visualpython-users

[Visualpython-users] text color problem?

[Symion <kn...@ip...>]

I have been exploring the Text object a little more and may have found a 
bug.
I may not be using the text object correctly but I receive the following 
error when changing text color.

from visual import *
  words = text(text="Test")
  words.color=(1,0,0)

Traceback (most recent call last):
   File "<pyshell#118>", line 1
     words.color=(1,0,0)
   File "C:\Python27\lib\site-packages\vis\primitives.py", line 945, in 
set_color
     for line in range(len(self.lines)):
AttributeError: 'text' object has no attribute 'lines'

The same error occurs with.

words.starts.__class__

Re: [Visualpython-users] text color problem?

[Bruce S. <Bru...@nc...>]

Thanks much for the report. In vis/primitives.py, the code for
changing color and material for a text object should look like this:

    def set_material(self, material):
        self.extrusion.material = material
    def get_material(self):
        return self.__material

    def set_color(self, color):
        self.extrusion.color = color
    def get_color(self):
        return self.__color

These corrections will of course be in the next update to VPython. I
also found a mistake in text.starts, but that's less used.

History: The year-old 3D text object had a component to convert text
to contours, and Python code to generate faces objects to render the
3D text. With the new extrusion object also needing to be able to
convert text to contours, that subroutine was split out as
shapes.text() and the text and extrusion objects both call
shapes.text(). In the process of doing this restructuring I failed to
change the setters for text.color and text.material. Note that the
text object creates an extrusion object, but this doesn't make the
text object obsolete, because it places emphasis on such things as
upper left and lower right locations, etc.

Bruce Sherwood

On Tue, Mar 1, 2011 at 2:54 AM, Symion <kn...@ip...> wrote:
> I have been exploring the Text object a little more and may have found a
> bug.
> I may not be using the text object correctly but I receive the following
> error when changing text color.
>
> from visual import *
>  words = text(text="Test")
>  words.color=(1,0,0)
>
> Traceback (most recent call last):
>   File "<pyshell#118>", line 1
>     words.color=(1,0,0)
>   File "C:\Python27\lib\site-packages\vis\primitives.py", line 945, in
> set_color
>     for line in range(len(self.lines)):
> AttributeError: 'text' object has no attribute 'lines'
>
> The same error occurs with.
>
> words.starts.__class__
>
>
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Re: [Visualpython-users] text color problem?

[Guy K. K. <guy...@au...>]

On Wed, 02 Mar 2011 06:45:04 Bruce Sherwood wrote:
> In vis/primitives.py, the code for
> changing color and material for a text object should look like this:
> 
>     def set_material(self, material):
>         self.extrusion.material = material
>     def get_material(self):
>         return self.__material
> 
>     def set_color(self, color):
>         self.extrusion.color = color
>     def get_color(self):
>         return self.__color

Are you *really* sure about that? Python usually does not use the concept of 
getters and setters. This turns out to be *very* unpythonic. I'd rather 
suggest the following:

    @material.setter
    def material(self, material):
        self.extrusion.material = material

    @property
    def material(self):
        return self.__material

    @color.setter
    def set_color(self, color):
        self.extrusion.color = color

    @property
    def get_color(self):
        return self.__color

This exposes the given methods to transparently handle access (setting and 
getting) to mock attributes as they would be normally used within Python 
classes. It makes a nice API that is idiomatically consistent to use for a 
Pythoneer.

For further reference on how to use the property() built-in, particularly in 
the way of decorators, have a look here:

http://docs.python.org/library/functions.html#property

Guy

-- 
Guy K. Kloss
School of Computing + Mathematical Sciences
Auckland University of Technology
Private Bag 92006, Auckland 1142
phone: +64 9 921 9999 ext. 5032
eMail: Guy...@au...

Re: [Visualpython-users] text color problem?

[Bruce S. <Bru...@nc...>]

I haven't used decorators myself, and because Visual was initiated in
2000, there aren't any decorators anywhere in the Python portions of
Visual. So I'm tone-deaf to the issue here and don't understand what
advantage would accrue either to developers of Visual or users of
Visual by replacing the following code (currently found in
vis/primitives.py)

    def set_color(self, color):
        self.extrusion.color = color

    def get_color(self):
        return self.__color

    color = property( get_color, set_color, None)

with

   @color.setter
   def set_color(self, color):
       self.extrusion.color = color

   @property
   def get_color(self):
       return self.__color

What am I missing? If I were to change this tiny piece of code to use
decorators, for consistency it would seem advisable to change all such
code segments, and I have no idea why this is advisable. Calling the
older scheme "unpythonic" doesn't help me see the light.

Bruce Sherwood

On Tue, Mar 1, 2011 at 11:11 PM, Guy K. Kloss <guy...@au...> wrote:
> On Wed, 02 Mar 2011 06:45:04 Bruce Sherwood wrote:
>> In vis/primitives.py, the code for
>> changing color and material for a text object should look like this:
>>
>>     def set_material(self, material):
>>         self.extrusion.material = material
>>     def get_material(self):
>>         return self.__material
>>
>>     def set_color(self, color):
>>         self.extrusion.color = color
>>     def get_color(self):
>>         return self.__color
>
> Are you *really* sure about that? Python usually does not use the concept of
> getters and setters. This turns out to be *very* unpythonic. I'd rather
> suggest the following:
>
>    @material.setter
>    def material(self, material):
>        self.extrusion.material = material
>
>    @property
>    def material(self):
>        return self.__material
>
>    @color.setter
>    def set_color(self, color):
>        self.extrusion.color = color
>
>    @property
>    def get_color(self):
>        return self.__color
>
> This exposes the given methods to transparently handle access (setting and
> getting) to mock attributes as they would be normally used within Python
> classes. It makes a nice API that is idiomatically consistent to use for a
> Pythoneer.
>
> For further reference on how to use the property() built-in, particularly in
> the way of decorators, have a look here:
>
> http://docs.python.org/library/functions.html#property
>
> Guy
>
> --
> Guy K. Kloss
> School of Computing + Mathematical Sciences
> Auckland University of Technology
> Private Bag 92006, Auckland 1142
> phone: +64 9 921 9999 ext. 5032
> eMail: Guy...@au...
>
> ------------------------------------------------------------------------------
> Free Software Download: Index, Search & Analyze Logs and other IT data in
> Real-Time with Splunk. Collect, index and harness all the fast moving IT data
> generated by your applications, servers and devices whether physical, virtual
> or in the cloud. Deliver compliance at lower cost and gain new business
> insights. http://p.sf.net/sfu/splunk-dev2dev
> _______________________________________________
> Visualpython-users mailing list
> Vis...@li...
> https://lists.sourceforge.net/lists/listinfo/visualpython-users
>
>