programming - 長留裕平のブログ

React className属性

index.html

<!DOCTYPE html>
<html lang="ja">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>My React App</title>
  <script src="https://unpkg.com/react@18/umd/react.development.js"></script>
  <script src="https://unpkg.com/react-dom@18/umd/react-dom.development.js"></script>
  <script src="https://unpkg.com/@babel/standalone/babel.min.js"></script>
</head>
  <link rel="stylesheet" href="style.css">
<body>
  <div id="container"></div>

  <script type="text/babel">
    'use strict';

    {
      const container = document.querySelector('#container');
      const root = ReactDOM.createRoot(container);
      root.render(
        <>
           <h1>アイテム</h1>
           <ul className="menus">
            <li>ポーション</li>
            <li>エリクサー</li>
            <li>ラストエリクサー</li>
           </ul>
           <p>合計: 0G</p>
        </>
      );
    }
  </script>
</body>

</html>

style.css

@charset "utf-8";

body{
    margin: 0;
}

#container{
    width: 400px;
    margin: auto;
}

h1{
    margin: 16px 0 0 0;
    font-size: 20px;
    text-align: center;
}

.menus{
    margin: 0;
    padding: 0;
    list-style-type: none;
}

.menus > li{
    border: 1px solid #ccc;
    padding: 8px;
    border-radius: 8px;
    margin-top: 16px;
}

p{
    margin: 0;
    text-align: right;
}

React CSSでスタイリングしていこう

index.html

<!DOCTYPE html>
<html lang="ja">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>My React App</title>
  <script src="https://unpkg.com/react@18/umd/react.development.js"></script>
  <script src="https://unpkg.com/react-dom@18/umd/react-dom.development.js"></script>
  <script src="https://unpkg.com/@babel/standalone/babel.min.js"></script>
</head>
  <link rel="stylesheet" href="style.css">
<body>
  <div id="container"></div>

  <script type="text/babel">
    'use strict';

    {
      const container = document.querySelector('#container');
      const root = ReactDOM.createRoot(container);
      root.render(
        <>
           <h1>アイテム</h1>
           <ul>
            <li>ポーション</li>
            <li>エリクサー</li>
            <li>ラストエリクサー</li>
           </ul>
           <p>合計: 0G</p>
        </>
      );
    }
  </script>
</body>

</html>

style.css

@charset "utf-8";

body{
    margin: 0;
}

#container{
    width: 400px;
    margin: auto;
    background: pink;
}

h1{
    margin: 0;
    font-size: 20px;
    text-align: center;
}

ul{
    margin: 0;
    padding: 0;
    list-style-type: none;
}

p{
    margin: 0;
    text-align: right;
}

React JSX記法

<!DOCTYPE html>
<html lang="ja">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>My React App</title>
  <script src="https://unpkg.com/react@18/umd/react.development.js"></script>
  <script src="https://unpkg.com/react-dom@18/umd/react-dom.development.js"></script>
  <script src="https://unpkg.com/@babel/standalone/babel.min.js"></script>
</head>

<body>
  <div id="container"></div>

  <script type="text/babel">
    'use strict';

    {
      const container = document.querySelector('#container');
      const root = ReactDOM.createRoot(container);
      root.render(
        <>
           <h1>アイテム</h1>
           <ul>
            <li>ポーション</li>
            <li>エリクサー</li>
            <li>ラストエリクサー</li>
           </ul>
           <p>合計: 0G</p>
        </>
      );
    }
  </script>
</body>

</html>

Reactでh1要素を描画してみよう

<!DOCTYPE html>
<html lang="ja">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>My React App</title>
  <script src="https://unpkg.com/react@18/umd/react.development.js"></script>
  <script src="https://unpkg.com/react-dom@18/umd/react-dom.development.js"></script>
  <script src="https://unpkg.com/@babel/standalone/babel.min.js"></script>
</head>

<body>
  <div id="container"></div>

  <script type="text/babel">
    'use strict';

    {
      const container = document.querySelector('#container');
      const root = ReactDOM.createRoot(container);
      root.render(
        React.createElement('h1', null, 'メニュー')
      );
    }
  </script>
</body>

