在GridBagLayout中设置任意宽度 [英] Setting an arbitrary width in GridBagLayout

问题描述

我正在尝试制作一种键盘布局，可以在其中指定按钮的宽度.因此，我尝试使用GridBagLayout，但没有成功. 为了说明我的问题，我做了一个简单的示例，希望在其中获得它(Button2，Button4，Button5，Button6):

I was trying to make a keyboard layout, where one can specify the buttons' width. Therefore, I made an attempt with GridBagLayout but without success. To illustrate my problem I did a simple example, where I expected to obtain this (Button2, Button4, Button5, Button6):

但是我得到的Button4和Button6的宽度是原来的两倍.

but instead I get Button4 and Button6 of double width.

代码是:

package views;

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class TestLayout  extends JFrame {

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                new TestLayout().setVisible(true);
            }
        });
    }

    public TestLayout() {
        JButton btn;
        setBounds(0, 0, 444, 111);
        setLayout(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.fill = GridBagConstraints.BOTH;

        gbc.gridy = 1;//ROW 1
        btn = new JButton("Button 1");gbc.gridx = 0;gbc.gridwidth = 1;add(btn, gbc);
        btn = new JButton("Button 2");gbc.gridx = 1;gbc.gridwidth = 2;add(btn, gbc);
        btn = new JButton("Button 3");gbc.gridx = 3;gbc.gridwidth = 1;add(btn, gbc);
        btn = new JButton("Button 4");gbc.gridx = 4;gbc.gridwidth = 2;add(btn, gbc);

        gbc.gridy = 2;//ROW 2
        btn = new JButton("Button 5");gbc.gridx = 0;gbc.gridwidth = 2;add(btn, gbc);
        btn = new JButton("Button 6");gbc.gridx = 2;gbc.gridwidth = 2;add(btn, gbc);
        btn = new JButton("Button 7");gbc.gridx = 4;gbc.gridwidth = 1;add(btn, gbc);
        btn = new JButton("Button 8");gbc.gridx = 5;gbc.gridwidth = 1;add(btn, gbc);
    }  
}

此外，我的目标是定义类似这样的键盘，行之间没有关联，而使用此布局管理器是无法实现的:

Moreover, my goal is to define the keyboard something like this, with no correlation between rows, which I couldn't achieved with this Layout manager:

推荐答案

我将此问题移交给了为什么GridBagLayout不能显示为有计划吗?& camickr使用虚拟行的组件来解决它，每个组件的宽度为gridwidth.

I took this matter over to Why does this GridBagLayout not appear as planned? & camickr solved it using a dummy row of components, each 1 gridwidth wide.

这2张图片显示:

1. 底部是使用1像素高的透明图像的代码的最低要求"版本.
2. 在顶部，最明显的版本使用的是高度为5像素的纯黑色图像.

---

import java.awt.*;
import java.awt.image.BufferedImage;
import javax.swing.*;
import javax.swing.border.*;

public class KeyBoardLayout {

    private JComponent ui = null;

    KeyBoardLayout(boolean lowImpact) {
        initUI(lowImpact);
    }

    public void initUI(boolean lowImpact) {
        if (ui != null) {
            return;
        }

        ui = new JPanel(new GridBagLayout());
        ui.setBorder(new EmptyBorder(4, 4, 4, 4));
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.weightx = .5;
        gbc.weighty = .5;
        gbc.fill = GridBagConstraints.BOTH;

        /* This code adds a dummy (invisible) row of components, 1 per 
         single gridwidth column.  It has the effect of forcing the GBL width 
         to the size we would expect, proportional to each gridwidth assigned.
         The problem with this (simple) approach is that the perfect 
         width will change according to PLAF and the content/preferred 
         size of the visible components. */
        // TODO! improve on use of 'magic numbers'
        int w = 30; // adjust width per requirement
        int h = lowImpact ? 1 : 5; // 1 for small height/border, 5 for large
        // TYPE_INT_RGB for black
        // TYPE_INT_ARGB for invisible
        int t = lowImpact ? 
                BufferedImage.TYPE_INT_ARGB : 
                BufferedImage.TYPE_INT_RGB;
        // an icon for the dummy row
        ImageIcon ii = new ImageIcon(new BufferedImage(w, h, t));
        ui.setBorder(new CompoundBorder(
                ui.getBorder(), new EmptyBorder(0, 0, h, 0)));
        // put a 'padding cell' in each column of the top row
        // to force the layout to respect each individual column
        for (int i = 0; i < 22; i++) {
            gbc.gridx = i;
            gbc.gridy = 4;
            ui.add(new JLabel(ii));
        }

