Edting PDF?

[louiesun]

I am using Foxit PDF Editor(a famous commencial PDF edtior), and I found that it needs some time to save the change while the comments in the PDF disappeared.

So, I suppose that the most advanced PDF editor also render the PDF file to some canvas like html or xml or canvas and exporting them into PDF file again when saving.

We've PDF.js to render PDF page on canvas Element and Fabric.js to create an editable 'canvas'.

Does this means we can got a PDF editor through translate the Canvas API which PDF.js use to Fabric.js API to edit the PDF page?

In addition, there are a lot of useful Image editors, they are mature techonology(Fabric.js is the basement of some of them), the editors based on absolute positition while PDF does so.

Though we may need to deal with the bookmarks and so on.

In brief, can we make a simple PDF editor which nobody made an opensource one so far especially on web?