Tabs in fixed positions in JTabbedPane or on a single line

Question

In our application with JTabbedPane with unlimited tabs, when the width of the tabs exceeds the width of the tabbed panel, the tabs begin to wrap on several lines. When you then click on a tab in one of the top lines, the full line goes down and to the front. For users who click between multiple tabs, this is very confusing since it is not possible to track the order of the tabs.

How can I - attach tabs to fixed positions, bringing their contents to the front (although this will optically distort the tab metaphor, I don’t care), or - limit the number of lines to one (so that the tabs become very narrow, rather than wrapping)?

Answer 1

Really quick and dirty (definitely needs improvements and changes), but I would suggest something like this might work for you (but this is not JTabbePane):

import java.awt.BorderLayout; import java.awt.Component; import java.awt.Container; import java.awt.Dimension; import java.awt.FlowLayout; import java.awt.Insets; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.util.ArrayList; import java.util.List; import javax.swing.JButton; import javax.swing.JComponent; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.SwingUtilities; public class Test { /** * FlowLayout subclass that fully supports wrapping of components. */ public static class WrapLayout extends FlowLayout { private Dimension preferredLayoutSize; /** * Constructs a new <code>WrapLayout</code> with a left alignment and a * default 5-unit horizontal and vertical gap. */ public WrapLayout() { super(); } /** * Constructs a new <code>FlowLayout</code> with the specified alignment * and a default 5-unit horizontal and vertical gap. The value of the * alignment argument must be one of <code>WrapLayout</code>, * <code>WrapLayout</code>, or <code>WrapLayout</code>. * * @param align * the alignment value */ public WrapLayout(int align) { super(align); } /** * Creates a new flow layout manager with the indicated alignment and * the indicated horizontal and vertical gaps. * <p> * The value of the alignment argument must be one of * <code>WrapLayout</code>, <code>WrapLayout</code>, or * <code>WrapLayout</code>. * * @param align * the alignment value * @param hgap * the horizontal gap between components * @param vgap * the vertical gap between components */ public WrapLayout(int align, int hgap, int vgap) { super(align, hgap, vgap); } /** * Returns the preferred dimensions for this layout given the * <i>visible</i> components in the specified target container. * * @param target * the component which needs to be laid out * @return the preferred dimensions to lay out the subcomponents of the * specified container */ @Override public Dimension preferredLayoutSize(Container target) { return layoutSize(target, true); } /** * Returns the minimum dimensions needed to layout the <i>visible</i> * components contained in the specified target container. * * @param target * the component which needs to be laid out * @return the minimum dimensions to lay out the subcomponents of the * specified container */ @Override public Dimension minimumLayoutSize(Container target) { Dimension minimum = layoutSize(target, false); minimum.width -= getHgap() + 1; return minimum; } /** * Returns the minimum or preferred dimension needed to layout the * target container. * * @param target * target to get layout size for * @param preferred * should preferred size be calculated * @return the dimension to layout the target container */ private Dimension layoutSize(Container target, boolean preferred) { synchronized (target.getTreeLock()) { // Each row must fit with the width allocated to the containter. // When the container width = 0, the preferred width of the // container // has not yet been calculated so lets ask for the maximum. int targetWidth = target.getSize().width; if (targetWidth == 0) { targetWidth = Integer.MAX_VALUE; } int hgap = getHgap(); int vgap = getVgap(); Insets insets = target.getInsets(); int horizontalInsetsAndGap = insets.left + insets.right + hgap * 2; int maxWidth = targetWidth - horizontalInsetsAndGap; // Fit components into the allowed width Dimension dim = new Dimension(0, 0); int rowWidth = 0; int rowHeight = 0; int nmembers = target.getComponentCount(); for (int i = 0; i < nmembers; i++) { Component m = target.getComponent(i); if (m.isVisible()) { Dimension d = preferred ? m.getPreferredSize() : m.getMinimumSize(); // Can't add the component to current row. Start a new // row. if (rowWidth + d.width > maxWidth) { addRow(dim, rowWidth, rowHeight); rowWidth = 0; rowHeight = 0; } // Add a horizontal gap for all components after the // first if (rowWidth != 0) { rowWidth += hgap; } rowWidth += d.width; rowHeight = Math.max(rowHeight, d.height); } } addRow(dim, rowWidth, rowHeight); dim.width += horizontalInsetsAndGap; dim.height += insets.top + insets.bottom + vgap * 2; // When using a scroll pane or the DecoratedLookAndFeel we need // to // make sure the preferred size is less than the size of the // target containter so shrinking the container size works // correctly. Removing the horizontal gap is an easy way to do // this. Container scrollPane = SwingUtilities.getAncestorOfClass(JScrollPane.class, target); if (scrollPane != null) { dim.width -= hgap + 1; } return dim; } } /* * A new row has been completed. Use the dimensions of this row * to update the preferred size for the container. * * @param dim update the width and height when appropriate * @param rowWidth the width of the row to add * @param rowHeight the height of the row to add */ private void addRow(Dimension dim, int rowWidth, int rowHeight) { dim.width = Math.max(dim.width, rowWidth); if (dim.height > 0) { dim.height += getVgap(); } dim.height += rowHeight; } } public static class MyTabbedPane extends JPanel { private JPanel buttonPanel; private JPanel currentview; private Tab currentTab; private class Tab { String name; JComponent component; } private List<Tab> tabs = new ArrayList<Tab>(); public MyTabbedPane() { super(new BorderLayout()); buttonPanel = new JPanel(new WrapLayout()); currentview = new JPanel(); add(buttonPanel, BorderLayout.NORTH); add(currentview); } public void addTab(String name, JComponent tabView, int index) { if (index < 0 || index > tabs.size()) { throw new IllegalArgumentException("Index out of bounds"); } final Tab tab = new Tab(); tab.component = tabView; tab.name = name; tabs.add(index, tab); JButton b = new JButton(name); b.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e) { setCurrentTab(tab); } }); buttonPanel.add(b, index); buttonPanel.validate(); } public void removeTab(int i) { Tab tab = tabs.remove(i); if (tab == currentTab) { if (tabs.size() > 0) { if (i < tabs.size()) { setCurrentTab(tabs.get(i)); } else { setCurrentTab(tabs.get(i - 1)); } } else { setCurrentTab(null); } } buttonPanel.remove(index); } void setCurrentTab(final Tab tab) { if (currentTab == tab) { return; } if (currentTab != null) { currentview.remove(currentTab.component); } if (tab != null) { currentview.add(tab.component); } currentTab = tab; currentview.validate(); } } public static void main(String[] args) { JFrame frame = new JFrame(); MyTabbedPane tabbedPane = new MyTabbedPane(); for (int i = 0; i < 100; i++) { tabbedPane.addTab("Button " + (i + 1), new JLabel("Dummy Label " + (i + 1)), i); } frame.add(tabbedPane); frame.pack(); frame.setSize(new Dimension(1000, 800)); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); } } 

WrapLayout was taken from another post in SO.