GetTextBlockCharUnicodeFlags

Text, Extraction, Diagnostics, Unicode

Description

Returns Unicode mapping and fallback flags for one character in a selected-document text block

Function TPDFlib.GetTextBlockCharUnicodeFlags(TextBlockListID, Index, CharIndex: Integer): Integer;

TextBlockListID	Handle returned by `ExtractPageTextBlocks`
Index	1-based text block index
CharIndex	1-based UTF-16 code-unit position inside the block text

-1	The handle, block index or character index is invalid
0 or flags	No source glyph mapping applies or the result contains one or more Unicode diagnostic flags

`PDF_TEXT_CHAR_UNICODE_EXPLICIT`	The character was produced by an explicit valid `ToUnicode` mapping
`PDF_TEXT_CHAR_UNICODE_FALLBACK`	The character was produced by a font encoding, glyph, CID or raw-code fallback
`PDF_TEXT_CHAR_UNICODE_MISSING_TOUNICODE`	The font has no `ToUnicode` entry
`PDF_TEXT_CHAR_UNICODE_UNMAPPED`	A valid `ToUnicode` CMap has no mapping for the source code
`PDF_TEXT_CHAR_UNICODE_INVALID`	The `ToUnicode` CMap is unusable or the selected mapping is invalid UTF-16
`PDF_TEXT_CHAR_UNICODE_REPLACEMENT`	The returned text contains U+FFFD because no usable fallback was available

Use bitwise tests because a fallback result also carries the missing, unmapped or invalid reason

Flags are retained during extraction and queried in constant time without reparsing page content

A supplementary Unicode scalar occupies two UTF-16 positions and both positions carry the same flags