Drop Shadow behind ui.view()

blmacbeth

Ask and he shall receive. It's not perfect, yet. There are some clipping problems I can't figure out.

# coding: utf-8
from objc_util import *
import ui

UIColor = ObjCClass('UIColor')

def Color(red=0, green=0, blue=0, alpha=1):
	return UIColor.colorWithRed_green_blue_alpha_(red, green, blue, alpha)

class ShadowView (ui.View):
	def __init__(self, *args, **kwargs):
		super(ShadowView, self).__init__()
		self.pntr = ObjCInstance(self)
		self.pntr.layer().setMasksToBounds_(False) ## Go ahead and do this.
		
	@property 
	def corner_radius(self):
		return self.pntr.layer().cornerRadius()
		
	@corner_radius.setter
	def corner_radius(self, val):
		self.pntr.layer().setCornerRadius_(val)
		
	@property
	def border_color(self):
		return self.pntr.layer().borderColor()
		
	@border_color.setter
	def border_color(self, color):
		self.pntr.layer().setBorderColor_(Color(*color).CGColor())
		
	@property
	def border_width(self):
		return self.pntr.layer().borderWidth()
		
	@border_width.setter
	def border_width(self, val):
		self.pntr.layer().setBorderWidth_(val)
		
	@property 
	def opacity(self):
		return self.pntr.layer().opacity()
		
	@opacity.setter
	def opacity(self, val):
		self.pntr.layer().setOpacity_(value)
		
	@property 
	def hidden(swlf):
		return self.pntr.layer().hidden()
		
	@hidden.setter
	def hidden(self, val):
		self.pntr.layer().setHidden_(val)
		
	@property 
	def masks_to_bounds(self):
		return self.pntr.layer().masksToBounds()
		
	@masks_to_bounds.setter
	def masks_to_bounds(self, val):
		self.pntr.layer().setMasksToBounds_(val)
		
	@property 
	def mask(self):
		return self.pntr.layer().mask()
		
	@mask.setter
	def mask(self, new_mask):
		self.pntr.layer().setMask_(new_mask)
		
	@property
	def double_sided(self):
		return self.pntr.layer().doubleSided()
		
	@double_sided.setter
	def double_sided(self, val):
		self.pntr.layer().setDoubleSided_(val)
		
	@property
	def shadow_opacity(self):
		return self.pntr.layer().shadowOpacity()
		
	@shadow_opacity.setter
	def shadow_opacity(self, val):
		self.pntr.layer().setShadowOpacity_(val)
		
	@property
	def shadow_radius(self):
		return self.pntr.layer().shadowRadius()
		
	@shadow_radius.setter
	def shadow_radius(self, val):
		self.pntr.layer().setShadowRadius_(val)
		
	@property
	def shadow_offset(self):
		return self.pntr.layer().shadowOffset()
		
	@shadow_offset.setter
	def shadow_offset(self, offset):
		## offset should be a tuple, but I'll take a CGSize
		if isinstance(offset, CGSize):
			self.pntr.layer().setShadowOffset_(offset)
		elif isinstance(offset, tuple):
			self.pntr.layer().setShadowOffset_(CGSize(*offset))
		else:
			raise TypeError("Cannot use type %s. Use CGSize or tuple" % type(offset))
			
	@property
	def shadow_color(self):
		return self.pntr.layer().shadowColor()
		
	@shadow_color.setter
	def shadow_color(self, color):
		if isinstance(color, UIColor.CGColor()):
			self.pntr.layer().setShadowColor_(color)
		elif isinstance(color, tuple) and len(color) == 4:
			self.pntr.layer().setShadowColor_(Color(*color).CGColor())
		else:
			raise ValueError('Cannot use type %s. Use UIColor or tuple' % type(color))
			
		@property
		def shadow_path(self):
			return self.pntr.layer().shadowPath()
			
		@shadow_path.setter
		def shadow_path(self, path):
			self.pntr.layer().setShadowPath_(path)
			
