So it's either poppler or parsing and rendering pdf files yourself. The project you mentioned in your original post only handled HTML and not PDF.
You posted a link to a "Nokia post" which "uses QML which you don't want to use". So first you want to handle PDF and not HTML which makes the post totally irrelevant to your problem (regardless if it uses QML or smoke signals). Instead of worrying about what widgets to use, you should answer the question "how do I parse PDF files?"
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