[REQ] [cpp-qt-client] Download Progress

[Jazzco]

Is your feature request related to a problem? Please describe.

When downloading larger files via the generated API I miss a possibility to get the download progress. This could be achieved by connecting to the signal QNetworkReply::downloadProgress.

Describe the solution you'd like

I see two possible ways:

1. pass the QNetworkReply::downloadProgress to the clients
   • add a downloadProgress signal to the HttpRequest header
   • connect the QNetworkReply::downloadProgress to the new signal in the HttpRequest body right before the connect to QNetworkReply::finished
   • add a downloadProgress signal to the api-header and connect this in the api-body right before the connect to HttpRequestWorker::on_execution_finished
2. OR make the QNetworkReply available
   • add a parameter to a changeable reference pointer to the HttpRequest::execute that can be read in the client's major call (the first occurrence of nickname)

Solution 2 would make more interaction with the reply available but may also enable misusing it.

Describe alternatives you've considered

Additional context

[Jazzco]

Here is an implementation of solution 1: https://github.com/Jazzco/openapi-generator/tree/qt-progress-info
On positive feedback I would create a PullRequest

[wing328]

can you please create a PR to start with? I'll tag some contributors to review. thanks

[Jazzco]

Sure: #18950