cpython/Lib/lib-stdwin/mainloop.py

258 lines
6.1 KiB
Python

# Standard main loop for *all* STDWIN applications.
# This requires that applications:
# - register their windows on creation and unregister them when closed
# - have a 'dispatch' function as a window member
import stdwin, stdwinq
from stdwinevents import *
# List of windows known to the main loop.
#
windows = []
# Last window that ever received an event
#
last_window = None
# Function to register a window.
#
def register(win):
# First test the dispatch function by passing it a null event --
# this catches registration of unconforming windows.
win.dispatch((WE_NULL, win, None))
if win not in windows:
windows.append(win)
# Function to unregister a window.
# It is not an error to unregister an already unregistered window
# (this is useful for cleanup actions).
#
def unregister(win):
global last_window
if win == last_window:
last_window = None
if win in windows:
windows.remove(win) # Not in 0.9.1
# 0.9.1 solution:
#for i in range(len(windows)):
# if windows[i] = win:
# del windows[i]
# break
# Interfaces used by WindowSched.
#
def countwindows():
return len(windows)
#
def anywindow():
if windows:
return windows[0]
else:
return None
# NEW: register any number of file descriptors
#
fdlist = []
select_args = None
select_handlers = None
#
def registerfd(fd, mode, handler):
if mode not in ('r', 'w', 'x'):
raise ValueError, 'mode must be r, w or x'
if type(fd) <> type(0):
fd = fd.fileno() # If this fails it's not a proper select arg
for i in range(len(fdlist)):
if fdlist[i][:2] == (fd, mode):
raise ValueError, \
'(fd, mode) combination already registered'
fdlist.append((fd, mode, handler))
make_select_args()
#
def unregisterfd(fd, *args):
if type(fd) <> type(0):
fd = fd.fileno() # If this fails it's not a proper select arg
args = (fd,) + args
n = len(args)
for i in range(len(fdlist)):
if fdlist[i][:n] == args:
del fdlist[i]
make_select_args()
#
def make_select_args():
global select_args, select_handlers
rlist, wlist, xlist = [], [], []
rhandlers, whandlers, xhandlers = {}, {}, {}
for fd, mode, handler in fdlist:
if mode == 'r':
rlist.append(fd)
rhandlers[`fd`] = handler
if mode == 'w':
wlist.append(fd)
whandlers[`fd`] = handler
if mode == 'x':
xlist.append(fd)
xhandlers[`fd`] = handler
if rlist or wlist or xlist:
select_args = rlist, wlist, xlist
select_handlers = rhandlers, whandlers, xhandlers
else:
select_args = None
select_handlers = None
#
def do_select():
import select
reply = apply(select.select, select_args)
for mode in 0, 1, 2:
list = reply[mode]
for fd in list:
handler = select_handlers[mode][`fd`]
handler(fd, 'rwx'[mode])
# Event processing main loop.
# Return when there are no windows left, or when an unhandled
# exception occurs. (It is safe to restart the main loop after
# an unsuccessful exit.)
# Python's stdwin.getevent() turns WE_COMMAND/WC_CANCEL events
# into KeyboardInterrupt exceptions; these are turned back in events.
#
recursion_level = 0 # Hack to make it reentrant
def mainloop():
global recursion_level
recursion_level = recursion_level + 1
try:
stdwin_select_handler() # Process events already in queue
while 1:
if windows and not fdlist:
while windows and not fdlist:
try:
event = stdwinq.getevent()
except KeyboardInterrupt:
event = (WE_COMMAND, \
None, WC_CANCEL)
dispatch(event)
elif windows and fdlist:
fd = stdwin.fileno()
if recursion_level == 1:
registerfd(fd, 'r', stdwin_select_handler)
try:
while windows:
do_select()
stdwin_select_handler()
finally:
if recursion_level == 1:
unregisterfd(fd)
elif fdlist:
while fdlist and not windows:
do_select()
else:
break
finally:
recursion_level = recursion_level - 1
# Check for events without ever blocking
#
def check():
stdwin_select_handler()
# XXX Should check for socket stuff as well
# Handle stdwin events until none are left
#
def stdwin_select_handler(*args):
while 1:
try:
event = stdwinq.pollevent()
except KeyboardInterrupt:
event = (WE_COMMAND, None, WC_CANCEL)
if event is None:
break
dispatch(event)
# Run a modal dialog loop for a window. The dialog window must have
# been registered first. This prohibits most events (except size/draw
# events) to other windows. The modal dialog loop ends when the
# dialog window unregisters itself.
#
passthrough = WE_SIZE, WE_DRAW
beeping = WE_MOUSE_DOWN, WE_COMMAND, WE_CHAR, WE_KEY, WE_CLOSE, WE_MENU
#
def modaldialog(window):
if window not in windows:
raise ValueError, 'modaldialog window not registered'
while window in windows:
try:
event = stdwinq.getevent()
except KeyboardInterrupt:
event = WE_COMMAND, None, WC_CANCEL
etype, ewindow, edetail = event
if etype not in passthrough and ewindow <> window:
if etype in beeping:
stdwin.fleep()
continue
dispatch(event)
# Dispatch a single event.
# Events for the no window in particular are sent to the active window
# or to the last window that received an event (these hacks are for the
# WE_LOST_SEL event, which is directed to no particular window).
# Windows not in the windows list don't get their events:
# events for such windows are silently ignored.
#
def dispatch(event):
global last_window
if event[1] == None:
active = stdwin.getactive()
if active: last_window = active
else:
last_window = event[1]
if last_window in windows:
last_window.dispatch(event)
# Dialog base class
#
class Dialog:
#
def init(self, title):
self.window = stdwin.open(title)
self.window.dispatch = self.dispatch
register(self.window)
return self
#
def close(self):
unregister(self.window)
del self.window.dispatch
self.window.close()
#
def dispatch(self, event):
etype, ewindow, edetail = event
if etype == WE_CLOSE:
self.close()
# Standard modal dialogs
# XXX implemented using stdwin dialogs for now
#
def askstr(prompt, default):
return stdwin.askstr(prompt, default)
#
def askync(prompt, yesorno):
return stdwin.askync(prompt, yesorno)
#
def askfile(prompt, default, new):
return stdwin.askfile(prompt, default, new)
#
def message(msg):
stdwin.message(msg)