JSplitPane中间的Divider的外观

    通常我们改变一个SWING的外观有两种方法,一种是UIManager.put("","");就可以了.但是这里的主键必须是已经有的.如:

UIManager.put("ProgressBarUI","com.test.MyProgressBarUI");

另一种是设置ComponentUI,

如:

JProgressBar jpb;

jpb.setUI(new MyProgressBarUI());

即可 

   下面我们来改写一下JSplitPane的UI.当我们调用setUI时提示的类是"SplitPaneUI",这个类是个抽象类,我们查看它的子类,它有BasicSplitPaneUI, MultiSplitPaneUI ,前者是SplitPaneUI 的基本 L&F 实现,后者是用于组合 SplitPaneUI 的多路 UI.所以我们重写前者.我们查看这个类的源码.可以看到,它主要有两个JButton,和一个Divider.

所以重点重写下面三个函数.

    public BasicSplitPaneDivider createDefaultDivider() {}

    protected JButton createLeftOneTouchButton() {}

    protected JButton createRightOneTouchButton() { }

重写成我们想要的效果就可以了.

下面是个人修改之后的效果

 

UI源码如下:

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package com.lgh.mail.components;

import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Cursor;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Insets;
import java.awt.LayoutManager;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JSplitPane;
import javax.swing.UIManager;
import javax.swing.border.Border;
import javax.swing.plaf.ComponentUI;
import javax.swing.plaf.basic.BasicSplitPaneDivider;
import javax.swing.plaf.basic.BasicSplitPaneUI;
import sun.swing.DefaultLookup;

/**
 *
 * @author lgh
 */
public class SearchSplitPaneUI extends BasicSplitPaneUI {

    private static final Color BG_COLOR = Color.BLACK;
    private static final SearchSplitPaneUI cornerButtonUI = new SearchSplitPaneUI();

    public SearchSplitPaneUI() {
        super();
    }

    public static ComponentUI createUI(JComponent c) {

        return new SearchSplitPaneUI();
    }

    @Override
    public void paint(Graphics g, JComponent c) {
        super.paint(g, c);
        g.setColor(Color.BLACK);
        int width = c.getWidth();
        int height = c.getHeight();
        g.drawRect(3, 3, width - 6, height - 6);
    }

    /**
     * Creates the default divider.
     */
    @Override
    public BasicSplitPaneDivider createDefaultDivider() {
        return new MyBasicSplitPaneDivider(this);
    }

    private class MyBasicSplitPaneDivider extends BasicSplitPaneDivider {

        private int oneTouchSize,  oneTouchOffset;
        boolean centerOneTouchButtons;
        //center空白区域
        private int x1,  y1;

        @SuppressWarnings("unchecked")
        public MyBasicSplitPaneDivider(SearchSplitPaneUI ui) {
            super(ui);
//            oneTouchSize = DefaultLookup.getInt(ui.getSplitPane(), ui,
//                    "SplitPane.oneTouchButtonSize", ONE_TOUCH_SIZE);
//            oneTouchOffset = DefaultLookup.getInt(ui.getSplitPane(), ui,
//                    "SplitPane.oneTouchButtonOffset", ONE_TOUCH_OFFSET);
//            centerOneTouchButtons = DefaultLookup.getBoolean(ui.getSplitPane(),
//                    ui, "SplitPane.centerOneTouchButtons", true);
            oneTouchSize = ONE_TOUCH_SIZE;
            oneTouchOffset = ONE_TOUCH_OFFSET;
            centerOneTouchButtons = true;

            setLayout(new DividerLayout());
            setBasicSplitPaneUI(ui);
            orientation = splitPane.getOrientation();
            setCursor((orientation == JSplitPane.HORIZONTAL_SPLIT) ? Cursor.getPredefinedCursor(Cursor.E_RESIZE_CURSOR) : Cursor.getPredefinedCursor(Cursor.S_RESIZE_CURSOR));
            setBackground(UIManager.getColor("SplitPane.background"));


        //            super(ui);
//            this.setBackground(BG_COLOR);
//            this.setPreferredSize(getSize());
        }

        private void revalidate() {
            invalidate();
            if (splitPane != null) {
                splitPane.revalidate();
            }
        }

