xdnnve reads its configuration parameters from .xdnnverc file during its startup. These parameters concern appearance of the program and other working parameters (i.e. the last edited file). The application expects to find its configuration file in a directory which name is kept in environmental variable $DAVIDPRIVDIR. When the file doesn't exist, the application begins its work with an empty document and with its default settings. When xdnnve finishes its work, it writes its current settings in the .xdnnverc file. The application, during its work, can write some errors on stderr instead of displaying message boxes.

A configuration files edition, on which control panels are generated, is made invisible for a user. A user builds a panel putting controls on it by using the mouse and specifying their properties and connections. All operations are made using a graphic interface and a user doesn't need to know a structure of edited files.

The main panel takes a central part of the application main view. The toolbar is usually above the main panel while the status bar is placed below it. On the left side of the main panel tool buttons are placed. They help you to create your control panels.

Some information is displayed on the status bar: coordinates of a left, top corner and a size of an object over which there is the mouse pointer. When no object contains the mouse cursor, coordinates and a size of the main panel are displayed on the status bar. There is only one exception when a rectangle area is marked using the mouse. Then, the displayed data are applied to it.

10.4.2.1. Main window buttons

Buttons on the toolbar allow you to edit a created panel. The first four buttons agree with File menu.

Table 10.2. xdnnve - File menu buttons

Button	Description
	It lets you close the program. A user will be asked earlier for saving some changes of an edited file (if he has made any changes).
	It allows you to create a new configuration file.
	It helps you to open the configuration file.
	It allows you to save the edited file as the same file (in case of a new file a user will be asked for specifying its name).
Save as	It doesn't appear on the toolbar, and it allows you to save information to a file which name is specified by a user.

The edited operations applies to specified objects. When there aren't the objects, the edited operations applies to the main panel. An object is marked when the mouse cursor is above it (exactly: the object has a focus). An object permanently can be marked when any part of it belongs to a rectangle area of the main panel drawn by pressing the left mouse button. The specified object can be selected or unselected pressing the left mouse button while the Ctrl key stays pressed. Specified objects can be unselected by clicking the mouse on the main panel or marking a new area of it.

Rest of buttons agree with Edit menu and they are shown below:

Table 10.3. xdnnve - Edit menu buttons

Button	Description
	It allows you to cut a specified item. A dialog will appears earlier and you will be able to confirm the operation. The dialog can also appear in the other cases.
	It lets you copy a specified item.
	It lets you paste a copied item.
	It helps you to delete a specified item.
	It allows you to delete all items of a created panel.
	It helps you to place an edited item on the first plan before other controls.
	It lets you place an edited item under other controls.
	It allows you to transform selected items to a specified type of a control.
	It helps you to configure properties of a specified control or panel.
	It allows you to test a created panel.

You can use Edit menu options by pressing the right mouse button on the selected control or the panel. Then a list with accessible options of the menu is displayed.

Through Help menu you can find out about the application version and its creation time.