As we're going to create several files for this add-on, we're starting with an overview of the form. It should help you to understand how all the different elements are working together.
The seven boxes shown in the preceding screenshot are the most important elements in the add-on. To make things easier, all elements are visible which is not going to happen once you're working with the add-on. There's no point displaying the please wait box if nothing is going on.
Each number is given a name, which is the value we're going to use as the ID of the element:
1: directory-structure-waiting: only shown when we load new data using our AJAX method to update the directory list.2: directory-structure-up: this element is shown if we aren't on the top level to get back to the parent directory.3: directory-structure-content: the actual list of directories and files. Always visible.4: file-access-waiting: the same for the files, displayed when a file is...