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Java JPanel中的JPanel太多（使用GridBagLayout）

java swing

Java JPanel中的JPanel太多（使用GridBagLayout）,java,swing,jpanel,gridbaglayout,Java,Swing,Jpanel,Gridbaglayout,因此，基本上，如果我将JPanels放在使用GridBagLayout的JPanel中，并使用setPreferredSize限制大小，它最终会达到无法容纳所有这些内容的程度，并显示出所附图片中所示的行为： 我正在做一个决定。这只是一个例子来展示我的问题。手风琴的每个部分都可以单独打开，它们的大小可以任意，并且可以动态添加。很容易获得所有单个面板的高度，并将其与总高度进行比较，但如果添加太多，则会显示出我所展示的嘎吱嘎吱的行为。这也会缩小高度，因此更难确定何时发生挤压。我必须缓存高度，并以某种

因此，基本上，如果我将
JPanel
s放在使用
GridBagLayout
的
JPanel
中，并使用
setPreferredSize
限制大小，它最终会达到无法容纳所有这些内容的程度，并显示出所附图片中所示的行为：

我正在做一个决定。这只是一个例子来展示我的问题。手风琴的每个部分都可以单独打开，它们的大小可以任意，并且可以动态添加。很容易获得所有单个面板的高度，并将其与总高度进行比较，但如果添加太多，则会显示出我所展示的嘎吱嘎吱的行为。这也会缩小高度，因此更难确定何时发生挤压。我必须缓存高度，并以某种方式预先计算添加的新零件的高度。最终目标是在添加新面板且没有足够空间放置时删除旧面板

是否有一种简单的方法来确定某个物体在不受约束的情况下的高度，或者有一种受支持的方法来检测何时发生了这种挤压（这样我就可以在它再次上漆之前快速将其变薄）？使
GridBagLayout
的行为与其他一些布局类似，并溢出到而不是压缩的选项也可以工作

代码，例如：

import java.awt.*;
import java.awt.event.*;
import javaisms.out;
import javax.swing.*;

public class FoldDrag extends JLayeredPane {
    public TexturedPanel backingPanel = new TexturedPanel(new GridBagLayout(),"data/gui/grayerbricks.png");
    static JPanel windowbase=new JPanel();
    static JPanel restrictedpanel=new JPanel(new GridBagLayout());

    GridBagConstraints gbc = new GridBagConstraints();

    public FoldDrag() {
        JButton addpan  = new JButton("Add things");
        windowbase.add(addpan);
        windowbase.add(restrictedpanel);
        restrictedpanel.setBackground(Color.red);
        restrictedpanel.setPreferredSize(new Dimension(200,200));
        gbc.weighty=1;
        gbc.weightx=1;
        gbc.gridx=0;
        gbc.gridy=0;
        gbc.gridheight=1;
        gbc.gridwidth=1;
        gbc.fill=GridBagConstraints.HORIZONTAL;
        addpan.addActionListener(new ActionListener() {
            int number=0;
            @Override
            public void actionPerformed(ActionEvent e)
            {
                number++;
                gbc.gridy=number;
                JPanel tmppanel = new JPanel();
                tmppanel.setPreferredSize(new Dimension(100,30));
                if(number%3==0)
                    tmppanel.setBackground(Color.blue);
                if(number%3==1)
                    tmppanel.setBackground(Color.yellow);
                if(number%3==2)
                    tmppanel.setBackground(Color.green);
                restrictedpanel.add(tmppanel,gbc);
                restrictedpanel.validate();
            }
        });
        windowbase.setVisible(true);
    }
    private static void createAndShowUI() {
        JFrame frame = new JFrame("DragLabelOnLayeredPane");
        frame.getContentPane().add(windowbase);
        FoldDrag thedrag=new FoldDrag();
        windowbase.add(thedrag);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setPreferredSize(new Dimension(300,300));
        frame.pack();
        frame.setResizable(true);
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        out.active=true;
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                createAndShowUI();
            }
        });
    }
}
编辑：看来我没有很好地描述我的手风琴版本。这里有一个。

当
面板.getPreferredSize（）.height！=panel.getHeight（）
和
panel.getPreferredSize（）.width！=panel.getWidth（）

您有特定的需求，通过使用它的布局管理器可以更好地满足这些需求。这使您能够控制布局的每一个方面，而无需求助于黑客或“变通方法”，因为这些方法从未真正起作用或产生奇怪的副作用

还有一个可运行的例子

这达到了第十级，创建了一个专门的组件作为每个“折叠”，但这只是从外部降低了API的复杂性，这意味着，您只需要考虑标题和内容，让API的其余部分自行处理

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.awt.Insets;
import java.awt.LayoutManager;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.LineBorder;

public class Test {

    public static void main(String[] args) {
        new Test();
    }

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        private AccordionLayout layout;

        public TestPane() {
            layout = new AccordionLayout();
            setLayout(layout);

            AccordionListener listener = new AccordionListener() {
                @Override
                public void accordionSelected(Component comp) {
                    layout.setExpanded(comp);
                    revalidate();
                    repaint();
                }
            };

            Color colors[] = {Color.RED, Color.BLUE, Color.CYAN, Color.GREEN, Color.MAGENTA, Color.ORANGE, Color.PINK, Color.YELLOW};
            String titles[] = {"Red", "Blue", "Cyan", "Green", "Magenta", "Orange", "Pink", "Yellow"};
            for (int index = 0; index < colors.length; index++) {
                AccordionPanel panel = new AccordionPanel(titles[index], new ContentPane(colors[index]));
                panel.setAccordionListener(listener);
                add(panel);
            }
        }

    }

    public class ContentPane extends JPanel {

        public ContentPane(Color background) {
            setBackground(background);
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(100, 100);
        }

    }

    public interface AccordionListener {

        public void accordionSelected(Component comp);

    }

    public class AccordionPanel extends JPanel {

        private JLabel title;
        private JPanel header;
        private Component content;

        private AccordionListener accordionListener;

        public AccordionPanel() {
            setLayout(new BorderLayout());

            title = new JLabel("Title");

            header = new JPanel(new FlowLayout(FlowLayout.LEADING));
            header.setBackground(Color.GRAY);
            header.setBorder(new LineBorder(Color.BLACK));
            header.add(title);
            add(header, BorderLayout.NORTH);

            header.addMouseListener(new MouseAdapter() {
                @Override
                public void mouseClicked(MouseEvent e) {
                    AccordionListener listener = getAccordionListener();
                    if (listener != null) {
                        listener.accordionSelected(AccordionPanel.this);
                    }
                }
            });
        }

        public AccordionPanel(String title) {
            this();
            setTitle(title);
        }

        public AccordionPanel(String title, Component content) {
            this(title);
            setContentPane(content);
        }

        public void setAccordionListener(AccordionListener accordionListener) {
            this.accordionListener = accordionListener;
        }

        public AccordionListener getAccordionListener() {
            return accordionListener;
        }

        public void setTitle(String text) {
            title.setText(text);
            revalidate();
        }

        public String getText() {
            return title.getText();
        }

        public void setContentPane(Component content) {
            if (this.content != null) {
                remove(this.content);
            }

            this.content = content;
            if (this.content != null) {
                add(this.content);
            }
            revalidate();
        }

        public Component getContent() {
            return content;
        }

        @Override
        public Dimension getMinimumSize() {
            return header.getPreferredSize();
        }

        @Override
        public Dimension getPreferredSize() {
            Dimension size = content != null ? content.getPreferredSize() : super.getPreferredSize();
            Dimension min = getMinimumSize();
            size.width = Math.max(min.width, size.width);
            size.height += min.height;
            return size;
        }

    }

    public class AccordionLayout implements LayoutManager {

        // This "could" be controled by constraints, but that would assume
        // that more then one component could be expanded at a time
        private Component expanded;

        public void setExpanded(Component expanded) {
            this.expanded = expanded;
        }

        public Component getExpanded() {
            return expanded;
        }

        @Override
        public void addLayoutComponent(String name, Component comp) {
        }

        @Override
        public void removeLayoutComponent(Component comp) {
        }

        @Override
        public Dimension preferredLayoutSize(Container parent) {
            Dimension size = minimumLayoutSize(parent);
            if (expanded != null) {
                size.height -= expanded.getMinimumSize().height;
                size.height += expanded.getPreferredSize().height;
            }

            return size;
        }

        @Override
        public Dimension minimumLayoutSize(Container parent) {
            int height = 0;
            int width = 0;
            for (Component comp : parent.getComponents()) {
                width = Math.max(width, comp.getPreferredSize().width);
                height += comp.getMinimumSize().height;
            }
            return new Dimension(width, height);
        }

        @Override
        public void layoutContainer(Container parent) {

            Insets insets = parent.getInsets();
            int availableHeight = parent.getHeight() - (insets.top + insets.bottom);
            int x = insets.left;
            int y = insets.top;

            int maxSize = 0;
            Dimension minSize = minimumLayoutSize(parent);
            if (expanded != null) {
                minSize.height -= expanded.getMinimumSize().height;
                // Try an honour the preferred size the expanded component...
                maxSize = Math.max(expanded.getPreferredSize().height, availableHeight - minSize.height);
            }

            int width = parent.getWidth() - (insets.left + insets.right);
            for (Component comp : parent.getComponents()) {
                if (expanded != comp) {
                    comp.setSize(width, comp.getMinimumSize().height);
                } else {
                    comp.setSize(width, maxSize);
                }
                comp.setLocation(x, y);
                y += comp.getHeight();
            }

        }

    }

}

导入java.awt.BorderLayout；
导入java.awt.Color；
导入java.awt.Component；
导入java.awt.Container；
导入java.awt.Dimension；
导入java.awt.EventQueue；
导入java.awt.FlowLayout；
导入java.awt.Insets；
导入java.awt.LayoutManager；
导入java.awt.event.MouseAdapter；
导入java.awt.event.MouseEvent；
导入javax.swing.JFrame；
导入javax.swing.JLabel；
导入javax.swing.JPanel；
导入javax.swing.UIManager；
导入javax.swing.UnsupportedLookAndFeelException；
导入javax.swing.border.LineBorder；
公开课考试{
公共静态void main（字符串[]args）{
新测试（）；
}
公开考试（）{
invokeLater（新的Runnable（）{
@凌驾
公开募捐{
试一试{
UIManager.setLookAndFeel（UIManager.getSystemLookAndFeelClassName（））；
}catch（ClassNotFoundException |实例化Exception | IllegalacessException |不支持ookandfeelException ex）{
例如printStackTrace（）；
}
JFrame=新JFrame（“测试”）；
frame.setDefaultCloseOperation（JFrame.EXIT_ON_CLOSE）；
frame.add（newtestpane（））；
frame.pack（）；
frame.setLocationRelativeTo（空）；
frame.setVisible（true）；
}
});
}
公共类TestPane扩展了JPanel{
私人手风琴布局；
公共测试窗格（）{
布局=新的AccordionLayout（）；
设置布局（布局）；
AccordionListener=新的AccordionListener（）{
@凌驾
已选择的公共组件（组件组件）{
布局。设置扩展（comp）；
重新验证（）；
重新油漆（）；
}
};
颜色[]={Color.RED，Color.BLUE，Color.CYAN，Color.GREEN，Color.洋红，Color.ORANGE，Color.PINK，Color.YELLOW}；
字符串标题[]={“红色”、“蓝色”、“青色”、“绿色”、“洋红”、“橙色”、“粉色”、“黄色”}；
对于（int index=0；indeximport java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.awt.Insets;
import java.awt.LayoutManager;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.LineBorder;

public class Test {

    public static void main(String[] args) {
        new Test();
    }

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        private AccordionLayout layout;

        public TestPane() {
            layout = new AccordionLayout();
            setLayout(layout);

            AccordionListener listener = new AccordionListener() {
                @Override
                public void accordionSelected(Component comp) {
                    layout.setExpanded(comp);
                    revalidate();
                    repaint();
                }
            };

            Color colors[] = {Color.RED, Color.BLUE, Color.CYAN, Color.GREEN, Color.MAGENTA, Color.ORANGE, Color.PINK, Color.YELLOW};
            String titles[] = {"Red", "Blue", "Cyan", "Green", "Magenta", "Orange", "Pink", "Yellow"};
            for (int index = 0; index < colors.length; index++) {
                AccordionPanel panel = new AccordionPanel(titles[index], new ContentPane(colors[index]));
                panel.setAccordionListener(listener);
                add(panel);
            }
        }

    }

    public class ContentPane extends JPanel {

        public ContentPane(Color background) {
            setBackground(background);
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(100, 100);
        }

    }

    public interface AccordionListener {

        public void accordionSelected(Component comp);

    }

    public class AccordionPanel extends JPanel {

        private JLabel title;
        private JPanel header;
        private Component content;

        private AccordionListener accordionListener;

        public AccordionPanel() {
            setLayout(new BorderLayout());

            title = new JLabel("Title");

            header = new JPanel(new FlowLayout(FlowLayout.LEADING));
            header.setBackground(Color.GRAY);
            header.setBorder(new LineBorder(Color.BLACK));
            header.add(title);
            add(header, BorderLayout.NORTH);

            header.addMouseListener(new MouseAdapter() {
                @Override
                public void mouseClicked(MouseEvent e) {
                    AccordionListener listener = getAccordionListener();
                    if (listener != null) {
                        listener.accordionSelected(AccordionPanel.this);
                    }
                }
            });
        }

        public AccordionPanel(String title) {
            this();
            setTitle(title);
        }

        public AccordionPanel(String title, Component content) {
            this(title);
            setContentPane(content);
        }

        public void setAccordionListener(AccordionListener accordionListener) {
            this.accordionListener = accordionListener;
        }

        public AccordionListener getAccordionListener() {
            return accordionListener;
        }

        public void setTitle(String text) {
            title.setText(text);
            revalidate();
        }

        public String getText() {
            return title.getText();
        }

        public void setContentPane(Component content) {
            if (this.content != null) {
                remove(this.content);
            }

            this.content = content;
            if (this.content != null) {
                add(this.content);
            }
            revalidate();
        }

        public Component getContent() {
            return content;
        }

        @Override
        public Dimension getMinimumSize() {
            return header.getPreferredSize();
        }

