The CSS tree view is located in the side panel (See the Section called The side panel in Chapter 2) and allows you to see all properties and values in the current CSS definition file (See the Section called CSS definition file in Chapter 6).
Using the tree view
Use the scroll bar on the right side to browse the tree.
Click on the arrow in the Version column to unfold the values of a given property. Click again to fold them.
Double-click on the desired value of any property. This will add the property/values pair, following by an end of line character. This way you can quickly insert various properties without typing the end of line character yourself.
A value embedded in parentheses leads to a dialog. Just double-click on it to access the dialog, fill it in, and click on OK.