		@property
		def style(self):
			return self.pntr.layer().style()
			
		@style.setter
		def style(self, style):
			self.pntr.layer().setStyle_(style)
			
if __name__ == '__main__':	
	view = ui.View(frame=(0,0,500,500))
	box  = ShadowView(frame=(0,0,100,100))
	
	view.background_color = 'white'
	box.background_color = 'red'
	box.center = view.center
	
	view.add_subview(box)
	
	box.masks_to_bounds = False
	box.corner_radius = 6.
	box.border_color = (0,1,0)
	box.border_width = 6
	box.shadow_radius = 10
	box.shadow_offset = (0,0)
	box.shadow_opacity = 1
	
	view.present('sheet')

I tested most of it, but there may still be some funny-ness.

B.

Phuket2

@blmacbeth , ok thanks. I will try it. Maybe I am wrong, but doesn't your call to super need to be like
super(ShadowView, self).init(self, *args, **kwargs)

If not, then I would love to know why not.

dgelessus

@Phuket2 Since you've already passed self as an argument to super, you already get (bound) methods instead of normal functions, so you don't need to pass self as the first parameter to __init__. Though you are right, the *args and **kwargs do need to be passed (if you want ui.View to interpret them, which I assume is the case). For ui.View the docs say that you don't need to call super().__init__() at all, perhaps everything important is already handled by __new__.

blmacbeth

@Phuket2 Ha! You caught me. That may be a problem… it should look like:

super(ShadowView, self).__init__(*args, **kwargs)

I must have been in a zone to miss that. There is no need to repeat self in the __init__ call because super(ShadowView, self) returns an instance of the superclass, which will pass self implicitly.

Phuket2

@dgelessus , thanks. I tend not to call super anymore. I normally call the class init method. I think I did that because I was doing multiple inheritance and was having a hard time following what was going on 😭, to this day I still don't know the most correct way.
I am pretty sure I have checked this theory of not having to pass on params to ui.View, I know it's in the docs. As far as I can see it does not work. Maybe if you have no init. Not sure that should cancel new, but maybe it's been written to work that way. So many combinations, I get confused 😱

Phuket2

@blmacbeth , lol. I understand. I thought you had some special trick up your sleeve 😝

blmacbeth

@Phuket2 I wish I have a cool trick up my sleeve! But to comment on your response about not calling super: it is best practice to call super when subclassing. This is because it allows you to refactor your code with less changes made afterwards.

For example: let's say I someday make a kick-ass version of UIView and UIViewController that make ui.View look like children's toys. So, you want to incorporate the new view classes into your old code. The way you have, you would need to change every instance of ui.View.__init__(...). By calling super you no longer have to do all that tedious work. It makes life slightly easier.

I'm not saying that what your doing is wrong; I have plenty of classes that do the same thing. But o have started using super because of the refactoring issue.

Now, this could all be a load of bullshit I am feeding you, so go look it up yourself and let me know if I'm correct! 😛

B.

Phuket2

@blmacbeth , hmmm, I am a little on the drunk side now 🎉😎 almost 11:30pm here now. So maybe I should wait until tomorrow to look it up 😱
But I started getting a problem when inheriting from multiple classes. Gets confusing about which base class is being called ( it did for me anyway). That's when I started using the implicit calls to base class's init methods instead. But I see your point though. I haven't managed to write anything significant enough in Python were it's been a problem to refactor 😭
Still trying though

JonB

re needing to call View.init, see
https://forum.omz-software.com/topic/2548/inheritance-and-kwargs-popping-consumption/5

If you do not implement your own init, you do not need to call super init.
If you have an init, you do need to call the View.init

dgelessus

From what I've heard, you need to use super() for some aspects of multiple inheritance to work properly. I know almost nothing about the details of multiple inheritance on Python though, so I can't tell you why exactly that is and what would break otherwise. Mostly because multiple inheritance is not needed very often.