I am new in Java programming. I need to get the indices of selected column and row. I am getting -1 as selected indices for both the column and row. I have searched for a solution but didn't find anything satisfactory.
My code is following:
private void deleteProductButtonActionPerformed(java.awt.event.ActionEvent evt) {
DefaultTableModel tableModel = (DefaultTableModel) this.productDisplaTable.getModel();
JTable table = new JTable(tableModel);
int selectedRowIndex = table.getSelectedRow();
int selectedColIndex = table.getSelectedColumn();
System.out.println(selectedRowIndex );
System.out.println(selectedColIndex);
}
You're checking if a row is selected before the JTable has been displayed before the user can even interact with it.
Instead why not have that code in an ActionListener or some other listener so that the user at least has a chance to select something? This suggests that you might have a misunderstanding on how event-driven programming works and need to study the concepts a little bit more.
What makes you think that creating a a new JTable would have any selected rows or columns
JTable table = new JTable(tableModel); //???
Try using a table that is actually visible to the user instead
In your code you create a new JTable but you don't add this component to any container. Thus it won't never be visible and no row nor column could ever be selected.
Now, while we can add components dynamically in Swing we tipically place all our components before the top-level container (window) is made visible. In this case you should place the table when you initialize your components (don't forget the scroll pane) and do whatever you need to do when the button is pressed.
On the other hand I'm not sure what are you trying to achieve. I mean you already have a table called productDisplaTable. If you want to print the selected row and column in that table then make this little change:
private void deleteProductButtonActionPerformed(java.awt.event.ActionEvent evt) {
//DefaultTableModel tableModel = (DefaultTableModel) this.productDisplaTable.getModel();
//JTable table = new JTable(tableModel);
int selectedRowIndex = this.productDisplaTable.getSelectedRow();
int selectedColIndex = this.productDisplaTable.getSelectedColumn();
System.out.println(selectedRowIndex );
System.out.println(selectedColIndex);
}
Thanks all for taking time to reply.
I got the answer I was looking from #dic19's comment.
Now I clearly see the mistake I was doing. This was due to my lack of knowledge in Java programming.
Related
I am trying to get the sum of column 4 on typing/editing the value on column 4. Immediately i change the figure i.e as i type on any row of column 4 it should change my sum which i set on a jTextField.
I have tried TableModelListener and ListSelectionListener but it has not worked efficiently because i have to click on the row for it to get the summary.
jTable1.getModel().addTableModelListener(new TableModelListener(){
public void tableChanged(TableModelEvent evt){
float sum = 0;
int[] rows = jTable1.getSelectedRows();
for(int i=0;i<jTable1.getRowCount();i++){
try{
sum = sum +
Float.parseFloat(jTable1.getValueAt(rows[i],4).toString());
}
catch(Exception e){
continue;
}
}
jTextField15.setText(Float.toString(sum));
getsummaries();
}
});
Immediately i change the value on Column 4 i would like it ot autosum on jTextField15.
it has not worked efficiently because i have to click on the row for it to get the summary.
The model is only updated when the cell loses focus because that is when the value you are typing is saved to the model. This is because you could start typing numbers and then use the "escape" key to cancel the editing.
If you really want to update the total as the user types into the editor, then instead of using a TableModelListener, you will need to add a DocumentListener to the text field used by the editor:
DefaultCellEditor editor = (DefaultCellEditor)table.getDefaultEditor(Integer.class);
JTextField textField = (JTextField)editor.getComponent();
textField.getDocument().addDocumentListener(...);
See the section from the Swing tutorial on Listening For Changes on a Document for more information and examples.
Of course if you do this, you will also need to handle the case when the editor is cancelled. So you will also need to add a PropertyChangeListener to the JTable and listen for tableCellEditor property change.
I have not yet gotten a solution to this yet. On typing on JTable it's difficult to record the sum. A workaround would be to create a button and it computes the total on the jTextField.
I have a table right now that's displaying a list of classes and everything works fine except the formatting of it inside of the scroll pane. Here's what I have right now for it.
String[] columns = {"Class","Period","Size", "Honors/AP"};
JTable classTable = new JTable(new DefaultTableModel(new Object[][] {}, columns));
DefaultTableModel model = (DefaultTableModel)classTable.getModel();
//populating the table based on the number of classes that the teacher has
for (Class c: t.getClasses()) {
model.addRow(new Object[]{c.getClassName(),c.getPeriod(),c.getSize(),c.isHonorsAP()});
}
if (classTable.getRowCount()==0)
model.addRow(new Object[]{});
JScrollPane scrollPane = new JScrollPane(classTable);
classTable.setPreferredSize(new Dimension(700,100));
classTable.setPreferredScrollableViewportSize(classTable.getPreferredSize());
classTable.setFillsViewportHeight(true);
if (classTable.getPreferredSize().getHeight() < scrollPane.getPreferredSize().getHeight())
scrollPane.setPreferredSize(classTable.getPreferredSize());
So the problem on one end is that when there aren't enough rows to fill the preferred size of the table, it leaves extra space at the bottom and I'm trying to get that removed.
