jython-users

Re: [Jython-users] Swing examples

[Noel R. <no...@ya...>]

At 12:08 AM 3/9/02, you wrote:


>I am looking for some Jython/ Swing sample code to code an utility. Any 
>links/ suggestions ?

Here's another shameless plug...  If you can wait a couple of weeks, 
_Jython Essentials_ has a full chapter with a number of Jython/Swing 
examples, and a lot of material on using Java Libraries in general.

Hope this helps.

Thanks,

Noel


_________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com address at http://mail.yahoo.com

Re: [Jython-users] Swing examples

[BillWorker 2. <bil...@in...>]

From: Ype Kingma <yk...@xs...>
Subject: Re: [Jython-users] Swing examples


> Ahish,
>
> >This is more of what I learnt while working with Jython and Swings!
> >
> >First, if you want to use Swings and its MVC architecture, you have to
> >remember Swing is designed to work it Java objects. For example, when
> >working with JList, I wanted to implement my own ListModel so I extended
the
> >AbstractListModel and went about writing my implementations of
> >getElementAt() and getSize(). It took me one whole day of fooling around
to
> >realize that the object returned by getElementAt() should be an instance
> >java.lang.Object.
>
> I suppose the compiler did not allow you to override the return value
> of getElementAt() to a java basic type like int or char?
> In case you override in jython code, jython will try and convert the
returned
> python object to an appropriate java object, which works surprisingly
> well.
What do you mean by override jython code? Sure, an easy way to convert
python object to java object is to inherit from java.lang.Object. or other
similar class. This is what I wanted to mention. Since, I started out with
Java and when we don't mention explicitly the base class it is automatically
made java.lang.Object. This is one thing we forget while working in Jython,
so I just wanted to have this thing mentioned in FAQ. It took me a day to
realise that Python objects do not inherit from java.lang.Object unless
explicitly mentioned. This would be a nice reminder to any Java programmers!
Of course, the other option is to make sure the whatever we return from
getElementAt() is wrapped by a Java object.

> >If you remember this and have the looks at the bean section of the docs,
> >then any Swing books is good.
> >
> >Somehow, you just don't remember that. The examples all use strings and
that
> >is automatically handled.
> >
> >Guess someone should add that section to the FAQ!
>
> I'm afraid I don't understand your problem well enough.
>
> >Oh, about the shameless plug for Jython Essentials, guess I will wait
till
> >it becomes available in my part of the world (Kathmandu, Nepal). If it
ever
> >comes :-( Since, I don't have International credit cards I can't do
online
> >shopping and I don't think I would really like to go through all the
hassel
> >at banks, getting permissions for making dollar payments .... In short,
> >visits to multiple organisations!
>
> You only need the Swing API docs, the Swing examples from Sun,
> and a few jython examples on using Swing to get going. All of
> this is downloadable, no paper needed.

Yup, I don't think I would by a Jython book to learn Swings. That I have all
the docs I need. I would by Jython book to see how Python works with Java!
Or rather how to write more Pythonlike (Pythonic??) code!

> Have fun,
That's exactly what I am doing!

> Ype
>
> P.S. You replied in private, which is ok to me, but it might not
> have been your intention. (My mail program does not by default
> reply to the list, but to the original sender, so I always have
> to cut and past the list address to return to the list.)
>
I just realised neither does mine!

Re: [Jython-users] Swing examples

[BillWorker 2. <bil...@in...>]

Let me explain myself!

In Java if I were to extend AbstractListModel and use an array internalArray
to hold my data internally, then for getElementAt() I could do
internalArray[i]. The object that I get from the array does not need to be
converted to java.lang.Object as it ALWAYS inherits from java.lang.Object

However, in Jython I have to either
i. ensure that the object that I get from the array (list) is an instance of
java.lang.Object or
ii. wrap the Python object into a wrapper class that inherits from
java.lang.Object

This is not obivous to a new Jython programmer who has come from Java!

Ashish

Re: [Jython-users] Swing examples

[Jeff E. <je...@ad...>]

This works for me.  No explicit java.lang.Objects in sight.


from javax.swing import *

class PythonClass:
   pass

pythonInstance = PythonClass()
pythonString = 'foo'
pythonInt = 3

l = [pythonInstance, pythonString, pythonInt]

class MyModel(AbstractListModel):
   def getElementAt(self, i):
     return l[i]
   def getSize(self):
     return len(l)

model = MyModel()
jlist = JList(model)

frame = JFrame()
frame.contentPane.add(jlist)
frame.setSize(100,300)
frame.show()



Perhaps you should post an example that shows your problem.


