_SCREENEXISTS

The _SCREENEXISTS function returns true (-1) once a screen has been created.

Syntax

screenReady%% = _SCREENEXISTS

Description

• Function returns true (-1) once a program screen is available to use or change.
• Can be used to avoid program errors because a screen was not ready for input or alterations.
  • Use before _TITLE, _SCREENMOVE and other functions that require the output window to have been created.

Examples

Example

Waiting in a loop until the screen exists to add the title. The _LIMIT prevents the loop from using all CPU time while waiting.

SCREEN 12 DO: _LIMIT 10: LOOP UNTIL _SCREENEXISTS _TITLE "My Title"

See also

• _FULLSCREEN
• _SCREENIMAGE
• $CONSOLE
• $RESIZE

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