Re: Ada and X/Motif

[Uliyana Markova <uliyana@array.ca>]

Christopher Green wrote:
> 
> In article <3394CED4.2BF7@interlog.com>,  Uliyana Markova <markovi@interlog.com> wrote
:
> >I am programming a user interface in Ada using X/Motif routines. The
> >interface between X and Ada is implemented through X bindings.
> >I have the following problem: to create a colormap, allocate colors
> >and store a color I call consequently the bindings for
> >XCreateColormap, XAllocColorCells and XStoreColor. When these
> >functions are called in the main ada routine, they work properly.
> >If I call any (or all) of the above functions in a separate procedure
> >and then call this procedure in the main routine, the XStoreColor
> >function does not store the color in the colormap. There is no error
> >message, just the function does not do what it is supposed to do. Any
> >help?
> 
> Any chance you could post or email an example, and provide information
> on what Ada compiler, set of bindings, and X11 implementation you are
> using?
 
Thanks a lot for responding. I am sorry I did not specify the versions
on a first place. I am using X11 Release 5, the ada compiler is 
VADSself Version 6.2.3-0 and the ada bindings are downloaded from the
DEC's web site. 
 
Here is an example of one of a version that does not work. 
------------------------------
with X_Lib;
with Xt;
with X;
with Xm_String;
with System;
 
package Color_Pkg is
        procedure Color;
end Color_Pkg;
 
package body Color_Pkg is
 
colormap        : X.Colormap_Type;
pixel_cells     : X_Lib.Vector_Of_Colormap_Index_Type ( 1..256 ) :=
                ( others => X_Lib.Colormap_Index_Init);
 
package Manipulate_Colormap is new Xt.Manipulate_Avt ( 
        X.Colormap_Type );
 
procedure Color is
 
plane_masks     : X_Lib.Vector_Of_Plane_Mask_Type ( 1..0 );
dpy             : X_Lib.Display_Type;
screen_num      : X_Lib.Screen_Number_Type;
Visual_Info     : X_Lib.Visual_Info_Type;
toplevel        : Ip_Toplevel.Toplevel_Widget;
al              : Xt.Arg_List_Type ( 0..0 );
color           : X_Lib.Color_Type;
color_test      : X_Lib.Color_Type;
success         : Boolean;

 
begin
        -- application initialize - create toplevel widget
 
        dpy := Xt.Display ( Xt.Widget_Type ( toplevel) );
 
        screen_num := X_Lib.Screen_Number_Of_Screen (
                        X_Lib.Default_Screen_Of_Display ( dpy ) );
 
        X_Lib.Match_Visual_Info ( success,
                dpy, screen_num, X_Lib.Depth_Type ( 8),
                X_Lib.Pseudo_Color,
                Visual_Info );
 
        if ( success ) then
                colormap := X_Lib.Create_Colormap (
                        dpy,
                        X_Lib.Default_Root_Window ( dpy ),
                        Visual_Info.Visual.all,
                        X_Lib.All_Of_Them );
         end if;
 
        X_Lib.Alloc_Color_Cells (
                success,
                dpy,
                colormap,
                False,
                plane_masks ( 1..0 ),
                pixel_cells );
 
        al ( 0 ) := ( Xm_String.NColormap_Ptr,
                Manipulate_Colormap.To_Avt ( colormap ) );
 
        Xt.Set_Values ( Xt.Widget_Type ( toplevel ),
                        al ( 0..0 ) );
 
        color.pixel := X_Lib.Colormap_Index_Type ( pixel_cells ( 4 ) );
        color.Do_Red := True;
        color.Do_Green := True;
        color.Do_Blue := True;
        color.Red := X_Lib.Color_Intensity_Unsigned_Short_Subtype (
                        65535 );
        color.Green := X_Lib.Color_Intensity_Unsigned_Short_Subtype (
                        0 );
        color.Blue := X_Lib.Color_Intensity_Unsigned_Short_Subtype (
                        0 );
 
        X_Lib.Store_Color (
                dpy,
                colormap,
                color);
 
        color_test.pixel :=  
                X_Lib.Colormap_Index_Type ( pixel_cells ( 4 ) );
 
        -- returns always black color
        X_Lib.Query_Color (
                dpy,
                colormap,
                color1 );
 
        -- realize toplevel and start the event loop
 
end Color;
end Color_Pkg;
 
with Color_Pkg;
procedure Color is
begin
	Color_pkg.Color;
end Color;
 
Note that a new colormap is installed. All it's entries contain the
black color ( r=0, g=0, b=0 ).
 
 
Uliyana Markova
------
Array Systems Computing Inc.
1120 Finch Ave. West, 8th Floor
North York, Ontario, Canada M3J 3H7
Tel.: 416-736-0900 ext 280
e-mail: uliyana@array.ca