JScrollPane setHorizo​​ntalScrollBarPolicy as_needed而无需调整内容大小 [英] JScrollPane setHorizontalScrollBarPolicy as_needed without resizing content

问题描述

我注意到setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED)在添加滚动条时会调整高度内容的大小的问题(由于内容超出了宽度).

I noticed an issue with the setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED) resizes the height content when the scrollbar gets added (due to the content going over the width).

代码...

import javax.swing.*;
import javax.swing.border.Border;
import java.awt.*;

public class TestGui extends JFrame {
    //**************************************************************************************
    //************************************* Constructor ************************************
    //**************************************************************************************
    private TestGui() {
        add(createTopScrollPane(), BorderLayout.NORTH);
        add(createCenterScrollPane(), BorderLayout.CENTER);

        setSize(800,600);
        setVisible(true);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    //**************************************************************************************
    //*********************************** Support Method ***********************************
    //**************************************************************************************
    private static GridBagConstraints setGbc(int gridx, int gridy, int gridWidth, int gridHeight, int ipadx, int ipady, String anchorLocation, double weightx, double weighty, Insets insets, boolean fillCell){
        GridBagConstraints gbc = new GridBagConstraints();

        if (anchorLocation.toUpperCase().equals("NORTHWEST")){
            gbc.anchor = GridBagConstraints.NORTHWEST;
        } else if (anchorLocation.toUpperCase().equals("NORTH")){
            gbc.anchor = GridBagConstraints.NORTH;
        } else if (anchorLocation.toUpperCase().equals("NORTHEAST")){
            gbc.anchor = GridBagConstraints.NORTHEAST;
        } else if (anchorLocation.toUpperCase().equals("WEST")){
            gbc.anchor = GridBagConstraints.WEST;
        } else if (anchorLocation.toUpperCase().equals("EAST")){
            gbc.anchor = GridBagConstraints.EAST;
        } else if (anchorLocation.toUpperCase().equals("SOUTHWEST")){
            gbc.anchor = GridBagConstraints.SOUTHWEST;
        } else if (anchorLocation.toUpperCase().equals("SOUTH")){
            gbc.anchor = GridBagConstraints.SOUTH;
        } else if (anchorLocation.toUpperCase().equals("SOUTHEAST")){
            gbc.anchor = GridBagConstraints.SOUTHEAST;
        } else {
            gbc.anchor = GridBagConstraints.CENTER;
        }

        gbc.gridx = gridx; // column
        gbc.gridy = gridy; // row
        gbc.gridwidth = gridWidth; // number of columns
        gbc.gridheight = gridHeight; // number of rows
        gbc.ipadx = ipadx; // width of object
        gbc.ipady = ipady; // height of object
        gbc.weightx = weightx; // shifts columns to side of set anchor
        gbc.weighty = weighty; // shifts rows to side of set anchor
        gbc.insets = insets; // placement inside cell
        if (fillCell){
            gbc.fill = GridBagConstraints.BOTH;
        }

        return gbc;
    }

    //**************************************************************************************
    //************************************ Panel Methods ***********************************
    //**************************************************************************************
    private JPanel createTopFrame() {
        JPanel pnl = new JPanel();

        Border lineBorder = BorderFactory.createMatteBorder(0, 0, 0, 5, Color.BLUE);
        JLabel lineSplitter = new JLabel();
        lineSplitter.setBorder(lineBorder);

        pnl.setLayout(new GridBagLayout());
        pnl.add(new JLabel("XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"),setGbc(0,0, 1,1, 0,0,"CENTER", 0, 0, new Insets(10, 10, 10, 10), false));
        pnl.add(new JLabel("XXXXXXXXXXXXXXXXXXXXXXXXXXXXX"),setGbc(0,1, 1,1, 0,0,"CENTER", 0, 0, new Insets(10, 10, 10, 10), false));
        pnl.add(lineSplitter, setGbc(1,0,1,2,0,0,"CENTER",0,0,new Insets(0,0,0,0),true));
        pnl.add(new JLabel("XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"),setGbc(2,0, 1,1, 0,0,"CENTER", 0, 0, new Insets(10, 10, 10, 10), false));
        pnl.add(new JLabel("XXXXXXXXXXXXXXXXXXXXXXXXXXXXX"),setGbc(2,1, 1,1, 0,0,"CENTER", 0, 0, new Insets(10, 10, 10, 10), false));