        /**
         * Creates and return an instance of JButton that can be used to
         * collapse the right component in the split pane.
         */
        @Override
        protected JButton createRightOneTouchButton() {
            JButton b = new JButton() {

                public void setBorder(Border border) {
                }

                @Override
                public void paint(Graphics g) {
                    if (splitPane != null) {
                        int[] xs = new int[3];
                        int[] ys = new int[3];
                        int blockSize;

                        // Fill the background first ...
                        g.setColor(Color.WHITE);
                        g.fillRect(0, 0, this.getWidth(),
                                this.getHeight());

                        // ... then draw the arrow.
                        if (orientation == JSplitPane.VERTICAL_SPLIT) {
                            blockSize = Math.min(getHeight(), oneTouchSize);
                            xs[0] = blockSize;
                            xs[1] = blockSize << 1;
                            xs[2] = 0;
                            ys[0] = blockSize;
                            ys[1] = ys[2] = 0;
                        } else {
                            blockSize = Math.min(getWidth(), oneTouchSize);
                            xs[0] = xs[2] = 0;
                            xs[1] = blockSize;
                            ys[0] = 0;
                            ys[1] = blockSize;
                            ys[2] = blockSize << 1;
                        }
                        g.setColor(BG_COLOR);
                        g.fillPolygon(xs, ys, 3);
                    }
                }
                // Don't want the button to participate in focus traversable.

                public boolean isFocusTraversable() {
                    return false;
                }
            };
            b.setMinimumSize(new Dimension(oneTouchSize, oneTouchSize));
            b.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
            b.setFocusPainted(false);
            b.setBorderPainted(false);
            b.setRequestFocusEnabled(false);
            return b;
        }

        /**
         * Creates and return an instance of JButton that can be used to
         * collapse the left component in the split pane.
         */
        protected JButton createLeftOneTouchButton() {
            JButton b = new JButton() {

                public void setBorder(Border b) {
                }

                public void paint(Graphics g) {
                    if (splitPane != null) {
                        int[] xs = new int[3];
                        int[] ys = new int[3];
                        int blockSize;

                        // Fill the background first ...
                        g.setColor(Color.WHITE);
                        g.fillRect(0, 0, this.getWidth(),
                                this.getHeight());

                        // ... then draw the arrow.
                        g.setColor(BG_COLOR);
                        if (orientation == JSplitPane.VERTICAL_SPLIT) {
                            blockSize = Math.min(getHeight(), oneTouchSize);
                            xs[0] = blockSize;
                            xs[1] = 0;
                            xs[2] = blockSize << 1;
                            ys[0] = 0;
                            ys[1] = ys[2] = blockSize;
                            g.drawPolygon(xs, ys, 3); // Little trick to make the
                        // arrows of equal size
                        } else {
                            blockSize = Math.min(getWidth(), oneTouchSize);
                            xs[0] = xs[2] = blockSize;
                            xs[1] = 0;
                            ys[0] = 0;
                            ys[1] = blockSize;
                            ys[2] = blockSize << 1;
                        }
                        g.fillPolygon(xs, ys, 3);
                    }
                }
                // Don't want the button to participate in focus traversable.

                public boolean isFocusTraversable() {
                    return false;
                }
            };
            b.setMinimumSize(new Dimension(oneTouchSize, oneTouchSize));
            b.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
            b.setFocusPainted(false);
            b.setBorderPainted(false);
            b.setRequestFocusEnabled(false);
            return b;
        }

        @Override
        public void paint(Graphics g) {
            super.paint(g);
            Dimension size = getSize();
            g.setColor(BG_COLOR);
            g.fillRect(1, 1, size.width - 1, size.height - 1);
            g.setColor(Color.GRAY);
            g.drawRect(0, 0, size.width, size.height);
            g.setColor(Color.WHITE);
            //分为水平时跟垂直时,白色区域
            if (orientation == JSplitPane.VERTICAL_SPLIT) {
                g.fillRect(x1, 1, 30, size.height - 1);
            } else {
                g.fillRect(1, y1, size.width - 1, 30);
            }
            if (leftButton != null) {
                leftButton.repaint();
            }
            if (rightButton != null) {
                rightButton.repaint();
            }
        }

