如何在JColorChooser中增加样本的大小？

Question

The size of color palette in JColorChooser/Swatches is very small, also the colors looks similar around a palette.

For my use I need to increase their size as well change the color variation. How to do this?

Answer 1

The size of the "swatches" is controlled by two UI properties, so you can adjust it as needed (default value being 10):

int length = 20;
UIManager.put("ColorChooser.swatchesRecentSwatchSize", new Dimension(length, length));
UIManager.put("ColorChooser.swatchesSwatchSize", new Dimension(length, length));

Customizing the palette itself requires a custom subclass of AbstractColorChooserPanel, mainly a c&p job (because it's package private) of DefaultSwatchChooserPanel in javx.swing.colorchooser. Then replace the default with your custom panel, something along the lines

JColorChooser chooser = new JColorChooser();
List<AbstractColorChooserPanel> choosers = 
        new ArrayList<>(Arrays.asList(chooser.getChooserPanels()));
choosers.remove(0);
MySwatchChooserPanel swatch = new MySwatchChooserPanel();
choosers.add(0, swatch);
chooser.setChooserPanels(choosers.toArray(new AbstractColorChooserPanel[0]));

Answer 2

• [JColorChooser][1] is compound JComponent

• you can to display/use only desired part of JColorChooser

• for easier workaround to use SwingUtils by @Darryl Burke

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.colorchooser.AbstractColorChooserPanel;
import javax.swing.event.*;
import javax.swing.plaf.metal.MetalComboBoxIcon;

public class DropDownComponent2 {

    private JWindow _window;
    private boolean _windowShouldBeShown = false;
    private JComponent _component;
    private AbstractButton _button;
    private JFrame _ownerFrame;

    public DropDownComponent2(JFrame ownerFrame, JComponent component, AbstractButton button) {
        _ownerFrame = ownerFrame;
        _component = component;
        _button = button;
        _button.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                _window.setVisible(false);
                Point pt = _button.getLocationOnScreen();
                pt.translate(0, _button.getHeight());
                _window.setLocation(pt);
                showWindow();
                _windowShouldBeShown = true;
                Window[] wins = Window.getWindows();
                System.out.println(wins.length);
            }
        });
        _button.addAncestorListener(new AncestorListener() {
            @Override
            public void ancestorAdded(AncestorEvent event) {
                _window.setVisible(false);
            }

            @Override
            public void ancestorRemoved(AncestorEvent event) {
                _window.setVisible(false);
            }

            @Override
            public void ancestorMoved(AncestorEvent event) {
                if (event.getSource() != _window) {
                    System.out.println("Ansestor moved");
                    _window.setVisible(false);
                }
            }
        });
        Toolkit.getDefaultToolkit().addAWTEventListener(
                new AWTEventListener() {
                    @Override
                    public void eventDispatched(AWTEvent event) {
                        if (event.getID() == MouseEvent.MOUSE_CLICKED) {
                            if (!_window.getBounds().contains(MouseInfo.getPointerInfo().getLocation())) {
                                if (_windowShouldBeShown) {
                                    _windowShouldBeShown = false;
                                } else {
                                    _window.setVisible(false);
                                }
                            }
                        }
                    }
                }, AWTEvent.MOUSE_EVENT_MASK);
        _window = new JWindow(_ownerFrame);
        _window.getContentPane().add(component);
        _window.addWindowFocusListener(new WindowAdapter() {
            @Override
            public void windowLostFocus(WindowEvent evt) {
                System.out.println("window lost focus");
                _window.setVisible(false);
            }
        });
        _window.pack();
    }

    private Rectangle getScreenRect() {
        return new Rectangle(java.awt.Toolkit.getDefaultToolkit().getScreenSize());
    }

    public void showWindow() {
        Rectangle screenRect = getScreenRect();
        Rectangle windowRect = _window.getBounds();
        int sx1 = screenRect.x;
        int sx2 = screenRect.x + screenRect.width;
        int sy1 = screenRect.y;
        int sy2 = screenRect.y + screenRect.height;
        int wx1 = windowRect.x;
        int wx2 = windowRect.x + windowRect.width;
        int wy1 = windowRect.y;
        int wy2 = windowRect.y + windowRect.height;
        if (wx2 > sx2) {
            _window.setLocation(wx1 - (wx2 - sx2), _window.getY());
        }
        if (wx1 < sx1) {
            _window.setLocation(0, _window.getY());
        }
        if (wy2 > sy2) {
            _window.setLocation(_window.getX(), wy1 - (wy2 - wy1));
        }
        if (wy2 < sy1) {
            _window.setLocation(_window.getX(), 0);
        }
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                _window.setVisible(true);
            }
        });
    }

    public void hideWindow() {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                _window.setVisible(false);
            }
        });
    }
}

class DropDownFrame extends JFrame {

    private static final long serialVersionUID = 1L;
    private JButton _button;
    private JColorChooser _colorChooser;
    private DropDownComponent2 _dropDown;
    private JWindow _window;

    public DropDownFrame() {
        _colorChooser = new JColorChooser();
        _colorChooser.setPreviewPanel(new JPanel());
        _colorChooser.setColor(Color.RED);
        // Remove panels other than Swatches
        AbstractColorChooserPanel[] panels = _colorChooser.getChooserPanels();
        for (int i = 0; i < panels.length; i++) {
            if (!panels[i].getDisplayName().equals("Swatches")) {
                _colorChooser.removeChooserPanel(panels[i]);
            } else {
                JPanel panel = panels[i];
                System.out.println(panel.getComponentCount()); // 1
                System.out.println(panel.getPreferredSize()); //width=424,height=112
                System.out.println(panel.getLayout()); //FlowLayout[hgap=5,vgap=5,align=center]
            }
        }
        _colorChooser.getSelectionModel().addChangeListener(new ChangeListener() {
            @Override // ### I think the key point is there
            public void stateChanged(ChangeEvent e) {
                _button.setForeground(_colorChooser.getColor());
                _dropDown.hideWindow();
            }
        });
        _button = new JButton("Show JWindow");
        _button.setIcon(new MetalComboBoxIcon());
        _button.setHorizontalTextPosition(SwingConstants.LEFT);
        this.getContentPane().add(_button);
        _dropDown = new DropDownComponent2(DropDownFrame.this, _colorChooser, _button);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pack();
        setVisible(true);
    }

    public static void main(String args[]) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                DropDownFrame dropDownFrame = new DropDownFrame();
            }
        });
    }
}