Thuban/UI/application.py

# Copyright (C) 2001, 2002, 2003 by Intevation GmbH
# Authors:
# Jan-Oliver Wagner <[email protected]>
# Bernhard Herzog <[email protected]>
#
# This program is free software under the GPL (>=v2)
# Read the file COPYING coming with Thuban for details.

"""
Thuban's application object.
"""

__version__ = "$Revision$"

import sys, os
import os.path

import traceback

from wxPython.wx import *

from Thuban.Lib.connector import Publisher
from Thuban.Lib.fileutil import get_application_dir

from Thuban import _
from Thuban.Model.session import create_empty_session
from Thuban.Model.save import save_session
from Thuban.Model.load import load_session, LoadCancelled
from Thuban.Model.messages import MAPS_CHANGED
from Thuban.Model.layer import RasterLayer
import Thuban.Model.resource

import view
import tree
import mainwindow
import dbdialog
import exceptiondialog

from messages import SESSION_REPLACED


class ThubanApplication(wxApp, Publisher):

    """
    Thuban's application class.

    All wxWindows programs have to have an instance of an application
    class derived from wxApp. In Thuban the application class holds
    references to the main window and the session.
    """

    def OnInit(self):
        sys.excepthook = self.ShowExceptionDialog
        self.splash = self.splash_screen()
        if self.splash is not None:
            self.splash.Show()
        self.read_startup_files()
        self.top = self.CreateMainWindow()
        self.SetTopWindow(self.top)
        if self.splash is None:
            self.ShowMainWindow()
        self.session = None
        self.create_session()
        return True

    def OnExit(self):
        """Clean up code.

        Extend this in derived classes if needed.
        """
        self.session.Destroy()
        self.session = None
        Publisher.Destroy(self)

    def read_startup_files(self):
        """Read the startup files."""
        # for now the startup file is ~/.thuban/thubanstart.py
        dir = get_application_dir()
        if os.path.isdir(dir):
            sys.path.append(dir)
            try:
                import thubanstart
            except ImportError:
                tb = sys.exc_info()[2]
                try:
                    if tb.tb_next is not None:
                        # The ImportError exception was raised from
                        # inside the thubanstart module.
                        sys.stderr.write(_("Cannot import the thubanstart"
                                         " module\n"))
                        traceback.print_exc(None, sys.stderr)
                    else:
                        # There's no thubanstart module.
                        sys.stderr.write(_("No thubanstart module available\n"))
                finally:
                    # make sure we delete the traceback object,
                    # otherwise there's be circular references involving
                    # the current stack frame
                    del tb
            except:
                sys.stderr.write(_("Cannot import the thubanstart module\n"))
                traceback.print_exc(None, sys.stderr)
        else:
            # There's no .thuban directory
            sys.stderr.write(_("No ~/.thuban directory\n"))

    def splash_screen(self):
        """Create and return a splash screen.

        This method is called by OnInit to determine whether the
        application should have a splashscreen. If the application
        should display a splash screen override this method in a derived
        class and have it create and return the wxSplashScreen instance.
        The implementation of this method in the derived class should
        also arranged for ShowMainWindow to be called.

        The default implementation simply returns None so that no splash
        screen is shown and ShowMainWindow will be called automatically.
        """
        return None

    def ShowMainWindow(self):
        """Show the main window

        Normally this method is automatically called by OnInit to show
        the main window. However, if the splash_screen method has
        returned a splashscreen it is expected that the derived class
        also arranges for ShowMainWindow to be called at the appropriate
        time.
        """
        self.top.Show(True)

    def CreateMainWindow(self):
        """Create and return the main window for the application.

        Override this in subclasses to instantiate the Thuban mainwindow
        with different parameters or to use a different class for the
        main window.
        """
        msg = (_("This is the wxPython-based Graphical User Interface"
               " for exploring geographic data"))
        return mainwindow.MainWindow(NULL, -1, "Thuban", self, None,
                                     initial_message = msg,
                                     size = (600, 400))

    def Session(self):
        """Return the application's session object"""
        return self.session

    def SetSession(self, session):
        """Make session the new session.

