Example of React Native Timer and Stopwatch

React Native Timer and React Native Stopwatch

This is an Example of React Native Timer and React Native Stopwatch. To make a Stopwatch and Timer we have a very good library called react-native-stopwatch-timer. It will provide Stopwatch and Timer component.

A Stopwatch is a special watch that can be used to count the time. In stopwatch time starts from zero and runs until we stop it but Timer is the exact opposite of it. In the Timer, we decide the time to count and it counts towards zero.

Stopwatch

<Stopwatch laps msecs 
    start={this.state.isStopwatchStart}
    //To start
    reset={this.state.resetStopwatch}
    //To reset
    options={options}
    //options for the styling
    getTime={this.getFormattedTime} 
/>

Timer

<Timer 
    totalDuration={this.state.timerDuration} msecs 
    //Time Duration
    start={this.state.isTimerStart}
    //To start
    reset={this.state.resetTimer}
    //To reset
    options={options}
    //options for the styling
    handleFinish={handleTimerComplete}
    //can call a function On finish of the time 
    getTime={this.getFormattedTime} 
/>

In this example, we will make a Stopwatch and a Timer. The Timer will show the count down from the given Millisecond.  So Let’s get started.

To Make a React Native App

Getting started with React Native will help you to know more about the way you can make a React Native project. We are going to use react-native init to make our React Native App. Assuming that you have node installed, you can use npm to install the react-native-cli command line utility. Open the terminal and go to the workspace and run

npm install -g react-native-cli

Run the following commands to create a new React Native project

react-native init ProjectName

If you want to start a new project with a specific React Native version, you can use the --version argument:

react-native init ProjectName --version X.XX.X

react-native init ProjectName --version react-native@next

This will make a project structure with an index file named App.js in your project directory.

Installation of Dependency

To use Stopwatch and Timer you need to install react-native-stopwatch-timer package.

To install this open the terminal and jump into your project using

cd ProjectName

Run the following command

npm install react-native-stopwatch-timer --save

This command will copy all the dependencies into your node_module directory, You can find the directory in node_module directory named react-native-stopwatch-timer.

–save is optional, it is just to update the react-native-app-intro-slider dependency in your package.json file.

Code

Now Open App.js in any code editor and replace the code with the following code

App.js

/*This is an Example of Timer/Stopwatch in React Native */
import React, { Component } from 'react';
//import React in our project
import { StyleSheet,Text,View, TouchableHighlight } from 'react-native';
//import all the required components
import { Stopwatch, Timer } from 'react-native-stopwatch-timer';
//importing library to use Stopwatch and Timer
 
export default class TestApp extends Component {
  constructor(props) {
    super(props);
    this.state = {
      isTimerStart: false,
      isStopwatchStart: false,
      timerDuration: 90000,
      resetTimer: false,
      resetStopwatch: false,
    };
    this.startStopTimer = this.startStopTimer.bind(this);
    this.resetTimer = this.resetTimer.bind(this);
    this.startStopStopWatch = this.startStopStopWatch.bind(this);
    this.resetStopwatch = this.resetStopwatch.bind(this);
  }
  startStopTimer() {
    this.setState({isTimerStart: !this.state.isTimerStart, resetTimer: false});
  }
  resetTimer() {
    this.setState({isTimerStart: false, resetTimer: true});
  }
  startStopStopWatch() {
    this.setState({isStopwatchStart: !this.state.isStopwatchStart, resetStopwatch: false});
  }
  resetStopwatch() {
    this.setState({isStopwatchStart: false, resetStopwatch: true});
  }
  getFormattedTime(time) {
      this.currentTime = time;
  }
  render() {
    return (
      <View style={{flex:1,justifyContent:'center',alignItems:'center'}}>
        <View style={{flex:1,marginTop:32, alignItems:'center', justifyContent:'center'}}>
          <Stopwatch laps msecs 
            start={this.state.isStopwatchStart}
            //To start
            reset={this.state.resetStopwatch}
            //To reset
            options={options}
            //options for the styling
            getTime={this.getFormattedTime} />
          <TouchableHighlight onPress={this.startStopStopWatch}>
            <Text style={{fontSize: 20, marginTop:10}}>
              {!this.state.isStopwatchStart ? "START" : "STOP"}
            </Text>
          </TouchableHighlight>
          <TouchableHighlight onPress={this.resetStopwatch}>
            <Text style={{fontSize: 20, marginTop:10}}>RESET</Text>
          </TouchableHighlight>
        </View>
        <View style={{flex:1,marginTop:32, alignItems:'center', justifyContent:'center'}}>
          <Timer 
            totalDuration={this.state.timerDuration} msecs 
            //Time Duration
            start={this.state.isTimerStart}
            //To start
            reset={this.state.resetTimer}
            //To reset
            options={options}
            //options for the styling
            handleFinish={handleTimerComplete}
            //can call a function On finish of the time 
            getTime={this.getFormattedTime} />
          <TouchableHighlight onPress={this.startStopTimer}>
            <Text style={{fontSize: 20, marginTop:10}}>
               {!this.state.isTimerStart ? "START" : "STOP"}
            </Text>
          </TouchableHighlight>
          <TouchableHighlight onPress={this.resetTimer}>
            <Text style={{fontSize: 20, marginTop:10}}>RESET</Text>
          </TouchableHighlight>
        </View>
      </View>
    );
  }
}
 
const handleTimerComplete = () => alert("Custom Completion Function");
const options = {
  container: {
    backgroundColor: '#FF0000',
    padding: 5,
    borderRadius: 5,
    width: 200,
    alignItems:'center',
  },
  text: {
    fontSize: 25,
    color: '#FFF',
    marginLeft: 7,
  }
};

To Run the React Native App

Open the terminal again and jump into your project using.

cd ProjectName

To run the project on an Android Virtual Device or on real debugging device

react-native run-android

or on the iOS Simulator by running

react-native run-ios (macOS only).

Output Screenshots

Output in Online Emulator

That was the React Native Timer and React Native Stopwatch. If you have any doubts or you want to share something about the topic you can comment below or contact us here. There will be more posts coming soon. Stay tuned!

Hope you liked it. 🙂