</html>

tailwindcss To-Do List

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>To-Do List</title>
  <link href="https://cdn.jsdelivr.net/npm/tailwindcss@2.2.19/dist/tailwind.min.css" rel="stylesheet">
</head>
<body class="bg-gray-100 flex items-center justify-center h-screen">
  <div class="bg-white p-8 rounded-lg shadow-lg w-full max-w-md">
    <h1 class="text-2xl font-bold mb-4">To-Do List</h1>
    <form id="todo-form" class="flex mb-4">
      <input id="todo-input" type="text" placeholder="Add a new task" class="flex-grow p-2 border rounded-l-lg focus:outline-none">
      <button type="submit" class="bg-blue-500 text-white px-4 py-2 rounded-r-lg hover:bg-blue-700">Add</button>
    </form>
    <div class="mb-4">
      <button id="filter-all" class="filter-btn bg-gray-200 text-black px-4 py-2 rounded-l-lg">All</button>
      <button id="filter-active" class="filter-btn bg-gray-200 text-black px-4 py-2">Active</button>
      <button id="filter-completed" class="filter-btn bg-gray-200 text-black px-4 py-2 rounded-r-lg">Completed</button>
    </div>
    <ul id="todo-list" class="list-disc pl-5">
      <!-- To-Do items will be added here -->
    </ul>
  </div>

  <script>
    const todoForm = document.getElementById('todo-form');
    const todoInput = document.getElementById('todo-input');
    const todoList = document.getElementById('todo-list');
    const filterButtons = document.querySelectorAll('.filter-btn');

    document.addEventListener('DOMContentLoaded', loadTodos);
    todoForm.addEventListener('submit', function(event) {
      event.preventDefault();
      addTodoItem(todoInput.value);
      todoInput.value = '';
    });

    filterButtons.forEach(button => {
      button.addEventListener('click', () => {
        document.querySelectorAll('.filter-btn').forEach(btn => btn.classList.remove('bg-blue-500', 'text-white'));
        button.classList.add('bg-blue-500', 'text-white');
        filterTodos(button.id);
      });
    });

    function addTodoItem(task) {
      if (task === '') return;

      const listItem = document.createElement('li');
      listItem.classList.add('flex', 'items-center', 'justify-between', 'py-2', 'border-b', 'border-gray-200');

      const taskText = document.createElement('span');
      taskText.textContent = task;
      taskText.classList.add('flex-grow', 'cursor-pointer');
      taskText.addEventListener('click', toggleComplete);

      const editButton = document.createElement('button');
      editButton.textContent = 'Edit';
      editButton.classList.add('bg-yellow-500', 'text-white', 'px-2', 'py-1', 'rounded', 'ml-2', 'hover:bg-yellow-700');
      editButton.addEventListener('click', () => editTodoItem(listItem, taskText));

      const priorityButton = document.createElement('button');
      priorityButton.textContent = 'Important';
      priorityButton.classList.add('bg-green-500', 'text-white', 'px-2', 'py-1', 'rounded', 'ml-2', 'hover:bg-green-700');
      priorityButton.addEventListener('click', () => togglePriority(taskText));

      const deleteButton = document.createElement('button');
      deleteButton.textContent = 'Delete';
      deleteButton.classList.add('bg-red-500', 'text-white', 'px-2', 'py-1', 'rounded', 'ml-2', 'hover:bg-red-700');
      deleteButton.addEventListener('click', () => deleteTodoItem(listItem));

      listItem.appendChild(taskText);
      listItem.appendChild(editButton);
      listItem.appendChild(priorityButton);
      listItem.appendChild(deleteButton);
      todoList.appendChild(listItem);

      saveTodos();
    }

    function toggleComplete(event) {
      event.target.classList.toggle('line-through');
      event.target.classList.toggle('text-gray-500');
      saveTodos();
    }

    function togglePriority(taskText) {
      taskText.classList.toggle('font-bold');
      saveTodos();
    }

    function editTodoItem(listItem, taskText) {
      const newTask = prompt('Edit your task:', taskText.textContent);
      if (newTask !== null && newTask !== '') {
        taskText.textContent = newTask;
        saveTodos();
      }
    }

    function deleteTodoItem(listItem) {
      listItem.remove();
      saveTodos();
    }

