Progress
Portability Guide


System Clipboard

The system Clipboard is a feature provided in Windows that allows a user to transfer data between one widget or application and another using standard mouse and keyboard operations. Each application typically provides some form of program support for how these operations interact with it. You can provide this support in a Progress application using the CLIPBOARD system handle.

CLIPBOARD System Handle

The CLIPBOARD system handle allows you to transfer data between the window system Clipboard and your Progress application. Using the CLIPBOARD attributes, you can paste (read) data from the Clipboard to a Progress field or variable and copy or cut (write) data from a field or variable to the Clipboard.

In Progress, you also have a choice of two data-transfer modes to implement these operations-single-item transfers and multiple-item transfers. In single-item transfers, a single write to the Clipboard immediately replaces all data in the Clipboard, and a single read from the Clipboard returns all data in the Clipboard to the Progress application. In multiple-item transfers, you can format the data transfer into multiple rows of multiple items. Each write to the Clipboard adds an item to a tab and new line-separated list of Clipboard items. Each read from the Clipboard returns one tab or new line-separated item to your Progress application. In one step, you can transfer aggregate units of data between Progress and other applications (such as spreadsheets) that support similar aggregate Clipboard operations.

These data transfers are made with the help of the CLIPBOARD handle attributes. For more information on handle attributes, see the Progress Language Reference.

Windows provides default Clipboard operations through control keys, whether or not you implement them with the CLIPBOARD handle. These operations are completely compatible with CLIPBOARD handle operations as single-item operations without any interaction with the MULTIPLE attribute. Also, these operations can be used if an interruption occurs in a 4GL Clipboard operation. Table 4–2 lists Windows default Clipboard operations and the control keys that activate them.

Table 4–2: Clipboard Operations 
Operation
Control Key for
Editors and Fill-ins
Control Key for
Fill-in Fields Only
Cut
CTRL-X
SHIFT-DEL
Copy
CTRL-C
CTRL-INS
Paste
CTRL-V
SHIFT-INS

Supported Environments

In character environments where there is no system Clipboard, Progress supports CLIPBOARD handle operations within a single Progress application. You can cut and paste between fields in one Progress application, but not between one Progress application and another Progress or non-Progress application. In graphical environments, Progress supports CLIPBOARD handle operations using the system Clipboard. This allows data transfers between Progress and non-Progress applications as well as within a single Progress application.

For more information on how Clipboard operations work in Windows, see the Microsoft Windows User’s Guide . For general information on the system Clipboard, see the Progress External Program Interfaces manual.


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