From QB64 Wiki
The VIEW PRINT statement defines the boundaries of a text viewport PRINT area.
- VIEW PRINT [topRow% TO bottomRow%]
- topRow% and bottomRow% specify the upper and lower rows of the text viewport.
- If topRow% and bottomRow% are not specified when first used, the text viewport is defined to be the entire screen.
- A second VIEW PRINT statement without parameters can also disable a viewport when no longer needed.
- CLS or CLS 2 statement will clear the active text viewport area only, and reset the cursor location to topRow%.
- A SCREEN mode change or RUN statement can also clear and disable viewports.
- After active viewport is disabled, normal screen printing and clearing can begin.
- Row coordinates may vary when a WIDTH statement has been used.
- Note: QB64 RUN statements will not close VIEW PRINT, VIEW or WINDOW view ports presently!
Example: Demonstrates how text scrolls within the text viewport.
' clear the entire screen and show the boundaries of the new text viewport CLS PRINT "Start at top..." LOCATE 9, 1: PRINT "<- row 9 ->" LOCATE 21, 1: PRINT "<- row 21 ->" ' define new text viewport boundaries VIEW PRINT 10 TO 20 ' print some text that will scroll the text viewport FOR i = 1 TO 15 PRINT "This is viewport line:"; i SLEEP 1 NEXT i ' clear only the active text viewport with CLS or CLS 2 CLS PRINT "After clearing, the cursor location is reset to the top of the text viewport." ' disable the viewport VIEW PRINT _DELAY 4 LOCATE 20, 20: PRINT "Print anywhere after view port is disabled" _DELAY 4 CLS PRINT "Back to top left after CLS!"
- Note: The bottom row of the VIEW PRINT port can be used only when located or prints end with semicolons.