title = 'More examples of subclassing'
# Import Pmw from this directory tree.
import sys
sys.path[:0] = ['../../..']
import Tkinter
import Pmw
class ExtraMethods(Pmw.EntryField):
# How to subclass a Pmw megawidget when you only want to add or
# override methods.
def doubletext(self):
self.setvalue(self.getvalue() + ' ' + self.getvalue())
class OverrideInit(Pmw.EntryField):
# How to subclass a Pmw megawidget when you want to define
# a new __init__ method.
def __init__(self, textToAdd, parent = None, **kw):
self._textToAdd = textToAdd
apply(Pmw.EntryField.__init__, (self, parent), kw)
def addtext(self):
self.setvalue(self.getvalue() + ' ' + self._textToAdd)
class DefaultOptions(Pmw.EntryField):
# How to subclass a Pmw megawidget when you only want to set
# existing options to new default values.
def __init__(self, parent = None, **kw):
kw['label_foreground'] = 'blue'
kw['entry_background'] = 'white'
apply(Pmw.EntryField.__init__, (self, parent), kw)
class NewOptions(Pmw.EntryField):
# How to subclass a Pmw megawidget when you want to add new options.
def __init__(self, parent=None , **kw):
# Define the megawidget options.
optiondefs = (
('backgrounds', None, self._backgrounds),
)
self.defineoptions(kw, optiondefs)
# Initialise the base class (after defining the options).
Pmw.EntryField.__init__(self, parent)
# Check keywords and initialise options.
self.initialiseoptions()
def _backgrounds(self):
background = self['backgrounds']
Pmw.Color.changecolor(self.component('hull'), background)
class Demo:
def __init__(self, parent):
# Create and pack the megawidgets.
self._extraMethod = ExtraMethods(parent,
labelpos = 'w',
label_text = 'Sub class with extra method:',
value = 'Hello'
)
self._overrideInit = OverrideInit('Again', parent,
labelpos = 'w',
label_text = 'Sub class with new __init__ method:',
value = 'Hello'
)
self._defaultOptions = DefaultOptions(parent,
labelpos = 'w',
label_text = 'Sub class with new default options:',
value = 'Hello'
)
self._newOptions = NewOptions(parent,
labelpos = 'w',
label_text = 'Sub class with new option:',
value = 'Hello',
backgrounds = 'white',
)
entries = (self._extraMethod, self._overrideInit,
self._defaultOptions, self._newOptions)
for entry in entries:
entry.pack(fill='x', expand=1, padx=10, pady=5)
Pmw.alignlabels(entries)
bb = Pmw.ButtonBox(parent)
bb.add('Double text', command = self._doubleText)
bb.pack()
bb.add('Add text', command = self._addText)
bb.pack()
bb.add('White', command = self._changeColorWhite)
bb.pack()
bb.add('Green', command = self._changeColorGreen)
bb.pack()
def _doubleText(self):
self._extraMethod.doubletext()
def _addText(self):
self._overrideInit.addtext()
def _changeColorWhite(self):
self._newOptions.configure(backgrounds = 'white')
def _changeColorGreen(self):
self._newOptions.configure(backgrounds = 'green')
######################################################################
# Create demo in root window for testing.
if __name__ == '__main__':
root = Tkinter.Tk()
Pmw.initialise(root)
root.title(title)
exitButton = Tkinter.Button(root, text = 'Exit', command = root.destroy)
exitButton.pack(side = 'bottom')
widget = Demo(root)
root.mainloop()
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