I have a JTable and a Model for that table.
Now I want to change the order of the columns and to hide or show some columns (e.g. like Windows Explorer in "Detail View" via Menu on rightclick).
My first problem here is, the getColumnName function. Do I have to keep track of, which column is at which place and then return the right columnName or is this already part of the model?
Same for the getValueAt function. Can I always return the value for the first column if I get columnIndex = 0, even if the user has dragged this column to the end of the table?
And nearly the same problem for adding/removing columns. If I do that, of course I have to fireTableStructureChanged, but do I also have to adapt e.g. the getColumnName function?
I haven't found a tutorial for that. All tutorials stop at "you can use a model".
I'd really like to see an example of such a dynamic model.
Thanks a lot.
You should use the getColumn(int) method of the model, and for accessing the model, you'll need to convert the row and column view indices with JTable's convertRowIndexToModel(int), convertColumnIndexToModel(int) and the equivalents for converting the model indices to view indices.
You need to understand the difference between the "View" and the "Model". When you reorder the columns in the JTable (view), this does not change the order of the data in the model.
If you want to access the first column that is displayed in the table you use:
table.getValueAt(row, 0);
if you want to access the first column in the model, then you use:
table.getModel().getValueAt(row, 0);
I want to hide or show some columns
See Table Column Manager.
Related
I have implemented a JTable, on which I can search entries with a textField.
When a request is made, my code gets the DefaultTableModel, looks for the element in each column and row, and then sets the selection in the table to the line where the element was found.
This works, but it's useless if I sort the table by clicking on any column, because the sorting doesn't seem to update the DefaultTableModel.
The table is part of a bigger project which is extremely complicated and full of dependencies so I cannot post a small example, but I think this will sum it up:
Given a DefaultTableModel A full of non-sorted data about a JTable B, where B.setAutoCreateRowSorter() is true , how does one update B after several/any cloumn-sortings of A?
I have read the docs and also looked into this:
http://www.codejava.net/java-se/swing/6-techniques-for-sorting-jtable-you-should-know
As well as dug a bit into TableRowSorter#addRowSorterListener, but it can only tell me that a column was sorted, not really useful. Unless of course I use what that column is to try and sort all the values in a multidimensional array, then clear the table, then assign everything back.. but clearly this is extremely slow for and not really an option in my case.
Refer to this for the info provided by a RowSorterEvent:
https://docs.oracle.com/javase/7/docs/api/javax/swing/event/RowSorterEvent.html
Can someone point me in the right direction ?
When a request is made, my code gets the DefaultTableModel, looks for the element in each column and row...
So don't search the TableModel. You can use the table.getValueAt(...) method to search for the element in each row/column of the table. The data will be accessed in the currently sorted order of the table.
because the sorting doesn't seem to update the DefaultTableModel.
Correct, only the View (JTable) is updated.
If you want to keep searching the TableModel directly then you need to convert the model indexes to the view indexes whenever you want to invoke a JTable method (ie. selecting a table row). This is done by using the following JTable methods:
int columnColumn = table.convertColumnIndexToView(modelColumn);
int row = table.convertRowIndexToView(modelRow);
There are also methods to convert the view values to the model values.
I want to create a table (that will finally exist in a new eclipse view). This table has a few text columns, and a column that has a different behavior based on the other columns. It can either be a field to enter text, or to popup a dialog for users to select data from (and it has to be a popup or a dynamically created combo). Anyway, I know which of the two I need for each row in the column.
My table is built using TableViewer and a few TableViewerColumn's in it. I later fill them with String data in TableItem's up to 4 columns. The fifth is the one I have this special behavior.
I tried experimenting with TableEditor, but failed:
When I used one for each TableItem it somehow got misaligned with the table rows and columns
When I use one for the entire table, I fail to set a Text entry on specific rows
What I need help with is figuring out exactly how to achieve this:
A Table that has 4 String columns, where the data is constant (cannot be changed by the user)
A fifth column where the cell contents is either a Text for the user to enter, or a (preferably transparent) Button that has a popup as action, or a Combo that I dynamically fill with data upon table creation
Any idea would be highly appreciated.
OK, got this figured out. The example here helped a lot:
http://www.java2s.com/Tutorial/Java/0280__SWT/TableCellEditorComboTextandButton.htm
Oren
How do I remove unused rows from a JTable?
