[kwvanderlinde]

Identify the Bug or Feature request

Resolves #6068

Description of the Change

The main feature in this PR is that the Increments field for the States tab is now disabled when editing a Mutiple Images bar:

When the bar is saved (Add'ed or Update'd), the increments for the bar is set to the number of images, ignoring the Increments field altogether. It is no longer required for the Increments to be manually set to the number of images before the bar can be saved. As a result, there is no more need for the "Unneeded" label for any images, since all images naturally always contribute. The other labels ("Empty Bar", "Full Bar", "Increment #") now have i18n keys rather than hardcoded the English text.

Also included is a performance improvement for image-based bars (and states). Rendering these no longer call ImageManager.getImageAndWait(...) (blocking the main thread), but instead pass an ImageObserver to ImageManager.getImage(...) for non-blocking behaviour. Until an image loads, it will be displayed as the "?" transferring image.

Some refactoring was also done to make bars a bit more robust and obvious:

• MultipleImageBarTokenOverlay now guarantees that its #getIncrements() returns the same as the number of assets it contains. Any #setIncrements() call is ignored now.
• Bar increment lookups are more robust now. There is no risk of returning out-of-bounds results when provided a value that is too small or large, or when the increments are set to 0. In particular, BarTokenOverlay#findIncrement() and BarTokenOverlay#calcBarSize() are both now internal to the bar hierarchy, where preconditions can be better ensured.
• The implementation of the getBarImage() is no longer responsible for indexing into a MultipleImageBarTokenOverlay asset array. Instead, the bar can safely do its own lookup, while keeping the macro code simpler as well.
• TwoToneBarTokenOverlay no longer inherits from DrawnBarTokenOverlay since it had to override all the meaningful behaviour anyways, and all they really shared was two fields. This also makes the instanceof logic in TokenBarController a little more obvious.
• Common bar DTO logic is handled entirely within BarTokenOverlay now. Child classes must set their type and custom fields in #toDtoImpl(), and must read their custom fields back in #fromDtoImpl(), while all common logic is handled in #toDto() and #fromDto().
• The default constructors for concrete bar classes have been removed as they aren't really needed, and sometimes created objects in invalid states.

Possible Drawbacks

Should be none.

Documentation Notes

N/A

Release Notes

• Improved the States tab of the Campaign Properties so that the increment field does not have to be manually matched to the number of images in a Multiple Images bar.

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