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 command line interface to make our React Native App.

If you have previously installed a global react-native-cli package, please remove it as it may cause unexpected issues:

npm uninstall -g react-native-cli @react-native-community/cli

Run the following commands to create a new React Native project

npx react-native init ProjectName

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

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

Note If the above command is failing, you may have old version of react-native or react-native-cli installed globally on your pc. Try uninstalling the cli and run the cli using npx.

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

// Example of React Native Timer and Stopwatch
// https://aboutreact.com/react-native-timer-stopwatch/

// import React in our code
import React, {useState} from 'react';

// import all the components we are going to use
import {
  SafeAreaView,
  StyleSheet,
  Text,
  View,
  TouchableHighlight,
} from 'react-native';

// importing library to use Stopwatch and Timer
import {Stopwatch, Timer} from 'react-native-stopwatch-timer';

const App = () => {
  const [isTimerStart, setIsTimerStart] = useState(false);
  const [isStopwatchStart, setIsStopwatchStart] = useState(false);
  const [timerDuration, setTimerDuration] = useState(90000);
  const [resetTimer, setResetTimer] = useState(false);
  const [resetStopwatch, setResetStopwatch] = useState(false);

  return (
    <SafeAreaView style={styles.container}>
      <View style={styles.container}>
        <Text style={styles.title}>
          Example of React Native Timer and Stopwatch
        </Text>
        <View style={styles.sectionStyle}>
          <Stopwatch
            laps
            msecs
            start={isStopwatchStart}
            // To start
            reset={resetStopwatch}
            // To reset
            options={options}
            // Options for the styling
            getTime={(time) => {
              console.log(time);
            }}
          />
          <TouchableHighlight
            onPress={() => {
              setIsStopwatchStart(!isStopwatchStart);
              setResetStopwatch(false);
            }}>
            <Text style={styles.buttonText}>
              {!isStopwatchStart ? 'START' : 'STOP'}
            </Text>
          </TouchableHighlight>
          <TouchableHighlight
            onPress={() => {
              setIsStopwatchStart(false);
              setResetStopwatch(true);
            }}>
            <Text style={styles.buttonText}>RESET</Text>
          </TouchableHighlight>
        </View>
        <View style={styles.sectionStyle}>
          <Timer
            totalDuration={timerDuration}
            msecs
            // Time Duration
            start={isTimerStart}
            // To start
            reset={resetTimer}
            // To reset
            options={options}
            // Options for the styling
            handleFinish={() => {
              alert('Custom Completion Function');
            }}
            // Can call a function On finish of the time
            getTime={(time) => {
              console.log(time);
            }}
          />
          <TouchableHighlight
            onPress={() => {
              setIsTimerStart(!isTimerStart);
              setResetTimer(false);
            }}>
            <Text style={styles.buttonText}>
              {!isTimerStart ? 'START' : 'STOP'}
            </Text>
          </TouchableHighlight>
          <TouchableHighlight
            onPress={() => {
              setIsTimerStart(false);
              setResetTimer(true);
            }}>
            <Text style={styles.buttonText}>RESET</Text>
          </TouchableHighlight>
        </View>
      </View>
    </SafeAreaView>
  );
};

export default App;

const styles = StyleSheet.create({
  container: {
    flex: 1,
    padding: 10,
    justifyContent: 'center',
    alignItems: 'center',
  },
  title: {
    textAlign: 'center',
    fontSize: 20,
    fontWeight: 'bold',
    padding: 20,
  },
  sectionStyle: {
    flex: 1,
    marginTop: 32,
    alignItems: 'center',
    justifyContent: 'center',
  },
  buttonText: {
    fontSize: 20,
    marginTop: 10,
  },
});

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

1. Start Metro Bundler

First, you will need to start Metro, the JavaScript bundler that ships with React Native. To start Metro bundler run following command:

npx react-native start

Once you start Metro Bundler it will run forever on your terminal until you close it. Let Metro Bundler run in its own terminal. Open a new terminal and run the application.

2. Start React Native Application

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

npx react-native run-android

or on the iOS Simulator by running (macOS only)

npx react-native run-ios

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. 🙂