Hide or disable

In redesigning the 21st puzzle, we came up with a new correct solution. However, we found that there was a way to complete the puzzle without the correct solution if we used the conventional puzzle movement procedure. To avoid this, we decided that the puzzle movement was only possible in certain places.

The problem with this is that we need to inform the user that the puzzle cannot be moved. Therefore, we decided to disable the operation UI. This was a new design because there was no such state before.

So we tried to create functions like DisableUIIcon()/EnableUIIcon(), but we found that similar functions already existed. We checked and found that these functions were for temporarily showing/hiding the UI in a different puzzle. So we changed them to HideUIIcon()/ShowUIIcon().

Last week involved a bit of refactoring, including creating a new disabled icon.