Initial revision

Lib/lib-stdwin/mainloop.py

@@ -0,0 +1,72 @@
+# 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 = []
+
+
+# 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):
+	if win in windows:
+		windows.remove(win) # Not in 0.9.1
+		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
+
+
+# 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.
+#
+def mainloop():
+	while windows:
+		try:
+			dispatch(stdwinq.getevent())
+		except KeyboardInterrupt:
+			dispatch(WE_COMMAND, stdwin.getactive(), WC_CANCEL)
+
+
+# Dispatch a single event.
+# Windows not in the windows list don't get their events:
+# events for such windows are silently ignored.
+#
+def dispatch(event):
+	if event[1] in windows:
+		event[1].dispatch(event)