I have created a program that has a JScrollPane. However, JScrollPane doesn’t seem to do what is supposed to. It won’t scroll although a component is larger in size than the JScrollPane.
Producing a SSCCE out of my program would be pain in the neck, so I will just give you the whole program with comment markers of important places. (IMPORTANT and END OF IMPORTANT) Anything out of the comment shouldn’t influence the issue.
When starting up a program click File>New then OK in the dialog. That will draw the problematic GUI.
P.S. Only height is important here, width-wise everything works.
package core;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Locale;
import java.util.Properties;
import java.util.ResourceBundle;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.JScrollPane;
import javax.swing.KeyStroke;
//IMPORTANT!
@SuppressWarnings("serial")
class Page extends JPanel
{
public int content;
public Page(JPanel panel, int index)
{
setMaximumSize(new Dimension(794, 1123));
setAlignmentX(Component.CENTER_ALIGNMENT);
setBackground(Color.WHITE);
panel.add(this, index);
content = 0;
}
}
/END OF IMPORTANT!
public class Main
{
public static Properties config;
public static Locale currentLocale;
public static ResourceBundle lang;
public static JFrame mWindow;
public static JMenuBar menu;
public static JMenu menuFile, menuEdit;
public static JMenuItem itmNew, itmClose, itmLoad, itmSave, itmSaveAs, itmExit, itmCut, itmCopy, itmPaste, itmProperties;
public static JDialog newDoc;
public static JLabel newDocText1, newDocText2;
public static JRadioButton questions, list;
public static ButtonGroup newDocButtons;
public static JButton newDocOk;
public static Boolean firstSegment;
public static JPanel workspace;
public static JScrollPane scroll;
public static ArrayList<Page> pages;
//IGNORE WHOLE METHOD, HAS NOTHING TO DO WITH THE PROBLEM
public static void newDocumentForm()
{
//new document dialog
mWindow.setEnabled(false);
newDoc = new JDialog(mWindow, lang.getString("newDoc"));
newDoc.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
newDoc.addWindowListener(new WindowListener ()
{
public void windowActivated(WindowEvent arg0) {}
public void windowClosing(WindowEvent arg0)
{
mWindow.toFront();
newDocText1 = null;
newDocText2 = null;
questions = null;
list = null;
newDocButtons = null;
newDocOk = null;
newDoc.dispose();
mWindow.setEnabled(true);
}
public void windowClosed(WindowEvent arg0) {}
public void windowDeactivated(WindowEvent arg0) {}
public void windowDeiconified(WindowEvent arg0) {}
public void windowIconified(WindowEvent arg0) {}
public void windowOpened(WindowEvent arg0) {}
});
newDoc.setSize(400, 200);
newDoc.setLocationRelativeTo(null);
newDoc.setResizable(false);
newDoc.setLayout(null);
newDoc.setVisible(true);
newDocText1 = new JLabel(lang.getString("newDocText1"));
newDocText1.setBounds(5, 0, 400, 20);
newDocText2 = new JLabel(lang.getString("newDocText2"));
newDocText2.setBounds(5, 20, 400, 20);
newDoc.add(newDocText1);
newDoc.add(newDocText2);
firstSegment = true;
questions = new JRadioButton(lang.getString("questions"));
questions.setSelected(true);
questions.setFocusPainted(false);
questions.setBounds(10, 60, 400, 20);
questions.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
firstSegment = true;
}
});
list = new JRadioButton(lang.getString("list"));
list.setFocusPainted(false);
list.setBounds(10, 80, 400, 20);
list.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
firstSegment = false;
}
});
newDoc.add(questions);
newDoc.add(list);
newDocButtons = new ButtonGroup();
newDocButtons.add(questions);
newDocButtons.add(list);
newDocOk = new JButton(lang.getString("ok"));
newDocOk.addKeyListener(new KeyListener()
{
public void keyPressed(KeyEvent e)
{
if (e.getKeyCode() == KeyEvent.VK_ENTER)
{
newDocOk.doClick();
}
}
public void keyReleased(KeyEvent e) {}
public void keyTyped(KeyEvent e) {}
});
newDocOk.setFocusPainted(false);
newDocOk.setBounds(160, 120, 80, 40);
newDocOk.setMnemonic(KeyEvent.VK_ACCEPT);
newDocOk.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
createNewDocument();
}
});
newDoc.add(newDocOk);
newDocOk.requestFocus();
}
public static void createNewDocument()
{
//dispose of new document dialog
mWindow.toFront();
newDocText1 = null;
newDocText2 = null;
questions = null;
list = null;
newDocButtons = null;
newDocOk = null;
newDoc.dispose();
mWindow.setEnabled(true);
//IMPORTANT!
