java - 如何使用 MigLayout 将内容集中在多个面板上？

Question

我有一个大面板，其中包含 3 个较小的面板(locationPanel、usagePanel、structuralAspectsPanel)。

每个较小的面板上都有一些 JLabels 和 JCheckBoxes。我继续将组件集中在每个面板上，但是如何才能将它们集中在所有 3 个面板上呢？ (请看中间的黑线)

我尝试在 MigLayout 中使用单元格布局选项(new JLabel("Label here"), "cell 0 0")，但无法创建相同大小的动态间隙，以便所有组件都居中。使用 gap 200 (180, 300, ...) 将组件“推”到视觉中心似乎可行，但我想避免使用绝对定位/间隙，因为它们可能很容易损坏.

我附上了我的问题的图片:

这是我的源代码:

public class RiskAssessmentPage extends JPanel {
  JPanel riskAssessmentPanel = new JPanel();

  JPanel locationPanel = new JPanel();
  JPanel usagePanel = new JPanel();
  JPanel structuralAspectsPanel = new JPanel();

  public RiskAssessmentPage() {
    setLayout(new MigLayout(""));
    riskAssessmentPanel.setLayout(
        new MigLayout("wrap", "[grow, fill]", "[grow, fill, push][grow, fill, push][grow, fill, push]"));

    locationPanel.setLayout(new MigLayout("gap rel 2", "[grow, center][grow, left]"));
    locationPanel.setBorder(BorderFactory.createTitledBorder("Location"));

    usagePanel.setLayout(new MigLayout("gap rel 2", "[grow, center][grow, left]"));
    usagePanel.setBorder(BorderFactory.createTitledBorder("Usage"));

    structuralAspectsPanel.setLayout(new MigLayout("gap rel 2", "[grow, center][grow, left]"));
    structuralAspectsPanel.setBorder(BorderFactory.createTitledBorder("Structural Aspects"));

    locationPanel.add(new JLabel("This is the first of all labels"));
    locationPanel.add(new JCheckBox("Checkbox with Label"), "wrap");
    locationPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    locationPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    locationPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    locationPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    locationPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    locationPanel.add(new JSeparator(), "growx, span");
    locationPanel.add(new JLabel("Second Label"));
    locationPanel.add(new JCheckBox("Checkbox with Label"), "wrap");
    locationPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    locationPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    locationPanel.add(new JSeparator(), "growx, span");
    locationPanel.add(new JLabel("This Label is fairly large and long and pushes the text around"));
    locationPanel.add(new JCheckBox("Checkbox with Label"), "wrap");
    locationPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    locationPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");

    usagePanel.add(new JLabel("A label in the usage panel"));
    usagePanel.add(new JCheckBox("Checkbox with Label"), "wrap");
    usagePanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    usagePanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    usagePanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    usagePanel.add(new JSeparator(), "growx, span");
    usagePanel.add(new JLabel("And another one and another one and another one"));
    usagePanel.add(new JCheckBox("Checkbox with Label"), "wrap");
    usagePanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    usagePanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    usagePanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    usagePanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    usagePanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    usagePanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");

    structuralAspectsPanel.add(new JLabel("Label here"));
    structuralAspectsPanel.add(new JCheckBox("Checkbox with Label"), "wrap");
    structuralAspectsPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    structuralAspectsPanel.add(new JSeparator(), "growx, span");
    structuralAspectsPanel.add(new JLabel("I am so uncreative with label names..."));
    structuralAspectsPanel.add(new JCheckBox("Checkbox with Label"), "wrap");
    structuralAspectsPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    structuralAspectsPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    structuralAspectsPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    structuralAspectsPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    structuralAspectsPanel.add(new JSeparator(), "growx, span");
    structuralAspectsPanel.add(new JLabel("Thats it. I give up with naming them."));
    structuralAspectsPanel.add(new JCheckBox("Checkbox with Label"), "wrap");
    structuralAspectsPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
    structuralAspectsPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");

