[Lazarus] Mouse wheel problem

[Fabio Luis Girardi]

Hi!

Even using this event, if the combobox selection is changed one time
(ItemIndex<>-1), the mouse wheel will change the selection if the mouse
cursor is over the combobox.

I tried to modify the qt widget, but no success. Appears to be an
LCL issue, since QT docs says to change the focus police to QtStrongFocus
to solve this problem (I don't find the fix for GTK2)

The best regards,

Fabio

Em ter, 18 de set de 2018 às 12:05, Vojtěch Čihák <vojtech.cihak at atlas.cz>
escreveu:

> Hi,
>
> you can use event
>
>
>
> procedure TForm1.ComboBox1MouseWheel(Sender: TObject; Shift: TShiftState;
> WheelDelta: Integer; MousePos: TPoint;
>
>   var Handled: Boolean);
>
> begin
>
>   Handled:=True;
>
> end;
>
>
>
> this will not scroll the scrollbox when mouse pointer is over combobox,
> but ComboBox.ItemIndex will at least not change.
>
>
>
> V.
>
>
>
> ______________________________________________________________
> > Od: "Fabio Luis Girardi via Lazarus" <lazarus at lists.lazarus-ide.org>
> > Komu: "Lazarus mailing list" <lazarus at lists.lazarus-ide.org>
> > Datum: 18.09.2018 16:27
> > Předmět: [Lazarus] Mouse wheel problem
> >
> Hi all!
> I'm experiencing a problem with the mouse wheel and combobox control. I
> have a big form (4900x1000) on a single monitor. I put this big form on a
> Scrollbox to make it scrollable. To make the things easy to user/system
> operator, I decided to move the screen using the mouse wheel. This works
> fine and makes the navigation on this screen/form easy.
> The problem appears when the mouse cursor stops (after mouse wheel) over a
> combobox control. Even the combobox over the mouse cursor doesn't have the
> focus, the next mouse wheel event doesn't move the screen, but changes the
> combobox selection.
> All combobox on my application has Style set to csDropDownList. Another
> point that I noted, is that mouse wheel change doesn't occur if ItemIndex =
> -1.
> The same behavior is in GTK2 and QT4. I don't have tried on QT5.
> Someone knows how workaround or fix this?
> --
> The best regards,
>
> Fabio Luis Girardi
> PascalSCADA Project
> http://sourceforge.net/projects/pascalscada
> http://www.pascalscada.com
>
>
> ----------
>
> --
> _______________________________________________
> Lazarus mailing list
> Lazarus at lists.lazarus-ide.org
> https://lists.lazarus-ide.org/listinfo/lazarus
>


-- 
The best regards,

Fabio Luis Girardi
PascalSCADA Project
http://sourceforge.net/projects/pascalscada
http://www.pascalscada.com
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