Jython is a Python interpreter which runs on top of Java. It provides the functionality of Python, plus a "pythonic" way to interact with existing Java APIs.
Consider initializing a Swing application in Jython. According to specifications, even constructing Swing components on the Main thread like this can be unsafe.
from javax.swing import *
jf = JFrame("Hi")
jf.contentPane.add(JButton("does nothing"))
# more unsafe initialization here
# ...
jf.pack()
jf.visible = 1
from javax.swing import *
from java.awt import EventQueue
from java.lang import Runnable
class initializeApp(Runnable):
def run(self):
global jf
jf = JFrame("Hi")
jf.contentPane.add(JButton("does nothing"))
# more unsafe initialization here
jf.pack()
jf.visible = 1
EventQueue.invokeAndWait(initializeApp())
from java.awt import EventQueue
from java.lang import Runnable
def EDTsafe(function):
def safe(*args,**kwargs):
if EventQueue.isDispatchThread():
return function(*args,**kwargs)
else:
class foo(Runnable):
def run(self):
self.result = function(*args,**kwargs)
f = foo()
EventQueue.invokeAndWait(f)
return f.result
safe.__name__ = function.__name__
safe.__doc__ = function.__doc__
safe.__dict__.update(function.__dict__)
return safe
from javax.swing import *
@EDTsafe
def initializeApp():
global jf
jf = JFrame("Hi")
jf.contentPane.add(JButton("does nothing"))
# more unsafe initialization here
jf.pack()
jf.visible = 1
initializeApp()
EDTsafe( lambda: jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE) )()
\[\alpha=\frac{1}{2}(2R - G - B)\]
\[\beta =\frac{\sqrt{3}}{2}(G - B)\]
\[H_2 =\operatorname{atan2}(\beta, \alpha)\]
\[C_2 =\sqrt{\alpha^2 + \beta^2}\]
