Dominoes: Now with level completion

In an earlier post, I claimed that the game was "playable" at some level - assuming the player understood the rules and was willing to enforce them.

This version now knows about the clues, and will indicate if the player has placed a domino in a slot that is clued differently than the placed domino. It also knows about adjacencies, so if you place a domino in conflict with an existing domino, you'll see that.

Also, once all dominoes have been placed, if there are no conflicts, you've found a solution, and you get notified.

So, pretty much, all working. There are a few more things I want to do:

• Detect if you drop a domino into a slot that already has a domino, and skip snapping the domino into the slot. This should make a certain class of sloppy mouse moves less annoying.
• Provide a "Reset" button to clean up the board to a start position.
• More puzzles. I have a few in mind, and it wouldn't be hard to create more. This one puzzle isn't very challenging.
• Puzzle navigation - once there are multiple puzzles, you'll need to be able to move from one to the next.

Even though the "more puzzles" one is important from the players' perspective, I'm ready to call this one feature complete, and everything else is polish. Which is good - I've got other things I want to do between now and the end of the month.