As a side project, I want to create a document template tool (desktop app) like JasperReports but it would just be a simple version that can handle text fields, image, parameters/fields (without data source feature that pulls from DB). I will need the output to be fed into a Java program which will put data into the template and output a PDF file (much like what jasper does).

I work as a web dev but I literally have no idea how a tool like this is developed and the concepts around it, like I don’t know how those text objects interact with the representation of the document, how objects adjust according to the objects above them (if they are set to Float instead of Fixed relative to position), how the representation of the document exports to a PDF, how the page has a header, footer, and margins, and so on. Sorry for the stupid question but does it work like a game where you have a camera to view the game world (the document)? I’d like to do it in Godot just because there’s already a UI I can use easily but if there’s a better approach let me know. I’m not asking for code, I just need the idea.