Delphi DLL Requires Chilkat v11.7.0+

Why a PDF Text Replacement Is Refused: the Font Rule

See more PDF Text Replacement Examples

A PDF stores glyphs drawn with particular fonts, so new text can only be drawn when the original font can draw it. This example shows the two common refusals. A font embedded as a subset carries only the glyphs the document used: a value made of other characters is refused with the reason missingGlyph, and the report names the font and the characters it lacks. A font that is neither one of the standard 14 nor embedded (here Verdana) is refused with nonStandardUnembeddedFont, because Chilkat cannot know what a viewer will draw for it. A non-embedded Arial, Times New Roman or Courier New is treated as the standard font every viewer substitutes for it. Delphi DLL

var
success: Boolean;
pdf: HCkPdf;
json: HCkJsonObject;
jsonOut: HCkJsonObject;
pdf2: HCkPdf;
json2: HCkJsonObject;

begin
success := False;

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

//  The PDF used in this example is available at quote_subset_font.pdf
//  and letter_verdana.pdf

//  1. An embedded subset font: only the glyphs the document uses are in the PDF.
pdf := CkPdf_Create();
success := CkPdf_LoadFile(pdf,'qa_data/pdf/quote_subset_font.pdf');
if (success = False) then
  begin
    Memo1.Lines.Add(CkPdf__lastErrorText(pdf));
    Exit;
  end;

json := CkJsonObject_Create();
jsonOut := CkJsonObject_Create();

//  The regular face's subset carries the characters of the quotation's text, among them the digits of
//  "58341".  A new number made of those digits can be drawn...
CkJsonObject_UpdateString(json,'labels[0].label','Quote #:');
CkJsonObject_UpdateString(json,'labels[0].value','58314');
success := CkPdf_TextReplace(pdf,'check',json,jsonOut);
if (success = False) then
  begin
    Memo1.Lines.Add(CkPdf__lastErrorText(pdf));
    Exit;
  end;
Memo1.Lines.Add('58314: ok = ' + IntToStr(Ord(CkJsonObject_BoolOf(jsonOut,'ok'))));

//  ...but "Q" and "-" are not in the subset (nothing in the quotation's regular text uses them).
CkJsonObject_UpdateString(json,'labels[0].value','Q-58341');
success := CkPdf_TextReplace(pdf,'check',json,jsonOut);
if (success = False) then
  begin
    Memo1.Lines.Add(CkPdf__lastErrorText(pdf));
    Exit;
  end;
Memo1.Lines.Add('Q-58341: ok = ' + IntToStr(Ord(CkJsonObject_BoolOf(jsonOut,'ok'))));
if (CkJsonObject_BoolOf(jsonOut,'ok') = False) then
  begin
    //  The problem names the font and the characters it cannot draw.
    Memo1.Lines.Add('    reason: ' + CkJsonObject__stringOf(jsonOut,'problems[0].reason'));
    Memo1.Lines.Add('    font: ' + CkJsonObject__stringOf(jsonOut,'problems[0].font'));
    Memo1.Lines.Add('    missing: ' + CkJsonObject__stringOf(jsonOut,'problems[0].chars'));
  end;

//  "apply" with a problem returns false and changes nothing.
success := CkPdf_TextReplace(pdf,'apply',json,jsonOut);
Memo1.Lines.Add('apply returned ' + IntToStr(Ord(success)) + ', applied = ' + IntToStr(Ord(CkJsonObject_BoolOf(jsonOut,'applied'))));

//  2. A font that is not embedded and not one of the standard 14.
pdf2 := CkPdf_Create();
success := CkPdf_LoadFile(pdf2,'qa_data/pdf/letter_verdana.pdf');
if (success = False) then
  begin
    Memo1.Lines.Add(CkPdf__lastErrorText(pdf2));
    Exit;
  end;

json2 := CkJsonObject_Create();
CkJsonObject_UpdateString(json2,'labels[0].label','Account Number:');
CkJsonObject_UpdateString(json2,'labels[0].value','0000099999');
success := CkPdf_TextReplace(pdf2,'check',json2,jsonOut);
if (success = False) then
  begin
    Memo1.Lines.Add(CkPdf__lastErrorText(pdf2));
    Exit;
  end;
Memo1.Lines.Add('Verdana, not embedded: ok = ' + IntToStr(Ord(CkJsonObject_BoolOf(jsonOut,'ok'))) + ', reason: ' + CkJsonObject__stringOf(jsonOut,'problems[0].reason')
     + ', font: ' + CkJsonObject__stringOf(jsonOut,'problems[0].font'));

//  Sample output:

//  58314: ok = true
//  Q-58341: ok = false
//      reason: missingGlyph
//      font: AAAAAA+DejaVuSans
//      missing: Q-
//  apply returned false, applied = false
//  Verdana, not embedded: ok = false, reason: nonStandardUnembeddedFont, font: Verdana

CkPdf_Dispose(pdf);
CkJsonObject_Dispose(json);
CkJsonObject_Dispose(jsonOut);
CkPdf_Dispose(pdf2);
CkJsonObject_Dispose(json2);