//create document display
workspace = new JPanel();
workspace.setLayout(new BoxLayout(workspace, BoxLayout.PAGE_AXIS));
workspace.add(new Box.Filler(new Dimension(0, 40), new Dimension(0, 40), new Dimension(0, 40)));
workspace.setBackground(Color.BLACK);
scroll = new JScrollPane(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
scroll.getVerticalScrollBar().setUnitIncrement(20);
scroll.setViewportView(workspace);
pages = new ArrayList<Page>();
@SuppressWarnings("unused")
Page p = new Page(workspace, 1);
mWindow.add(scroll, BorderLayout.CENTER);
mWindow.repaint();
mWindow.validate();
}
//END OF IMPORTANT
public static void main(String[] args) throws FileNotFoundException, IOException
{
//load properties
config = new Properties();
config.load(new FileInputStream("src\\config.properties"));
//load language
currentLocale = new Locale(config.getProperty("language"), config.getProperty("country"));
lang = ResourceBundle.getBundle("language", currentLocale);
//IMPORTANT!
//create main window
mWindow = new JFrame(lang.getString("title"));
mWindow.setSize(1000, 800);
mWindow.setMinimumSize(new Dimension(1000, 800));
mWindow.setLocationRelativeTo(null);
mWindow.setLayout(new BorderLayout());
mWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mWindow.setVisible(true);
//END OF IMPORTANT
//create menu bar
menu = new JMenuBar();
menuFile = new JMenu(lang.getString("file"));
menuEdit = new JMenu(lang.getString("edit"));
itmNew = new JMenuItem(lang.getString("new"));
itmNew.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_N, ActionEvent.CTRL_MASK));
itmNew.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
newDocumentForm();
}
});
itmClose = new JMenuItem(lang.getString("close"));
itmClose.setActionCommand("Close");
itmClose.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_W, ActionEvent.CTRL_MASK));
itmLoad = new JMenuItem(lang.getString("load"));
itmLoad.setActionCommand("Load");
itmLoad.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_L, ActionEvent.CTRL_MASK));
itmSave = new JMenuItem(lang.getString("save"));
itmSave.setActionCommand("Save");
itmSave.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_S, ActionEvent.CTRL_MASK));
itmSaveAs = new JMenuItem(lang.getString("saveAs"));
itmSaveAs.setActionCommand("SaveAs");
itmExit = new JMenuItem(lang.getString("exit"));
itmExit.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
//Add confirmation window!
System.exit(0);
}
});
itmCut = new JMenuItem(lang.getString("cut"));
itmCut.setActionCommand("Cut");
itmCut.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_X, ActionEvent.CTRL_MASK));
itmCopy = new JMenuItem(lang.getString("copy"));
itmCopy.setActionCommand("Copy");
itmCopy.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_C, ActionEvent.CTRL_MASK));
itmPaste = new JMenuItem(lang.getString("paste"));
itmPaste.setActionCommand("Paste");
itmPaste.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_V, ActionEvent.CTRL_MASK));
itmProperties = new JMenuItem(lang.getString("properties"));
itmProperties.setActionCommand("properties");
itmProperties.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_P, ActionEvent.CTRL_MASK));
menuFile.add(itmNew);
menuFile.add(itmClose);
menuFile.addSeparator();
menuFile.add(itmLoad);
menuFile.addSeparator();
menuFile.add(itmSave);
menuFile.add(itmSaveAs);
menuFile.addSeparator();
menuFile.add(itmExit);
menuEdit.add(itmCut);
menuEdit.add(itmCopy);
menuEdit.add(itmPaste);
menuEdit.addSeparator();
menuEdit.add(itmProperties);
menu.add(menuFile);
menu.add(menuEdit);
//create actionListener for menus
mWindow.add(menu, BorderLayout.NORTH);
mWindow.repaint();
mWindow.validate();
}
}
You set the maximum size of the viewport panel while
JScollPanechecks the preferred size.