Question

如何将GlassPane中的JLabel粘贴到JProgressBar的相对浮动坐标，而不使用ComponentListener或其他侦听器，
标准版面管理器中是否有built_in通知程序可以通知其内部状态，并且可以访问覆盖，而不是使用ComponentListener和NullLayout进行尝试

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关于ComponentListener和NullLayout

的SSCCE

import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.GridBagConstraints;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JProgressBar;
import javax.swing.JRadioButton;
import javax.swing.UIManager;
//http://stackoverflow.com/questions/14560680/jprogressbar-low-values-will-not-be-displayed
public class ProgressSample {

    private JFrame frame = new JFrame("GlassPane instead of JLayer");
    private JLabel label;
    private GridBagConstraints gbc = new GridBagConstraints();
    private JProgressBar progressSeven;

    public ProgressSample() {
        frame.setLayout(new FlowLayout());
        frame.add(new JButton("test"));
        frame.add(new JCheckBox("test"));
        frame.add(new JRadioButton("test"));
        // Nothing is displayed if value is lover that 6
        JProgressBar progressSix = new JProgressBar(0, 100);
        progressSix.setValue(2);
        frame.add(progressSix);
        // but this works value is higher that 6
        progressSeven = new JProgressBar(0, 100);
        progressSeven.addComponentListener(new ComponentAdapter() {
            @Override
            public void componentMoved(ComponentEvent e) {
                label.setBounds(
                        (int) progressSeven.getBounds().getX(),
                        (int) progressSeven.getBounds().getY(),
                        progressSeven.getPreferredSize().width,
                        label.getPreferredSize().height);
            }
        });
        progressSeven.setValue(7);
        frame.add(progressSeven);
        label = new JLabel();
        label.setText("<html>Blablabla, Blablablabla<br>"
                + "Blablabla, Blablablabla<br>"
                + "Blablabla, Blablablabla</html>");
        label.setPreferredSize(new Dimension(
                progressSeven.getPreferredSize().width,
                label.getPreferredSize().height));
        Container glassPane = (Container) frame.getRootPane().getGlassPane();
        glassPane.setVisible(true);
        glassPane.setLayout(null);
        glassPane.add(label, gbc);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        try {
            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        } catch (Exception e) {
            e.printStackTrace();
        }
        ProgressSample dialogTest = new ProgressSample();
    }
}

Answer 1

如何将GlassPane中的JLabel粘贴到相对的浮动坐标上来自JProgressBar而不使用ComponentListener或其他侦听器

我的想法是将两个组件包装在一个容器中，OverlayLayout和“play”用AlignementX / AlignementY作为相对坐标。然后将包装容器放在原始层次结构中。（见下面我的SSCCE）

标准布局管理器中是否有可以通知的内置通知程序关于它的内部状态，并且可以替换为覆盖我尝试使用ComponentListener和NullLayout

LayoutManager API中没有此类合同，因此您无法安全地依赖任何此类机制。此外，您将面临标准LayoutManager的问题，因为它们会在布局中考虑额外的JLabel。

想象一下，您使用FlowLayout并将1个组件，然后是额外的JLabel，然后是另一个组件。当您移动额外的JLabel时，最后一个组件将与第一个组件保持“距离”，您将看到这两个组件之间存在差距。

如果最后一个问题不是问题，您只需延长FlowLayout（或任何其他LayoutManager），覆盖layoutContainer并将额外的JLabel放在任何地方等。

import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.GridBagConstraints;

import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.JRadioButton;
import javax.swing.OverlayLayout;
import javax.swing.UIManager;

//http://stackoverflow.com/questions/14560680/jprogressbar-low-values-will-not-be-displayed
public class ProgressSample {

    private JFrame frame = new JFrame("GlassPane instead of JLayer");
    private JLabel label;
    private GridBagConstraints gbc = new GridBagConstraints();
    private JProgressBar progressSeven;

    public ProgressSample() {
        frame.setLayout(new FlowLayout());
        frame.add(new JButton("test"));
        frame.add(new JCheckBox("test"));
        frame.add(new JRadioButton("test"));
        // Nothing is displayed if value is lover that 6
        JProgressBar progressSix = new JProgressBar(0, 100);
        progressSix.setValue(2);
        frame.add(progressSix);
        JPanel wrappingPanel = new JPanel();
        OverlayLayout mgr = new OverlayLayout(wrappingPanel);
        wrappingPanel.setLayout(mgr);
        progressSeven = new JProgressBar(0, 100);
        progressSeven.setAlignmentX(0.0f);
        progressSeven.setAlignmentY(0.0f);
        frame.add(wrappingPanel);
        label = new JLabel();
        label.setText("<html>Blablabla, Blablablabla<br>" + "Blablabla, Blablablabla<br>" + "Blablabla, Blablablabla</html>");
        label.setAlignmentX(0.0f);
        label.setAlignmentY(0.0f);
        wrappingPanel.add(label);
        wrappingPanel.add(progressSeven);
        Container glassPane = (Container) frame.getRootPane().getGlassPane();
        glassPane.setVisible(true);
        glassPane.setLayout(new FlowLayout());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        try {
            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        } catch (Exception e) {
            e.printStackTrace();
        }
        ProgressSample dialogTest = new ProgressSample();
    }
}

布局管理器和定位

1 个答案: