Continued work on GEP008: Move BasicUtils/UpdateCallback.py to gen/updatecallback.py.

svn: r14025

src/gen/updatecallback.py

@@ -0,0 +1,91 @@
+#
+# Gramps - a GTK+/GNOME based genealogy program
+#
+# Copyright (C) 2004-2007 Donald N. Allingham
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+
+# $Id$
+
+"""
+A set of basic utilities that everything in GRAMPS can depend upon.
+
+The goal is to have this module not depend on any other gramps module.
+That way, e.g. database classes can safely depend on that without
+other GRAMPS baggage.
+"""
+
+#-------------------------------------------------------------------------
+#
+# Python modules
+#
+#-------------------------------------------------------------------------
+import time
+
+#-------------------------------------------------------------------------
+#
+# Callback updater
+#
+#-------------------------------------------------------------------------
+class UpdateCallback(object):
+    """
+    Basic class providing way of calling the callback to update
+    things during lenghty operations.
+    """
+
+    def __init__(self, callback, interval=1):
+        """
+        @param callback: a function with one arg to execute every so often
+        @type callback: function
+        @param interval: number of seconds at most between the updates
+        @type interval: int
+        """
+        if callable(callback): # callback is really callable
+            self.update = self.update_real
+            self.callback = callback
+            self.interval = interval
+            self.reset()
+        else:
+            self.update = self.update_empty
+        self.text = ""
+
+    def reset(self, text=""):
+        self.count = 0
+        self.oldval = 0
+        self.oldtime = 0
+        self.text = text
+
+    def set_total(self, total):
+        self.total = total
+
+    def update_empty(self, count=None):
+        pass
+
+    def update_real(self, count=None):
+        self.count += 1
+        if not count:
+            count = self.count
+        newval = int(100*count/self.total)
+        newtime = time.time()
+        time_has_come = self.interval and (newtime-self.oldtime>self.interval)
+        value_changed = newval!=self.oldval
+        if value_changed or time_has_come:
+            if self.text:
+                self.callback(newval, text=self.text)
+            else:
+                self.callback(newval)
+            self.oldval = newval
+            self.oldtime = newtime