JTabbedPane: tab location set to LEFT, but the icons are not aligned

Question

I have JTabbedPanewith a tab setting set to LEFT. The problem is that the icons on each tab are not vertically aligned with each other.

Consider this image:

As you can see, the “Editar Protocolo” icon (second tab) does not quite match the “Distribuir Protocolo” icon (first tab), and this also happens with other tabs. I want all the icons to be vertically aligned to the left.

This is the code I use to install the tab components:

...
jtabbedPane.setTabComponentAt(1, configurarJtabbedPane("Editar Protocolo", iconEditarProtocolo));
...

public JLabel configurarJtabbedPane(String title, ImageIcon icon) {
    JLabel l = new JLabel(title);
    l.setIcon(icon);
    l.setIconTextGap(5);
    l.setHorizontalTextPosition(SwingConstants.RIGHT);
    return l;
}

The code is extracted from this Q & A: JTabbedPane: symbol on the left side of the tabs .

Answer 1

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• WindowsLookAndFeel
• WindowsClassicLookAndFeel
• NimbusLookAndFeel
• MetalLookAndFeel
• SeaglassLookAndFeel

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import java.awt.Component;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import javax.swing.Icon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;
import javax.swing.SwingConstants;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;

public class Demo {

    private void createAndShowGUI() {

        JXTabbedPane tabbedPane = new JXTabbedPane(JTabbedPane.LEFT);
        AbstractTabRenderer renderer = (AbstractTabRenderer)tabbedPane.getTabRenderer();
        renderer.setPrototypeText("This text is a prototype");
        renderer.setHorizontalTextAlignment(SwingConstants.LEADING);

        tabbedPane.addTab("Short", UIManager.getIcon("OptionPane.informationIcon"), createEmptyPanel(), "Information tool tip");
        tabbedPane.addTab("Long text", UIManager.getIcon("OptionPane.warningIcon"), createEmptyPanel(), "Warning tool tip");
        tabbedPane.addTab("This is a really long text", UIManager.getIcon("OptionPane.errorIcon"), createEmptyPanel(), "Error tool tip");

        JFrame frame = new JFrame("Demo");
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        frame.add(tabbedPane);
        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);

    }

    private JPanel createEmptyPanel() {
        JPanel dummyPanel = new JPanel() {

            @Override
            public Dimension getPreferredSize() {
                return isPreferredSizeSet() ?
                            super.getPreferredSize() : new Dimension(400, 300);
            }

        };
        return dummyPanel;
    }

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

    class JXTabbedPane extends JTabbedPane {

        private ITabRenderer tabRenderer = new DefaultTabRenderer();

        public JXTabbedPane() {
            super();
        }

        public JXTabbedPane(int tabPlacement) {
            super(tabPlacement);
        }

        public JXTabbedPane(int tabPlacement, int tabLayoutPolicy) {
            super(tabPlacement, tabLayoutPolicy);
        }

        public ITabRenderer getTabRenderer() {
            return tabRenderer;
        }

        public void setTabRenderer(ITabRenderer tabRenderer) {
            this.tabRenderer = tabRenderer;
        }

        @Override
        public void addTab(String title, Component component) {
            this.addTab(title, null, component, null);
        }

        @Override
        public void addTab(String title, Icon icon, Component component) {
            this.addTab(title, icon, component, null);
        }

        @Override
        public void addTab(String title, Icon icon, Component component, String tip) {
            super.addTab(title, icon, component, tip);
            int tabIndex = getTabCount() - 1;
            Component tab = tabRenderer.getTabRendererComponent(this, title, icon, tabIndex);
            super.setTabComponentAt(tabIndex, tab);
        }
    }

    interface ITabRenderer {

        public Component getTabRendererComponent(JTabbedPane tabbedPane, String text, Icon icon, int tabIndex);

    }

    abstract class AbstractTabRenderer implements ITabRenderer {

        private String prototypeText = "";
        private Icon prototypeIcon = UIManager.getIcon("OptionPane.informationIcon");
        private int horizontalTextAlignment = SwingConstants.CENTER;
        private final PropertyChangeSupport propertyChangeSupport = new PropertyChangeSupport(this);

        public AbstractTabRenderer() {
            super();
        }

        public void setPrototypeText(String text) {
            String oldText = this.prototypeText;
            this.prototypeText = text;
            firePropertyChange("prototypeText", oldText, text);
        }

        public String getPrototypeText() {
            return prototypeText;
        }

        public Icon getPrototypeIcon() {
            return prototypeIcon;
        }

        public void setPrototypeIcon(Icon icon) {
            Icon oldIcon = this.prototypeIcon;
            this.prototypeIcon = icon;
            firePropertyChange("prototypeIcon", oldIcon, icon);
        }

