard RefreshControl will be added for "Pull to Refresh" functionality. Make
* sure to also set the `refreshing` prop correctly.
*/
onRefresh?: ?() => void,
/**
* Called when the viewability of rows changes, as defined by the
* `viewabilityConfig` prop.
*/
onViewableItemsChanged?: ?({
viewableItems: Array<ViewToken>,
changed: Array<ViewToken>,
}) => void,
/**
* Set this true while waiting for new data from a refresh.
*/
refreshing?: ?boolean,
};
export type Props<SectionT> = RequiredProps<SectionT> &
OptionalProps<SectionT> &
VirtualizedListProps;
type DefaultProps = typeof VirtualizedList.defaultProps & {
data: $ReadOnlyArray<Item>,
};
type State = {childProps: VirtualizedListProps};
/**
* Right now this just flattens everything into one list and uses VirtualizedList under the
* hood. The only operation that might not scale well is concatting the data arrays of all the
* sections when new props are received, which should be plenty fast for up to ~10,000 items.
*/
class VirtualizedSectionList<SectionT: SectionBase> extends React.PureComponent<
Props<SectionT>,
State,
> {
static defaultProps: DefaultProps = {
...VirtualizedList.defaultProps,
data: [],
};
scrollToLocation(params: {
animated?: ?boolean,
itemIndex: number,
sectionIndex: number,
viewPosition?: number,
}) {
let index = params.itemIndex + 1;
for (let ii = 0; ii < params.sectionIndex; ii++) {
index += this.props.sections[ii].data.length + 2;
}
const toIndexParams = {
...params,
index,
};
this._listRef.scrollToIndex(toIndexParams);
}
getListRef(): VirtualizedList {
return this._listRef;
}
constructor(props: Props<SectionT>, context: Object) {
super(props, context);
this.state = this._computeState(props);
}
UNSAFE_componentWillReceiveProps(nextProps: Props<SectionT>) {
this.setState(this._computeState(nextProps));
}
_computeState(props: Props<SectionT>): State {
const offset = props.ListHeaderComponent ? 1 : 0;
const stickyHeaderIndices = [];
const itemCount = props.sections.reduce((v, section) => {
stickyHeaderIndices.push(v + offset);
return v + section.data.length + 2; // Add two for the section header and footer.
}, 0);
return {
childProps: {
...props,
renderItem: this._renderItem,
ItemSeparatorComponent: undefined, // Rendered with renderItem
data: props.sections,
getItemCount: () => itemCount,
getItem,
keyExtractor: this._keyExtractor,
onViewableItemsChanged: props.onViewableItemsChanged
? this._onViewableItemsChanged
: undefined,
stickyHeaderIndices: props.stickySectionHeadersEnabled
? stickyHeaderIndices
: undefined,
},
};
}
render() {
return (
<VirtualizedList {...this.state.childProps} ref={this._captureRef} />
);
}
_keyExtractor = (item: Item, index: number) => {
const info = this._subExtractor(index);
return (info && info.key) || String(index);
};
_subExtractor(
index: number,
): ?{
section: SectionT,
key: string, // Key of the section or combined key for section + item
index: ?number, // Relative index within the section
header?: ?boolean, // True if this is the section header
leadingItem?: ?Item,
leadingSection?: ?SectionT,
trailingItem?: ?Item,
trailingSection?: ?SectionT,
} {
let itemIndex = index;
const defaultKeyExtractor = this.props.keyExtractor;
for (let ii = 0; ii < this.props.sections.length; ii++) {
const section = this.props.sections[ii];
const key = section.key || String(ii);
itemIndex -= 1; // The section adds an item for the header
if (itemIndex >= section.data.length + 1) {
itemIndex -= section.data.length + 1; // The section adds an item for the footer.
