Card alternate text property

[samreid]

From #204

The user story is:

Card visible property - per card

@marlitas and I observed that each card currently has a visibleProperty that can be toggled off. This leaves a hole in the card container like so:

Therefore, we would like to know more about this user story. Is it so that clients can ask students to predict the value of a card? If so, would it be better to have a card with a '?' question mark on it?

[catherinecarter]

I would think the user story would, indeed, be to hide the card with the intent of predicting what value would be in it's place. I agree having something there would be useful, especially if the card hidden is the far most right card (you wouldn't know one is missing). Here's what it would look like with one card with a ?:

And if multiple cards were 'hidden:'

[samreid]

We would like to add an "alternate text" feature to each card. By default it would be null, which means no alternate text (and hence just show the number). This would be documented in examples #136. We will use maxWidth to make sure it stays within the card. Once done, we can review the behavior with @kathy-phet

[samreid]

Before starting, we should check if the alternate text needs to be internationalized. I recommend against it, because that would make the cost exceed the value. And clients could use the wrapper to specify different placeholders in different languages.

[catherinecarter]

@kathy-phet is questioning the pedagogical advantage to hiding the card's values and replacing with something else. Some example user stories/pedagogical moves could include:

• Making an explicit 1:1 correspondence connection between the ball positions and the values on the cards
• A question could be posed to ask students to work backwards, show the median, and then fill in the cards with possible values
  • This could be done if the balls are all hidden so there wouldn't be the visual cue

The underlying question is to create a move using the sim, and this feature doesn't seem to support these pedagogical user stories because they don't leverage the sim.

Recommendation: Do not implement this feature.

Don't support visibility but continue to support enable/disable in the case that the "Sort Data" checkbox is checked, the user shouldn't be able to interact with the cards because if they did, the "Sort Data" would automatically uncheck. This is not desirable because if the checkbox is disabled, the user couldn't re-check the box.

In examples.md, note this possible unwanted interaction if a student moves the card while the "Sort Data" checkbox is disabled or hidden. #136

[samreid]

In the commits, we uninstrumented card visibility, and instrumented the cardNodeContainer.enabledProperty. But we still need to hide the hand when cardNodeContainer.enabledProperty is false. And make them a bit grayed out.

[samreid]

We reviewed that behavior, and agreed it is good, closing. Does not need code review since it was trivial.