Shield. A class for blocking touch events.

[polymerchm]

# Sheild 
# covers the designated view to suppress touch events. 

import ui

class Shield(object):
	def __init__(self,view): # view is view to cover
		self.view = view
		self.shield = ui.View(frame=view.bounds,background_color=(1.0, 1.0, 1.0, 0.7),flex='WH')
		self.shield.frame = self.view.frame
		
		
	def conceal(self): # ui seems to ignore multiple requests to add the same subview.  Good.
		if self.view.superview:
			self.view.superview.add_subview(self.shield)
		else: #its the root view
			self.view.add_subview(self.shield)
		
	def reveal(self): #ui is also happy to ignore requests to remove an non-existant subview.  Also good.
		if self.view.superview:
			self.view.superview.remove_subview(self.shield)
		else: #see above
			self.view.remove_subview(self.shield)
		
	def delete(self):
		del self.shield

if __name__ == '__main__':
	
	class LDS(ui.ListDataSource):
		def __init__(self,items=None):
			super(LDS,self).__init__(items)
			
		def tableview_did_select(self,tv,section,row):
			t1.text = self.items[row]

	def shieldsUp(sender):
		s1.conceal()
		s2.conceal()
	def shieldsDown(sender):
		global s1
		s1.reveal()
		s2.reveal()
		
				
	v = ui.View(frame=(0,0,600,600),name='main')

	tv = ui.TableView(name='tv')
	lds = LDS(items='one two three four five'.split())
	tv.data_source = tv.delegate = lds
	v.add_subview(tv)
	tv.frame=(10,10,400,500)
	
	b1 = ui.Button(frame=(450,10,100,50),
	               background_color = 'white',
	               title = 'Shields up!',
	               )
	b2 = ui.Button(frame=(450,100,100,50),
	               background_color = 'white',
	               title = 'Shields down',
	               )
	b1.action = shieldsUp
	b2.action = shieldsDown
	
	v.add_subview(b1)
	v.add_subview(b2)
	
	t1 = ui.TextView()
	v.add_subview(t1)
	t1.frame=(100,550,200,30)
	t1.text = 'READY'
	s1 = Shield(tv)
	s2 = Shield(t1)
	
	v.present('sheet')
	v.wait_modal()
	s1.delete()
	s2.delete()

[reefboy1]

What does a class mean?

[ccc]

Classes are described here https://docs.python.org/2.7/tutorial/classes.html

[polymerchm]

Short description. A template for a python object. Defines its instance variables and method.

Learn this fast or you are not really using Python to its ultimate potential.

[ccc]

Let's make sure that Reefboy1 masters functions and data structures (lists, dicts, sets) before he embarks on the advanced topic of classes.

[polymerchm]

Gotcha.

[reefboy1]

Ok I've got it down, ive made this

class Cat(object):
	type = 'fuzzy'
	name = 'cuddlez'

In the shell you can do Cat.type or Cat.name and they will pop up. I believe I did this correctly, did I?

[polymerchm]

@reefboy1

should be

class Cat(object):
     def __init__(self):
          self.type = 'fuzzy'
          self.name = 'cudelez'

myPet = Cat()
print myPet.type      [would print fuzzy]
print myPet.name    [would print cudelez]

yourPet = Cat()
yourPet.type = "ferocious'
yourPet.name = "tiger'

#A SIMPLE TUTORIAL FOR CLASSES

#A class is a "template" for a python object.  
#the object it builds is a "instance" of that class.  

#Objects have attributes (variables) and methods (functions)
#Each instance of a class has its own unique copies of its instances and methods 
#that only operatate on that particular instance of the class.  This is at the core of object oriented programming: 
# protecting instances for accidently affecting other instances

#for example:
	
class Adder():                # this defines the classes name.  
													
# What else can go in the  parenthesis is for another day.
															 
	def __init__(self):         # this is the method that creates this instance and does anything
					     # needed when it is created.  
					     # "self" stands in for the actual instance that is created.
					     # any method in the class will get this as it first parameter
                                   # the init method can have parameters besides the required self
                                  # typically used to set up values or attributes at the creation of the instance.
															
		self.sum = 0	     # sum is an attribute (variable).  the "self." in front says its
					     # an attribute of the instance.  Without the "self." in front, 
					     # its local to the methdod and disappears after the method runs.
					      # all methods in the instance can assess this attribute.
															
	def add(self,value):	      # this method will increment the sum attribute of the instance .  Note
					      # the first parameter is self, even if down below, its not in the call.
		self.sum += value
		
	def reset(self):						# set the attribute sum to zero for ths instance.
		self.sum = 0
		
	def retrieve(self):					# returns the current value of the sum attribute 
		return self.sum
		
	def display(self):					# prints out the current value of the 
		print "The current sum = {}".format(self.sum)
		
if __name__ == '__main__':		# this test only runs the code below it if this file is run directly.
							# mainly for testing a class.  to have another python file have access to
							# class with explicitly writing it again, you use the import statement
																
	myAdder = Adder()						# creates an instance of the class Adder
                                                                                # note the absence of the self parameter in the call.
                                                                                # python handles that for you

	yourAdder = Adder()					# creates a second different instance
	myAdder.add(10)							# increments the first one by 10
	yourAdder.add(5)						# increments the other one by 5
	myAdder.add(-5)
	myAdder.display()						# prints out the current value of sum in the first instance
	yourAdder.display()					# ditto for the second instance.
	myAdder.reset()
	myAdder.display()
	

[reefboy1]

Oh I see, cool. Thanks

[JonB]

Poly, your shield example really needs some sound effects :)