    function saveTodos() {
      const todos = [];
      document.querySelectorAll('#todo-list li').forEach((item) => {
        todos.push({
          text: item.querySelector('span').textContent,
          completed: item.querySelector('span').classList.contains('line-through'),
          important: item.querySelector('span').classList.contains('font-bold')
        });
      });
      localStorage.setItem('todos', JSON.stringify(todos));
    }

    function loadTodos() {
      const savedTodos = JSON.parse(localStorage.getItem('todos')) || [];
      savedTodos.forEach((todo) => {
        const listItem = document.createElement('li');
        listItem.classList.add('flex', 'items-center', 'justify-between', 'py-2', 'border-b', 'border-gray-200');

        const taskText = document.createElement('span');
        taskText.textContent = todo.text;
        taskText.classList.add('flex-grow', 'cursor-pointer');
        if (todo.completed) {
          taskText.classList.add('line-through', 'text-gray-500');
        }
        if (todo.important) {
          taskText.classList.add('font-bold');
        }
        taskText.addEventListener('click', toggleComplete);

        const editButton = document.createElement('button');
        editButton.textContent = 'Edit';
        editButton.classList.add('bg-yellow-500', 'text-white', 'px-2', 'py-1', 'rounded', 'ml-2', 'hover:bg-yellow-700');
        editButton.addEventListener('click', () => editTodoItem(listItem, taskText));

        const priorityButton = document.createElement('button');
        priorityButton.textContent = 'Important';
        priorityButton.classList.add('bg-green-500', 'text-white', 'px-2', 'py-1', 'rounded', 'ml-2', 'hover:bg-green-700');
        priorityButton.addEventListener('click', () => togglePriority(taskText));

        const deleteButton = document.createElement('button');
        deleteButton.textContent = 'Delete';
        deleteButton.classList.add('bg-red-500', 'text-white', 'px-2', 'py-1', 'rounded', 'ml-2', 'hover:bg-red-700');
        deleteButton.addEventListener('click', () => deleteTodoItem(listItem));

        listItem.appendChild(taskText);
        listItem.appendChild(editButton);
        listItem.appendChild(priorityButton);
        listItem.appendChild(deleteButton);
        todoList.appendChild(listItem);
      });
    }

    function filterTodos(filter) {
      const allTodos = document.querySelectorAll('#todo-list li');
      allTodos.forEach((todo) => {
        switch (filter) {
          case 'filter-all':
            todo.style.display = 'flex';
            break;
          case 'filter-active':
            todo.querySelector('span').classList.contains('line-through') ? todo.style.display = 'none' : todo.style.display = 'flex';
            break;
          case 'filter-completed':
            todo.querySelector('span').classList.contains('line-through') ? todo.style.display = 'flex' : todo.style.display = 'none';
            break;
        }
      });
    }
  </script>
</body>
</html>

Tailwind CSS入門　インタラクティブにスタイルを変えてみよう

index.html

<!DOCTYPE html>
<html lang="ja">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>My Tailwind CSS</title>
    <script src="https://cdn.tailwindcss.com"></script>
</head>

<body>
    <button
        class="bg-orange-400 text-white m-4 py-2 px-4 rounded-full shadow-black/30 shadow-md hover:opacity-80 transition duration-500 active:translate-y-1">
        Buy now!
    </button>
</body>

</html>

Tailwind CSS入門ボタンのスタイリングをしてみよう

<!DOCTYPE html>
<html lang="ja">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>My Tailwind CSS</title>
    <script src="https://cdn.tailwindcss.com"></script>
</head>

<body>
<button class="bg-orange-400 text-white m-4 py-2 px-4 rounded-full shadow-black/30 shadow-md">
        Buy now!
    </button>
</body>

</html>

Tailwind CSS入門境界線を設定してみよう

<!DOCTYPE html>
<html lang="ja">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>My Tailwind CSS</title>
    <script src="https://cdn.tailwindcss.com"></script>
</head>

<body>
    <div class="bg-red-400 w-20 h-20 border-solid border-gray-200 border-8">Box 1</div>
    <div class="bg-sky-400 w-20 h-20 border-dashed border-gray-200 border-b-8">Box 2</div>
</body>

