--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/grease/impl/mode.py	Tue Jul 12 10:16:48 2011 +0200
@@ -0,0 +1,203 @@
+#############################################################################
+#
+# Copyright (c) 2010 by Casey Duncan and contributors
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the MIT License
+# A copy of the license should accompany this distribution.
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+#
+#############################################################################
+"""
+Modes manage the state and transition between different application modes.
+Typically such modes are presented as different screens that the user can
+navigate between, similar to the way a browser navigates web pages. Individual
+modes may be things like:
+
+- Title screen
+- Options dialog
+- About screen
+- In-progress game
+- Inventory interface
+
+The modal framework provides a simple mechanism to ensure that modes are
+activated and deactivated properly. An activated mode is running and receives
+events. A deactivated mode is paused and does not receive events.
+
+Modes may be managed as a *last-in-first-out* stack, or as a list, or ring
+of modes in sequence, or some combination of all.
+
+For example usage see: :ref:`the mode section of the tutorial <tut-mode-section>`.
+"""
+
+__version__ = '$Id$'
+
+import abc
+import pyglet
+from grease.mode import *
+
+class PygletManager(BaseManager):
+	"""Mode manager abstract base class using pyglet.
+	
+	The mode manager keeps a stack of modes where a single mode
+	is active at one time. As modes are pushed on and popped from 
+	the stack, the mode at the top is always active. The current
+	active mode receives events from the manager's event dispatcher.
+	"""
+
+	event_dispatcher = None
+	""":class:`pyglet.event.EventDispatcher` object that the
+	active mode receive events from.
+	"""
+	
+	def activate_mode(self, mode):
+		"""Perform actions to activate a node
+		
+		:param mode: The :class: 'Mode' object to activate
+		"""
+		BaseManager.activate_mode(self, mode)
+		self.event_dispatcher.push_handlers(mode)
+		
+	def deactivate_mode(self, mode):
+		"""Perform actions to deactivate a node
+		
+		:param mode: The :class: 'Mode' object to deactivate
+		"""
+		BaseManager.deactivate_mode(self, mode)
+		self.event_dispatcher.remove_handlers(mode)
+
+class Manager(PygletManager):
+	"""A basic mode manager that wraps a single
+	:class:`pyglet.event.EventDispatcher` object for use by its modes.
+	"""
+
+	def __init__(self, event_dispatcher):
+		self.modes = []
+		self.event_dispatcher = event_dispatcher
+
+
+class ManagerWindow(PygletManager, pyglet.window.Window):
+	"""An integrated mode manager and pyglet window for convenience.
+	The window is the event dispatcher used by modes pushed to
+	this manager.
+
+	Constructor arguments are identical to :class:`pyglet.window.Window`
+	"""
+	
+	def __init__(self, *args, **kw):
+		super(ManagerWindow, self).__init__(*args, **kw)
+		self.modes = []
+		self.event_dispatcher = self
+
+	def on_key_press(self, symbol, modifiers):
+		"""Default :meth:`on_key_press handler`, pops the current mode on ``ESC``"""
+		if symbol == pyglet.window.key.ESCAPE:
+			self.pop_mode()
+
+	def on_last_mode_pop(self, mode):
+		"""Hook executed when the last mode is popped from the manager.
+		When the last mode is popped from a window, an :meth:`on_close` event
+		is dispatched.
+
+		:param mode: The :class:`Mode` object just popped from the manager
+		"""
+		self.dispatch_event('on_close')
+
+
+class Mode(BaseMode):
+	"""Application mode abstract base class using pyglet
+
+	Subclasses must implement the :meth:`step` method
+	
+	:param step_rate: The rate of :meth:`step()` calls per second. 
+
+	:param master_clock: The :class:`pyglet.clock.Clock` interface used
+		as the master clock that ticks the world's clock. This 
+		defaults to the main pyglet clock.
+	"""
+	clock = None
+	"""The :class:`pyglet.clock.Clock` instance used as this mode's clock.
+	You should use this clock to schedule tasks for this mode, so they
+	properly respect when the mode is active or inactive
+
+	Example::
+
+		my_mode.clock.schedule_once(my_cool_function, 4)
+	"""
+
+	def __init__(self, step_rate=60, master_clock=pyglet.clock, 
+		         clock_factory=pyglet.clock.Clock):
+		BaseMode.__init__(self)
+		self.step_rate = step_rate
+		self.time = 0.0
+		self.master_clock = master_clock
+		self.clock = clock_factory(time_function=lambda: self.time)
+		self.clock.schedule_interval(self.step, 1.0 / step_rate)
+	
+	def on_activate(self):
+		"""Being called when the Mode is activated"""
+		self.master_clock.schedule(self.tick)
+	
+	def on_deactivate(self):
+		"""Being called when the Mode is deactivated"""
+		self.master_clock.unschedule(self.tick)
+		
+	def tick(self, dt):
+		"""Tick the mode's clock.
+
+		:param dt: The time delta since the last tick
+		:type dt: float
+		"""
+		self.time += dt
+		self.clock.tick(poll=False)
+	
+	@abc.abstractmethod
+	def step(self, dt):
+		"""Execute a timestep for this mode. Must be defined by subclasses.
+		
+		:param dt: The time delta since the last time step
+		:type dt: float
+		"""
+
+class Multi(BaseMulti, Mode):
+	"""A mode with multiple submodes. One submode is active at one time.
+	Submodes can be switched to directly or switched in sequence. If
+	the Multi is active, then one submode is always active.
+
+	Multis are useful when modes can switch in an order other than
+	a LIFO stack, such as in "hotseat" multiplayer games, a
+	"wizard" style ui, or a sequence of slides.
+
+	Note unlike a normal :class:`Mode`, a :class:`Multi` doesn't have it's own
+	:attr:`clock` and :attr:`step_rate`. The active submode's are used
+	instead.
+	"""
+	
+	def __init__(self, submodes):
+		BaseMulti.__init__(self, submodes)
+		self.time = 0.0
+
+	
+	def _set_active_submode(self, submode):
+		BaseMulti._set_active_submode(self, submode)
+		self.master_clock = submode.master_clock
+		self.clock = submode.clock
+
+	def clear_subnode(self):
+		"""Clear any subnmode data"""
+		BaseMulti.clear_subnode(self)
+		self.master_clock = None
+		self.clock = None
+
+	def tick(self, dt):
+		"""Tick the active submode's clock.
+
+		:param dt: The time delta since the last tick
+		:type dt: float
+		"""
+		self.time += dt
+		if self.active_submode is not None:
+			self.active_submode.clock.tick(poll=False)
+