title: How to build GTK GUI application as I want?
body: <p>Recently I started to have a look at the GTK library in C, and wanted to create GUI application. In fact, I want to create an image application, but I don't know how to make my application looking exactly the same as my drawing, I've looked throught the gtk3-demo and also the widget factory but problems remains;
  How to create GUI application, how do I know which container should I use, how do I know what kind of widget ? etc... So I have a picture of what I want to do, but I have absolutly no idea how. What is the process, what question should I ask myself in order to get my GUI application done ? <a href="https://i.stack.imgur.com/YGRmc.png" rel="nofollow noreferrer">Drawing of my application link</a></p>