I first create a table of a fixed size in a JPanel and then fill elements as needed.
Now I don't want unused rows to be displayed in my table. Please help.
I presently get a table with lots of empty rows in bottom, only top 5-6 rows being used, with rest blank. I want to hide them or remove them somehow
Work the other way around. Start with an empty DefaultTableModel. DefaultTableModel supports an addRow() method. So, as you get data to add to the model use:
model.addRow(...);
Don't let the GUI editor determine how you code your GUI. Adding cleanup code to remove rows is a bad design.
DefaultTableModel has a method removeRow which removes a row from the table. Pass the row index which you want to remove from the table.
Now I don't want unused rows to be displayed in my table.
This I am not sure please post an SSCCE to show us what is the flag that says these rows are not used.
I am using Java Swingx framework. I have 4 columns in my DefaultTableModel object. I wish to display only 3 of the columns. But, I need all four for computing.
Actual data model
S.No. | ID | GDC ID | Decsription
What I want to display in table
S.No.| GDC ID | Decsription
Is it possible to hide or omit only one column from rendering? Please guide me.
by default minimum size is 10 pixels widht,
you can to remove / add column from JTable view, column presents in the XxxTableModel, you can to hide and show any of column(s)
No need to adjust your model, or to try to make that column very small. JTable has built-in functionality for this: the removeColumn method. As stated in the javadoc of that method
Removes aColumn from this JTable's array of columns. Note: this method does not remove the column of data from the model; it just removes the TableColumn that was responsible for displaying it.
Also note the existence of the following methods:
JTable#convertColumnIndexToModel
JTable#convertColumnIndexToView
Since the column order and column count in the view (the JTable) might be different from the one in the model you need those methods to switch between view and model
You can hide it by setting its width to 0.
_table.getColumn("ID").setPreferredWidth(0);
_table.getColumn("ID").setMinWidth(0);
_table.getColumn("ID").setWidth(0);
_table.getColumn("ID").setMaxWidth(0);
try this to remove a single column:
myTableModel = new DefaultTableModel();
myTableModel.setColumnIdentifiers(new Object[]{"S.No.", "ID", "GDC ID", "Decsription"});
JTable myTable = new JTable(myTableModel);
// remember to save the references
TableColumn myTableColumn0 = guiLoteryNumbersTable.getColumnModel().getColumn(0);
TableColumn myTableColumn1 = guiLoteryNumbersTable.getColumnModel().getColumn(1);
TableColumn myTableColumn2 = guiLoteryNumbersTable.getColumnModel().getColumn(2);
TableColumn myTableColumn3 = guiLoteryNumbersTable.getColumnModel().getColumn(3);
myTable.getColumnModel().removeColumn(myTableColumn1);
Then to show the column again keeping the order:
// 1- remove all the existent columns
myTable.getColumnModel().removeColumn(myTableColumn0);
myTable.getColumnModel().removeColumn(myTableColumn2);
myTable.getColumnModel().removeColumn(myTableColumn3);
// 2- add all the columns again in the right order
myTable.getColumnModel().addColumn(myTableColumn0);
myTable.getColumnModel().addColumn(myTableColumn1);
myTable.getColumnModel().addColumn(myTableColumn2);
myTable.getColumnModel().addColumn(myTableColumn3);
Sorry, but that's the best way I know.
You manipulate the getValueAt , getColumnCount to achieve this.
So for example the getColumnCount you give it as 3
and on getValueAt - to skip if the column index is above the skipped column
JTable will first call getColumnCount and getRowCount and fetch calling getValueAt for each of the cells.
NOTE: Ignore this and see link by trashgod below.
I have a swing layout with some labels and a jTable.
On the left side, I have the jTable, and on the right side I have the labels.
I want to set the page up as a master / detail page, where the jTable is the master, while the labels act as details.
I have found a way to get the index from the jTable - my question. What kind of listener can I use to tell if the user selects a row in the table?
You need to get the JTable's selection model (using getSelectionModel()) and add a ListSelectionListener to this model.
Make sure to use convertRowIndexToModel to convert the index of the selected row to an index in the table model: if the table is sorted or filtered, the view and model indices won't be the same.