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Author

removing a scrollpane, yet still see it

Bob Bender
Greenhorn

Joined: Feb 26, 2004
Posts: 6
I have a JFrame that is split in 2 pieces (top and bottom, and should
never have more than 2 panes)...

JFrame f = new JFrame(title);
f.setSize(300,500);
f.getContentPane().setLayout(new GridLayout(2,1));

Top part is a text area defined as...
JtextArea jta = new JTextArea();
f.getContentPane().add(jta);
f.show();

Bottom is filled by adding a ScrollPane from a database after removing
the existing one....
ResultSet rs2 = stmt.executeQuery(query);
MyResultSetTableModel model = new MyResultSetTableModel(rs2);
JTable table = new JTable(model);
if (scrollPane != null)
f.getContentPane().remove(scrollPane);
JScrollPane scrollPane = new JScrollPane(table);
f.getContentPane().add(scrollPane);
f.show();
NOTE: I can click on this table and select cells/rows,etc

Next, I try clearing out the 2 areas using ...
jta.setText("");
if (scrollPane != null)
f.getContentPane().remove(scrollPane);
f.show();
Results.....
The text area clears off, but the scrollpane is still viewable. But,
I cannot click on the scrollpane with the mouse, so it must be gone
from memory, but not off the screen physically.

What am I doing wrong that I can still see the pane, but it is not there??
Bob
Jose Botella
Ranch Hand

Joined: Jul 03, 2001
Posts: 2120
Welcome to the Ranch Bob.
You do not need to call show several times. But after the first time you do, call Container.validate when adding or removing a component.
But because getContentPane returns a JPanel, use revalidate. Maybe repaint is also needed.
[ February 26, 2004: Message edited by: Jose Botella ]

SCJP2. Please Indent your code using UBB Code
Bob Bender
Greenhorn

Joined: Feb 26, 2004
Posts: 6
Okay, I'll bite. How would I do that "call Container.validate"?
Jose Botella
Ranch Hand

Joined: Jul 03, 2001
Posts: 2120
f.getContentPane().revalidate();
Bob Bender
Greenhorn

Joined: Feb 26, 2004
Posts: 6
Gosh, no luck so far..... What fun this language is1
Don Kiddick
Ranch Hand

Joined: Dec 12, 2002
Posts: 580
I don't think you're removing the scrollpane. You shouldn't have to call revalidate, it *should* just work. Can you post the whole class code please.
D.
Don Kiddick
Ranch Hand

Joined: Dec 12, 2002
Posts: 580
My guess is that :
if (scrollPane != null) {
f.getContentPane().remove(scrollPane);
JScrollPane scrollPane = new JScrollPane(table);
f.getContentPane().add(scrollPane);
f.show();
}
should become :
if (scrollPane != null) {
f.getContentPane().remove(scrollPane);
scrollPane = new JScrollPane(table);
f.getContentPane().add(scrollPane);
f.show();
}

D.
Bob Bender
Greenhorn

Joined: Feb 26, 2004
Posts: 6
Would this be like showing an empty scrollpane? Or, how would I show an empty one?
Here is my source.