} else if (itemIndex === -1) {
return {
section,
key: key + ':header',
index: null,
header: true,
trailingSection: this.props.sections[ii + 1],
};
} else if (itemIndex === section.data.length) {
return {
section,
key: key + ':footer',
index: null,
header: false,
trailingSection: this.props.sections[ii + 1],
};
} else {
const keyExtractor = section.keyExtractor || defaultKeyExtractor;
return {
section,
key: key + ':' + keyExtractor(section.data[itemIndex], itemIndex),
index: itemIndex,
leadingItem: section.data[itemIndex - 1],
leadingSection: this.props.sections[ii - 1],
trailingItem: section.data[itemIndex + 1],
trailingSection: this.props.sections[ii + 1],
};
}
}
}
_convertViewable = (viewable: ViewToken): ?ViewToken => {
invariant(viewable.index != null, 'Received a broken ViewToken');
const info = this._subExtractor(viewable.index);
if (!info) {
return null;
}
const keyExtractor = info.section.keyExtractor || this.props.keyExtractor;
return {
...viewable,
index: info.index,
/* $FlowFixMe(>=0.63.0 site=react_native_fb) This comment suppresses an
* error found when Flow v0.63 was deployed. To see the error delete this
* comment and run Flow. */
key: keyExtractor(viewable.item, info.index),
section: info.section,
};
};
_onViewableItemsChanged = ({
viewableItems,
changed,
}: {
viewableItems: Array<ViewToken>,
changed: Array<ViewToken>,
}) => {
if (this.props.onViewableItemsChanged) {
this.props.onViewableItemsChanged({
viewableItems: viewableItems
.map(this._convertViewable, this)
.filter(Boolean),
changed: changed.map(this._convertViewable, this).filter(Boolean),
});
}
};
_renderItem = ({item, index}: {item: Item, index: number}) => {
const info = this._subExtractor(index);
if (!info) {
return null;
}
const infoIndex = info.index;
if (infoIndex == null) {
const {section} = info;
if (info.header === true) {
const {renderSectionHeader} = this.props;
return renderSectionHeader ? renderSectionHeader({section}) : null;
} else {
const {renderSectionFooter} = this.props;
return renderSectionFooter ? renderSectionFooter({section}) : null;
}
} else {
const renderItem = info.section.renderItem || this.props.renderItem;
const SeparatorComponent = this._getSeparatorComponent(index, info);
invariant(renderItem, 'no renderItem!');
return (
<ItemWithSeparator
SeparatorComponent={SeparatorComponent}
LeadingSeparatorComponent={
infoIndex === 0 ? this.props.SectionSeparatorComponent : undefined
}
cellKey={info.key}
index={infoIndex}
item={item}
leadingItem={info.leadingItem}
leadingSection={info.leadingSection}
onUpdateSeparator={this._onUpdateSeparator}
prevCellKey={(this._subExtractor(index - 1) || {}).key}
ref={ref => {
this._cellRefs[info.key] = ref;
}}
renderItem={renderItem}
section={info.section}
trailingItem={info.trailingItem}
trailingSection={info.trailingSection}
/>
);
}
};
_onUpdateSeparator = (key: string, newProps: Object) => {
const ref = this._cellRefs[key];
ref && ref.updateSeparatorProps(newProps);
};
_getSeparatorComponent(
index: number,
info?: ?Object,
): ?React.ComponentType<any> {
info = info || this._subExtractor(index);
if (!info) {
return null;
}
const ItemSeparatorComponent =
info.section.ItemSeparatorComponent || this.props.ItemSeparatorComponent;
const {SectionSeparatorComponent} = this.props;
const isLastItemInList = index === this.state.childProps.getItemCount() - 1;
const isLastItemInSection = info.index === info.section.data.length - 1;
if (SectionSeparatorComponent && isLastItemInSection) {
return SectionSeparatorComponent;
}
if (ItemSeparatorComponent && !isLastItemInSection && !isLastItemInList) {
return ItemSeparatorComponent;
}
return null;
}
_cellRefs = {};
_listRef: VirtualizedList;
_captureRef = ref => {
/* $FlowFixMe(>=0.53.0 site=react_native_fb,react_native_oss) This comment
* suppresses an error when upgrading Flow's support for React. To see the
* error delete this comment and run Flow. */
this._listRef = ref;
};
}
