Get the clip path attached to a page object

A PDF clip path defines the geometric region inside which a page object is allowed to draw. Wraps FPDFPageObj_GetClipPath. Most page objects have no clip path; this function returns NULL for those.

Usage

pdf_obj_clip_path(obj)

Arguments

obj

A pdfium_obj (from pdf_page_objects(), pdf_form_objects() or pdf_annot_objects()).

Value

A pdfium_clip_path object, or NULL when obj has no clip path or only an empty one.

Details

PDFium returns a non-NULL clip handle even for objects whose clip is "empty" (the underlying CPDF_ClipPath exists but has no sub-paths attached). This wrapper normalizes that case to NULL so callers only see clip-path objects with at least one real sub-path.

The clip path is part of obj and is valid for as long as the obj handle is: pdf_clip_path_count() and pdf_clip_path_segments() refuse it once obj is closed, whether by closing its page or document, by deleting the annotation or form object that holds it, or by pdf_obj_delete(), pdf_form_obj_remove_object() or pdf_annot_append_object() on obj itself.

See also

pdf_clip_path_count(), pdf_clip_path_segments().

Examples

fixture <- system.file("extdata", "fixtures", "clip.pdf",
  package = "pdfium"
)
if (nzchar(fixture)) {
  doc <- pdf_doc_open(fixture)
  page <- pdf_page_load(doc, 1L)
  objs <- pdf_page_objects(page)
  clipped <- Filter(function(o) !is.null(pdf_obj_clip_path(o)), objs)
  length(clipped)
  pdf_page_close(page)
  pdf_doc_close(doc)
}