问题描述

In our application that has a JTabbedPane with unlimited tabs, when the width of the tabs exceeds the tabbed pane's width, the tabs start wrapping into several rows.然后，当您单击上面一行中的一个选项卡时，整个行会下降到前台.对于在多个选项卡之间单击的用户来说，这是非常令人困惑的，因为无法跟踪选项卡顺序.

In our application that has a JTabbedPane with unlimited tabs, when the width of the tabs exceeds the tabbed pane's width, the tabs start wrapping into several rows. When you then click on a tab in one of the upper rows, the complete row comes down and to the foreground. For users who click around between several tabs, it's highly confusing as it's not possible to keep track of the tab order.

我该怎么做- 将选项卡固定到固定位置，同时将它们的内容放在前面(尽管这会在视觉上破坏选项卡的隐喻，但我不在乎)，或者- 将行数限制为一(这样标签会变得非常窄而不是环绕)?

How can I either - nail the tabs to fixed positions while bringing their contents to the front (though this would optically corrupt the tab metaphor but I don't care), or - limit the number of rows to one (so the tabs get very narrow instead of wrapping)?

推荐答案

真的又快又脏(肯定需要改进和改变)，但我想这样的东西可以为你工作(但不是 JTabbePane):

Really quick and dirty (definitely needs improvements and changes), but I would imagine that something like that could work for you (but is not a 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 取自 SO 上的另一篇文章.

The WrapLayout was taken from another post on SO.

这篇关于JTabbedPane 或一行中固定位置的选项卡的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持跟版网！