THPDFPage.SetPageThumbnail / ClearPageThumbnail

THPDFPage

 

Supported Image Formats

Prikačuje ili uklanja sličicu stranice (PDF page /Thumb unos, ISO 32000-1 §12.3.4). PDF pregledači (Adobe Acrobat, Foxit, browser viewers) prikazuju referenciranu sliku u navigacionom panelu bez rasterizacije sadržaja stranice, što otvaranje arhiva sa mnogo slika čini primetno bržim

 

Delphi syntax:

procedure SetPageThumbnail(ImageIndex: Integer);

procedure ClearPageThumbnail;

 

Parameters

ImageIndex je vrednost vraćena prethodnim pozivom THotPDF.AddImage ili THotPDF.AddImageFromFile. Osnovni Image XObject se prema specifikaciji referencira indirektno, tako da ista slika može da se nacrta i na običnoj stranici bez konflikta. Prosledite negativan indeks da biste uklonili postojeći /Thumb unos

 

Opis

Each PDF page can carry an indirect reference to an Image XObject in its /Thumb key. The image is normally a downsampled 8-bit DeviceGray, DeviceRGB, or Indexed bitmap (Acrobat uses roughly one thumbnail point per page point), but HotPDF does not validate the color space – the caller chooses what to attach. ClearPageThumbnail removes any previously attached thumbnail. SetPageThumbnail(-1) is equivalent to ClearPageThumbnail. Passing an ImageIndex that is not in range of the document’s image list raises a descriptive exception.

 

Primer

PDF := THotPDF.Create(nil);
PDF.FileName := 'archive.pdf';
PDF.BeginDoc;
Idx := PDF.AddImageFromFile('preview.jpg', icJpeg);
PDF.CurrentPage.SetPageThumbnail(Idx);
PDF.EndDoc;

 

Availability

HotPDF v2.119.13. The PDF /Thumb entry is a PDF 1.0 feature and is not gated under PDF/A, PDF/X, or PDF/UA compliance modes. To make the viewer open with the thumbnail panel visible, also set THotPDF.PageMode := pmUseThumbs.

 

See also: Supported Image Formats, THPDFPage