BoxLayout ignores setYAlighment

Question

Here is the function:

/** * Creates an instance of a JLabel with the given arguments * @param text The text to be displayed on the Label * @param font The font of the label * @param bold set to true if you want the label text to be bold * @param fontSize The size of the font to be rendered * @param alignment An alignment (Eg CENTER_ALIGNMENT) * @param verticleAlignment an optional argument to allow one to choose the Y alignment * **/ public JLabel createLabel(String text, String font, boolean bold, int fontSize, float alignment, float...verticleAlignment){ JLabel label = new JLabel(text); label.setFont(new Font(font, bold ? Font.BOLD : Font.PLAIN, fontSize)); label.setAlignmentX(alignment); if(verticleAlignment.length > 0){ label.setAlignmentY(verticleAlignment[0]); } return label; } 

For some reason, no matter what I enter in varArg verticleAlignment, does it really not apply?

 add(createLabel("ChatBytes™ - Do not steal.", "Arial", false, 12, CENTER_ALIGNMENT, BOTTOM_ALIGNMENT)); 

Can anyone see the reason why it is ignoring the setYAlignment part of my function?

Answer 1

using

  add(Box.createVerticalGlue()); 

to create a vertical space that pushes the component to the bottom of the JFrame

Answer 2

As an alternative, consider a nested layout . In the example below, the corresponding label is added to the SOUTH a BorderLayout , by default for JFrame , and the extra sheet for your login panel is added to CENTER . Examine the resizing behavior of each approach for suitability.

Addendum: I hope [to find out] why setAlignmentY() ignored.

As stated in How to use BoxLayout features: Box layout options : "When BoxLayout exposes components from top to bottom, ... any extra space appears at the bottom of the container." This explains your initial observation and correction.

In the API, note that setAlignmentX() "Sets the vertical alignment" and setAlignmentY() "Sets the horizontal alignment". In this context, vertical means the vertical axis of the layout from top to bottom, for example BoxLayout.Y_AXIS , and horizontal means the horizontal axis of the layout from left to right, for example BoxLayout.X_AXIS . In How to use BoxLayout: troubleshooting alignment problems , BoxAlignmentDemo contrasts two. In the diagram from left to right, shown in the figure below, setAlignmentY() used to adjust the vertical position relative to the horizontal layout axis. At the top, such as yours, setAlignmentY() just doesn't work.

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 import java.awt.BorderLayout; import java.awt.EventQueue; import java.awt.Font; import javax.swing.Box; import javax.swing.BoxLayout; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.border.EmptyBorder; /** @see https://stackoverflow.com/a/18805146/230513 */ public class Test { private void display() { JFrame f = new JFrame("Test"); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); f.add(createLogin(), BorderLayout.CENTER); JLabel admonition = new JLabel("ChatBytes™—Do not steal.", JLabel.CENTER); f.add(admonition, BorderLayout.SOUTH); f.pack(); f.setLocationRelativeTo(null); f.setVisible(true); } private static JPanel createLogin() { JPanel p = new JPanel(); p.setLayout(new BoxLayout(p, BoxLayout.Y_AXIS)); JLabel label = new JLabel("Existing CHATBYTES login panel."); label.setFont(label.getFont().deriveFont(Font.ITALIC, 24f)); label.setAlignmentX(0.5f); label.setBorder(new EmptyBorder(0, 20, 0, 20)); p.add(Box.createVerticalStrut(36)); p.add(label); p.add(Box.createVerticalStrut(144)); return p; } public static void main(String[] args) { EventQueue.invokeLater(new Runnable() { @Override public void run() { new Test().display(); } }); } }