[Lazarus] Mouse wheel scroll bar increment size?

Martin Friebe lazarus at mfriebe.de
Sat Jun 27 14:46:34 CEST 2009


Graeme Geldenhuys wrote:
> Martin Friebe wrote:
>>
>> Under windows you can set the amount of lines, in the windows control 
>> center.
>
> Thanks not how it works in Mac OS X. Windows and Linux works my 
> detecting the mousewheel delta and move a set about of lines. eg: 1, 
> 3, 5 lines etc...  Mac OS X scrolls by detecting the speed at which 
> you roll the mouse wheel... msec between deltas or something, and then 
> calculates the scroll distance.
>
I know what you mean, windows has (or had) a similar feature for moving 
the pointer (it would accelerate the movement).

So your point is, that for all other (non Mac) widgetsets, you want the 
widgetsets to emulate this?
IMHO the widgetset is the wrong place:

1) this would make the applications feel less native. And "NO", I am not 
implying that they are feeling 100% native now, but whatever amount of 
nativeness they have now, this would reduce it.

2) It could cause big problems, because if this is done in the 
widgetset, then this would be done with the assumption that such a 
feature does not exist under Win/Linux. The widgetset only gets what 
ever the OS is telling, the widgetset does not know, what the OS already 
did or did not do to the data.
Hence, if anyone has a driver that does exactly this under windows or 
Linux => and the widget set does it again, then scrolling would be 
unusable fast.

Therefore in my opinion this is an OS function, (on MAC), it shouldn't 
be part of the Widgetset. I wouldn't mind it on an application Level. 
Because then the application can switch it on or off, as the user 
requests (configurable), and that means if your OS (or mouse driver) 
does it, you do not have the application do it.

Best Regards
Martin




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