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;
import java.sql.*;
import javax.swing.*;
import javax.swing.table.*;
import java.util.*;
public class REB_mdbBrowser {
// Listener class needs declared here, as static fields
private static JavaFilter javaFilter = new JavaFilter();
private static JFrame f;
private static JMenu j1, j2, j3;
private static JMenuBar jb;
private static JMenuItem jmi, j1mi1, j3mi1, j3mi2;
private static JScrollPane scrollPane;
private static JTable table ;
private static JTextArea jta;
private static ResultSetTableModel model;
private static Connection conn;
private static Statement stmt;
private static DatabaseMetaData meta;
private static ResultSet rs;
private static String query = "";
private static int debugCtr = 0;
public static void main(String[ ] args) throws Exception {
String title="My Access .mdb Browser";
f = new JFrame(title);
f.setSize(300,500);
f.getContentPane().setLayout(new GridLayout(2,1));
// set up the menu bar.
jb = new JMenuBar();
j1 = new JMenu("Database");
j2 = new JMenu("Tables");
j3 = new JMenu("Actions");
// 1st menu has 1 items: Open
j1mi1 = new JMenuItem("Open");
j1.add(j1mi1);
// 2nd menu must be populated with the names of the tables
getTableNames(openFile());
// 3rd menu has 2 items: Execute and Clear
j3mi1 = new JMenuItem("Execute");
j3.add(j3mi1);
j3mi2 = new JMenuItem("Clear");
j3.add(j3mi2);
jb.add(j1);
jb.add(j2);
jb.add(j3);
f.setJMenuBar(jb);
// top half of the JFrame will contain a TextArea
// bottom half is initially empty,
jta = new JTextArea();
f.getContentPane().add(jta);
f.show();
// set up event handling
ActionListener a = new MyActionListener();
j1mi1.addActionListener(a);
j3mi1.addActionListener(a);
j3mi2.addActionListener(a);
}
// inner class -- it has access to all fields of the outer class
// must be declared static because it's referenced in main
static class MyActionListener implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
// Figure out menu item was selected by the user
String sel = e.getActionCommand();
// need to execute FileChooser
if (sel.equals("Open"))
{
getTableNames(openFile());
}
// need to execute query typed in JTextArea
else if (sel.equals("Execute"))
{
query = jta.getText();
try
{
ResultSet rs2 = stmt.executeQuery(query);
model = new MyResultSetTableModel(rs2);
table = new JTable(model);
if (scrollPane != null)
f.getContentPane().remove(scrollPane);
scrollPane = new JScrollPane(table);
f.getContentPane().add(scrollPane);
f.show();
}
catch(SQLException ex)
{
ex.printStackTrace();
}
}
else if (sel.equals("Clear"))
{
jta.setText("");
if (scrollPane != null)
{
f.getContentPane().remove(scrollPane);
scrollPane = new JScrollPane(table);
f.getContentPane().add(scrollPane);
}
f.show();
}
else
{
//else it's a table name
try
{
query = "Select * from " + sel;
ResultSet rs3 = stmt.executeQuery(query);
ResultSetMetaData rm = rs3.getMetaData();
model = new MyResultSetTableModel(rs3);
table = new JTable(model);
// Add the table to a scrolling pane
if (scrollPane != null)
f.getContentPane().remove(scrollPane);
scrollPane = new JScrollPane(table);
f.getContentPane().add(scrollPane);
f.show();
}
catch(SQLException ex)
{
ex.printStackTrace();
}
}
}
}

/**
Prompts the user for a database and gets the database metatable info
*/
public static void getTableNames(String file)
{
String table_name = "";
try
{
conn = getConnection(file);
stmt = conn.createStatement();
meta = conn.getMetaData();
// rs is a "metatable" that contains information about each table in the db
rs = meta.getTables(null, null, null, null);
//clear the menu out and populate
j2.removeAll();
while (rs.next())
{
if (rs.getString("TABLE_TYPE").equals("TABLE"))
{
jmi = new JMenuItem(rs.getString("TABLE_NAME"));
j2.add(jmi);
ActionListener a = new MyActionListener();
jmi.addActionListener(a);
}
}
}
catch(SQLException e)
{
e.printStackTrace();
}
}

/**
Use a JFileChooser in Open mode to select files
to open. Use a filter for FileFilter subclass
to select for *.mdb files.
*/
public static String openFile()
{
JFileChooser fc = new JFileChooser();
fc.setDialogTitle("Open File");
// Choose only files, not directories
fc.setFileSelectionMode( JFileChooser.FILES_ONLY);
// Start in current directory
fc.setCurrentDirectory(new File("."));
// Set filter for Java source files.
fc.setFileFilter(javaFilter);
// Now open chooser
int result = fc.showOpenDialog(jta);
if (result == JFileChooser.APPROVE_OPTION)
{
return (fc.getSelectedFile().toString());
}
else
{
return "";
}
}

