The class Pdf (gb.poppler) is static and provides 4 numerical constants in relation to the search in a PDF document with the method hPdfDocument.Find(argSuchtext, [ argSuchOption ]):

Table 23.12.4.1 : Constants of the Pdf class

The following source code can be used to search for a specific text in a PDF file. The coordinates of the text-enclosing rectangle are displayed in the IDE console:

Public Sub SearchText(sSearchText As String, Optional iSearchOption As Integer)
 
  Dim i As Integer
  Dim aRectF As New RectF[]
 
  If IsNull(iSearchOption) Then iSearchOption = 0
 
  For i = 0 To $hPdfDocument.Max
      aRectF = $hPdfDocument[i].FindText(sSearchText, iSearchOption)
      If aRectF.Count > 0 Then
         For Each hRectF As RectF In aRectF
             Print "x: "; Round(hRectF.X, -1); "  y: "; Round(hRectF.Y, -1);
             Print "  |  w: "; Round(hRectF.W, -1); "  h: "; Round(hRectF.H, -1)
         Next
      Endif
  Next
 
End

This text is located in the file simpletext.pdf:

Er programmiert in der Programmiersprache Gambas.
Fazit: Gambas ist toll!

Calling the procedure with the search text “Gambas” and two search options:

SearchText("Gambas", Pdf.CaseSensitive Or Pdf.WholeWordsOnly)

results in this display in the console:

Rechteck-Koordinaten:
----------------------------------------
x: 66,6  y: 736,3  |  w: 52,9  h: 15,6