Re: gtkada evenhandler on_procedure method , how to access children of topwindow in the eventhandler

[Alain De Vos <devosalain71@gmail.com>]

On Saturday, November 2, 2019 at 11:22:49 AM UTC+1, Alain De Vos wrote:
> I have a window with obe button and one label and want to change the text on the label when the button is pressed in the eventhandler, I pass the top window.
> 
> procedure hello is
>    Top     : Gtk.Window.Gtk_Window;
>    Button  : Gtk_Button;
>    Label   : Gtk_Label;
>    VBox    : Gtk_Box;
>    procedure Create_Window is
>    begin
>       Gtk.Window.Gtk_New
>         (Window   => Top,
>          The_Type => Gtk.Enums.Window_Toplevel);
>       Gtk.Window.Set_Title (Window => Top, Title  => "Hello from ADA");
>       Gtk_New(Button);
>       Button.On_Clicked (Call => On_Button_Click'Access, 
>                          Slot => Top);
>       Gtk_New(Label);
>       Gtk_New_Vbox(VBox);
>       Add (VBox,Button);
>       Add (VBox,Label);
>       Add (Top,VBox);
>       Gtk.Window.Show_All (Top);
>    end Create_Window;
> begin
>    Gtk.Main.Init;
>    Create_Window;
>    Gtk.Main.Main;
> end hello;
> 
> I pass the topwindow to the eventhandler(slot).
> In the eventhandler I need go from the Top to the Vbox to the Label and set the text on the label ... button pressed. I probably need to set a property in the main and query it in the handler and cast the correct type ...
> {The label is not directly visible in the handler ...}
> 
> package body buttonhandler is
>    procedure On_Button_Click (Top : access Glib.Object.GObject_Record'Class) is
>    begin
>       Put_line ("Hallo");
>       -- I need to go from Top to Vbox to Label and set text ... ????
>    end On_Button_Click;
> end buttonhandler;

In the main program I can have,
MyVBox.Button.On_Clicked (Call => On_Button_Click'Access, Slot => Top);
MyVBox.Button.On_Clicked (Call => On_Button_Click'Access, Slot => MyVBox);
with
Top     : Gtk.Window.Gtk_Window;
MyVBox  : MyVBoxT;
Both work fine,

In handler i can have,
procedure On_Button_Click (Top : access Glib.Object.GObject_Record'Class),
this works fine,
But when i try :
procedure On_Button_Click (MyVBox : access Gtk_Button_Record'Class)
the error received is :

hello.adb:33:56: expected type "Cb_GObject_Void" defined at gtk-button.ads:445
hello.adb:33:56: found type access to procedure "On_Button_Click" defined at...

In the docs procedure On_Clicked is defined as :
   (Self  : not null access Gtk_Button_Record;
    Call  : Cb_Gtk_Button_Void;
    After : Boolean := False);