Event Handler when a Row is deleted from Table View - java

i need to know how to catch the event that happens when a row is deleted from the TableView and the index of the row. At this moment when a row is deleted from the Table View the TableView.getSelectionModel().clearSelection() method is called. But i want is to select the last index available in the Table View.
Tableview.getSelectionModel().clearAndSelect() is not an option, because sometimes a row is deleted automatically.
Regards

For a table with type, for example, Person:
import javafx.collections.ListChangeListener.Change ;
// ....
TableView<Person> table = ... ;
table.getItems().addListener((Change<? extends Person> c) -> {
while(c.next()) {
if (c.wasRemoved()) {
int numRemoved = c.getRemoved().size();
int index = c.getFrom();
System.out.println(numRemoved + " items removed from table at index "+index);
}
}
});
The ListChangeListener.Change documentation describes the values returned by c.getFrom(), c.getTo(), c.wasRemoved(), c.getAdded(), etc. under various scenarios.

Related

How to get the column of a sort key used by JTable's RowSorter?

I have two JTables which share a TableModel.
This is so that I can set them up in a scroll pane such that one of them has a few columns showing on the left and does not scroll sideways, visually 'freezing' those columns, and the other contains the rest of the columns.
They are always sorted the same so that the rows match up. This is done using a RowSorter listener, shown below. (frozenTable and tableView are the names of my JTables).
RowSorterListener rowSorterListener = new RowSorterListener() {
#Override
public void sorterChanged(RowSorterEvent e) {
if (RowSorterEvent.Type.SORT_ORDER_CHANGED == e.getType()) {
RowSorter source = e.getSource();
if (source == tableView.getRowSorter()) {
frozenTable.getRowSorter().removeRowSorterListener(this);
frozenTable.getRowSorter().setSortKeys(source.getSortKeys());
frozenTable.getRowSorter().addRowSorterListener(this);
} else {
tableView.getRowSorter().removeRowSorterListener(this);
tableView.getRowSorter().setSortKeys(source.getSortKeys());
tableView.getRowSorter().addRowSorterListener(this);
}
}
}
};
At another point in my code, I want to be able to get the TableColumn objects that are currently being sorted on. Before I added the frozentable, I was able to do this with the following code:
List<? extends SortKey> sortKeys = tableView.getRowSorter().getSortKeys();
for(SortKey key : sortKeys){
TableColumn column = tableView.getColumnModel().getColumn(key.getColumn());
// other stuff in the loop
}
It seems as though a SortKey only has two things in it, a column index and a SortOrder. This raises two questions:
How is my RowSorterListener even managing to sort the tables based on columns from one or the other table? If all I'm passing when I say 'setSortKeys' is 'sort by column 3' and column 3 is different for each JTable, then how is this working in the first place? Because it does work. If I have a Name column in the frozenTable and an Age column in the tableView and I sort by Age, it does sort both JTables by the Age column.
How do I get the TableColumn object associated with a SortKey?
Check out the Fixed Column Table which is a reusable class that allows you to share a model between two tables
The code to create the fixed column table is:
JTable table = new JTable(...);
table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
JScrollPane scrollPane= new JScrollPane( table );
FixedColumnTable fct = new FixedColumnTable(2, scrollPane);
JTable fixed = fct.getFixedTable();
I don't think you need the sorter listener.
You should just be able to share the RowSorter using code something like:
table.setAutoCreateRowSorter(true);
fixed.setRowSorter(table.getRowSorter());
table.setUpdateSelectionOnSort(true);
fixed.setUpdateSelectionOnSort(false);

How to Insert row data from database into specific columns of a JTable?

