Keypad.java

Hello, I have a question on page 85 regarding SetListeners() in Keypad.java. We use a for loop to set listeners for all keypad values and then we do the same for keypad. My question is, does setting listeners on keys[] alone suffice? Do we really need to set listener for keypad and call returnResult with a zero?

Thanks!

The short answer is ‘yes’. The explanation in the paragraph after the code says why, to paraphrase clicking a button with a number on it returns the number, clicking a blank tile returns zero to indicate there is no number.

Thanks for reply. But since invalid buttons views are already set invisible, could we simply not register onclickListeners to those buttons that are set invisible and simply do nothing when clicked? Other words, no events would be raised when they are tapped on/clicked upon?

I did it that way so if you clicked anywhere in the Keypad view where there wasn’t a number, it would erase the current tile. It does this whether you clicked on the spot an invisible number would normally have been, or in the padding between or around the numbers, or off to the side, as long as you’re still somewhere in the Keypad view’s rectangle.

Another way to do it would have been to add a “Clear” button to the Keypad view.