        /**
         * Used to layout a <code>BasicSplitPaneDivider</code>.
         * Layout for the divider
         * involves appropriately moving the left/right buttons around.
         * <p>
         */
        protected class DividerLayout implements LayoutManager {

            public void layoutContainer(Container c) {
                if (leftButton != null && rightButton != null) {
                    if (splitPane.isOneTouchExpandable()) {
                        Insets insets = getInsets();

                        if (orientation == JSplitPane.VERTICAL_SPLIT) {
                            int extraX = (insets != null) ? insets.left : 0;
                            int blockSize = getHeight();

                            if (insets != null) {
                                blockSize -= (insets.top + insets.bottom);
                                blockSize = Math.max(blockSize, 0);
                            }
                            blockSize = Math.min(blockSize, oneTouchSize);

                            int y = (c.getSize().height - blockSize) / 2;

                            if (!centerOneTouchButtons) {
                                y = (insets != null) ? insets.top : 0;
                                extraX = 0;
                            }
                            int width = (int) MyBasicSplitPaneDivider.this.getSize().getWidth();
                            x1 = width / 2 - oneTouchSize;
                            leftButton.setBounds(extraX - oneTouchOffset + width / 2, y,
                                    blockSize * 2, blockSize);
                            rightButton.setBounds(extraX - oneTouchOffset +
                                    oneTouchSize * 2 + width / 2, y,
                                    blockSize * 2, blockSize);
                        } else {
                            int extraY = (insets != null) ? insets.top : 0;
                            int blockSize = getWidth();
                            if (insets != null) {
                                blockSize -= (insets.left + insets.right);
                                blockSize = Math.max(blockSize, 0);
                            }
                            blockSize = Math.min(blockSize, oneTouchSize);

                            int x = (c.getSize().width - blockSize) / 2;

                            if (!centerOneTouchButtons) {
                                x = (insets != null) ? insets.left : 0;
                                extraY = 0;
                            }
                            int height = (int) MyBasicSplitPaneDivider.this.getSize().getHeight();
                            y1 = height / 2 - oneTouchSize;
                            leftButton.setBounds(x, extraY - oneTouchOffset + height / 2,
                                    blockSize, blockSize * 2);
                            rightButton.setBounds(x, extraY - oneTouchOffset +
                                    oneTouchSize * 2 + height / 2, blockSize,
                                    blockSize * 2);
                        }
                    } else {
                        leftButton.setBounds(-5, -5, 1, 1);
                        rightButton.setBounds(-5, -5, 1, 1);
                    }
                }
            }

            public Dimension minimumLayoutSize(Container c) {
                // NOTE: This isn't really used, refer to
                // BasicSplitPaneDivider.getPreferredSize for the reason.
                // I leave it in hopes of having this used at some point.
                if (splitPane == null) {
                    return new Dimension(0, 0);
                }
                Dimension buttonMinSize = null;

                if (splitPane.isOneTouchExpandable() && leftButton != null) {
                    buttonMinSize = leftButton.getMinimumSize();
                }

                Insets insets = getInsets();
                int width = getDividerSize();
                int height = width;

                if (orientation == JSplitPane.VERTICAL_SPLIT) {
                    if (buttonMinSize != null) {
                        int size = buttonMinSize.height;
                        if (insets != null) {
                            size += insets.top + insets.bottom;
                        }
                        height = Math.max(height, size);
                    }
                    width = 1;
                } else {
                    if (buttonMinSize != null) {
                        int size = buttonMinSize.width;
                        if (insets != null) {
                            size += insets.left + insets.right;
                        }
                        width = Math.max(width, size);
                    }
                    height = 1;
                }
                return new Dimension(width, height);
            }

            public Dimension preferredLayoutSize(Container c) {
                return minimumLayoutSize(c);
            }

            public void removeLayoutComponent(Component c) {
            }

            public void addLayoutComponent(String string, Component c) {
            }
        } // End of class BasicSplitPaneDivider.DividerLayout
    }
}