react-native-largelist

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React-native-largelist is a high performance large list component for React-Native. It's performance is much better than SectionList.

react-native-largelist is a high performance list component for React Native(iOS & Android).

Features

react-native-largelist is better than SectionList

Preview

This is a react-native-largelist with 3000 cells

Getting Started

iOS:

Make sure your project is react-native project.
Using this command to install:

npm install react-native-largelist --save

Using it like this:

import { LargeList } from "react-native-largelist";

//other code
...
<LargeList
        style={{ flex: 1 }}
        bounces={true}
        refreshing={this.state.refreshing}
        onRefresh={() => {
          this.setState({ refreshing: true });
          setTimeout(() => this.setState({ refreshing: false }), 2000);
        }}
        safeMargin={600}
        numberOfRowsInSection={section => this.props.numberOfEachSection}
        numberOfSections={this.props.numberOfSections}
        heightForCell={(section, row) =>
          row % 2 ? this.minCellHeight : this.maxCellHeight}
        renderCell={this.renderItem.bind(this)}
        heightForSection={section =>
          section % 2 ? this.minSectionHeight : this.maxSectionHeight}
        renderHeader={this.renderHeader.bind(this)}
        renderFooter={this.renderFooter.bind(this)}
        renderSection={section => {
          return (
            <View
              style={{
                flex: 1,
                backgroundColor: section % 2 ? "grey" : "yellow",
                justifyContent: "center",
                alignItems: "center"
              }}
            >
              <Text>
                I am section {section}
              </Text>
            </View>
          );
        }}
      />
...

Usage

import { LargeList } from "react-native-largelist"

Props:

Props	type	default	effect
（ViewPropTypes）	（ViewPropTypes）		All props of View
numberOfSections	number	1	number of sections in tableview
numberOfRowsInSection	(section:number) => number	section=>0	function：return the number of rows in section
renderCell	(section:number,row:number) => React.Element	required	function: render of cell with section and row index
heightForCell	(section:number,row:number) => number	required	function：return height for cell with section and row index
renderSection	(section:number) => React.Element	section=>null	function：render of section with section index
heightForSection	(section:number) => number	0	function：return height of section with section index
renderHeader	() => React.Element	null	function：render of header in the tableview
renderFooter	() => React.Element	null	function：render of footer in tableview
bounces	boolean	true	bounces
refreshing	boolean	true	refreshing
onRefresh	() => any	()=>{}	callback of pulling to refresh
onScroll	({nativeEvent:{contentOffset:{x:number,y:number}}})=> any		Callback when scrolling.

Principle

Before we learn advanced usage, we must first understand the basic principles:

Every Cell/Item is reused just like UITableView/RecyclerView. The top Cell/Item which is Slided to the outside of the visible region does not need to show. So, I move it bottom, render it with the new datasource.

But,as you know, It is different with native UITableView/RecyclerView. They are not one thread between Main Thread(UI Thread) and JavaScript Thread. And They are synchronous, and the communication between them may take not a few time. So, I try to render more Cells/Items at the upper and lower ends of the visual area. I call it safeArea. And I use it to buffer, to avoid the user slide suddenly and the visual view of the upper and lower edges is flickering.

Look up the design of react-native-largelist:

Advanced Usage

safeMargin ( type:number ,default: 600)

The height of rendering children out side of visiable area. The greater the value is, the less easily you see the blank in the fast sliding process, but the longer the first time it is loaded

dynamicMargin (type:number,default: 500)

The height of dynamic safe margin when sliding too fast. For example, if safeMargin=600 and dynamicMargin=500, it will render 100 height on top and 1100 height on bottom out side of the visiable area when sliding down too fast.

Notice:

It does not work when the speed of sliding is slow.
It can not be set larger than safeMargin

scrollEventThrottle (type: number ,default: ios:16 android:32)

It is the same as scrollEventThrottle on ScrollView

onIndexPathDidEnterSafeArea (type:(indexPath:IndexPath)=>any)

The callback when an indexpath did enter safeArea.

onIndexPathDidLeaveSafeArea (type:(indexPath:IndexPath)=>any)

The callback when an indexpath did leave safeArea.

Method

scrollTo(offset:Offset, animated:boolean=true)

Scroll to offset.

scrollToIndexPath(indexPath:IndexPath, animated:boolean = true)

Scroll to an indexpath.

scrollToEnd(animated:boolean=true)

Scroll to the end of the LargeList.

visiableIndexPaths():IndexPath[]

Get the visiable indexpaths at this time.

renderedIndexPaths():IndexPath[]

Get the rendered indexpaths at this time.

freeCount(): number

Get the count of free views at this time.

Dynamic variable

size:Size

Current size of LargeList. Size：{width:number,height:number}

contentOffset:Offset

Current contentOffset of LargeList. Offset：{x:number,y:number}

safeArea: Range

Current safeArea of LargeList.. Range:{top:number,bottom:number}

topIndexPath: IndexPath

Current topIndexPath of LargeList. IndexPath:{section:number,row:number}

bottomIndexPath: IndexPath

Current bottomIndexPath of LargeList. IndexPath:{section:number,row:number}

contentSize:Size

Current contentSize of LargeList. Size:{width:number, height:number}

currentSection:number

Current section index of LargeList.

headerHeight:number

Get LargeList's header height

footerHeight:number

Get LargeList's footer height

mouseliu / react-native-largelist