Connections can be highlighted multiple times

[maribethb]

Describe the bug

A connection can be highlighted multiple times, and there's no way to unhighlight it multiple times, as only the last reference is saved. This problem is exacerbated by the fact that there is no API to tell if a connection is already highlighted, as highlightPath is a private property.

Suggestion:

• in highlight, if highlightPath already exists, then silently return early because it's already highlighted.
• provide a isHighlighted method that returns true if highlightPath exists.

only one of the two is required, but both could be useful.

To Reproduce

connection.highlight();
connection.highlight();
connection.unhighlight();
connection.unhighlight();

connection is still highlighted.

Expected behavior

Connection is not highlighted multiple times.

Screenshots

Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Stack Traces

Additional context

https://groups.google.com/g/blockly/c/lYbTqXR2yq4

[maribethb]

Closed by #6502 Thanks Koen!