/**
Gets a connection from the filename specified
@return the database connection
*/
public static Connection getConnection(String dbName) throws SQLException
{
try
{
Class.forName ("com.inzoom.jdbcado.Driver");
}
catch (ClassNotFoundException e)
{
System.out.println(e);
}
String url = "jdbc:izmado rovider=Microsoft.Jet.OLEDB.4.0;Data Source=" + dbName;
return DriverManager.getConnection(url);
}
/*
//ALTERNATE CONNECTION CODE NOT USING THE IZMADO DRIVER
//Gets a connection from the properties specified in the file database.properties
//@return the database connection
public static Connection getConnection() throws SQLException, IOException
{
Properties props = new Properties();
String fileName = "airlines.properties";
FileInputStream in = new FileInputStream(fileName);
props.load(in);
String drivers = props.getProperty("jdbc.drivers");
if (drivers != null)
System.setProperty("jdbc.drivers", drivers);
String url = props.getProperty("jdbc.url");
String username = props.getProperty("jdbc.username");
String password = props.getProperty("jdbc.password");
return DriverManager.getConnection(url, username, password);
}
PROPERTIES FILE DEFINITIONChange "JavaClass" in line 2 to match your ODBC definition
jdbc.drivers=sun.jdbc.odbc.JdbcOdbcDriver
jdbc.url=jdbc dbc:JavaClass
jdbc.username=PUBLIC
jdbc.password=PUBLIC
*/
/*
Debugging routines for System.out.println
*/
public static void debugPrint(int opt, String desc)
{
if (opt == 1)
System.out.println(desc + "..." + debugCtr);
}
}

abstract class ResultSetTableModel extends AbstractTableModel
{
/**
Constructs the table model.
@param aResultSet the result set to display.
*/
public ResultSetTableModel(ResultSet aResultSet)
{
rs = aResultSet;
try
{
rsmd = rs.getMetaData();
}
catch(SQLException e)
{
e.printStackTrace();
}
}
public String getColumnName(int c)
{
try
{
return rsmd.getColumnName(c + 1);
}
catch(SQLException e)
{
e.printStackTrace();
return "";
}
}
public int getColumnCount()
{
try
{
return rsmd.getColumnCount();
}
catch(SQLException e)
{
e.printStackTrace();
return 0;
}
}
/**
Gets the result set that this model exposes.
@return the result set
*/
protected ResultSet getResultSet()
{
return rs;
}
private ResultSet rs;
private ResultSetMetaData rsmd;
}

class MyResultSetTableModel extends ResultSetTableModel
{
public MyResultSetTableModel(ResultSet aResultSet)
{
super(aResultSet);
try
{
cache = new ArrayList();
int cols = getColumnCount();
ResultSet rs = getResultSet();
/**
Place all data in an array list of Object[] arrays
We don't use an Object[][] because we don't know
how many rows are in the result set
*/
while (rs.next())
{
Object[] row = new Object[cols];
for (int j = 0; j < row.length; j++)
row[j] = rs.getObject(j + 1);
cache.add(row);
}
}
catch(SQLException e)
{
System.out.println("Error " + e);
}
}
public Object getValueAt(int r, int c)
{
if (r < cache.size())
return ((Object[])cache.get(r))[c];
else
return null;
}
public int getRowCount()
{
return cache.size();
}
private ArrayList cache;
}
/*
*/
class JavaFilter extends javax.swing.filechooser.FileFilter
{
public boolean accept(File f)
{
return f.getName().toLowerCase().endsWith(".mdb") || f.isDirectory();
}
public String getDescription()
{
return "Access files (*.mdb)";
}
}
Don Kiddick
Ranch Hand

Joined: Dec 12, 2002
Posts: 580
Rath than :

Why don't you just do :

much simpler.
D.
Jose Botella
Ranch Hand

Joined: Jul 03, 2001
Posts: 2120
If you call lengthy operations from the Event-dispacthing thread, it is likely your GUI will have pauses in its repainting.
 
I agree. Here's the link: http://aspose.com/file-tools
 
subject: removing a scrollpane, yet still see it
 
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