And then on the other end, when there are more rows that can fit, I need the size to stay but add in the scroll bar.
I'm really confused right now. Any help would be greatly appreciated
Hi I have a problem with separate data in jTable.
My jTable:
When I click to Second button, so I have two data in jTable.
It's correct but when I click to First button again I get same jTable that as jTable in Second button.
This is my code:
DefaultTableModel model = new DefaultTableModel();
model = (DefaultTableModel) jTable1.getModel();
for(int i = 0; i < jTable1.getRowCount(); i++)
{
if(jTable1.getValueAt(i, 0) == Boolean.FALSE)
{
model.removeRow(i);
}
}
jTable2.setModel(model);
But it doesn't work. Is there anyone who tells me why ?
But it doesn't work. Is there anyone who tells me why ?
When you remove, for example, row 0, then all the rows shift down by one, but the value of "I" keeps increasing by one so you will "skip" rows every time you remove a row.
The solution is to start on the last row and decrement "I":
for(int i = jTable.getRowCount() - 1; i >=0; I--)
It's not a problem.
Yes it is. You posted example only works because you selected every other row in the table. Try selecting the first two rows and see what happens. Have said that, this is not the real solution to your problem, because you should NOT be removing data from the first TableModel.
It's correct but when I click to First button again I get same jTable that as jTable in Second button.
The problem is that you can't delete the data from the first TableModel. You need to create a new TableModel and then "copy" the data from the first TableModel to the second TableModel.
I have a JTable with multiple rows and every row is presented via Point on a scatter plot. What I have to do is when a given point is selected on the scatter plot I have to associate this selection with selecting of the corresponding row in the JTable.
I have an Integer that represents, which row I have to highlight.
What I tried is:
JTable table = new JTable();
...
...// a bit of code where I have populated the table
...
table.setRowSelectionInterval(index1,index2);
So the problem here is that this method selects all rows in the given range [index1,index2]. I want to select for example rows 1,15,28,188 etc.
How do you do that?
To select just one row, pass it as both the start and end index:
table.setRowSelectionInterval(18, 18);
Or, if you want to select multiple, non-contiguous indices:
ListSelectionModel model = table.getSelectionModel();
model.clearSelection();
model.addSelectionInterval(1, 1);
model.addSelectionInterval(18, 18);
model.addSelectionInterval(23, 23);
Alternately, you may find that implementing your own subclass of ListSelectionModel and using it to track selection on both the table and the scatterplot is a cleaner solution, rather than listening on the scatterplot and forcing the table to match.
It also works without using the ListSelectionModel:
table.clearSelection();
table.addRowSelectionInterval(1, 1);
table.addRowSelectionInterval(15, 15);
table.addRowSelectionInterval(28, 28);
...
Just don't call the setRowSelectionInterval, as it always clears the current selection before.
There is no way to set a random selection with a one method call, you need more than one to perform this kind of selection
table.setRowSelectionInterval(1, 1);
table.addRowSelectionInterval(15, 15);
table.setRowSelectionInterval(28, 28);
table.addRowSelectionInterval(188 , 188 );
And So On....
Here is a generic method to accomplish this:
public static void setSelectedRows(JTable table, int[] rows)
{
ListSelectionModel model = table.getSelectionModel();
model.clearSelection();
for (int row : rows)
{
model.addSelectionInterval(row, row);
}
}
I'm trying to create a JTable that's only showing one row at the time. When you press Next/Previous, the table will display either the next or the previous row, depending on the button pressed. If there is no Next/Previous, the JTable shall display the first/last element.
Code for only showing one row at a time:
tableModel = new DefaultTableModel(data, columnNames);
tableModel.setRowCount(0); //If I remove this, the things I add ends up att the 2nd line.
tableModel.addTableModelListener(resultTable);
resultTable = new JTable(tableModel);
scroll = new JScrollPane(resultTable, JScrollPane.VERTICAL_SCROLLBAR_NEVER, JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
final int rows = 1;
Dimension d = resultTable.getPreferredSize();
resultTable.setPreferredSize(new Dimension(d.width,resultTable.getRowHeight()*rows));
Code for Next-button (Not working, what do to? Shows the same element as before):
int height = resultTable.getRowHeight()*(rows-1);
JScrollBar bar = scroll.getVerticalScrollBar();
bar.setValue( bar.getValue()+height);
Code for Previous-button (Not working, same as above, nothing happens/changes.)
int height = resultTable.getRowHeight()*(rows-1);
JScrollBar bar = scroll.getVerticalScrollBar();
bar.setValue(bar.getValue()-height);
What do to? Some help would be greatly appreciated. Been trying to solve this forever.
Edit: Trying to follow the code from here: JTable row limitation but can't get it to work.. Though I only want to show 1 row, not 10.
From the above you specify row count to get single row in a table
final int rows = 2;
Alternatively you could try with table with Row header. Here is a sample
http://www.java2s.com/Code/Java/Swing-Components/TableRowHeaderExample.htm