Screen Manipulation and Query APIs

The screen manipulation and query APIs are used to query and manipulate the state of the screen. They are:

• Change Low-Level Environment (QsnChgEnv) changes the low-level environment description.
• Clear Field Table (QsnClrFldTbl) clears the format table but does not alter the display.
• Clear Screen (QsnClrScr) clears the screen and sets the screen size.
• Create Low-Level Environment (QsnCrtEnv) creates the environment for the low-level services APIs.
• Delete Low-Level Environment (QsnDltEnv) deletes the environment for the low-level services APIs.
• Initialize Low-Level Environment Description (QsnInzEnvD) initializes the low-level environment description.
• Query 5250 (QsnQry5250) returns the results of the 5250 Query command.
• Query Color Support (QsnQryColorSup) determines if the display device supports color.
• Query Display Mode Support (QsnQryModSup) queries if the display device allows a given mode.
• Restore Screen (QsnRstScr) restores the contents of a screen saved with Save Screen (QsnSavScr) API.
• Retrieve Display Mode (QsnRtvMod) queries the current device mode.
• Retrieve Low-Level Environment Description (QsnRtvEnvD) retrieves the low-level environment description.
• Retrieve Low-Level Environment User Data (QsnRtvEnvDta) returns a pointer to the user data for the low-level environment.
• Retrieve Low-Level Environment Window Mode (QsnRtvEnvWinMod) retrieves the low-level interface environment window mode description.
• Retrieve Screen Dimensions (QsnRtvScrDim) retrieves the screen dimensions.
• Roll Down (QsnRollDown) rolls the screen down by the given number of rows.
• Roll Up (QsnRollUp) rolls the screen up by the given number of rows.
• Save Screen (QsnSavScr) saves the present display so it can be restored later.
• Set Low-Level Environment Window Mode (QsnSetEnvWinMod) sets the window mode for the low-level interface environment.