QPictureDownloader, overview of the software

The average user should deal exclusively with the main window.

The common sequence of events is:

1. The user enters an URL in the top text field
2. The user chooses to interpret the URLs either as indexes or as files through the couple of radio buttons
3. If the URLs are interpreted as indexes, then the user have to select the extensions of the files to be downloaded either through the check boxes or through a space-separed list of extensions
4. The user clicks the [Load] button, in order to compile the URL into a set of URLs: if they are interpreted as indexes, then they are downloaded and filtered in order to determine the set of files to be downloaded
5. The bottom view shows the files to be downloaded and the folders where they are placed in the local machine
6. The user chooses the working directory, where the downloaded files and folders are placed
7. The user clicks the [Download] button
8. The program attempts to download every file in the Default state