from Components.HTMLSkin import HTMLSkin
from Components.GUISkin import GUISkin
from Components.Sources.Source import Source
from Components.GUIComponent import GUIComponent

class Screen(dict, HTMLSkin, GUISkin):

	ALLOW_SUSPEND = False

	global_screen = None

	def __init__(self, session, parent = None):
		self.skinName = self.__class__.__name__
		self.session = session
		self.parent = parent
		GUISkin.__init__(self)

		self.onClose = [ ]
		self.onFirstExecBegin = [ ]
		self.onExecBegin = [ ]
		self.onShown = [ ]

		self.onShow = [ ]
		self.onHide = [ ]

		self.execing = False
		
		self.shown = True
		# already shown is false until the screen is really shown (after creation)
		self.already_shown = False

		self.renderer = [ ]

		# in order to support screens *without* a help,
		# we need the list in every screen. how ironic.
		self.helpList = [ ]

		self.close_on_next_exec = None

		# stand alone screens (for example web screens)
		# don't care about having or not having focus.
		self.stand_alone = False

	def execBegin(self):
		self.active_components = [ ]
		if self.close_on_next_exec is not None:
			tmp = self.close_on_next_exec
			self.close_on_next_exec = None
			self.execing = True
			self.close(*tmp)
		else:
			single = self.onFirstExecBegin
			self.onFirstExecBegin = []
			for x in self.onExecBegin + single:
				x()
				if not self.stand_alone and self.session.current_dialog != self:
					return

#			assert self.session == None, "a screen can only exec once per time"
#			self.session = session

			for val in self.values() + self.renderer:
				val.execBegin()
				if not self.stand_alone and self.session.current_dialog != self:
					return
				self.active_components.append(val)

			self.execing = True
	
			for x in self.onShown:
				x()
	
	def execEnd(self):
#		for (name, val) in self.items():
		for val in self.active_components:
			val.execEnd()
		del self.active_components
#		assert self.session != None, "execEnd on non-execing screen!"
#		self.session = None
		self.execing = False
	
	# never call this directly - it will be called from the session!
	def doClose(self):
		self.hide()
		for x in self.onClose:
			x()
		
		# fixup circular references
		del self.helpList
		GUISkin.close(self)

		# first disconnect all render from their sources.
		# we might split this out into a "unskin"-call,
		# but currently we destroy the screen afterwards
		# anyway.
		for val in self.renderer:
			val.disconnectAll()  # disconnected converter/sources and probably destroy them
		
		del self.session
		for (name, val) in self.items():
			val.destroy()
			del self[name]
		
		for val in self.renderer:
			val.destroy()
		
		self.renderer = [ ]
		
		# really delete all elements now
		self.__dict__.clear()
	
	def close(self, *retval):
		if not self.execing:
			self.close_on_next_exec = retval
		else:
			self.session.close(self, *retval)

	def setFocus(self, o):
		self.instance.setFocus(o.instance)

	def show(self):
		if (self.shown and self.already_shown) or not self.instance:
			return
		self.shown = True
		self.already_shown = True
		self.instance.show()
		for x in self.onShow:
			x()
		for val in self.values() + self.renderer:
			if isinstance(val, GUIComponent) or isinstance(val, Source):
				val.onShow()

	def hide(self):
		if not self.shown or not self.instance:
			return
		self.shown = False
		self.instance.hide()
		for x in self.onHide:
			x()
		for val in self.values() + self.renderer:
			if isinstance(val, GUIComponent) or isinstance(val, Source):
				val.onHide()

	def __repr__(self):
		return str(type(self))

	def getRelatedScreen(self, name):
		if name == "session":
			return self.session.screen
		elif name == "parent":
			return self.parent
		elif name == "global":
			return self.global_screen
		else:
			return None