Re: Add mousewheel support to riched20

[Joris Huizer]

Hannu Valtonen wrote:
> Hi,
>
> This patch adds mousewheel support to the rapidly maturing riched20.
>
> Changelog:
> Add mousewheel support to riched20
> - Hannu Valtonen
> - case WM_MOUSEWHEEL:
> - {
> - int gcWheelDelta = 0, nPos = editor->nScrollPosY;
> - UINT pulScrollLines;
> -
> - SystemParametersInfoW(SPI_GETWHEELSCROLLLINES,0, &pulScrollLines, 0);
> - gcWheelDelta -= GET_WHEEL_DELTA_WPARAM(wParam);
> - if (abs(gcWheelDelta) >= WHEEL_DELTA && pulScrollLines)
> -
>  nPos += pulScrollLines * (gcWheelDelta / WHEEL_DELTA) * 8;

Why not like
> - SystemParametersInfoW(SPI_GETWHEELSCROLLLINES,0,

&pulScrollLines, 0);
> - gcWheelDelta = GET_WHEEL_DELTA_WPARAM(wParam);
> - if (gcWheelDelta >= WHEEL_DELTA && pulScrollLines)
> -
>  nPos += pulScrollLines * (-gcWheelDelta / WHEEL_DELTA) * 8;

just seems simpler;

regards,

Joris

Add mousewheel support to riched20

[Hannu Valtonen]

Joris Huizer wrote:
> Why not like
> > - SystemParametersInfoW(SPI_GETWHEELSCROLLLINES,0,
>
> &pulScrollLines, 0);
> > - gcWheelDelta = GET_WHEEL_DELTA_WPARAM(wParam);
> > - if (gcWheelDelta >= WHEEL_DELTA && pulScrollLines)
> > -
> >  nPos += pulScrollLines * (-gcWheelDelta / WHEEL_DELTA) * 8;
>
> just seems simpler;

It doesn't work quite that way. GET_WHEEL_DELTA_WPARAM() can return both 
positive and negative numbers so the abs() is still essential.

It's a question of taste whether to put it on to:

gcWheelDelta -= GET_WHEEL_DELTA_WPARAM(wParam);

or on to:

nPos += pulScrollLines * (-gcWheelDelta / WHEEL_DELTA) * 8;

Me, I like the first one but I don't really care one way or the other.

- Hannu Valtonen
[e-mail]