Source code for pyface.i_gui

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""" The interface of a pyface GUI. """


import logging
import os


from traits.etsconfig.api import ETSConfig
from traits.api import Bool, HasTraits, Interface, Str


# Logging.
logger = logging.getLogger(__name__)


[docs]class IGUI(Interface): """ The interface of a pyface GUI. """ # 'GUI' interface -----------------------------------------------------# #: Is the GUI busy (i.e. should the busy cursor, often an hourglass, be #: displayed)? busy = Bool(False) #: Has the GUI's event loop been started? started = Bool(False) #: A directory on the local file system that we can read and write to at #: will. This is used to persist layout information etc. Note that #: individual toolkits will have their own directory. state_location = Str() # ------------------------------------------------------------------------ # 'object' interface. # ------------------------------------------------------------------------ def __init__(self, splash_screen=None): """ Initialise a new GUI. Parameters ---------- splash_screen : ISplashScreen instance or None An optional splash screen that will be displayed until the event loop is started. """ # ------------------------------------------------------------------------ # 'GUI' class interface. # ------------------------------------------------------------------------
[docs] @staticmethod def allow_interrupt(): """ Override SIGINT to prevent swallowing KeyboardInterrupt Override the SIGINT handler to ensure the process can be interrupted. This prevents GUI toolkits from swallowing KeyboardInterrupt exceptions. Warning: do not call this method if you intend your application to be run interactively. """
[docs] @classmethod def invoke_after(cls, millisecs, callable, *args, **kw): """ Call a callable after a specific delay in the main GUI thread. Parameters ---------- millisecs : float Delay in milliseconds callable : callable Callable to be called after the delay args, kwargs : Arguments and keyword arguments to be used when calling. """
[docs] @classmethod def invoke_later(cls, callable, *args, **kw): """ Call a callable in the main GUI thread. Parameters ---------- callable : callable Callable to be called after the delay args, kwargs : Arguments and keyword arguments to be used when calling. """
[docs] @classmethod def set_trait_after(cls, millisecs, obj, trait_name, new): """ Sets a trait after a specific delay in the main GUI thread. Parameters ---------- millisecs : float Delay in milliseconds obj : HasTraits instance Object on which the trait is to be set trait_name : str The name of the trait to set new : any The value to set. """
[docs] @classmethod def set_trait_later(cls, obj, trait_name, new): """ Sets a trait in the main GUI thread. Parameters ---------- obj : HasTraits instance Object on which the trait is to be set trait_name : str The name of the trait to set new : any The value to set. """
[docs] @staticmethod def process_events(allow_user_events=True): """ Process any pending GUI events. Parameters ---------- allow_user_events : bool If allow_user_events is ``False`` then user generated events are not processed. """
[docs] @staticmethod def set_busy(busy=True): """Specify if the GUI is busy. Parameters ---------- busy : bool If ``True`` is passed, the cursor is set to a 'busy' cursor. Passing ``False`` will reset the cursor to the default. """
# ------------------------------------------------------------------------ # 'GUI' interface. # ------------------------------------------------------------------------
[docs] def start_event_loop(self): """ Start the GUI event loop. """
[docs] def stop_event_loop(self): """ Stop the GUI event loop. """
[docs]class MGUI(HasTraits): """ The mixin class that contains common code for toolkit specific implementations of the IGUI interface. Implements: _default_state_location() """
[docs] @staticmethod def allow_interrupt(): """ Override SIGINT to prevent swallowing KeyboardInterrupt Override the SIGINT handler to ensure the process can be interrupted. This prevents GUI toolkits from swallowing KeyboardInterrupt exceptions. Warning: do not call this method if you intend your application to be run interactively. """ import signal signal.signal(signal.SIGINT, signal.SIG_DFL)
def _default_state_location(self): """ Return the default state location. """ state_location = os.path.join( ETSConfig.application_home, "pyface", ETSConfig.toolkit ) if not os.path.exists(state_location): os.makedirs(state_location) logger.debug("GUI state location is <%s>", state_location) return state_location