making JTable appear after initial load

[Alan Shiers]

Hi Guys,

I'm creating an app that includes a JTable. However, I don't want the JTable to appear upon the initial launch of the application. I have a File/New menu that I want the user to use to make the JTable appear for the first time with one new row in it. This is what I have for my actionPerformed(ActionEvent event) method:

 public void actionPerformed(ActionEvent event)
	 {
		 if(event.getSource() == mnuNew)
		 {   
			 if(fileOpen)
			 {
				if(isDirty)
				{
				    ...	
				}
			 }
			 else
			 {
			   if(isDirty == false)
			   {   System.out.println("setting up new table");
				   createTable();
				   addNewBlankRow();
				   table.validate();  //DOESN'T DO ANYTHING
				   table.repaint();   //DOESN'T DO ANYTHING
				   container.repaint();  //DOESN'T DO ANYTHING
			   } 
			 }
		 }
                                 ...
  }

In the method createTable() the JTable is added to the JFrame's contentPane. When the app loads only the menus appears, which is what I want. Now, when the user selects File/New this actionPerformed(...) method runs. The problem is the three calls to table.validate(), table.repaint(), and container.repaint() do nothing. The JTable doesn't appear. Please advise.

Alan

[Michael Dunn]

how is it 'not' initially showing?

setVisible(false), or not added to anything?

do you change this/these?

if you drag the frame a little wider, does the table show up?

would be a lot easier if you'd posted a sample demo program,
just a frame, menu, non-showing table, and the listener code.

[Alan Shiers]

If I select the File/New menu, no JTable appears, however, if I resize the window, then yes the JTable suddenly appears. setVisible(true) is called initially when the app launches, I just don't include the creation of the Jtable at that time. The user must select the File/New menu to make that happen. Following is most of the code that makes up the application:

private Container container = null;

public void init()
	 {		
	   //System.out.println("init");
	   this.setTitle("Job Log");
	   container = getContentPane();
	   container.setLayout(new FlowLayout());
	   if(currentLocale.getDisplayLanguage().equals("English"))
	   {
		 messages = new PNSResource_en_CA();
		 loadEnglishMenus();
	   }
	   else if(currentLocale.getDisplayLanguage().equals("French"))
	   {
         messages = new PNSResource_fr_CA();
		 loadFrenchMenus();
	   }
	   else if(currentLocale.getDisplayLanguage().equals("Spanish"))
	   {
		 messages = new PNSResource_es_ES();
		 loadSpanishMenus();
	   }	   
		
	   this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	   this.setState(JFrame.NORMAL);
	   Toolkit toolkit = Toolkit.getDefaultToolkit();
	   Dimension dimension = toolkit.getScreenSize();
	   this.setSize(dimension);
	   this.setVisible(true);
			
	}

private void createTable()
	 {
		   JLtm = new JLTableModel(new Object[0][0], this.getHeaders());
		   
		   table = new JTable(JLtm)
		   {
			   public Component prepareRenderer(TableCellRenderer renderer, int row, int column)
			   {
				   Component component = super.prepareRenderer(renderer, row, column);
				   //int rendererWidth = component.getPreferredSize().width;
				   int rendererWidth = 160;
				   TableColumn tableColumn = getColumnModel().getColumn(column);
				   tableColumn.setPreferredWidth(Math.max(rendererWidth + getIntercellSpacing().width, tableColumn.getPreferredWidth()));
				   return  component;
				}
		   };
		
		   table.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
		   if (ALLOW_ROW_SELECTION) { // true by default
	           ListSelectionModel rowSM = table.getSelectionModel();
	           rowSM.addListSelectionListener(new ListSelectionListener() {
	               public void valueChanged(ListSelectionEvent e) {
	                   ListSelectionModel lsm = (ListSelectionModel)e.getSource();
	                   if (lsm.isSelectionEmpty()) {
	                       System.out.println("No rows are selected.");
	                   } else {
	                	   rowSelected = lsm.getMinSelectionIndex();
	                       System.out.println("Row " + rowSelected
	                                          + " is now selected.");
	                   }
	               }
	           });
	       } else {
	           table.setRowSelectionAllowed(false);
	       }

	       if (ALLOW_COLUMN_SELECTION) { // false by default
	           if (ALLOW_ROW_SELECTION) {
	               //We allow both row and column selection, which
	               //implies that we *really* want to allow individual
	               //cell selection.
	               table.setCellSelectionEnabled(true);
	           } 
	           table.setColumnSelectionAllowed(true);
	           ListSelectionModel colSM =
	               table.getColumnModel().getSelectionModel();
	           colSM.addListSelectionListener(new ListSelectionListener() {
	               public void valueChanged(ListSelectionEvent e) {
	                   ListSelectionModel lsm = (ListSelectionModel)e.getSource();
	                   if (lsm.isSelectionEmpty()) {
	                       System.out.println("No columns are selected.");
	                   } else {
	                       colSelected = lsm.getMinSelectionIndex();
	                       System.out.println("Column " + colSelected
	                                          + " is now selected.");
	                   }
	               }
	           });
	       }


		   //Set up the renderer and editor for the following column types
		   TableColumn resumeSubmittedColumn = table.getColumnModel().getColumn(9);
		   resumeSubmittedColumn.setCellEditor(new DateCellEditor());
		   resumeSubmittedColumn.setCellRenderer(new DateCellRenderer());
		   
		   TableColumn jobDescriptionColumn = table.getColumnModel().getColumn(13);
		   jobDescriptionColumn.setCellEditor(new TextAreaEditor());
		   jobDescriptionColumn.setCellRenderer(new TextAreaRenderer());
		   
		   TableColumn commentsColumn = table.getColumnModel().getColumn(15);
		   commentsColumn.setCellEditor(new TextAreaEditor());
		   commentsColumn.setCellRenderer(new TextAreaRenderer());
		   
		   //Set up the column handling drop down combo box
		   setUpHowResumeSubmittedColumn(table.getColumnModel().getColumn(10));
		   //Set up the column handling drop down combo box
		   setUpJobPostingTypeColumn(table.getColumnModel().getColumn(12));
		   setUpApplicationStatusColumn(table.getColumnModel().getColumn(14));
		   JScrollPane jsp = new JScrollPane(table);
		   table.setPreferredScrollableViewportSize(new Dimension(1200, 800));
		   table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
		   container.add(jsp, BorderLayout.CENTER); 
	 }

private void addNewBlankRow()
	 {
		 Object[] newRow = new Object[]{"", "", "", "", "", "", "",
				  "", "", new Date() , "", Boolean.FALSE, "", "",
				  "", ""};
		 JLtm.addRow(newRow);
	 }

public void actionPerformed(ActionEvent event)
	 {
		 if(event.getSource() == mnuNew)
		 {   System.out.println("mnuNew");
			 if(fileOpen)
			 {
				if(isDirty)
				{
			                   ...		
				}
			 }
			 else
			 {
			   if(isDirty == false)
			   {   System.out.println("setting up new table");
				   createTable();
				   addNewBlankRow();
				   table.validate();  //DON'T DO ANYTHING
				   table.repaint();  //DON'T DO ANYTHING
				   container.repaint();  //DON'T DO ANYTHING
			   } 
			 }
		 }
                                   ...
}

[Michael Dunn]

if it shows after making the frame wider, you're probably missing the indicated line

table.validate();  //DOESN'T DO ANYTHING  //probably not required
table.repaint();   //DOESN'T DO ANYTHING  //ditto
container.revalidate();//<---------------------------------------
container.repaint();  //DOESN'T DO ANYTHING  //will now

[Alan Shiers]

Aaahh! That was it. Thanks.

Alan