property FormSelectionRects: TPdfFormSelectionRects read GetFormSelectionRects;
FormSelectionRects returns the accumulated TPdfFormSelectionRect array that the form layer reported since the last clear; each entry carries a one-based PageNumber and page-space Bounds
Duplicate consecutive rectangles are suppressed, so the array contains one entry per distinct selection rectangle
ClearFormSelectionRects to reset before drawing overlaysOnFormSelectionRectfor R in Pdf1.FormSelectionRects do
DrawFocusRing(R.PageNumber, R.Bounds);