As Spinebot said, the web player does not have built-in drag and zoom. What language you use on the backend does not matter, as implementing that functionality is done on the frontend with JavaScript.
I'm afraid the code you posted is either incomplete or got cut off. Depending on your use case, it might be simpler to use a different web runtime, like spine-pixie or spine-phaser, which are more geared towards games where dragging and pinch zoom are common interactions provided by the game engine.