I have written a GUI Java program that manages a MySQL database. The user selects which columns (which tables and columns will be selected from the database) he/she wants to populate the JTable with.
I hard-coded the column names for the JTable so even if the user chooses to only display the data from a subset of columns, all of the column-names will be visible.
The problem is that when the user chooses columns in a different order than my JTable is anticipating, the data gets displayed in the wrong column.. It's a bit hard to explain so here's a screenshot of the genre data being loaded into the length column:
tableGenerator class:
package gui;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Vector;
public class TableGenerator
{
private ArrayList columnNames = new ArrayList();
private ArrayList data = new ArrayList();
private Vector columnNamesVector = new Vector();
private Vector dataVector = new Vector();
private int columns = 0;
private int rows = 0;
#SuppressWarnings("unchecked")
public TableGenerator(ResultSet rs)
{
try{
ResultSetMetaData md = rs.getMetaData();
columns = md.getColumnCount();
// Get column names
columnNames.add("Title");
columnNames.add("Year");
columnNames.add("Length");
columnNames.add("Genre");
columnNames.add("Actor");
columnNames.add("Producer");
columnNames.add("Director");
columnNames.add("Writer");
// Get row data
while (rs.next())
{
ArrayList row = new ArrayList(columnNames.size());
for (int i = 1; i <= columns; i++)
{
row.add(rs.getObject(i));
}
data.add( row );
rows++;
}
}
catch (SQLException e)
{
System.out.println( e.getMessage() );
}
// Create Vectors and copy over elements from ArrayLists to them
// Vector is deprecated but I am using them in this example to keep
// things simple - the best practice would be to create a custom defined
// class which inherits from the AbstractTableModel class
for (int i = 0; i < data.size(); i++)
{
ArrayList subArray = (ArrayList)data.get(i);
Vector subVector = new Vector();
for (int j = 0; j < subArray.size(); j++)
{
subVector.add(subArray.get(j));
}
dataVector.add(subVector);
}
for (int i = 0; i < columnNames.size(); i++ )
columnNamesVector.add(columnNames.get(i));
}
public Vector getColumns(){
return columnNamesVector;
}
public Vector getData(){
return dataVector;
}
public ArrayList getColumnNames(){
return columnNames;
}
public int getNumberOfRows(){
return rows;
}
}
I'm using the DefaultTableModel with some modifications.. :
model = new DefaultTableModel(rows, columns){
private static final long serialVersionUID = 1L;
#Override
public boolean isCellEditable(int row, int column) {
return false;
}
#Override
public Class<?> getColumnClass(int column) {
if (column < classes.length)
return classes[column];
return super.getColumnClass(column);
};};
Your query should always return the data for all columns. This means the data will be stored in the same manner in the TableModel.
You can then change the view for the columns to be displayed. That is you can remove TableColumns from the TableColumnModel of the JTable and only the data the user want to view will be displayed, even though it is still available in the model. Then means the user can click on any check box at any time and you don't need to redo the database query, only add the TableColumn back to the table.
Check out Table Column Manager for an example of this approach. This class uses a popup menu to manage the columns, but you can still use your check boxes. You just need to invoke the appropriate method of the TableColumnManager to hide/show a column. That is, assuming the labels of the check boxes match the headings in the table you can just use the check box text to hide/show a column.
The other approach is to NOT hard code the column names (if you build your query to only get specific columns) but instead get the column names from the meta data of the ResultSet. The TableFromDatabaseExample.java from Table From Database shows how this can be done. The code is generic so that appropriate renderers are used for Dates, Integers etc.

How to add a row to JTable after populating data using DbUtils.resultSetToTableModel?

I have a JTable defined in this way:
public JTable table_1;
model_3 = new DefaultTableModel();
table_1 = new JTable(model_3);
scrollPane_5.setViewportView(table_1);
Add row:
model_3.addRow(new Object[]{table.getValueAt(row,0) , table.getValueAt(row,1) ,table.getValueAt(row,2) , commentFood });
Remove Row:
model_3.removeRow(row); //row is an integer
Until here, it used to work properly. As you can see this table is defined as public because sometimes I need to fill it up from another JFrame in this way:
takeOrder to = new takeOrder();
//Get data from DB to resultSet
to.table_1.setModel(DbUtils.resultSetToTableModel(resultSet));
If I fill up the table in this way and try to add or remove my model_3, it will not work! Any suggestion that how I can add or remove to the table after using DbUtils.resultSetToTableModel(resultSet) will be appreciated.
As I couldn't find any information on the internet and I saw couple of people asked same question with no answer. I came up with this solution:
if (formOut) {
for (int i = 0; i < table_1.getRowCount(); i++) {
model_3.addRow(new Object[]{table_1.getValueAt(i,0),
table_1.getValueAt(i, 1), table_1.getValueAt(i, 2)});
}
}
formOut = false;
table_1.setModel(model_3);
fromOut is a boolean to check if I have used another model for my table. If so I add data from table to previous model, and then I reference that model to my table. Now I can add to that model as well.

