GWT: include undefined class parameter on function

Question

I have this function in my GWT project:

private InputElement getInputElement(int rowIndex, int columnIndex, 
CellTable<MyClassA> cellTable) {
        InputElement input = null;
        if (isColumnEditable(columnIndex)) {
            input = (InputElement) cellTable.getRowElement(rowIndex).getCells().getItem(columnIndex).getFirstChild().getFirstChild();
        }  
        return input;
    }

If would like to re-use this function when the last parameter is CellTable<MyClassB>, because the rest of the code is exactly the same. How can I do that?

Answer 1

You can write the following code -

public interface MyClassInterface { ... }

public class MyClassA implements MyClassInterface { ... }

public class MyClassB implements MyClassInterface { ... }

private <T extends MyClassInterface> InputElement getInputElement(int rowIndex, int columnIndex, CellTable<T> cellTable)                    
{             
    InputElement input = null;              
    if (isColumnEditable(columnIndex))  
    {  
        input = (InputElement)  cellTable.getRowElement(rowIndex).getCells().getItem(columnIndex).getFirstChild().getFirstChild();  
    }  
    return input;

}

Answer 2

You need to make a interface MyClassInterface and implement it in both classes.

public interface MyClassInterface {

}

public class MyClassA implements MyClassInterface {
   ...
}
public class MyClassB implements MyClassInterface {
   ...
}
private InputElement getInputElement(int rowIndex, int columnIndex, 
CellTable<? extends MyClassInterface> cellTable) {
        InputElement input = null;
        if (isColumnEditable(columnIndex)) {
            input = (InputElement) cellTable.getRowElement(rowIndex).getCells().getItem(columnIndex).getFirstChild().getFirstChild();
        }  
        return input;
    }