[Oberon] Re: n-o: How to dynamically insert ListGadgets ?

25 Nov 2003

      ...
easlab@absamail.co.za wrote:
...
We know that
    Gadgets.Insert  Lists.NewList ~
inserts a ListGadget AT THE CARET, but I can't see how to position it
on the panel, absolutely or relative to it's 'called by button'.
You probably should send a consume message. 
Have a look at Chapter5.Text .
Cheers, Edgar
P.S. Warning: no easy reading :-)
...
I agree, not easy reading. Have a look at Example 16 (page 217) of the 
Oberon Companion. 
You first need to locate the container object by using the 
ThisFrame procedure in the Gadgets module. 
The example uses the mouse pointer coordinates 
(Oberon.Pointer.X, Oberon.Pointer.Y), but you can use the 
absolute coordinates of the container to obtain a reference to the 
Frame that needs to get the Consume message
-- 
OK. Chapter5.Text  Example15 & Example16 both demonstrate the 
method(s) nicely, except when slightly modified (successive refinement)
Jacques Eloff wrote:
they appear to be bluff-ghosts.

I've just added a line to re-set C.u, C.v to absolute values, instead of
  those returned by the 'pointer'.
By incrementing the C.u, C.v values, I expect to see the button be
inserted on a diagonal trajectory.
Instead it only moves to the left. Ie. the Y coordinate is not changed.

Similarly the extra extra statement added to Example16 to 
effect the Y coordinate has no effect ?!  
---------------   Compiler.Compile @  \s    
	MODULE Example15;

	IMPORT Display, Gadgets, Oberon;

	PROCEDURE Drop*;
	VAR F: Display.Frame; u, v: INTEGER;
		C: Display.ConsumeMsg;
	BEGIN
		Gadgets.ThisFrame(Oberon.Pointer.X, Oberon.Pointer.Y, F, u, v);
				(* gets F, u, v *)
		C.F := F;
		C.id := Display.drop;
		C.obj := Gadgets.CreateObject("BasicGadgets.NewButton");
		C.u := u; C.v := v;	(* relative position in container *)
C.u := 44; C.v := 44;
		Display.Broadcast(C)
	END Drop;

	END Example15.  
Example15.Drop == Insert Button @ F1:star ; modified to insert @ 44,44
--------------- 
	MODULE Example16;

	IMPORT Display, Gadgets, Oberon, Objects;

	PROCEDURE Drop*;
	VAR F: Display.Frame; u, v: INTEGER;
		C: Display.ConsumeMsg; obj, obj1: Objects.Object;
	BEGIN
		Gadgets.ThisFrame(Oberon.Pointer.X, Oberon.Pointer.Y, F, u, v);
				(* get Display.Frame, u, v  *)
		obj := Gadgets.CreateObject("BasicGadgets.NewCheckBox");
		obj1 := Gadgets.CreateObject("BasicGadgets.NewButton");
(*		obj1(Gadgets.Frame).X := obj(Gadgets.Frame).W + 10;	 position it *)
obj1(Gadgets.Frame).Y := obj(Gadgets.Frame).H + 10;	
		obj.slink := obj1;	(* link gadgets together *)
		C.F := F;
		C.id := Display.drop;
		C.obj := obj;
		C.u := u; C.v := v;
		Display.Broadcast(C)
	END Drop;

	END Example16. 
Example16.Drop == Insert CheckBox + Button @ star

The documentation tells me that "obj(Gadgets.Frame).W + 10"
is to put the button to the right of the width of the CheckBox,
instead of on top of it. 
So with my modified version I expect to see the button displaced verticaly
w.r.t. the first inserted object.

What am I doing wrong ?

 == Chris Glur.

[Oberon] Re: n-o: How to dynamically insert ListGadgets ?

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