Add checking the compactType null value to avoid breaking the layout when overlapping is allowed.

[jaloveeye]

When allowOverlap is true and compactType is null, the layout is unintentionally transformed like the AS-IS gif.

Adding an exception when compactType is null in compactItem avoids unintended layout transformed.

[STRML]

Shouldn't this also be checking if allowOverlap is true? Otherwise, when it is the default value, no collisions will occur when compactType is null.

[jaloveeye]

@STRML
Thank you for your advice.
I was missing out that.
Your advice has been reflected.

[STRML]

Thanks!