Scroll to last added row in JTable

I use a HashMap to fill a JTable, which is more or less continuously updated:
public Map< Long, MyObject > tableData = new HashMap< Long, MyObject >();
Every time a new element is added to the map the table model is notified:
tableData.put(id, anObject);
AbstractTableModel atm = (AbstractTableModel)model;
atm.fireTableDataChanged();
In Addition I have a TableRowSorter which sorts the rows according to a specific criteria:
TableRowSorter<TableModel> sorter = new TableRowSorter<TableModel>(model);
.
.
.
table.setRowSorter(sorter);
My goal is that the (vertical) scrollbar always jumps to the last added row, which can be somwhere in the mid
of the table because of the sorter probably using this:
table.scrollRectToVisible(table.getCellRect(row,0, true));
The problem is I do not know the index of the row :) Where can I hook in to get this index?
Scrolling to a newly inserted row in a potentially sorted table involves
listening to changes in the table model
converting the rowIndex of the event (it is in model coordiates) to view coordinates
scrolling to the view position
In code:
final JTable table = new JTable();
TableModelListener l = new TableModelListener() {
#Override
public void tableChanged(TableModelEvent e) {
if (TableUtilities.isInsert(e)) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
int viewRow = table.convertRowIndexToView(e.getFirstRow());
table.scrollRectToVisible(table.getCellRect(viewRow, 0, true));
}
});
}
}
};
table.getModel().addTableModelListener(l);
Two important aspects:
your model implemenation must fire the correct event, that is a insert, not a dataChanged
invoking both index conversion and scrolling guarantees that the table (which is listening to the model as well) has updated all internal state according to the model change.

How do I get an updated post-sort TableModel?

I have a JTable using setAutoCreateRowSorter(true) and a RowSorterListener attached, per below, because I need to perform some operations elsewhere in my application upon a sort of the JTable.
I find that whenever I click a column header to sort, the JTable redisplays the rows in the proper order and the listener is called, but the TableModel I pull out is always the original pre-sort table model.
table.getRowSorter().addRowSorterListener(new RowSorterListener() {
#Override
public void sorterChanged(RowSorterEvent rsevent) {
rsevent.getSource().getModel(); // Nope, original ordering here
table.getModel(); // Same thing
}
};
How do I get the new post-sort ordering of the rows, as is now displayed in the JTable?
The data in the TableModel never changes, only the view of the data changes.
If you want the data from the model in the order it is displayed in the table then you just use:
table.getValueAt(row, column);
In other words you need to iterate through all the rows and columns to get the data in the currently viewed order.
I think you can use table.convertRowIndexToModel(int ...), however I think that there's a better solution available.
If you define your own convertRowIndexToModel() that's a quick lookup (perhaps through a map, O(1)), that solution should be sufficient. If it's O(n), then that's what needs to be fixed.
Simply go through a loop of the rows, convert each one and do the lookup using the resulting index.
Here's 2 methods in TableSorter that should be of interest:
private Row[] getViewToModel() {
if (viewToModel == null) {
int tableModelRowCount = tableModel.getRowCount();
viewToModel = new Row[tableModelRowCount];
for (int row = 0; row < tableModelRowCount; row++) {
viewToModel[row] = new Row(row);
}
if (isSorting()) {
Arrays.sort(viewToModel);
}
}
return viewToModel;
}
and:
private int[] getModelToView() {
if (modelToView == null) {
int n = getViewToModel().length;
modelToView = new int[n];
for (int i = 0; i < n; i++) {
modelToView[modelIndex(i)] = i;
}
}
return modelToView;
}
Hi I know this is a really late answer, but I tried the code used on the comment of #LazyCubicleMonkey and it did work here is my code in getting the row when the jTable is sorted.
DefaultTableModel search_model = (DefaultTableModel) jTable.getModel();
search_model.removeRow(jTable.convertRowIndexToModel(row));
jTable.setModel = (search_model)

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