CODEWITHSUNDEEP
javaswingjcombobox
iXô
iXô

Reputation: 1181

Hide the button of a JComboBox if is !enabled

I would like to extends JComboBox class no change something, I want the new component to hide the selection button when the combobox is disabled.

I can't find where this button is created

EDIT : so far I am using this code :

@Override
public void setEnabled(boolean b)
{
    super.setEnabled(b);

    Component[] comps = getComponents();
    for(Component comp : comps)
    {
        if(comp instanceof MetalComboBoxButton)
        {
            final MetalComboBoxButton dropDownButton = (MetalComboBoxButton) comp;
            dropDownButton.setVisible(b);
            break;
        }
    }
}

EDIT 2 : I was unable to do what I want finally, as if I switch to Nimbus PLAF, even if I hide the button the background is drawn, so only the arrow is hidded, everything else is still there.

I will have to do with a JPanel.

Upvotes: 3

Views: 5188

Answers (3)

Jarek Przygódzki
Jarek Przygódzki

Reputation: 4412

You may have trouble finding it because you're looking in wrong place - try javax.swing.plaf.basic.BasicComboBoxUI.installComponents() and javax.swing.plaf.basic.BasicComboBoxUI.configureArrowButton()

Upvotes: 0

kleopatra
kleopatra

Reputation: 51535

technically, you can subclass the JComboBox and either remove/add the button (as shown by @flash) or toggle its visibility

    final JComboBox box = new JComboBox(new Object[] {1, 2, 3}) {

        /** 
         * @inherited <p>
         */
        @Override
        public void setEnabled(boolean b) {
            if (b == isEnabled()) return;
            for (Component child : getComponents()) {
                if (child instanceof JButton) {
                    child.setVisible(b);
                    break;
                }
            }
            super.setEnabled(b);
        }

    };

You might want to reconsider the requirement, though, because it is non-standard ui behaviour - and as such might confuse users

Upvotes: 4

flash
flash

Reputation: 6820

You could use something like this:

public class CustomCombo extends JComboBox {

@Override
public void setEnabled(boolean enabled) {
    super.setEnabled(enabled);
    if(!enabled) {
        removeArrowButton();
    }
    else {
        addArrowButton();         
    }
}

private void removeArrowButton() {
    Component[] comp = this.getComponents();
    Component removeComponent = null;
    for (int i = 0; i < comp.length; i++) {
        if(comp[i] instanceof JButton) {
            removeComponent = comp[i];
        }
    }
    if(removeComponent != null) {
        this.remove(removeComponent);
    }
}
}

This will remove the arrow button when you call customCombo.setEnabled(false).

The method addArrowButton() is left up to you. This should just give you an idea.

Upvotes: 0

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