Common Desktop Environment: Style Guide and Certification Checklist

Type of Item Being Dragged

The visual feedback for drag and drop is based on the concept that what you see is what you drag. For example, if the user selects a folder icon in File Manager and starts dragging it, the drag icon should show the folder icon as part of the drag icon, as illustrated in Figure 3-1.

Figure 3-1 Drag icon showing the object being dragged

Graphic

Required 

dt: 

During a drag operation, your application changes the current pointer to a drag icon. 

Recommended 

du: 

During a drag operation, your application changes the current drag cursor to include a source indicator. 

While this may seem like an obvious behavior, it is critical to give users feedback showing exactly what they are dragging. Providing this kind of consistency makes drag and drop more predictable to the user. Text drags are the exception in that the actual text is not dragged. Figure 3-2 shows a text drag icon.

Figure 3-2 Example of a text drag icon

Graphic

Applications are responsible for supplying a graphic to be used in the drag icon. This graphic is usually one of the icons already supplied with the application, such as the 32x32 icons used in File Manager to represent documents. The graphic used depends on what is being dragged.

In cases where the user does not select an icon to start a drag, it is still appropriate to show a relevant graphic in the drag icon especially if that graphic will be used by the destination application upon drop. For example, in Calendar Appointment Editor, the user can select an appointment from the scrolling list, which does not show icons. An appointment icon is used as part of the drag icon. If the appointment were dropped on File Manager, File Manager would display the appointment using the same graphic.