As an alternative to the mouse you can use the following keys:
To toggle between the menu bar, the folder tree, the side bar, and the display area, use the key combination [Ctrl]+[F6].
To move the cursor within input fields, use the following keys: cursor keys, [Home], [End].
To browse the folder tree or the side bar, use the following keys: [Page up], [Page down], [Space bar], [Shift]+[Space bar].
To open or close a folder in the folder tree, use the [Space bar] or [Enter].
To select elements in the folder tree, in the side bar or in the display area, use the cursor keys.
To select a function, an input field or a checkbox, use the [Tab] key, [Shift]+[Tab]. The selected element will be highlighted.
With [Shift]+[Tab] you can select elements in reverse order.
To execute the function selected, press [Enter].
To enable or disable a selected checkbox, press the [Space bar].
To toggle the checkboxes, use the cursor keys.
To close a pop-up or cancel a dialog window, press [Esc].