Clipboard

The clipboard provides a temporary storage area for a piece of text, a bitmap or a metafile. It enables the user to move data within a single application or exchange data among applications. Typically, a user selects data in the application using the mouse or keyboard, then initiates a cut or copy operation on that selection. Using the paste command the user can insert this data into another place in the same application or in another application. All these operations are performed by applications.

Generally an application should first verify that no other applications are trying to retrieve or set clipboard data. Finally, when the application finishes its access to the clipboard data, it releases the clipboard so that other applications can use it.

These operations are described below:

Operation

Description

Deletes the selected data from the application and copies it to the clipboard. Any previous contents of the clipboard are destroyed.

Copies the selected data to the clipboard. The selection remains unchanged. Previous contents of the clipboard are destroyed. Before an application performs a cut or copy operation, it removes any previously stored data in the clipboard. Then it writes its data to the clipboard in as many standard formats as possible.

Deletes any selected data from the application and replaces it with the contents of the clipboard. The contents of the clipboard are not changed. When the application performs a paste operation it verifies the format where the data are stored. If the clipboard contains one of the requested formats, such as text data, the application gets a pointer to a shareable memory object containing the text. For bitmap data or metafile, it gets a corresponding handle.

The clipboard is a small amount of system memory for user-driven data exchange. The clipboard only stores pointers to data. A set of API functions enables the application to move and exchange data. Figure "Clipboard Copy from an OS/2 Window into an OS/2 PM Editor" is an example of copying data from one application and pasting it to another, by way of the clipboard.

The data in the clipboard is maintained in memory only. Clipboard data is lost when the computer is turned off.