MOUSEWHEEL: Difference between revisions
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Code by Ted Weissgerber
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(Created page with "{{DISPLAYTITLE:_MOUSEWHEEL}} The _MOUSEWHEEL function returns a positive or negative INTEGER value indicating mouse scroll events since the last read of _MOUSEINPUT. {{PageSyntax}} : {{Parameter|scrollAmount%}} = _MOUSEWHEEL {{PageDescription}} * Returns -1 when scrolling up and 1 when scrolling down with 0 indicating no movement since last read. * After an event has been read, the value resets to 0 automatically so cumulative position values must be...") |
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{{PageExamples}} | {{PageExamples}} | ||
''Example 1:'' Reading the cumulative mouse wheel "clicks". | ''Example 1:'' Reading the cumulative mouse wheel "clicks". | ||
{{CodeStart}} | {{CodeStart}} | ||
DO: {{Cl|_LIMIT}} 100 | DO: {{Cl|_LIMIT}} 100 | ||
DO WHILE {{Cl|_MOUSEINPUT}} | DO WHILE {{Cl|_MOUSEINPUT}} | ||
| Line 21: | Line 21: | ||
LOCATE 10, 20: PRINT Scroll | LOCATE 10, 20: PRINT Scroll | ||
LOOP | LOOP | ||
LOOP UNTIL INKEY$ = CHR$(13) ' press Enter to quit | LOOP UNTIL INKEY$ = CHR$(13) ' press Enter to quit | ||
{{CodeEnd}} | {{CodeEnd}} | ||
''Example 2:'' A simple text scrolling routine using the mouse wheel value to read a text array. | ''Example 2:'' A simple text scrolling routine using the mouse wheel value to read a text array. | ||
{{CodeStart}} | {{CodeStart}} | ||
{{Cl|DIM}} Array$(100) | {{Cl|DIM}} Array$(100) | ||
{{Cl|LINE INPUT}} "Enter a file name with 100 or more lines of text: ", file$ | {{Cl|LINE INPUT}} "Enter a file name with 100 or more lines of text: ", file$ | ||
| Line 51: | Line 51: | ||
prevrow = row 'store previous row value | prevrow = row 'store previous row value | ||
{{Cl|LOOP}} | {{Cl|LOOP}} | ||
{{Cl|LOOP}} {{Cl|UNTIL}} {{Cl|INKEY$}} > "" | {{Cl|LOOP}} {{Cl|UNTIL}} {{Cl|INKEY$}} > "" | ||
{{CodeEnd}} | {{CodeEnd}} | ||
{{small|Code by Ted Weissgerber}} | {{small|Code by Ted Weissgerber}} | ||
| Line 65: | Line 65: | ||
{{PageNavigation}} | {{PageNavigation}} | ||
[[Category:Latest]] | |||
Revision as of 09:19, 25 June 2022
The _MOUSEWHEEL function returns a positive or negative INTEGER value indicating mouse scroll events since the last read of _MOUSEINPUT.
Syntax
- scrollAmount% = _MOUSEWHEEL
Description
- Returns -1 when scrolling up and 1 when scrolling down with 0 indicating no movement since last read.
- After an event has been read, the value resets to 0 automatically so cumulative position values must be added.
- If no movement on the wheel has occurred since the last _MOUSEINPUT read, _MOUSEWHEEL returns 0.
Examples
Example 1: Reading the cumulative mouse wheel "clicks".
DO: _LIMIT 100 DO WHILE _MOUSEINPUT Scroll = Scroll + _MOUSEWHEEL LOCATE 10, 20: PRINT Scroll LOOP LOOP UNTIL INKEY$ = CHR$(13) ' press Enter to quit |
Example 2: A simple text scrolling routine using the mouse wheel value to read a text array.
DIM Array$(100) LINE INPUT "Enter a file name with 100 or more lines of text: ", file$ OPEN file$ FOR INPUT AS #1 DO UNTIL EOF(1) inputcount = inputcount + 1 LINE INPUT #1, Array$(inputcount) IF inputcount = 100 THEN EXIT DO LOOP FOR n = 1 TO 21: PRINT Array$(n): NEXT CLOSE #1 DO DO WHILE _MOUSEINPUT IF row >= 0 THEN row = row + _MOUSEWHEEL ELSE row = 0 'prevent under scrolling IF row > inputcount - 20 THEN row = inputcount - 20 'prevent over scrolling IF prevrow <> row THEN 'look for a change in row value IF row > 0 AND row <= inputcount - 20 THEN CLS: LOCATE 2, 1 FOR n = row TO row + 20 PRINT Array$(n) NEXT END IF END IF prevrow = row 'store previous row value LOOP LOOP UNTIL INKEY$ > "" |
See also