Question

Using Java and a mouse or keyboard listener, create
an image containing some object whose color can be changed when
some input is received from the keyboard or mouse. If you are
adventurous, you can try inputting a color name from the keyboard
and change the color to the one named in that input.

Answer 1

 import java.awt.*; import javax.accessibility.AccessibleContext; import javax.swing.*; import javax.swing.plaf.basic.BasicComboPopup; public class ComboTest { public JComponent makeUI() { // TEST: // UIManager.put("ComboBox.selectionBackground", Color.GREEN); // UIManager.put("ComboBox.selectionForeground", Color.CYAN); String[] model = {"Male", "Female"}; JComboBox<String> combo1 = new JComboBox<>(model); AccessibleContext ac = combo1.getAccessibleContext(); BasicComboPopup pop = (BasicComboPopup) ac.getAccessibleChild(0); JList list = pop.getList(); list.setSelectionForeground(Color.WHITE); list.setSelectionBackground(Color.ORANGE); // ???: The focus border of the JComboBox is not drawn. JComboBox<String> combo2 = new JComboBox<>(model); combo2.setRenderer(new DefaultListCellRenderer() { @Override public Component getListCellRendererComponent( JList list, Object value, int index, boolean isSelected, boolean hasFocus) { JLabel l = (JLabel) super.getListCellRendererComponent( list, value, index, isSelected, hasFocus); if (isSelected) { l.setForeground(Color.WHITE); l.setBackground(Color.ORANGE); } else { l.setForeground(Color.BLACK); l.setBackground(Color.WHITE); } return l; } }); // // TEST: // JComboBox<String> combo3 = new JComboBox<>(model); // combo3.setRenderer(new DefaultListCellRenderer() { // @Override public Component getListCellRendererComponent( // JList list, Object value, int index, // boolean isSelected, boolean hasFocus) { // list.setSelectionForeground(Color.WHITE); // list.setSelectionBackground(Color.ORANGE); // return super.getListCellRendererComponent( // list, value, index, isSelected, hasFocus); // } // }); JPanel box = new JPanel(new GridLayout(0, 1, 10, 10)); box.add(combo1); box.add(combo2); // box.add(combo3); JPanel p = new JPanel(new BorderLayout()); p.setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20)); p.add(box, BorderLayout.NORTH); return p; } public static void main(String[] args) { EventQueue.invokeLater(() -> { try { UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); // UIManager.setLookAndFeel("javax.swing.plaf.nimbus.NimbusLookAndFeel"); } catch (Exception e) { e.printStackTrace(); } JFrame f = new JFrame(); f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE); f.getContentPane().add(new ComboTest().makeUI()); f.setSize(320, 240); f.setLocationRelativeTo(null); f.setVisible(true); }); } }