</html>

Java 電卓

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class Calculator extends JFrame implements ActionListener {
    private JTextField display;
    private JPanel panel;
    private StringBuilder currentInput;
    private double result;
    private String operator;

    public Calculator() {
        // Frame settings
        setTitle("Calculator");
        setSize(400, 600);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        // Display settings
        display = new JTextField();
        display.setEditable(false);
        display.setFont(new Font("Arial", Font.BOLD, 24));
        add(display, BorderLayout.NORTH);

        // Button panel settings
        panel = new JPanel();
        panel.setLayout(new GridLayout(4, 4));

        // Create and add buttons
        String[] buttons = {
            "7", "8", "9", "/",
            "4", "5", "6", "*",
            "1", "2", "3", "-",
            "0", ".", "=", "+"
        };

        for (String text : buttons) {
            JButton button = new JButton(text);
            button.setFont(new Font("Arial", Font.BOLD, 24));
            button.addActionListener(this);
            panel.add(button);
        }

        add(panel, BorderLayout.CENTER);

        currentInput = new StringBuilder();
        result = 0;
        operator = "";
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        String command = e.getActionCommand();

        if ("0123456789.".contains(command)) {
            currentInput.append(command);
            display.setText(currentInput.toString());
        } else if (command.equals("=")) {
            calculate();
            display.setText(String.valueOf(result));
            currentInput.setLength(0);
        } else {
            if (currentInput.length() > 0) {
                calculate();
                operator = command;
                display.setText(String.valueOf(result));
                currentInput.setLength(0);
            }
        }
    }

    private void calculate() {
        double input = currentInput.length() > 0 ? Double.parseDouble(currentInput.toString()) : 0;

        switch (operator) {
            case "+":
                result += input;
                break;
            case "-":
                result -= input;
                break;
            case "*":
                result *= input;
                break;
            case "/":
                result /= input;
                break;
            default:
                result = input;
                break;
        }
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> {
            Calculator calculator = new Calculator();
            calculator.setVisible(true);
        });
    }
}

javac Calculator.java
java Calculator

Java メモ帳

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class SimpleNotepad extends JFrame implements ActionListener {
    private JTextArea textArea;
    private JMenuItem openItem, saveItem, exitItem;

    public SimpleNotepad() {
        // Frame settings
        setTitle("Simple Notepad");
        setSize(800, 600);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        // Text area settings
        textArea = new JTextArea();
        JScrollPane scrollPane = new JScrollPane(textArea);
        add(scrollPane, BorderLayout.CENTER);

        // Menu bar creation
        JMenuBar menuBar = new JMenuBar();
        JMenu fileMenu = new JMenu("File");
        openItem = new JMenuItem("Open");
        saveItem = new JMenuItem("Save");
        exitItem = new JMenuItem("Exit");

        openItem.addActionListener(this);
        saveItem.addActionListener(this);
        exitItem.addActionListener(this);

        fileMenu.add(openItem);
        fileMenu.add(saveItem);
        fileMenu.add(exitItem);
        menuBar.add(fileMenu);
        setJMenuBar(menuBar);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == openItem) {
            openFile();
        } else if (e.getSource() == saveItem) {
            saveFile();
        } else if (e.getSource() == exitItem) {
            System.exit(0);
        }
    }

    private void openFile() {
        JFileChooser fileChooser = new JFileChooser();
        int option = fileChooser.showOpenDialog(this);
        if (option == JFileChooser.APPROVE_OPTION) {
            try (BufferedReader reader = new BufferedReader(new FileReader(fileChooser.getSelectedFile()))) {
                textArea.read(reader, null);
            } catch (IOException ex) {
                JOptionPane.showMessageDialog(this, "File could not be opened", "Error", JOptionPane.ERROR_MESSAGE);
            }
        }
    }

    private void saveFile() {
        JFileChooser fileChooser = new JFileChooser();
        int option = fileChooser.showSaveDialog(this);
        if (option == JFileChooser.APPROVE_OPTION) {
            try (FileWriter writer = new FileWriter(fileChooser.getSelectedFile())) {
                textArea.write(writer);
            } catch (IOException ex) {
                JOptionPane.showMessageDialog(this, "File could not be saved", "Error", JOptionPane.ERROR_MESSAGE);
            }
        }
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> {
            SimpleNotepad notepad = new SimpleNotepad();
            notepad.setVisible(true);
        });
    }
}