JavaFX copying over a object from one tableview to another with a button - button

Question

So I´m building a warband calculator for a tabletop game and currently it looks like this
What I wanna do is that when I click on a "add" button it copies that unit/creature over to the tableview on the right side(So if I click on the "add" button on the Zombie row, a zombie gets copied over the tableview on the right).
The problem is I can only make it work if you select the row THEN click the button, but I want to be able to rely solely on the button. I think the problem is that I use "getSelectionModel().getSelectedItem()" in the button class to get the object to be copied over, But I cant find any other way to do it.
The relevant code parts from the main class
//Creates the lists
ObservableList<Unit> rightSideList = FXCollections.observableArrayList();
ObservableList<Unit> leftSideList = FXCollections.observableArrayList();
// Puts some test data in the lists
public Main() {
rightSideList.add(new Unit("Skeleton",5,4,9,4,1,6,9));
rightSideList.add(new Unit("Ghoul",6,4,010,4,1,6,7));
rightSideList.add(new Unit("Zombie",4,5,1,3,1,6,5));
rightSideList.add(new Unit("Wraith",4,5,19,3,1,6,5));
rightSideList.add(new Unit("Spectre",4,5,1,3,1,6,5));
leftSideList.add(new Unit("Skeleton",5,4,0,4,1,6,9));
}
//Creates the tables
final TableView<Unit> table1 = new TableView<>(
rightSideList
);
final TableView<Unit> table2 = new TableView<>(
leftSideList
);
//Defines the table columns
//Columns for table 1
TableColumn<Unit,String> unitNameCol = new TableColumn<>("Unit");
unitNameCol.setCellValueFactory(new PropertyValueFactory("unitName"));
unitNameCol.setMinWidth(100);
TableColumn<Unit,Integer> speedCol = new TableColumn<>("Spd");
speedCol.setCellValueFactory(new PropertyValueFactory("speed"));
TableColumn<Unit,Integer> meleeCol = new TableColumn<>("Me");
meleeCol.setCellValueFactory(new PropertyValueFactory("melee"));
TableColumn<Unit,Integer> rangedCol = new TableColumn<>("Ra");
rangedCol.setCellValueFactory(new PropertyValueFactory("ranged"));
TableColumn<Unit,Integer> defenseCol = new TableColumn<>("Def");
defenseCol.setCellValueFactory(new PropertyValueFactory("defense"));
TableColumn<Unit,Integer> attackCol = new TableColumn<>("Att");
attackCol.setCellValueFactory(new PropertyValueFactory("attack"));
TableColumn<Unit,Integer> toughnessCol = new TableColumn<>("To");
toughnessCol.setCellValueFactory(new PropertyValueFactory("toughness"));
TableColumn<Unit,Integer> costCol = new TableColumn<>("Cost");
costCol.setCellValueFactory(new PropertyValueFactory("cost"));
TableColumn<Unit, Boolean> actionCol = new TableColumn<>("Action");
actionCol.setSortable(false);
actionCol.setMinWidth(35);
// define a simple boolean cell value for the action column so that the column will only be shown for non-empty rows for table 1
actionCol.setCellValueFactory(new Callback<TableColumn.CellDataFeatures<Unit, Boolean>, ObservableValue<Boolean>>() {
#Override public ObservableValue<Boolean> call(TableColumn.CellDataFeatures<Unit, Boolean> features) {
return new SimpleBooleanProperty(features.getValue() != null);
}
});
// create a cell value factory with an add button for each row in the table for table 1
actionCol.setCellFactory(new Callback<TableColumn<Unit, Boolean>, TableCell<Unit, Boolean>>() {
#Override public TableCell<Unit, Boolean> call(TableColumn<Unit, Boolean> unitBooleanTableColumn) {
return new AddUnitCell(mainStage, table1);
}
});
And here is the button class
/** A table cell containing a button for adding a unit */
private class AddUnitCell extends TableCell<Unit, Boolean> {
// a button for adding a new Unit.
final Button addButton = new Button("Add");
// pads and centers the add button in the cell.
final StackPane paddedButton = new StackPane();
/**
* AddUnitCell constructor
* #param stage the stage in which the table is placed.
* #param table the table to which a unit can be added.
*/
AddUnitCell(final Stage stage, final TableView<Unit> table) {
paddedButton.setPadding(new Insets(3));
paddedButton.getChildren().add(addButton);
addButton.setOnAction(new EventHandler<ActionEvent>() {
#Override public void handle(ActionEvent actionEvent) {
Unit selectedUnit = table.getSelectionModel().getSelectedItem();
leftSideList.add(selectedUnit);
}
});
}
/** places an add button in the row only if the row is not empty. */
#Override protected void updateItem(Boolean item, boolean empty) {
super.updateItem(item, empty);
if (!empty) {
setContentDisplay(ContentDisplay.GRAPHIC_ONLY);
setGraphic(paddedButton);
} else {
setGraphic(null);
}
}
}
If you need to check in detail here is a link to the projects repository
https://github.com/MagnusLindstrom88/Star-Struck-City-Warband-Calculator/blob/master/src/application/Main.java

Answer 1

Instead of
Unit selectedUnit = table.getSelectionModel().getSelectedItem();
in the button event handler's handle() method, do
Unit selectedUnit = table.getItems().get(getIndex());

Answer 2

Instead of relying on the selection model to get the item, you should get the item from the TableRow:
Unit selectedUnit = (Unit) getTableRow().getItem();