Question

我正在寻找一个Swing组件，它是滚动窗口/视口的扩展，允许打开并导航到当前显示的内容的概述。我确信我在过去的monthes（几年？）中看过一些博客文章，显示了这样一个组件但是找不到组件了。

这是我正在寻找的图片：

scrollpane with overview

如果您记得这样的帖子，或者您的书签中有链接，我会感谢您分享信息。

感谢您的帮助。

Answer 1

这是一个工作示例，但您需要java-image-scaling库（其LGPL） - 它用于平滑缩放预览图像，否则您将获得完全破坏的图像：

public static void main ( String[] args )
{
    final JFrame mainFrame = new JFrame ();

    JPanel content = new JPanel ( new GridLayout ( 20, 20 ) );
    for ( int i = 0; i < 20; i++ )
    {
        for ( int j = 0; j < 20; j++ )
        {
            content.add ( new JLabel ( "Test " + i + ":" + j )
            {
                {
                    setBorder ( BorderFactory.createEmptyBorder ( 20, 20, 20, 20 ) );
                }
            } );
        }
    }

    final JScrollPane pane = new JScrollPane ( content );
    pane.setCorner ( JScrollPane.LOWER_TRAILING_CORNER, new JButton ()
    {
        {
            final JButton button = this;
            addActionListener ( new ActionListener ()
            {
                public void actionPerformed ( ActionEvent e )
                {
                    JComponent comp = ( JComponent ) pane.getViewport ().getView ();
                    Dimension size = comp.getSize ();
                    Rectangle viewRect = comp.getVisibleRect ();

                    // Drawing preview
                    BufferedImage image = new BufferedImage ( size.width, size.height,
                            BufferedImage.TYPE_INT_RGB );
                    Graphics2D g2d = image.createGraphics ();
                    comp.print ( g2d );
                    g2d.dispose ();

                    // Rescaling preview
                    int width = 200;
                    int height = comp.getHeight () * width / comp.getHeight ();
                    BufferedImage rescaled =
                            new ResampleOp ( width, height ).filter ( image, null );

                    // Drawing view rect
                    float diff = (float)width / size.width;
                    g2d = rescaled.createGraphics ();
                    g2d.setPaint ( Color.RED );
                    g2d.drawRect ( Math.round ( viewRect.x * diff ),
                            Math.round ( viewRect.y * diff ),
                            Math.round ( viewRect.width * diff ),
                            Math.round ( viewRect.height * diff ) );
                    g2d.dispose ();

                    // Displaying preview
                    final JDialog preview = new JDialog ( mainFrame );
                    preview.setUndecorated ( true );
                    preview.add ( new JLabel ( new ImageIcon ( rescaled ) )
                    {
                        {
                            setBorder ( BorderFactory.createLineBorder ( Color.BLACK ) );
                            setFocusable ( true );
                        }
                    } );
                    Point los = button.getLocationOnScreen ();
                    preview.setSize ( width + 2, height + 2 );
                    preview.setLocation ( los.x - width - 2, los.y - height - 2 );
                    preview.setVisible ( true );

                    preview.requestFocus ();
                    preview.addFocusListener ( new FocusAdapter ()
                    {
                        public void focusLost ( FocusEvent e )
                        {
                            preview.dispose ();
                        }
                    } );
                }
            } );
        }
    } );
    mainFrame.add ( pane );

    mainFrame.setSize ( 600, 600 );
    mainFrame.setLocationRelativeTo ( null );
    mainFrame.setDefaultCloseOperation ( JFrame.EXIT_ON_CLOSE );
    mainFrame.setVisible ( true );
}

所以基本上我创建了一个面板的快照，重新缩放它并放入按钮附近打开的小对话框，关闭焦点丢失。创建快照可能会浪费时间，但我不知道有什么更好的方法来创建整个滚动窗格容器的渲染预览 - 你必须将它绘制到某些东西上以显示预览，这意味着它将花费相同的时间。

此外，您可以轻松修改预览组件，以便通过拖动预览对话框上的RED矩形来移动可见的矩形：）

Answer 2

可以并且JComponent(s)到

1）GlassPane

2）JLayer (Java7)基于JXLayer（Java6）

3）JViewport

4）Translucent JDialog

的定位

Answer 3

Jide-OSS中有CornerScroller。

http://java.net/projects/jide-oss/sources/svn/content/trunk/src/com/jidesoft/swing/CornerScroller.java

Scrollpane / Viewport swing组件显示概述

3 个答案: