Java中JInternalFrame中JTabbedPane上JPanel的尺寸设置

Question

我的软件的用户需要能够单击不同的选项卡来查看不同类型的数据表示形式。但是，当用户单击选项卡时，我在下面包含的代码不会显示请求的数据面板。

您可以通过运行下面的代码轻松地重新创建问题，然后在代码将生成的 GUI 中执行以下步骤：

1.) Select "New" from the file menu    
2.) Click on "AnotherTab" in the internal frame which will appear

根据您在下面注释掉的代码行，该选项卡将只显示一个空白面板，或者将在面板顶部的中间显示一个小红色方块。

您可以切换/注释掉以重现此问题的代码行是：

GraphPanel myGP = new GraphPanel();
//GraphPanel myGP = new GraphPanel(width,height);

这些代码行位于下面的 GraphGUI.java 中。

谁能告诉我如何修复下面的代码，以便 myGP 以包含它的面板的完整尺寸显示？

以下是重新创建此问题所需的三个 java 文件：

ParentFrame.java

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Panel;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;

import javax.swing.JDesktopPane;
import javax.swing.JFrame;
import javax.swing.JInternalFrame;
import javax.swing.JLabel;
import javax.swing.JLayeredPane;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JTabbedPane;
import javax.swing.KeyStroke;

public class ParentFrame extends JFrame implements ActionListener{
private static final long serialVersionUID = 1L;
JLayeredPane desktop;
JInternalFrame internalFrame;

public ParentFrame() {
    super("Parent Frame");
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    this.setPreferredSize(new Dimension(800, 400));
    Panel p = new Panel();
    this.add(p, BorderLayout.SOUTH);
    desktop = new JDesktopPane();
    setJMenuBar(createMenuBar());
    this.add(desktop, BorderLayout.CENTER);
    this.pack();
    this.setSize(new Dimension(800, 600));
    this.setLocationRelativeTo(null);
}
protected JMenuBar createMenuBar() {
    JMenuBar menuBar = new JMenuBar();
    //Set up the File menu.
    JMenu FileMenu = new JMenu("File");
    FileMenu.setMnemonic(KeyEvent.VK_F);
    menuBar.add(FileMenu);
    //Set up the first menu item.
    JMenuItem menuItem = new JMenuItem("New");
    menuItem.setMnemonic(KeyEvent.VK_N);
    menuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_N, ActionEvent.ALT_MASK));
    menuItem.setActionCommand("new");
    menuItem.addActionListener(new OpenListener());
    FileMenu.add(menuItem);
    //Set up the second menu item.
    menuItem = new JMenuItem("Quit");
    menuItem.setMnemonic(KeyEvent.VK_Q);
    menuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_Q, ActionEvent.ALT_MASK));
    menuItem.setActionCommand("quit");
    menuItem.addActionListener(this);
    FileMenu.add(menuItem);

    return menuBar;
    }
class OpenListener implements ActionListener {
    private static final int DELTA = 40;
    private int offset = DELTA;
    public void actionPerformed(ActionEvent e) {
        // create internal frame
        int ifWidth = 600;
        int ifHeight = 300;
        internalFrame = new JInternalFrame("Internal Frame", true, true, true, true);
        internalFrame.setLocation(offset, offset);
        offset += DELTA;

        // create jtabbed pane
        JTabbedPane jtp = createTabbedPane();
        internalFrame.add(jtp);
        desktop.add(internalFrame);
        internalFrame.pack();
        internalFrame.setSize(new Dimension(ifWidth,ifHeight));
        internalFrame.setVisible(true);
    }
}
private JTabbedPane createTabbedPane() {
    JTabbedPane jtp = new JTabbedPane();
    jtp.setMinimumSize(new Dimension(600,300));
    createTab(jtp, "One Tab");
    createTab(jtp, "AnotherTab");
    createTab(jtp, "Tab #3");
    return jtp;
}
private void createTab(JTabbedPane jtp, String s) {
    if(s=="AnotherTab"){
        jtp.getHeight();
        jtp.getWidth();
        GraphGUI myGraphGUI = new GraphGUI(jtp.getHeight(),jtp.getWidth());
        jtp.add(s, myGraphGUI);
    }
    else{jtp.add(s, new JLabel("TabbedPane " + s, JLabel.CENTER));}
}
public static void main(String args[]) {
    ParentFrame myParentFrame = new ParentFrame();
    myParentFrame.setVisible(true);
}
public void actionPerformed(ActionEvent e) {if ("quit".equals(e.getActionCommand())){System.exit(0);}}
}

GraphGUI.java：您可以在其中切换注释以重新创建问题。

import javax.swing.*;

class GraphGUI extends JPanel{
GraphGUI(int height,int width) {
    //REPRODUCE ERROR BY COMMENTING OUT EITHER ONE OF NEXT TWO LINES:
    GraphPanel myGP = new GraphPanel();
//      GraphPanel myGP = new GraphPanel(width,height);
    this.add(myGP);
    this.setVisible(true);// Display the panel.
}
}

GraphPanel.java：

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

class GraphPanel extends JPanel {
Insets ins; // holds the panel's insets
double[] plotData;
double xScale;

GraphPanel(int w, int h) {
    setOpaque(true);// Ensure that panel is opaque.
    setPreferredSize(new Dimension(w, h));// Set preferred dimension as specfied.
    setMinimumSize(new Dimension(w, h));// Set preferred dimension as specfied.
    setMaximumSize(new Dimension(w, h));// Set preferred dimension as specfied.
}
GraphPanel() {
    setOpaque(true);// Ensure that panel is opaque.
}

protected void paintComponent(Graphics g){// Override paintComponent() method.
    super.paintComponent(g);// Always call superclass method first.
    int height = getHeight();// Get height of component.
    int width = getWidth();// Get width of component.
    System.out.println("height, width are: "+height+" , "+width);
    ins = getInsets();// Get the insets.
    // Get dimensions of text
    Graphics2D g2d = (Graphics2D)g;
    FontMetrics fontMetrics = g2d.getFontMetrics();
    String xString = ("x-axis label");
    int xStrWidth = fontMetrics.stringWidth(xString);
    int xStrHeight = fontMetrics.getHeight();
    String yString = "y-axis label";
    int yStrWidth = fontMetrics.stringWidth(yString);
    int yStrHeight = fontMetrics.getHeight();
    String titleString ="Title of Graphic";
    int titleStrWidth = fontMetrics.stringWidth(titleString);
    int titleStrHeight = fontMetrics.getHeight();
    //get margins
    int leftMargin = ins.left;
    //set parameters for inner rectangle
    int hPad=10;
    int vPad = 6;
    int numYticks = 10;
    int testLeftStartPlotWindow = ins.left+5+(3*yStrHeight);
    int testInnerWidth = width-testLeftStartPlotWindow-ins.right-hPad;
    int remainder = testInnerWidth%numYticks;
    int leftStartPlotWindow = testLeftStartPlotWindow-remainder;
    System.out.println("remainder is: "+remainder);
    int blueWidth = testInnerWidth-remainder;
    int blueTop = ins.bottom+(vPad/2)+titleStrHeight;
    int bottomPad = (3*xStrHeight)-vPad;
    int blueHeight = height-bottomPad-blueTop;

    g.setColor(Color.red);
    int redWidth = width-leftMargin-1;
    //plot outer rectangle
    g.drawRect(leftMargin, ins.bottom, redWidth, height-ins.bottom-1);
    System.out.println("blueWidth is: "+blueWidth);
    // fill inner rectangle
    g.setColor(Color.white);
    g.fillRect(leftStartPlotWindow, blueTop, blueWidth, blueHeight);

    //write top label
    g.setColor(Color.black);
    g.drawString(titleString, (width/2)-(titleStrWidth/2), titleStrHeight);

    //write x-axis label
    g.setColor(Color.red);
    g.drawString(xString, (width/2)-(xStrWidth/2), height-ins.bottom-vPad);
    g2d.rotate(Math.toRadians(-90), 0, 0);//rotate text 90 degrees counter-clockwise
    //write y-axis label
    g.drawString(yString, -(height/2)-(yStrWidth/2), yStrHeight);
    g2d.rotate(Math.toRadians(+90), 0, 0);//rotate text 90 degrees clockwise
    // plot inner rectangle
    g.setColor(Color.blue);
    g.drawRect(leftStartPlotWindow, blueTop, blueWidth, blueHeight);
}
}

Answer 1

class GraphGUI extends JPanel {

    .
    .
    GraphGUI(int height,int width) {
    // components in a GridLayout are stretched to fit space available
    setLayout(new GridLayout());