        @Override
        public Dimension getPreferredSize() {
            Dimension size = content != null ? content.getPreferredSize() : super.getPreferredSize();
            Dimension min = getMinimumSize();
            size.width = Math.max(min.width, size.width);
            size.height += min.height;
            return size;
        }

    }

    public class AccordionLayout implements LayoutManager {

        // This "could" be controled by constraints, but that would assume
        // that more then one component could be expanded at a time
        private Component expanded;

        public void setExpanded(Component expanded) {
            this.expanded = expanded;
        }

        public Component getExpanded() {
            return expanded;
        }

        @Override
        public void addLayoutComponent(String name, Component comp) {
        }

        @Override
        public void removeLayoutComponent(Component comp) {
        }

        @Override
        public Dimension preferredLayoutSize(Container parent) {
            Dimension size = minimumLayoutSize(parent);
            if (expanded != null) {
                size.height -= expanded.getMinimumSize().height;
                size.height += expanded.getPreferredSize().height;
            }

            return size;
        }

        @Override
        public Dimension minimumLayoutSize(Container parent) {
            int height = 0;
            int width = 0;
            for (Component comp : parent.getComponents()) {
                width = Math.max(width, comp.getPreferredSize().width);
                height += comp.getMinimumSize().height;
            }
            return new Dimension(width, height);
        }

        @Override
        public void layoutContainer(Container parent) {

            Insets insets = parent.getInsets();
            int availableHeight = parent.getHeight() - (insets.top + insets.bottom);
            int x = insets.left;
            int y = insets.top;

            int maxSize = 0;
            Dimension minSize = minimumLayoutSize(parent);
            if (expanded != null) {
                minSize.height -= expanded.getMinimumSize().height;
                // Try an honour the preferred size the expanded component...
                maxSize = Math.max(expanded.getPreferredSize().height, availableHeight - minSize.height);
            }

            int width = parent.getWidth() - (insets.left + insets.right);
            for (Component comp : parent.getComponents()) {
                if (expanded != comp) {
                    comp.setSize(width, comp.getMinimumSize().height);
                } else {
                    comp.setSize(width, maxSize);
                }
                comp.setLocation(x, y);
                y += comp.getHeight();
            }

        }

    }

}

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class ExpandingPanel extends JPanel
{
    private JPanel expanding;

    public ExpandingPanel(String text, Color color)
    {
        setLayout( new BorderLayout() );

        JButton button = new JButton( text );
        add(button, BorderLayout.NORTH);

        expanding = new JPanel();
        expanding.setBackground( color );
        expanding.setVisible( false );
        add(expanding, BorderLayout.CENTER);

        button.addActionListener( new ActionListener()
        {
            @Override
            public void actionPerformed(ActionEvent e)
            {
                expanding.setVisible( !expanding.isVisible() );

                Container parent = ExpandingPanel.this.getParent();
                LayoutManager2 layout = (LayoutManager2)parent.getLayout();

                if (expanding.isVisible())
                    layout.addLayoutComponent(ExpandingPanel.this, new Float(1));
                else
                    layout.addLayoutComponent(ExpandingPanel.this, null);

                revalidate();
                repaint();
            }
        });
    }

    private static void createAndShowGUI()
    {
        RelativeLayout rl = new RelativeLayout(RelativeLayout.Y_AXIS);
        rl.setFill( true );

        JPanel content = new JPanel( rl );
        content.add( new ExpandingPanel("Red", Color.RED) );
        content.add( new ExpandingPanel("Blue", Color.BLUE) );
        content.add( new ExpandingPanel("Green", Color.GREEN) );

        JFrame frame = new JFrame("Expanding Panel");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add( content);
        frame.setLocationByPlatform( true );
        frame.setSize(200, 300);
        frame.setVisible( true );
    }

    public static void main(String[] args)
    {
        EventQueue.invokeLater(new Runnable()
        {
            public void run()
            {
                createAndShowGUI();
            }
        });
    }
}