| Re: Wrapper for WIDGET_DRAW [message #16079] |
Tue, 29 June 1999 00:00 |
Pavel Romashkin
Messages: 166
Registered: April 1999
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Senior Member |
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Phil,
I see what you are saying. Maybe the following will work:
a) Make the DERA_Draw return the ID of the draw widget, so that no error
occurs if the user calls "Widget_Control, drawID, /MOTION_EVENTS" - this
will then work fine.
b) Create compound widget, but place some other widget (a table) hiding
under the DRAW widget.
c) Use that other widget's VALUE and/or UVALUE through PRO_SET_VALUE and
FUNC_GET_VALUE to store and retrieve the DRAW widget type. This way, a
structure may be placed into VALUE and anything - into UVALUE.
Another way - use the UVALUE of the top base of compound widget (the true
parent of the drawID) to store DRAW type, again using PRO_SET_VALUE and
FUNC_GET_VALUE. This UVALUE is not going to be accessible otherwise because
the ID of the base is not known to the user: DERA_Draw returns the ID of the
draw widget. Compared to the first way, you lose one location for storing
information (VALUE), but you still have UVALUE which is sufficient. Don't
let PRO_SET_VALUE modify the stored information; let DERA_Draw do it.
Either way, "widget_control, drawID, set_uvalue='arbitrary' " will not cause
loss of DRAW type information, and all keywords to that drawID that are
valid for the draw widget will work ok. The flaw I see is that cleanup must
be well designed, should a pointer be placed into UVALUEs of the base or
table, because these widgets' IDs and even their existence are not obvious.
Good luck,
Pavel
> ;Create a draw widget
> drawID = DERA_Draw(parent, XSIZE=400, YSIZE=400, GRAPHICS_LEVEL = 2)
> ;Get its value which will be a window object of class
> ;DERAgrWindow
> Widget_Control, drawID, GET_VALUE=thingyWindow
> ;Now draw a view into it
> thingyWindow->draw, thisView
>
> That's what I would like, so obviously you could have a compound
> widget, with a FUNC_GET_VALUE, which returned either the window
> number, the IDLgrWindow class or the DERAgrWindow class.
>
> However if its a compound widget and the top of the compund widget is
> a base, then when the user does
>
> Widget_Control, drawID, /MOTION_EVENTS
>
> ......they will be a little surprised to get an error mesage along the
> lines of
>
> Keyword MOTION_EVENTS not allowed in call to Widget_Control for a base
> widget
>
> However if I have just a draw widget then I have no way to store what
> type it is, except by using the UVALUE. However, if the UVALUE was set
> to something different by the user using Widget_Control, then that
> would be game over for my widget.
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| Re: Wrapper for WIDGET_DRAW [message #16092 is a reply to message #16079] |
Tue, 29 June 1999 00:00  |
philaldis
Messages: 32
Registered: March 1999
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Member |
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On Tue, 29 Jun 1999 02:16:39 GMT, davidf7203@my-deja.com wrote:
> Phil Aldis writes:
>
>> In this object/direct graphics thing that I'm doing, I've created all
>> my own direct graphics destination objects. The window object takes a
>> draw widget ID and is then bound to that. I would really like it
>> though if I could have a wrapper for WIDGET_DRAW, whereby if
>> GRPHICS_LEVEL is set to 0, then direct graphics and GET_VALUE returns
>> a window number, 1, object graphics and GET_VALUE retruns an
>> IDLgrWindow object and 2, obj/direct graphics and GET_VALUE returns an
>> DERAgrWindow object.
>>
>> The problems I am having is that the user still wants to be able to
>> use Widget_Control to what they think is a draw widget. They don't
>> want what they think is a draw widget to be in fact a base. I can't
>> think of any way to store the object I create and the information
>> about it.
>>
>> Can anyone think of a way to do this?
>
> I don't see the problem here. A draw widget is a draw widget whether
> is in direct graphics or object graphics. The same keywords still
> apply and you still interact with it in the same way. The "thingy"
> (my own object-oriented terminology, what do you think?) that you
> draw into is the only thing that is different and is set by the
> GRAPHICS_LEVEL keyword.
>
> Cheers,
>
> David
>
>
> Sent via Deja.com http://www.deja.com/
> Share what you know. Learn what you don't.
I didn't make myself clear.Here's an example of how I would like it to
work:
;Create a draw widget
drawID = DERA_Draw(parent, XSIZE=400, YSIZE=400, GRAPHICS_LEVEL = 2)
;Get its value which will be a window object of class
;DERAgrWindow
Widget_Control, drawID, GET_VALUE=thingyWindow
;Now draw a view into it
thingyWindow->draw, thisView
That's what I would like, so obviously you could have a compound
widget, with a FUNC_GET_VALUE, which returned either the window
number, the IDLgrWindow class or the DERAgrWindow class.
However if its a compound widget and the top of the compund widget is
a base, then when the user does
Widget_Control, drawID, /MOTION_EVENTS
......they will be a little surprised to get an error mesage along the
lines of
Keyword MOTION_EVENTS not allowed in call to Widget_Control for a base
widget
However if I have just a draw widget then I have no way to store what
type it is, except by using the UVALUE. However, if the UVALUE was set
to something different by the user using Widget_Control, then that
would be game over for my widget.
I hope that that explains it better.
Cheers,
Phil
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| Re: Wrapper for WIDGET_DRAW [message #16095 is a reply to message #16079] |
Tue, 29 June 1999 00:00 |
davidf7203
Messages: 12
Registered: August 1998
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Junior Member |
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Phil Aldis writes:
> In this object/direct graphics thing that I'm doing, I've created all
> my own direct graphics destination objects. The window object takes a
> draw widget ID and is then bound to that. I would really like it
> though if I could have a wrapper for WIDGET_DRAW, whereby if
> GRPHICS_LEVEL is set to 0, then direct graphics and GET_VALUE returns
> a window number, 1, object graphics and GET_VALUE retruns an
> IDLgrWindow object and 2, obj/direct graphics and GET_VALUE returns an
> DERAgrWindow object.
>
> The problems I am having is that the user still wants to be able to
> use Widget_Control to what they think is a draw widget. They don't
> want what they think is a draw widget to be in fact a base. I can't
> think of any way to store the object I create and the information
> about it.
>
> Can anyone think of a way to do this?
I don't see the problem here. A draw widget is a draw widget whether
is in direct graphics or object graphics. The same keywords still
apply and you still interact with it in the same way. The "thingy"
(my own object-oriented terminology, what do you think?) that you
draw into is the only thing that is different and is set by the
GRAPHICS_LEVEL keyword.
Cheers,
David
Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.
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