type ItemWithSeparatorCommonProps = $ReadOnly<{|
leadingItem: ?Item,
leadingSection: ?Object,
section: Object,
trailingItem: ?Item,
trailingSection: ?Object,
|}>;
type ItemWithSeparatorProps = $ReadOnly<{|
...ItemWithSeparatorCommonProps,
LeadingSeparatorComponent: ?React.ComponentType<any>,
SeparatorComponent: ?React.ComponentType<any>,
cellKey: string,
index: number,
item: Item,
onUpdateSeparator: (cellKey: string, newProps: Object) => void,
prevCellKey?: ?string,
renderItem: Function,
|}>;
type ItemWithSeparatorState = {
separatorProps: $ReadOnly<{|
highlighted: false,
...ItemWithSeparatorCommonProps,
|}>,
leadingSeparatorProps: $ReadOnly<{|
highlighted: false,
...ItemWithSeparatorCommonProps,
|}>,
};
class ItemWithSeparator extends React.Component<
ItemWithSeparatorProps,
ItemWithSeparatorState,
> {
state = {
separatorProps: {
highlighted: false,
leadingItem: this.props.item,
leadingSection: this.props.leadingSection,
section: this.props.section,
trailingItem: this.props.trailingItem,
trailingSection: this.props.trailingSection,
},
leadingSeparatorProps: {
highlighted: false,
leadingItem: this.props.leadingItem,
leadingSection: this.props.leadingSection,
section: this.props.section,
trailingItem: this.props.item,
trailingSection: this.props.trailingSection,
},
};
_separators = {
highlight: () => {
['leading', 'trailing'].forEach(s =>
this._separators.updateProps(s, {highlighted: true}),
);
},
unhighlight: () => {
['leading', 'trailing'].forEach(s =>
this._separators.updateProps(s, {highlighted: false}),
);
},
updateProps: (select: 'leading' | 'trailing', newProps: Object) => {
const {LeadingSeparatorComponent, cellKey, prevCellKey} = this.props;
if (select === 'leading' && LeadingSeparatorComponent != null) {
this.setState(state => ({
leadingSeparatorProps: {...state.leadingSeparatorProps, ...newProps},
}));
} else {
this.props.onUpdateSeparator(
(select === 'leading' && prevCellKey) || cellKey,
newProps,
);
}
},
};
static getDerivedStateFromProps(
props: ItemWithSeparatorProps,
prevState: ItemWithSeparatorState,
): ?ItemWithSeparatorState {
return {
separatorProps: {
...prevState.separatorProps,
leadingItem: props.item,
leadingSection: props.leadingSection,
section: props.section,
trailingItem: props.trailingItem,
trailingSection: props.trailingSection,
},
leadingSeparatorProps: {
...prevState.leadingSeparatorProps,
leadingItem: props.leadingItem,
leadingSection: props.leadingSection,
section: props.section,
trailingItem: props.item,
trailingSection: props.trailingSection,
},
};
}
updateSeparatorProps(newProps: Object) {
this.setState(state => ({
separatorProps: {...state.separatorProps, ...newProps},
}));
}
render() {
const {
LeadingSeparatorComponent,
SeparatorComponent,
item,
index,
section,
} = this.props;
const element = this.props.renderItem({
item,
index,
section,
separators: this._separators,
});
const leadingSeparator = LeadingSeparatorComponent && (
<LeadingSeparatorComponent {...this.state.leadingSeparatorProps} />
);
const separator = SeparatorComponent && (
<SeparatorComponent {...this.state.separatorProps} />
);
return leadingSeparator || separator ? (
<View>
{leadingSeparator}
{element}
{separator}
</View>
) : (
element
);
}
}
function getItem(sections: ?$ReadOnlyArray<Item>, index: number): ?Item {
if (!sections) {
return null;
}
let itemIdx = index - 1;
for (let ii = 0; ii < sections.length; ii++) {
if (itemIdx === -1 || itemIdx === sections[ii].data.length) {
// We intend for there to be overflow by one on both ends of the list.
// This will be for headers and footers. When returning a header or footer
// item the section itself is the item.
return sections[ii];
} else if (itemIdx < sections[ii].data.length) {
// If we are in the bounds of the list's data then return the item.
return sections[ii].data[itemIdx];
} else {
itemIdx -= sections[ii].data.length + 2; // Add two for the header and footer
}
}
return null;
}
module.exports = VirtualizedSectionList;