How to center text and a JComponent in a JTextPane vertically?

Question

Currently it looks so

What to do so that it looks so?

Below is my code:

    JFrame f = new JFrame();
    JTextPane textPane = new JTextPane();

    JTextField component = new JTextField("      ");
    component.setMaximumSize(component.getPreferredSize());
    textPane.setSelectionStart(textPane.getDocument().getLength());
    textPane.setSelectionEnd(textPane.getDocument().getLength());
    textPane.insertComponent(component);
    try {
        textPane.getDocument().insertString(textPane.getDocument().getLength(), "text",
            new SimpleAttributeSet());
    } catch (BadLocationException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    f.add(new JScrollPane(textPane));
    f.setSize(200, 100);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setVisible(true);

The single question which is near to this topic I found: JTextPane insert component, faulty vertical alignment But there is no answer how to change the alignment. But it must be possible according to the discussion there.

Answer 1

You can use this http://java-sl.com/tip_center_vertically.html

It should work with JComponents as well.

You can also override LabelView's getPreferredSpan() adding some space to the bottom.

Alternatively you can try to override RowView inner class in ParagraphView

http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/6-b14/javax/swing/text/ParagraphView.java#ParagraphView.Row

That points to inner class Row extends BoxView

You should replace it with own one. Try to override

public float getAlignment(int axis) 

to return CENTER (0.5). If this does not help override layoutMinorAxis(0 to return proper offsets (shifted).

Answer 2

Define a style for your document with a JLabel and set the vertical aligment on it:

Style s = doc.addStyle("icUf", regular);        
ImageIcon icUf = createImageIcon("uf.png", "Unidad Funcional");
if (icUf != null) {
    JLabel jl = new JLabel(icUf);
    jl.setVerticalAlignment(JLabel.CENTER);
    StyleConstants.setComponent(s, jl);
}

Insert the label:

doc.insertString(doc.getLength(), " ", doc.getStyle("icUf"));

and the text:

doc.insertString(doc.getLength(), " text ", doc.getStyle("bold"));

Answer 3

Based on the answer above (which didn't work for me, but helped me find this), I used:

Style s = doc.addStyle("icUf", regular);        
ImageIcon icUf = createImageIcon("uf.png", "Unidad Funcional");
if (icUf != null) {
    // create label with icon AND text
    JLabel jl = new JLabel("some text",icUf, SwingConstants.LEFT);
    StyleConstants.setComponent(s, jl);
}
doc.insertString(doc.getLength(), " ", doc.getStyle("icUf"))

This properly aligned the text 'some text' and the icon.