Swing/BrickLayout のバックアップ(No.12)

  • title: GridBagLayoutを使ってレンガ状に配置 tags: [GridBagLayout, LayoutManager] author: aterai pubdate: 2009-03-09T14:08:29+09:00 description: GridBagLayoutを使ってコンポーネントをレンガ状に配置します。

概要

GridBagLayoutを使ってコンポーネントをレンガ状に配置します。Swing - GridBagLayout to create a boardを参考にしています。

Screenshot

screenshot

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サンプルコード

JPanel panel = new JPanel(new GridBagLayout());
panel.setBorder(BorderFactory.createTitledBorder("Brick Layout"));
GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.HORIZONTAL;
//c.weightx = 1.0; c.weighty = 0.0;
for (int i = 0; i < SIZE; i++) {
  int x = i & 1; //= (i%2==0)?0:1;
  for (int j = 0; j < SIZE; j++) {
    c.gridy = i;
    c.gridx = 2 * j + x;
    c.gridwidth = 2;
    panel.add(new JButton(" "), c);
  }
}
//<blockquote cite="https://forums.oracle.com/thread/1357310">
//<dummy-row>
c.gridwidth = 1;
c.gridy = 10;
for (c.gridx = 0; c.gridx <= 2 * SIZE; c.gridx++) {
  panel.add(Box.createHorizontalStrut(24), c);
}
//</dummy-row>
//</blockquote>
View in GitHub: Java, Kotlin

解説

上記のサンプルでは、GridBagLayoutを使って、JButtonをレンガ状に配置します。互い違いに二列ずつ占めるようにボタンを配置していますが、<dummy-row>が無い場合、うまくレンガ状にはなりません。

以下、Swing - GridBagLayout to create a boardのDarryl.Burkeさんの投稿を引用

A column (or row) in a GridBagLayout is not well defined unless there is at least one component which occupies only that column (or row). All your rows have components spanning 2 columns.

列の基準となる行は、どこでも(先頭でも最後でも)構わないようです。

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

public class KeyboardTest {
  private static final String[][] keys = {
    {"`", "1", "2", "3", "4", "5", "6", "7", "8", "9", "0", "-", "=", "Backspace"},
    {"Tab", "Q", "W", "E", "R", "T", "Y", "U", "I", "O", "P", "[", "]", "\\", ""},
    {"Caps", "A", "S", "D", "F", "G", "H", "J", "K", "L", ";", "'", "Enter", ""},
    {"Shift", "Z", "X", "C", "V", "B", "N", "M", ",", ".", "/", "", "\u2191"},
    {" ", " ", " ", "", "                         ", " ", "\u2190", "\u2193", "\u2192"}
  };
  public JComponent makeUI() {
    JPanel keyboard = new JPanel(new GridBagLayout());
    keyboard.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));

    GridBagConstraints c = new GridBagConstraints();
    c.weightx = 1d;
    c.weighty = 1d;
    c.fill = GridBagConstraints.BOTH;
    c.gridheight = 1;
    c.gridx = 0;

    c.gridy = 50;
    for (int i = 0; i < keys[0].length * 2; i++) {
      c.gridx = i;
      keyboard.add(Box.createHorizontalStrut(24));
    }

    for (int row = 0; row < keys.length; row++) {
      c.gridx = 0;
      c.gridy = row;
      for (int col = 0; col < keys[row].length; col++) {
        String key = keys[row][col];
        int l = key.length();
        c.gridwidth = l > 10 ? 14 :
                      l > 4  ?  4 :
                      l > 1  ?  3 :
                      l == 1 ?  2 : 1;
        if (l > 2) {
          keyboard.add(new JButton(key), c);
        } else if (key.trim().length() == 0) {
          keyboard.add(Box.createHorizontalStrut(24), c);
        } else {
          keyboard.add(new KeyButton(key), c);
        }
        c.gridx += c.gridwidth;
      }
    }
    return keyboard;
  }
  public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
      @Override public void run() {
        createAndShowGUI();
      }
    });
  }
  public static void createAndShowGUI() {
    JFrame f = new JFrame("Keyboard");
    f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    f.getContentPane().add(new KeyboardTest().makeUI());
    f.setResizable(false);
    f.pack();
    f.setLocationRelativeTo(null);
    f.setVisible(true);
  }
}

class KeyButton extends JButton {
  public KeyButton(String str) {
    super(str);
  }
  @Override public Dimension getPreferredSize() {
    return new Dimension(48, 48);
  }
}

参考リンク

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