BillWorker 2i wrote:

> Let me explain myself!
> 
> In Java if I were to extend AbstractListModel and use an array internalArray
> to hold my data internally, then for getElementAt() I could do
> internalArray[i]. The object that I get from the array does not need to be
> converted to java.lang.Object as it ALWAYS inherits from java.lang.Object
> 
> However, in Jython I have to either
> i. ensure that the object that I get from the array (list) is an instance of
> java.lang.Object or
> ii. wrap the Python object into a wrapper class that inherits from
> java.lang.Object
> 
> This is not obivous to a new Jython programmer who has come from Java!
> 
> Ashish
> 
> 
> 
> 
> 
> _______________________________________________
> Jython-users mailing list
> Jyt...@li...
> https://lists.sourceforge.net/lists/listinfo/jython-users
> 

Re: [Jython-users] Swing examples

[BillWorker 2. <bil...@in...>]

Okay, I just have modified your code to include a few more classes. If you
run the script you will see that only for PyClass5, the one that inherits
from java.lang.Object, the JList shows a proper string in the list.

Ashish

----------  code ---------
import java
import javax.swing as swing

class PyClass1:
pass

class PyClass2:
def __repr__(self):
return 'PyClass2'

class PyClass3:
def __str__(self):
return 'PyClass3'

class PyClass4:
def toString(self):
return 'PyClass4'

class PyClass5(java.lang.Object):
def toString(self):
return 'PyClass5'


class TestModel(swing.AbstractListModel):
def __init__(self):
self.classList = [PyClass1(), PyClass2(), PyClass3(), PyClass4(),
PyClass5()]

def getElementAt(self, i):
return self.classList[i]

def getSize(self):
return len(self.classList)


frame = swing.JFrame('test')
jlist = swing.JList(TestModel())
frame.contentPane.add(jlist)
frame.pack()
frame.visible = 1

[Jython-users] Newbie problems

[Brad C. <bc...@vi...>]

I've just begun experimenting with jpython (just today). Hope to use 
it to replace velocity as the teacher-programmable component of the 
interactive learning environment at http://virtualschool.edu/jile.

My first problem is that tutorial chapter on strings isn't working 
right (on Linux 7.0 Redhat)
>>>	"Hello world"
"Hello world"

>>>	"Hello\
Syntax error: LexicalScanner Encountered <EOF> after \

This one is critical and preventing me from exploring deeper.

Second problem is that command history isn't working. readline is 
definitely installed but isn't being recognized by the installer.

Can someone please help? Sorry if these are faqs; I've not made it 
through all the docs yet.
-- 
Brad Cox, PhD; bc...@vi... 703 361 4751
o For industrial age goods there were checks and credit cards.
    For everything else there is http://virtualschool.edu/mybank
o Java Interactive Learning Environment http://virtualschool.edu/jile
o Java Web Application Architecture: http://virtualschool.edu/jwaa

Re: [Jython-users] Newbie problems

[Brian Z. <bri...@ya...>]

Brad,

Honored to have you here.

Apparently you hit a known bug:
http://sourceforge.net/tracker/index.php?func=detail&aid=222805&group_id=128
67&atid=112867

In Robert W. Bill's book, page 5 about Line Separators and Block Indentation
Syntax:

"""
A Current Interactive Limitation
One disclaimer concerning the interactive interpreter: The current
implementation of Jython produces an error when employing backslashes, open
enclosures, and triple-quotes in interactive mode despite it being legal
syntax. This syntax does work in Jython files as well as in the interactive
interpreter for CPython (Jython's counterpart implemented in C). It could be
working in interactive mode as well by the time you read this, but if not,
those examples with extended logical lines should be placed in a file and
run as an argument to the Jython interpreter (such as   jython example.py).
"""

Wonder how hard it is to fix? Any idea from the developers?

-Brian

----- Original Message -----
From: "Brad Cox" <bc...@vi...>
To: <jyt...@li...>
Sent: Tuesday, March 19, 2002 8:16 AM
Subject: [Jython-users] Newbie problems


> I've just begun experimenting with jpython (just today). Hope to use
> it to replace velocity as the teacher-programmable component of the
> interactive learning environment at http://virtualschool.edu/jile.
>
> My first problem is that tutorial chapter on strings isn't working
> right (on Linux 7.0 Redhat)
> >>> "Hello world"
> "Hello world"
>
> >>> "Hello\
> Syntax error: LexicalScanner Encountered <EOF> after \
>
> This one is critical and preventing me from exploring deeper.
>
> Second problem is that command history isn't working. readline is
> definitely installed but isn't being recognized by the installer.
>
> Can someone please help? Sorry if these are faqs; I've not made it
> through all the docs yet.
> --
> Brad Cox, PhD; bc...@vi... 703 361 4751
> o For industrial age goods there were checks and credit cards.
>     For everything else there is http://virtualschool.edu/mybank
> o Java Interactive Learning Environment http://virtualschool.edu/jile
> o Java Web Application Architecture: http://virtualschool.edu/jwaa
>
>
>
> _______________________________________________
> Jython-users mailing list
> Jyt...@li...
> https://lists.sourceforge.net/lists/listinfo/jython-users
>

