Question

I am using a third-party control (Aspose.Cells.GridWeb). It is basically a web based Excel control. When a user selects a cell, the onCellSelected event is raised by the control.

The thing is, I need to know what key was pressed by the user to cause this event to be raised. I need this information to determine how to handle the event.

I am using JQuery’s keydown event to capture the button clicked.

    $(document).keydown(function(event) {
        isKeyLastClicked = true;
        keyLastClickedId = event.which;
        isMouseButtonLastClicked = false;
        mouseButtonLastClickedId = null;
    });

The problem is that the control’s onCellSelected event is raised BEFORE the keydown event is raised. Is this expected behavior?

Is there any way to get the id of the key before the control’s event is raised?

Thanks in advance.

Answer 1

After a long discussion at the SO chat…
Since binding the keydown event does not produce the desired results, you have to alter the onCellSelected function. It should follow the next pattern:

1. When onCellSelected is triggered for the first time, the first argument (cell) is assigned to a (temporary) variable.
2. Then, when a keydown event occurs, the key code is checked:
   • If the pressed key (ev.which or ev.keyCode) equals a certain key, the onCellSelected function is called again, passing the value of the temporary variable as a first argument.
   • Else, the temporary variable is cleared, since it makes no sense to remember it.

The code would have the following structure. Modify it to suit your application:

var lastCell = null;
function onCellSelected (cell) {
    if(lastCell == null) {
        lastCell = cell;
        return; //Wait for the next listener
    }
    ... //Rest of code
}

$(document).keydown(function(e){
    if(lastCell == null) return; //No need to do unnecessary calculations
    //Whatever you want, example:
    if(e.keyCode == 32) {
        onCellSelected(lastCell);
        lastCell = null; //Reset
    }
    ... //Rest of code
});

Note: keyCode, charCode and which, see also: http://asquare.net/javascript/tests/KeyCode.html