TableView delete column via contextual menu - dynamic

Question

It is my first time asking here, sorry if i do something wrong (also not in my mother tongue).
Recently, i moved from Swing&AWT to JavaFX.
I am discovering the new Table which is quite different from the Swing version. Better i would say, it needs less operation and do more things, but ... lord, it's way more difficult to understand !
I am currently trying to modify the TableView dynamically. While the addColumn method is not a big challenge, i need help for my deleteColumn method :/
Let's talk about my problem :
I have a scene with many components on it (panes, buttons, menus, ...) and one pane (actually an anchorpane) hosts a TableView.
I would like to dynamically delete an entire column when this operation occurs :
The user right clicks on the TableView > a contextual menu shows up > he selects the item "delete"
So, basically a contextual menu that offers the option to delete the column where the user right-clicked.
I tried this :
-> When the user right-clicks on the TableView, this method is called :
public void setTargetForContext(ContextMenuEvent event){
if(event.getTarget() instanceof Label){
ObservableList list =(((Label)event.getTarget()).getChildrenUnmodifiable());
activeColumn = ((Text)((ObservableList)list)).getText();
}...
And the goal was to set the column name in "activeColumn".
Then, when the user will select the "delete" option from the contextual menu, another method would be called to compare the name of the columns and delete the right one.
But it seems that i can't call a getChildren() method on the label, only an unmodifiable one. And it does not allow a cast and throw the exception.
Do you have a solution to allow me to get the column name ?
Or maybe i am going the wrong way and i have to find another way to delete the right-clicked column, but in this case i will need your help too.
Thanks a lot for reading, and thanks in advance for your help.

Answer 1

First, let me point out that if you call
table.setTableMenuButtonVisible(true);
then the table will have a built-in menu button with radio buttons allowing the user to select which columns are displayed. Maybe this is all you need.
In Swing, the renderers for table cells are just "rubber stamps" that are painted onto the table. Thus you can't register listeners for UI events with them.
By contrast, in JavaFX, the cells in a table are real UI controls with full functionality. This means there's no real need for API that gets the cell coordinates from a table. You should not register your listener with the TableView, but with the actual cells on which you want to operate. You access the cells from the table column's cell factory.
// the table:
TableView<RowDataType> table = new TableView<>();
//...
// A table column:
TableColumn<RowDataType, CellDataType> column = new TableColum<>("Header text");
// A context menu for the table column cells:
ContextMenu contextMenu = new ContextMenu();
MenuItem deleteColumnItem = new MenuItem("Remove Column");
deleteColumnItem.setOnAction(e -> table.getColumns().remove(column));
contextMenu.getItems().add(deleteColumnItem);
// Cell factory for the column
column.setCellFactory(col -> {
// basically a cell with default behavior:
TableCell<RowDataType, CellDataType> cell = new TableCell<RowDataType, CellDataType>() {
#Override
public void updateItem(CellDataType item, boolean empty) {
super.updateItem(item, empty);
if (item == null) {
setText(null);
} else {
setText(item.toString());
}
}
});
// add the context menu to the cell:
cell.setContextMenu(contextMenu);
return cell ;
});
If you want the context menu to appear in the table column header as well, you just need to do
column.setContextMenu(contextMenu);