THPDFViewerHighlight Record

Stores one page-anchored highlight rectangle and its color in the viewer model

Declaration

THPDFViewerHighlight= record
  PageIndex: Integer;
  PageRect: THPDFRectangle;
  Color: TColor;
end;

HPDFViewerModel

Field	Purpose
`PageIndex`	Zero-based index of the page the highlight is anchored to
`PageRect`	Rectangle in PDF user space; `AddHighlightRegion` normalizes it and clamps it to the visible page box (the CropBox clipped to the MediaBox) before storing
`Color`	TColor used to draw the highlight, `clYellow` by default

Create highlights with THPDFViewerModel.AddHighlightRegion, read them back with TryGetHighlightRegion, and remove them with RemoveHighlightRegion or ClearHighlightRegions
Rectangles that collapse after clamping to the visible page box are rejected and AddHighlightRegion returns -1
Every change fires the model's OnHighlightChange event so hosts can repaint