Re: How to get the mouse position with JEWL?

[tolkamp <f.tolkamp@gmail.com>]

On 21 okt, 00:22, Manuel Collado <m.coll...@domain.ivalid> wrote:
> El 20/10/2010 19:20, tolkamp escribi :
>
>
>
>
>
> > On 20 okt, 13:42, Manuel Collado<m.coll...@domain.invalid>  wrote:
> >> El 20/10/2010 11:04, tolkamp escribi :
>
> >>> I use JEWL in several of my applications.
> >>> Now I try to get the mouse position within a JEWL canvas by using the
> >>> function "End_Point(Canavas)".
> >>> The resulting mouse position (x,y) is always zero. What is going wrong?
>
> >> Please try:
>
> >>    point := Start_Point( canvas );
>
> >> It works for me.
>
> > Also when I try:
> >   point := Start_Point( canvas );
> > the x and y position remains zero.
>
> > Here is the code:
>
> > task body Task_2Hz is
> > My_Frame  : Frame_Type;
> > My_Canvas : Canvas_Type;
> > My_Mouse_Position : Point_Type;
> > begin
> >      accept Start do
> >         My_Frame   := Frame (1200, 500, "", 0);
> >         My_Canvas  := Canvas (Frame, (850,10),      300, 300);
> > loop
> >         My_Mouse_Position := Start_Point(My_Canvas);
> >         Put("Mouse-x = "); Int_Io.Put(My_Mouse_Position.x); New_Line;
> >         Put("Mouse-y = "); Int_Io.Put(My_Mouse_Position.y); New_Line;
> >     delay 0.5;
> > end loop;
> > end Task_2Hz;
>
> IIRC, you must wait for a mouse event before reading the coordinates.
> Here is a code fragment of a real program that uses a canvas. You may
> figure how to adapt it to your needs:
>
>     function Get_Point return Point_Type is
>        Here: Point_Type;
>     begin
>        loop
>           case Next_Command is
>              when Cmd_Mouse =>
>                 exit;
>              when Cmd_Quit =>
>                 raise Program_Aborted;
>              when others =>
>                 null;
>           end case;
>        end loop;
>        Here := Start_Point( Main_Canvas );
>        return Logical( Here );
>     end Get_Point;
>
> Hope it helps.
> --
> Manuel Collado -http://lml.ls.fi.upm.es/~mcollado- Tekst uit oorspronkelijk bericht niet weergeven -
>
> - Tekst uit oorspronkelijk bericht weergeven -

What is the type of the following variables:
Next_Command, Cmd_Mouse, Program_Aborted?
What means Logical?