CODEWITHSUNDEEP
smalltalksqueak
Eric Clack
Eric Clack

Reputation: 1926

How do I animate a morph without using step?

I want to animate a dice being rolled, but don't want to use the Morph>>step methods because I want more control over when the roll finishes. I know that I can use Delay>>wait within a forked block to see my animation, but then how should I call this method from other methods to ensure I get the final numberRolled?

Here's my roll method:

roll
    | n t |
    numberRolled := nil.
    [
        t := 10 + (10 atRandom).
        t timesRepeat: [
            n := 6 atRandom.
            self showNumber: n.
            (Delay forSeconds: 0.1) wait.
        ].
        numberRolled := n.
    ] fork.

So if I call this from a method like guessLower the roll method returns instantly because the real work is completed in the forked process.

guessLower
    previousNumberRolled := numberRolled.
    self roll.
    "this next line is called before the dice has finished rolling"
    self checkWin: (numberRolled < previousNumberRolled)

My current solution is to modify roll method to take a block, which that executes after the rolling has finished e.g. rollAndThen: aBlock but is there a more elegant / simpler solution?

Upvotes: 3

Views: 290

Answers (1)

codefrau
codefrau

Reputation: 4623

In Morphic it is a Really Bad Idea to use Delays and explicit looping.

But it is really simple to make the step method do what you want: Inside you simply check if it should continue rolling or not. Then you do self stopStepping. self checkWin: ....

Upvotes: 1

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