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POCustom painting of JPanel
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copied!<p>I'm not very good at this and I hope to get some help from people who understands the issue a lot more that I do. </p> <p>So here's the deal. In my application there is background JPanel with Image drawn over it. Then there is a small JPanel which I'm trying to create custom painting for. I wanted to have JPanel with rounded corners and semi-transparent background so I modified paintComponent method to fill semi-transparent rounded rectangle. But when I place components inside like say JComboBox, the list of items appears and I click somewhere else to close it JPanel paints itself in original way making it semitransparent all around but with small rectangle painted with original grey background color. I see that it has to do something with invoking paintComponent on its parrent or paintChildren but I don't know how to organize those methods or where to put them. I also have proble with transparent colors overlaping each other.</p> <p>Here is an example source code:</p> <pre><code>public class RoundedPanel extends JPanel { private final int radius; public RoundedPanel(int cornerRadius) { radius=cornerRadius; } public void paintComponent(Graphics g) { Color bg = getBackground(); g.setColor(new Color(bg.getRed(),bg.getGreen(),bg.getBlue(),40)); g.fillRoundRect(0,0, getWidth()-1, getHeight()-1, radius, radius); g.setColor(new Color(0,0,0,70)); g.drawRoundRect(0,0, getWidth()-1, getHeight()-1, radius, radius); } public static void main(String[] args) { JFrame frame = new JFrame(); frame.setSize(400, 300); frame.setLocation(400, 300); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JPanel content = new JPanel(); JPanel wl = new JPanel(); JPanel el = new JPanel(); JPanel sl = new JPanel(); JPanel nl = new JPanel(); RoundedPanel rp = new RoundedPanel(50); JComboBox combobox = new JComboBox(); frame.setContentPane(content); content.setBackground(Color.red); content.setLayout(new BorderLayout()); wl.add(new JButton("west")); el.add(new JButton("east")); sl.add(new JButton("south")); nl.add(new JButton("north")); content.add(wl,BorderLayout.WEST); content.add(el,BorderLayout.EAST); content.add(nl,BorderLayout.NORTH); content.add(sl,BorderLayout.SOUTH); content.add(rp,BorderLayout.CENTER); rp.setBackground(Color.BLACK); combobox.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "Třída 1.B", "Třída 1.C", "Třída 2.C" })); rp.add(combobox); frame.setVisible(true); } } </code></pre> <p>I hope some of will help me out :-) thanks</p> <p>EDIT: I found out that JComboBox (and its pop-up menu) draws correctly if pop-up menu overlaps outside the JPanel that contains JComboBox and has the custom paintComponent method.</p>

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