The way this function works at the moment is a little unreliable depending on how small the component is made.
The zone testing currently checks for a proportion of the component area (10%), which is obviously much smaller if the component is very small. As the resizer has a border thickness (which should stay constant regardless of size) i think it makes more sense to check that it’s within the the actual border area.
In my version i’ve changed the testing portion of it to this (i’ve left in comments the lines that i’ve changed)
// if (e.x < proportionOfWidth (0.1f)) if (e.x < leftBorder) newZone |= zoneL; // else if (e.x > proportionOfWidth (0.9f)) else if (e.x > getWidth () - rightBorder) newZone |= zoneR; // if (e.y < proportionOfHeight (0.1f)) if (e.y < topBorder) newZone |= zoneT; // else if (e.y > proportionOfHeight (0.9f)) else if (e.y > getHeight () - bottomBorder) newZone |= zoneB;