Question

Is it possible to navigate an NSTableView’s editable cell around the NSTableView using arrow keys and enter/tab? For example, I want to make it feel more like a spreadsheet.

The users of this application are expected to edit quite a lot of cells (but not all of them), and I think it would be easier to do so if they didn’t have to double-click on each cell.

Answer 1

Well it isn’t easy but I managed to do it without having to use RRSpreadSheet or even another control. Here’s what you have to do:

1. Create a subclass of NSTextView, this will be the field editor. For this example the name MyFieldEditorClass will be used and myFieldEditor will refer to an instance of this class.

2. Add a method to MyFieldEditorClass called ‘- (void) setLastKnownColumn:(unsigned)aCol andRow:(unsigned) aRow‘ or something similar, and have it save both the input parameter values somewhere.

3. Add another method called ‘setTableView:’ and have it save the NSTableView object somewhere, or unless there is another way to get the NSTableView object from the field editor, use that.

4. Add another method called - (void) keyDown:(NSEvent *) event. This is actually overriding the NSResponder‘s keyDown:. The source code should be (be aware that StackOverflow’s MarkDown is changing < and > to < and >):

   - (void) keyDown:(NSEvent *) event {     unsigned newRow = row, newCol = column;     switch ([event keyCode])     {         case 126: // Up             if (row)             newRow = row - 1;             break;          case 125: // Down             if (row < [theTable numberOfRows] - 1)                 newRow = row + 1;             break;          case 123: // Left             if (column > 1)                 newCol = column - 1;             break;          case 124: // Right             if (column < [theTable numberOfColumns] - 1)                 newCol = column + 1;             break;          default:             [super keyDown:event];             return;     }      [theTable selectRow:newRow byExtendingSelection:NO];     [theTable editColumn:newCol row:newRow withEvent:nil select:YES];     row = newRow;     column = newCol; } 

5. Give the NSTableView in your nib a delegate, and in the delegate add the method:

   - (BOOL) tableView:(NSTableView *)aTableView shouldEditColumn:(NSTableColumn *) aCol row:aRow {     if ([aTableView isEqual:TheTableViewYouWantToChangeBehaviour])         [myFieldEditor setLastKnownColumn:[[aTableView tableColumns] indexOfObject:aCol] andRow:aRow];     return YES; } 

6. Finally, give the Table View’s main window a delegate and add the method:

   - (id) windowWillReturnFieldEditor:(NSWindow *) aWindow toObject:(id) anObject {     if ([anObject isEqual:TheTableViewYouWantToChangeBehaviour])     {         if (!myFieldEditor)         {             myFieldEditor = [[MyFieldEditorClass alloc] init];             [myFieldEditor setTableView:anObject];         }         return myFieldEditor;     }     else     {         return nil;     } } 

Run the program and give it a go!