        public int getHorizontalTextAlignment() {
            return horizontalTextAlignment;
        }

        public void setHorizontalTextAlignment(int horizontalTextAlignment) {
            this.horizontalTextAlignment = horizontalTextAlignment;
        }

        public PropertyChangeListener[] getPropertyChangeListeners() {
            return propertyChangeSupport.getPropertyChangeListeners();
        }

        public PropertyChangeListener[] getPropertyChangeListeners(String propertyName) {
            return propertyChangeSupport.getPropertyChangeListeners(propertyName);
        }

        public void addPropertyChangeListener(PropertyChangeListener listener) {
            propertyChangeSupport.addPropertyChangeListener(listener);
        }

        public void addPropertyChangeListener(String propertyName, PropertyChangeListener listener) {
            propertyChangeSupport.addPropertyChangeListener(propertyName, listener);
        }

        protected void firePropertyChange(String propertyName, Object oldValue, Object newValue) {
            PropertyChangeListener[] listeners = getPropertyChangeListeners();
            for (int i = listeners.length - 1; i >= 0; i--) {
                listeners[i].propertyChange(new PropertyChangeEvent(this, propertyName, oldValue, newValue));
            }
        }
    }

    class DefaultTabRenderer extends AbstractTabRenderer implements PropertyChangeListener {

        private Component prototypeComponent;

        public DefaultTabRenderer() {
            super();
            prototypeComponent = generateRendererComponent(getPrototypeText(), getPrototypeIcon(), getHorizontalTextAlignment());
            addPropertyChangeListener(this);
        }

        private Component generateRendererComponent(String text, Icon icon, int horizontalTabTextAlignmen) {
            JPanel rendererComponent = new JPanel(new GridBagLayout());
            rendererComponent.setOpaque(false);

            GridBagConstraints c = new GridBagConstraints();
            c.insets = new Insets(2, 4, 2, 4);
            c.fill = GridBagConstraints.HORIZONTAL;
            rendererComponent.add(new JLabel(icon), c);

            c.gridx = 1;
            c.weightx = 1;
            rendererComponent.add(new JLabel(text, horizontalTabTextAlignmen), c);

            return rendererComponent;
        }

        @Override
        public Component getTabRendererComponent(JTabbedPane tabbedPane, String text, Icon icon, int tabIndex) {
            Component rendererComponent = generateRendererComponent(text, icon, getHorizontalTextAlignment());
            int prototypeWidth = prototypeComponent.getPreferredSize().width;
            int prototypeHeight = prototypeComponent.getPreferredSize().height;
            rendererComponent.setPreferredSize(new Dimension(prototypeWidth, prototypeHeight));
            return rendererComponent;
        }

        @Override
        public void propertyChange(PropertyChangeEvent evt) {
            String propertyName = evt.getPropertyName();
            if ("prototypeText".equals(propertyName) || "prototypeIcon".equals(propertyName)) {
                this.prototypeComponent = generateRendererComponent(getPrototypeText(), getPrototypeIcon(), getHorizontalTextAlignment());
            }
        }
    }
}

MetalLookAndFeel

NimbusLookAndFeel

SeaglassLookAndFeel

WindowsLookAndFeel

Answer 2

, . TabComponentsDemo , , , ButtonTabComponent , FlowLayout FlowLayout.LEFT. .

Answer 3

HTML:

final String PRE_HTML = "<html><p style=\"text-align: left; width: 230px\">"; 
final String POST_HTML = "</p></html>"; 

tabbedpane.setTitleAt(0, PRE_HTML + "your title" + POST_HTML);
tabbedpane.setTitleAt(2, PRE_HTML + "your title 2" + POST_HTML);

Answer 4

what I did was add a component (in this case JPanel) for the tab. I needed to add a flag to the tabs, so instead of a flag, you can add the icon manually.

here is my code:

private JPanel makeTabPanel(JCheckBox checkBox) {
    String title = checkBox.getText();
    checkBox.setText("");
    JPanel pane = new JPanel();
    pane.setLayout(new BoxLayout(pane, BoxLayout.LINE_AXIS));
    pane.add(checkBox);
    pane.add(new JLabel(title, SwingUtilities.LEFT));
    pane.setMinimumSize(new Dimension(150, 25));
    pane.setPreferredSize(new Dimension(180, 25));
    pane.setMaximumSize(new Dimension(220, 25));
    return pane;
    }
     //then I call it with
    tabbed.setTabComponentAt(0, makeTabPanel(checkIncluderesume));

I know that it’s not a good practice to add size to panels, but this is the easiest way I could find. Results:

sample