When Dia is executed, two windows open: the canvas, which contains the diagram, and the Toolbox, which contains the object palettes and other controls. The Toolbox is divided into three regions. The top region contains 14 buttons. The first three are controls used to adjust the diagram. The next 11 are the icons for the built-in basic objects.
The middle portion of the Toolbox contains the selected Special Objects. This is used to select among the many built-in object sheets supplied with Dia, such as UML, Flowchart, Network, etc.
The bottom portion of the Toolbox contains special controls that set default properties for objects placed on the canvas. These include foreground color, background color, and line width. There are also three controls that set the default properties for line objects. These are beginning arrow style, ending arrow style, and line style.