The HostScreen object is used to control screen navigation and transitions. It also allows text manipulation on the host screens.
Use the HostConnection.getScreen method to return a HostScreen object.
The HostScreen object is able to set or retrieve text on host screens in a number of ways. The simplest methods to use are the putKeys and getText methods, in conjunction with the putCommand method. Using these three methods will provide all the functionality most applications would require.
In order to handle screen navigation and transitioning smoothly the Inventu Viewer+ package includes some very powerful features. A XML definitions file containing screen recognition and screen map meta data enables screens to be automatically identified and named. The screen maps in the definition file allows fields to be defined and named, simplifying the development process.
Methods such as waitForScreen and getScreenName use the recognition information in the definitions file to get the names of the active host screens. This allows developers to build their applications to behave in a reactive manner when screens change.
The usage of screen maps allows developers to refer to fields on a screen by name and not by location simplifying the development process. Another advantage of using maps is that if the host screen gets reformatted, only the map definition need be changed - the underlying code only makes reference to the map field name which means it does not have to be edited and recompiled!
Another strong feature of the HostScreen object is its support of development for a VT host system. Cursor location is one of the methods of identification in these type of systems and the HostScreen object provides the waitForCursor, waitForUpdate and the putWithWait methods, along with the hostWriteCount, cursorCol, cursorRow, waitErrorColumn, waitErrorRow and waitForUpdateFlag properties.
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