Re: [Jython-users] Swing examples

[Jeff E. <je...@ad...>]

Ashish,


The default list cell renderer renders the objects in the list
with the result of toString.  Instances of Python classes do
not return the result of __repr__ or __str__ for the Java
toString method.  You could write a replacement cell renderer
that calls the __str__ method for PyInstances.

Perhaps something like in Jython:

class PyInstanceListCellRenderer(DefaultListCellRenderer):
   def getListCellRendererComponent(self,list, \
           value, index, selected, focus):
     return DefaultListCellRenderer.getListCellRendererComponent(self,\
           list,`value`,index,selected,focus)


myList = JList(cellRenderer=PyInstanceListCellRenderer())


Jeff Emanuel



BillWorker 2i wrote:

> Okay, I just have modified your code to include a few more classes. If you
> run the script you will see that only for PyClass5, the one that inherits
> from java.lang.Object, the JList shows a proper string in the list.
> 
> Ashish
> 
> ----------  code ---------
> import java
> import javax.swing as swing
> 
> class PyClass1:
> pass
> 
> class PyClass2:
> def __repr__(self):
> return 'PyClass2'
> 
> class PyClass3:
> def __str__(self):
> return 'PyClass3'
> 
> class PyClass4:
> def toString(self):
> return 'PyClass4'
> 
> class PyClass5(java.lang.Object):
> def toString(self):
> return 'PyClass5'
> 
> 
> class TestModel(swing.AbstractListModel):
> def __init__(self):
> self.classList = [PyClass1(), PyClass2(), PyClass3(), PyClass4(),
> PyClass5()]
> 
> def getElementAt(self, i):
> return self.classList[i]
> 
> def getSize(self):
> return len(self.classList)
> 
> 
> frame = swing.JFrame('test')
> jlist = swing.JList(TestModel())
> frame.contentPane.add(jlist)
> frame.pack()
> frame.visible = 1
> 
> 
> 
> _______________________________________________
> Jython-users mailing list
> Jyt...@li...
> https://lists.sourceforge.net/lists/listinfo/jython-users
> 

Re: [Jython-users] Newbie problems

[Ype K. <yk...@xs...>]

Brad,

>I've just begun experimenting with jpython (just today). Hope to use it to replace velocity as the teacher-programmable component of the interactive learning environment at http://virtualschool.edu/jile.
>
>My first problem is that tutorial chapter on strings isn't working right (on Linux 7.0 Redhat)
>>>>	"Hello world"
>"Hello world"
>
>>>>	"Hello\
>Syntax error: LexicalScanner Encountered <EOF> after \
>
>This one is critical and preventing me from exploring deeper.

Use triple quotes around your string when you need it to contain
newlines:

"""Hello
world.
"""

>
>Second problem is that command history isn't working. readline is definitely installed but isn't being recognized by the installer.

Have a look at the registry file in the jython directory (where
jython.jar is), and look for the readline option.
It needs a java class that accesses the native readline lib
that you may have to download iirc.

There is also a simple Console.py in the demo dir that has
an up arrow which is good enough for me.

Regards,
Ype

-- 

Re: [Jython-users] Newbie problems

[Brad C. <bc...@vi...>]

Thanks. But """ doesn't work either....

At 7:28 PM +0100 3/19/02, Ype Kingma wrote:
>  >I've just begun experimenting with jpython (just today). Hope to 
>use it to replace velocity as the teacher-programmable component of 
>the interactive learning environment at 
>http://virtualschool.edu/jile.
>>
>>My first problem is that tutorial chapter on strings isn't working 
>>right (on Linux 7.0 Redhat)
>>>>>	"Hello world"
>>"Hello world"
>>
>>>>>	"Hello\
>>Syntax error: LexicalScanner Encountered <EOF> after \
>>
>>This one is critical and preventing me from exploring deeper.
>
>Use triple quotes around your string when you need it to contain
>newlines:
>
>"""Hello
>world.
>"""

>>>  """Hello         
Traceback (innermost last):
   (no code object) at line 0
   File "<console>", line 2
SyntaxError: Lexical error at line 2, column 0.  Encountered: <EOF> after : ""
>>>

Any other suggestions?

