Make a highlighted region resizable or not.
void pdfSetRegionResizable(PDFViewerHandle viewer, PDFRegionHandle region, BOOL resizable)
This function sets the resizability of the specified highlighted region. If resizable is true, selecting the region will make resize handles visible. If resizable is false, selecting the region will not make it resizable.

A region must be selectable to be resizable. The initial state, after a region is created with pdfAddRegion, is resizable if the region is selectable.

The region handle comes from pdfAddRegion, pdfGetRegion, or pdfGetSelectedRegion.

pdfSetRegionResizable(viewer, region, FALSE);