        gbc.gridx = 0;
        gbc.gridy = 1;
        gbc.gridwidth = 3;
        ui.add(new JButton("1,1 (3)"), gbc);

        gbc.gridx = 3;
        gbc.gridwidth = 2;
        ui.add(new JButton("2,1 (2)"), gbc);

        gbc.gridx = 5;
        ui.add(new JButton("3,1 (2)"), gbc);

        gbc.gridx = 7;
        ui.add(new JButton("4,1 (2)"), gbc);

        gbc.gridx = 9;
        ui.add(new JButton("5,1 (2)"), gbc);

        gbc.gridx = 11;
        ui.add(new JButton("6,1 (2)"), gbc);

        gbc.gridx = 13;
        ui.add(new JButton("7,1 (2)"), gbc);

        gbc.gridx = 15;
        gbc.gridwidth = 3;
        ui.add(new JButton("8,1 (3)"), gbc);

        gbc.gridx = 18;
        gbc.gridwidth = 4;
        ui.add(new JButton("9,1 (4)"), gbc);

        gbc.gridx = 0;
        gbc.gridy = 2;
        ui.add(new JButton("1,2 (4)"), gbc);

        gbc.gridx = 4;
        gbc.gridwidth = 2;
        ui.add(new JButton("2,2 (2)"), gbc);

        gbc.gridx = 6;
        ui.add(new JButton("3,2 (2)"), gbc);

        gbc.gridx = 8;
        ui.add(new JButton("4,2 (2)"), gbc);

        gbc.gridx = 10;
        ui.add(new JButton("5,2 (2)"), gbc);

        gbc.gridx = 12;
        ui.add(new JButton("6,2 (2)"), gbc);

        gbc.gridx = 14;
        ui.add(new JButton("7,2 (2)"), gbc);

        gbc.gridx = 16;
        ui.add(new JButton("8,2 (2)"), gbc);

        gbc.gridx = 18;
        gbc.gridwidth = 4;
        ui.add(new JButton("9,2 (4)"), gbc);

        gbc.gridx = 0;
        gbc.gridy = 3;
        gbc.gridwidth = 5;
        ui.add(new JButton("1,3 (5)"), gbc);

        gbc.gridx = 5;
        gbc.gridwidth = 2;
        ui.add(new JButton("2,3 (2)"), gbc);

        gbc.gridx = 7;
        ui.add(new JButton("3,3 (2)"), gbc);

        gbc.gridx = 9;
        ui.add(new JButton("4,3 (2)"), gbc);

        gbc.gridx = 11;
        ui.add(new JButton("5,3 (2)"), gbc);

        gbc.gridx = 13;
        ui.add(new JButton("6,3 (2)"), gbc);

        gbc.gridx = 15;
        ui.add(new JButton("7,3 (2)"), gbc);

        gbc.gridx = 17;
        ui.add(new JButton("8,3 (2)"), gbc);

        gbc.gridx = 19;
        gbc.gridwidth = 3;
        ui.add(new JButton("9,3 (3)"), gbc);

        gbc.gridx = 0;
        gbc.gridy = 4;
        gbc.gridwidth = 3;
        ui.add(new JButton("1,4 (3)"), gbc);

        gbc.gridx = 3;
        ui.add(new JButton("2,4 (3)"), gbc);

        gbc.gridx = 6;
        gbc.gridwidth = 10;
        ui.add(new JButton("3,4 (10)"), gbc);

        gbc.gridx = 16;
        gbc.gridwidth = 3;
        ui.add(new JButton("4,4 (3)"), gbc);

        gbc.gridx = 19;
        ui.add(new JButton("5,4 (3)"), gbc);

        gbc.gridx = 0;
        gbc.gridy = 4;
        gbc.gridwidth = 1;
    }

    public JComponent getUI() {
        return ui;
    }

    public static void main(String[] args) {
        Runnable r = new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(
                            UIManager.getSystemLookAndFeelClassName());
                } catch (Exception useDefault) {
                }
                for (int ii = 0; ii < 2; ii++) {
                    KeyBoardLayout o = new KeyBoardLayout(ii==0);

                    JFrame f = new JFrame("Keyboard Layout");
                    f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
                    f.setLocationByPlatform(true);

                    f.setContentPane(o.getUI());
                    f.pack();
                    f.setMinimumSize(f.getSize());

                    f.setVisible(true);
                }
            }
        };
        SwingUtilities.invokeLater(r);
    }
}

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