Layout Manager and Positioning

你说的曾经没有我的故事 提交于 2019-12-01 17:34:55

how to stick JLabel in GlassPane to rellative, floating coordinates from JProgressBar without using ComponentListener or another listener

My idea would be to wrap the two components in a container with the OverlayLayout and "play" with AlignementX/AlignementY for the relative coordinates. Then just put the wrapping container in the original hierarchy. (See my SSCCE below)

is there built_in notifiers in Standard LayoutManagers that can notify about its internal state, and can be accesible for override, instead my attempt with ComponentListener and NullLayout

There is no such contract in the LayoutManager API, hence you can't rely safely on any such mechanism. Moreover, you will face issues with standard LayoutManager because they will take your extra JLabel into account in the layout.

Imagine you use FlowLayout and you put 1 component, then your extra JLabel, then another component. When you move the extra JLabel the last component will remain "away" from the first component and you will see a gap between these two.

If this last issue is not a problem, you could simply extend FlowLayout (or any other LayoutManager), override layoutContainer and place the extra JLabel wherever you would like.

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();
    }
}
易学教程内所有资源均来自网络或用户发布的内容,如有违反法律规定的内容欢迎反馈
该文章没有解决你所遇到的问题?点击提问,说说你的问题,让更多的人一起探讨吧!