Summary

The Common Desktop Environment contains an application program interface (API) for drag and drop that is layered on top of Motif to provide convenient, consistent, and interoperable drag and drop across the desktop. The Common Desktop Environment drag-and-drop API makes it easier for developers to implement drag and drop. With drag and drop, users can manipulate objects on the screen directly by grabbing them, dragging them around the display, and dropping them on other objects to perform a transfer of data.

Text, files, and buffers are the three categories of data that are used with the Common Desktop Environment drag-and-drop API. Text is defined, in this context, as any user-visible text such as text in type-in fields. A file is a container of data that resides in the file system. Each file also has a format that describes its contents. Buffers are data contained in memory. Typically, each buffer also has a format that describes its contents.

Library and Header Files

To use drag and drop, you need to link to the DtSvc library. The header file is Dt/Dnd.h.

Demo Program

A demo program containing an example of drag and drop is in /usr/dt/examples/dtdnd.

Using Drag and Drop

To Integrate with Drag and Drop

To integrate your application with drag and drop, follow these steps:

1. Include Dt/Dnd.h.

2. Link to libDtsvc.

3. As recipient:

   1. Register as a drop zone using DtDndDropRegister.

   2. Optionally, write a drop animate callback.

   3. Write a transfer callback.

4. As source:

   1. Recognize user action (possibly requiring a modification of translation tables) and call DtDndDragStart.

   2. Write a convert callback.

   3. Write a drag finish callback.