的GridBagLayout - 意外增加/改变和间距

Question

所以，我有一个面板（含JTextAreas）之间的间距变化的一个问题，当我添加面板，请参阅本picture。 ：d

例

当按下一个按钮，在第一时间addTextArea()被调用。状况1 - >状态2的图片。而问题是，panel_buttons不接近新增WorkDescription（JTextArea）。而当按钮被按下多次，它们之间的间距变化。

按钮之前做了一个大的跳跃，但是， c.weighty = 0.1 - 0.3跳较小。

// The panel is placed in the center of a JFrame (BorderLayout)
public CONSTRUCTOR {

    JPanel panel = new JPanel(new GridBagLayout());
    GridBagConstraints c = new GridBagConstraints();
    // ...
    c.anchor = GridBagConstraints.NORTHWEST;
    c.gridx = 0;
    c.gridy = 0;
    c.weightx = 1;
    c.weighty = 1;
    c.gridwidth = 1;
    c.gridheight = 1;
    // this is how everything looks at (first pic) start.
    panel.add(panel_buttons, c);   // panel_buttons is at the right place
}

增加了一个新的WorkDescription，即JTextArea的方法：

public void addTextArea() {

    WorkDescription wd = new WorkDescription(); //WorkDescription extends JPanel

    panel.remove(panel_buttons); 
    c.weighty = 0.25;       // I've messed around with the weighty alot.
                            // 0.2-0.25 makes the panel_buttons do the least amout of 'down-jump'
    panel.add(wd, c);

    if(c.gridy < 3 ) {
        c.gridy ++;
        c.weighty = 1;

        panel.add(panel_buttons, c);
    }
    panel.revalidate();
    panel.repaint();
}

Answer 1

我找到了最好的解决办法是，

从GridBagLayout切换到GridLayout。

private JPanel panel_Center = new JPanel(new GridLayout(5,1)); 

然后，当然，删除所有GridBagConstraints

public void addTextArea() {

    WorkDescription wd = new WorkDescription();

    panel.remove(panel_buttons); 
    panel.add(wd);

    if(addedWorks < 4 ) {       

        addedWorks++;
        panel.add(panel_buttons);

    }

    panel.revalidate();
    panel.repaint();
}