React EVENTS play

by lasha

HTML

<div id="app"></div>

CSS

body {
  background: #20262E;
  padding: 20px;
  font-family: Helvetica;
}

#app {
  background: #fff;
  border-radius: 4px;
  padding: 20px;
  transition: all 0.2s;
}

li {
  margin: 8px 0;
}

h2 {
  font-weight: bold;
  margin-bottom: 15px;
}

.done {
  color: rgba(0, 0, 0, 0.3);
  text-decoration: line-through;
}

input {
  margin-right: 5px;
}

React

class TodoApp extends React.Component {
  constructor(props) {
    super(props)
    this.state = {
    	items: [
      	{ id: 1, text: "Learn JavaScript", done: false },
        { id: 2, text: "Learn React", done: false },
        { id: 3, text: "Play around in JSFiddle", done: true },
        { id: 4, text: "Build something awesome", done: true }
      ],
      mouseClicked: false,
      inputText: 'Hello world',
      formInputText: 'Hello world 2',
      mousePositionX: 0,
      mousePositionY: 0,
      windowScrollY: 0
    }
    
    this.handleScroll = this.handleScroll.bind(this)
  }
  
  componentDidMount () {
    window.addEventListener('scroll', this.handleScroll)
  }

  componentWillUnmount () {
    window.removeEventListener('scroll', this.handleScroll)
  }

  handleScroll (event) {
    let scrollTop = Math.floor(window.scrollY)

    this.setState({
      windowScrollY: scrollTop
    })
  }
  
  render() {
    return (
      <div>
        <h2>Todos:</h2>
        <ol>
        {this.state.items.map(item => (
          <li key={item.id}>
            <label>
              <input type="checkbox" disabled readOnly checked={item.done} /> 
              <span className={item.done ? "done" : ""}>{item.text}</span>
            </label>
          </li>
        ))}
        </ol>
        
        <hr />
        
        <button
          onMouseDown={() => {this.setState({mouseClicked: true})} }
          onMouseUp={() => {this.setState({mouseClicked: false})} }
        >
          Click me
        </button>
        <div>Button state: {this.state.mouseClicked ? 'true' : 'false'}</div>
        
        <hr />
        
        {/* <input defaultValue="hey" /> */}
        <input
          type="text"
          value={this.state.inputText}
          onChange={(e) => {this.setState({inputText: e.target.value})}}
        /><br />
        Input value: {this.state.inputText}
        
        <hr />
        
        <form
          onSubmit={(e) => {
         ...