>  >
>>Second problem is that command history isn't working. readline is 
>>definitely installed but isn't being recognized by the installer.
>
>Have a look at the registry file in the jython directory (where
>jython.jar is), and look for the readline option.
>It needs a java class that accesses the native readline lib
>that you may have to download iirc.

Apparently readline isn't installed on mac osx (haven't tried this on 
linux yet). Will track it down and try again.

Jython 2.1 on java1.3.1 (JIT: null)
Exception in thread "main" java.lang.NoClassDefFoundError: 
org/gnu/readline/ReadlineLibrary
         at org.python.util.ReadlineConsole.<init>(ReadlineConsole.java)
         at org.python.util.ReadlineConsole.<init>(ReadlineConsole.java)
         at java.lang.Class.newInstance0(Native Method)
         at java.lang.Class.newInstance(Class.java:237)
         at org.python.util.jython.main(jython.java)

>There is also a simple Console.py in the demo dir that has
>an up arrow which is good enough for me.
>
>Regards,
>Ype
>
>--
>
>_______________________________________________
>Jython-users mailing list
>Jyt...@li...
>https://lists.sourceforge.net/lists/listinfo/jython-users


-- 
Brad Cox, PhD; bc...@vi... 703 361 4751
o For industrial age goods there were checks and credit cards.
    For everything else there is http://virtualschool.edu/mybank
o Java Interactive Learning Environment http://virtualschool.edu/jile
o Java Web Application Architecture: http://virtualschool.edu/jwaa

Re: [Jython-users] Newbie problems

[Kevin B. <kb...@ca...>]

Brad Cox wrote:
 > Thanks. But """ doesn't work either....

This appears to be a bug in the parser in Jython's interactive interpreter:

Jython 2.1 on java1.3.1_02 (JIT: null)
Type "copyright", "credits" or "license" for more information.
 >>> """hello
Traceback (innermost last):
  (no code object) at line 0
  File "<console>", line 2
SyntaxError: Lexical error at line 2, column 0.  Encountered: <EOF> 
after : ""
 >>> print """hello
Traceback (innermost last):
  (no code object) at line 0
  File "<console>", line 2
SyntaxError: Lexical error at line 2, column 0.  Encountered: <EOF> 
after : ""
 >>> def go():
...    print """Hello
Traceback (innermost last):
  (no code object) at line 0
  File "<console>", line 3
SyntaxError: Lexical error at line 3, column 0.  Encountered: <EOF> 
after : ""
 >>> ^Z

In contrast, with CPython:

PYTHON:/e/work/cp$ python
Python 2.2 (#28, Dec 21 2001, 12:21:22) [MSC 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
 >>> """Hello
... world"""
'Hello\nworld'
 >>> ^Z

If you create & execute a file, they both work identically:

PYTHON:d:/temp$ cat >> hello.py
print """Hello
world"""
PYTHON:d:/temp$ jython hello.py
Hello
world
PYTHON:d:/temp$ python hello.py
Hello
world
PYTHON:d:/temp$

kb

[Jython-users] Re: Swing examples

[Gerald G. <gu...@fn...>]

Hi,
   This is a few years old, but it shows how to do some swing examples. 
    http://home.fnal.gov/~gug/docs/jpython.ps

Fermipython:
------------
FermiPython is a collection of scripts, modules and documents useful for
demonstrating the use of python and jpython. The aim is to
help provide information and demonstrate techniques to help a new user
of these scripted languages get started programming. As of
version 2_0, Fermipython now includes examples of how to use XML in
JPython applications. 

The product can be downloaded from:  
 ftp://ftp.fnal.gov/pub/fermipython/v2_0

and is released under the Fermi Software Tools Program:
 http://www.fnal.gov/fermitools/



> Message: 6
> Date: Sat, 09 Mar 2002 13:45:32 -0500
> To: R Datta <rd...@cr...>,jyt...@li...
> From: Noel Rappin <no...@ya...>
> Subject: Re: [Jython-users] Swing examples
> 
> At 12:08 AM 3/9/02, you wrote:
> 
> >I am looking for some Jython/ Swing sample code to code an utility. Any
> >links/ suggestions ?
> 
> Here's another shameless plug...  If you can wait a couple of weeks,
> _Jython Essentials_ has a full chapter with a number of Jython/Swing
> examples, and a lot of material on using Java Libraries in general.
> 
> Hope this helps.
> 
> Thanks,
> 
> Noel
> 
> _________________________________________________________
> Do You Yahoo!?
> Get your free @yahoo.com address at http://mail.yahoo.com
> 

-- 
-Jerry->
gu...@fn...
Pepe's Theory of everything: "Under the right circumstances, things
happen."