    riskAssessmentPanel.add(locationPanel);
    riskAssessmentPanel.add(usagePanel);
    riskAssessmentPanel.add(structuralAspectsPanel);

    add(riskAssessmentPanel, "grow, push");
  }
}

Answer 1

为了使面板列对齐，您需要将它们设置为相同的大小。在 MigLayout 中，您可以通过将第一列的首选大小和增长率设置为与所有列相同的值来实现此目的。面板。例如

panel1.new MigLayout("", //Unchanged Layout Constraints
        "[:500, grow, center][grow, left]", //Column Constraints
        ""); //Unchanged Row Constraints

panel2.new MigLayout("", //Unchanged Layout Constraints
        "[:500, grow, center][grow, left]", //Column Constraints
        ""); //Unchanged Row Constraints

在此示例中，panel1 和 panel2 的第一列的首选大小均设置为 500，并且增长设置为其默认值，因此这也是一样。

可以在此处查看所描述内容的工作示例

import java.awt.*;
import javax.swing.*;
import net.miginfocom.swing.MigLayout;

public class MigLay extends JFrame {

    private MigLay() {
        super("Button Layout");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLayout(new MigLayout("wrap", //Layout Constraints
        "grow, fill", //Column Constraints
        "grow, fill")); //Row Constraints
        createPanels();
        pack();
        setMinimumSize(getSize()); //Sets minimum size to the preferred size. Remove or change this line if you do not want that to happen
        setVisible(true);
    }

    private void createPanels() {

        JPanel locationPanel = new JPanel();
        JPanel usagePanel = new JPanel();
        JPanel structuralAspectsPanel = new JPanel();

        //JLabels for font metrics
        JLabel one = new JLabel("This is the first of all labels");
        JLabel two = new JLabel("Second Label");
        JLabel three = new JLabel("This Label is fairly large and long and pushes the text around");
        JLabel four = new JLabel("A label in the usage panel");
        JLabel five = new JLabel("And another one and another one and another one");

        //Font Metrics
        FontMetrics metrics = three.getFontMetrics(three.getFont()); //Take longest label manually or dynamically (You will have to add that code)
        int width = metrics.stringWidth(three.getText());

        locationPanel.setLayout(new MigLayout("gap rel 2", "[:" + width + ", grow, center][grow, left]"));
        locationPanel.setBorder(BorderFactory.createTitledBorder("Location"));

        usagePanel.setLayout(new MigLayout("gap rel 2", "[:" + width + ", grow, center][grow, left]"));
        usagePanel.setBorder(BorderFactory.createTitledBorder("Usage"));

        locationPanel.add(one);
        locationPanel.add(new JCheckBox("Checkbox with Label"), "wrap");
        locationPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
        locationPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
        locationPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
        locationPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
        locationPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
        locationPanel.add(new JSeparator(), "growx, span");
        locationPanel.add(two);
        locationPanel.add(new JCheckBox("Checkbox with Label"), "wrap");
        locationPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
        locationPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
        locationPanel.add(new JSeparator(), "growx, span");
        locationPanel.add(three);
        locationPanel.add(new JCheckBox("Checkbox with Label"), "wrap");
        locationPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
        locationPanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");

        usagePanel.add(four);
        usagePanel.add(new JCheckBox("Checkbox with Label"), "wrap");
        usagePanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
        usagePanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
        usagePanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
        usagePanel.add(new JSeparator(), "growx, span");
        usagePanel.add(five);
        usagePanel.add(new JCheckBox("Checkbox with Label"), "wrap");
        usagePanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
        usagePanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
        usagePanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
        usagePanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
        usagePanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");
        usagePanel.add(new JCheckBox("Checkbox with Label"), "skip, wrap");

        getContentPane().add(locationPanel);
        getContentPane().add(usagePanel);
    }

    public static void main(String[] args) {
        new MigLay();
    }
}