        return pnl;
    }

    private JScrollPane createTopScrollPane(){
        JScrollPane scrollPane = new JScrollPane();
        Border raisedBevel = BorderFactory.createRaisedBevelBorder();
        Border lineBorder = BorderFactory.createMatteBorder(2, 2, 2, 2, new Color(224,224,224));
        Border loweredBevel = BorderFactory.createLoweredBevelBorder();
        Border compoundSetup = BorderFactory.createCompoundBorder(raisedBevel, lineBorder);
        Border compoundFinal = BorderFactory.createCompoundBorder(compoundSetup, loweredBevel);

        //scrollPane.setPreferredSize(new Dimension(0, 160));
        scrollPane.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED);
        scrollPane.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_NEVER);
        scrollPane.setBorder(compoundFinal);
        scrollPane.getViewport().setView(createTopFrame());
        return scrollPane;
    }

    private JScrollPane createCenterScrollPane(){
        JScrollPane scrollPane = new JScrollPane();
        Border raisedBevel = BorderFactory.createRaisedBevelBorder();
        Border lineBorder = BorderFactory.createMatteBorder(2, 2, 2, 2, new Color(224,224,224));
        Border loweredBevel = BorderFactory.createLoweredBevelBorder();
        Border compoundSetup = BorderFactory.createCompoundBorder(raisedBevel, lineBorder);
        Border compoundFinal = BorderFactory.createCompoundBorder(compoundSetup, loweredBevel);

        scrollPane.setBorder(compoundFinal);
        return scrollPane;
    }

    //**************************************************************************************
    //************************************ Start Program ***********************************
    //**************************************************************************************
    public static void main(String[] args) {
        new TestGui();
    }
}

注意:如果我使用setPreferredSize，则会在最大化窗口时增加边框之间的间距，而我不希望这样做.

Note: If I use setPreferredSize, it adds spacing between borders when maximizing the window, and I don't want that.

如您所见，第二行被截断了，是否还有不调整大小的设置(将其设置为HORIZONTAL_SCROLLBAR_ALWAYS除外，如果您最大化窗口，它仍会显示条形)?

As you can see, the 2nd row gets cut off, is there anyway to have it not resize (other than setting it to HORIZONTAL_SCROLLBAR_ALWAYS, which still shows the bar if you maximize the window)?

推荐答案

您需要覆盖滚动窗格的methodd getPreferredSize().另外，当组件更改时，您还需要提供重新验证.

You need to override the methothd getPreferredSize() of your scroll pane. Also you need provide revalidation when component changed.

private TestGui() {
    add(createTopScrollPane(), BorderLayout.NORTH);
    add(createCenterScrollPane(), BorderLayout.CENTER);
    addComponentListener(new ComponentAdapter() {
        @Override
        public void componentResized(ComponentEvent e) {
            SwingUtilities.invokeLater(new Runnable() {

                @Override
                public void run() {
                    revalidate();
                    repaint();
                }
            });
        }
    });

    setSize(800,600);
    setVisible(true);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

// another stuff

private JScrollPane createTopScrollPane(){
    JScrollPane scrollPane = new JScrollPane() {
        @Override
        public Dimension getPreferredSize() {
            Dimension size = super.getPreferredSize();
            if (getHorizontalScrollBar() != null && getHorizontalScrollBar().isVisible()) {
                size.height += getHorizontalScrollBar().getHeight();
            }
            return size;
        }
    };
    Border raisedBevel = BorderFactory.createRaisedBevelBorder();
    Border lineBorder = BorderFactory.createMatteBorder(2, 2, 2, 2, new Color(224,224,224));
    Border loweredBevel = BorderFactory.createLoweredBevelBorder();
    Border compoundSetup = BorderFactory.createCompoundBorder(raisedBevel, lineBorder);
    Border compoundFinal = BorderFactory.createCompoundBorder(compoundSetup, loweredBevel);

    //scrollPane.setPreferredSize(new Dimension(0, 160));
    scrollPane.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED);
    scrollPane.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_NEVER);
    scrollPane.setBorder(compoundFinal);
    scrollPane.getViewport().setView(createTopFrame());
    return scrollPane;
}

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