Overglyph Function

Hello I was wondering whether someone could explain what the overglyph function is doing in LabelTrack.h/cpp. I am new to the forum, what exactly are the glyphs that the function is looking for. Are they track labels?

The “glyphs” are the various elements that make up the label graphic, such as the circle in the middle of the stem (the “drag handle center”), the triangles either side of the circle (the left/right “drag handles”), and so on.

When is the function being called, what would I have to reproduce in a project to make the program call this function

Where is this going? The function is clearly called in two places, once in LabelTrack::HandleClick and once in TrackPanel::SetCursorAndTipWhenInLabelTrack. Why do you need to know?