title: A blocking but non-modal QDialog?
body: <p>I have a stack of images on which I want to perform some operations. After processing each image, my program should pop up a dialog to prompt the user if they want to proceed with the next image or to abort. Before that, they should have an opportunity to do some manual changes either on the images or on the parameters. Anyway, they must have access to the windows of the applications, while the execution of the method that called the dialog should be blocked until the dialog is closed.</p>
  
  <p>I tried to solve this with a QMessageBox, but if I open it via exec(), it blocks the entire application, and if I use show(), the execution of the program goes on without waiting for user's reaction.</p>
  
  <p>Is there a convenient way to block the calling method or function with a dialog but permit the user to interact with other windows?</p>
  
  <p>Thanks in advance for any hint.</p>