Each host session that your viewer can interact with is configured to use a specific number of columns and rows that define the area within which the host or user can display or type data. For Viewer API methods, this area (as shown below) is called the presentation space:
The presentation space is an area in PC memory where screen data are stored, and through which an automation application and the host communicate. Each running session has a presentation space. Its contents are read, changed, or monitored with the Viewer API.
The status line that appears at the bottom of the screen (also known as the operator information area, or OIA) is not included in the presentation space. There are separate functions for accessing the presentation space and the OIA.
Many Viewer API methods interact with the presentation space. For example, your application can perform the following tasks:
|Even small changes in a host application can cause your application to fail. For example, a host can send an escape sequence that changes the size of the presentation space. Be sure there is close coordination between the local and host sites when the host access application changes.|
The following topics explain the characteristics of the presentation space:
|Viewer API, Overview|
|Standard Presentation Space Sizes|
|Fields and Attributes, Overview|