Program Dia może być zmieniany na wiele sposobów, umożliwiając użytkownikowi dostosowanie go do własnych potrzeb.
Aby zmienić preferencje zachowania aplikacji należy wybrać File->Preferencje... z głównego paska menu. This opens the Preferences dialog, shown in
The configurable properties in the User Interface tab are:
Reset tools after create — If this button is checked…
Number of undo levels customizes how many steps that the undo tool remembers. Higher numbers let the user go back more steps to fix an error, but take up more memory.
Width controls the width, in pixels, of a new diagram.
Height controls the height, in pixels, of a new diagram.
Magnify sets a multiplier that controls what the default zoom level on a new diagram is.
Snap To allows makes objects attract to a grid created by the program. This makes it easier for the user to align objects, as separate objects snap to the same line.
X Size lets the user set a multiplier which sets how far the horizontal grid lines are from eachother.
Y Size lets the user set a multiplier which sets how far the vertical grid lines are from eachother.
Colour sets the color that the grid lines display as.
After you have made all the changes you want, click on to apply the changes and close the Preferences dialog. To cancel the changes and return to previous values, click the button. You may preview the effect of your changes using the Apply button.