        Issue SESSION_REPLACED after self.session has become the new
        session. After the session has been assigned call
        self.subscribe_session() with the new session and
        self.unsubscribe_session with the old one.
        """
        oldsession = self.session
        self.session = session
        self.subscribe_session(self.session)
        self.issue(SESSION_REPLACED)
        self.maps_changed()
        if oldsession is not None:
            self.unsubscribe_session(oldsession)
            oldsession.Destroy()

    def subscribe_session(self, session):
        """Subscribe to some of the sessions channels.

        Extend this method in derived classes if you need additional
        channels.
        """
        session.Subscribe(MAPS_CHANGED, self.maps_changed)

    def unsubscribe_session(self, session):
        """Unsubscribe from the sessions channels.

        Extend this method in derived classes if you subscribed to
        additional channels in subscribe_session().
        """
        session.Unsubscribe(MAPS_CHANGED, self.maps_changed)

    def create_session(self):
        """Create a default session.

        Override this method in derived classes to instantiate the
        session differently or to use a different session class. Don't
        subscribe to channels here yet. Do that in the
        subscribe_session() method.
        """
        self.SetSession(create_empty_session())

    def OpenSession(self, filename, db_connection_callback = None):
        """Open the session in the file named filename"""
        # Make sure we deal with an absolute pathname. Otherwise we can
        # get problems when saving because the saving code expects an
        # absolute directory name
        filename = os.path.abspath(filename)
        if db_connection_callback is None:
            db_connection_callback = self.run_db_param_dialog
        try:
            session = load_session(filename,
                               db_connection_callback=db_connection_callback)
        except LoadCancelled:
            return
        session.SetFilename(filename)
        session.UnsetModified()
        self.SetSession(session)

        for map in session.Maps():
            for layer in map.Layers():
                if isinstance(layer, RasterLayer) \
                    and not Thuban.Model.resource.has_gdal_support():
                    msg = _("The current session contains Image layers,\n"
                            "but the GDAL library is not available to "
                            "draw them.")
                    dlg = wx.wxMessageDialog(None,
                                             msg,
                                             _("Library not available"),
                                             wx.wxOK | wx.wxICON_INFORMATION)
                    print msg
                    dlg.ShowModal()
                    dlg.Destroy()
                    break

    def run_db_param_dialog(self, parameters, message):
        """Implementation of the db_connection_callback for loading sessions"""
        dlg = dbdialog.DBDialog(None, _("DB Connection Parameters"),
                                parameters, message)
        return dlg.RunDialog()


    def SaveSession(self):
        save_session(self.session, self.session.filename)

    def maps_changed(self, *args):
        """Subscribed to the session's MAPS_CHANGED messages.

        Set the toplevel window's map to the map in the session. This is
        done by calling the window's SetMap method with the map as
        argument. If the session doesn't have any maps None is used
        instead.

        Currently Thuban can only really handle at most one map in a
        sessions so the first map in the session's list of maps as
        returned by the Maps method is used.
        """
        if self.session.HasMaps():
            self.top.SetMap(self.session.Maps()[0])
        else:
            self.top.SetMap(None)

    in_exception_dialog = 0 # flag: are we already inside the exception dialog?

    def ShowExceptionDialog(self, exc_type, exc_value, exc_traceback):
        """Show a message box with information about an exception.
    
        The parameters are the usual values describing an exception in
        Python, the exception type, the value and the traceback.
    
        This method can be used as a value for the sys.excepthook.
        """

        if self.in_exception_dialog:
            return
        self.in_exception_dialog = 1
        while wxIsBusy():
            wxEndBusyCursor() # reset the mouse cursor

        try:
            lines = traceback.format_exception(exc_type, exc_value,
                                            exc_traceback)
            message = _("An unhandled exception occurred:\n%s\n") % exc_value+\
                    _("(please report to") +\
                    " http://thuban.intevation.org/bugtracker.html)"\
                    "\n\n\n"+\
                    "".join(lines)
            print message

            # We don't use an explicit parent here because this method might
            # be called in circumstances where the main window doesn't exist
            # anymore.
            exceptiondialog.run_exception_dialog(None, message)

        finally:
            self.in_exception_dialog = 0
            # delete the last exception info that python keeps in
            # sys.last_* because especially last_traceback keeps
            # indirect references to all objects bound to local
            # variables and this might prevent some object from being
            # collected early enough.
            sys.last_type = sys.last_value = sys.last_traceback = None

1	# Copyright (C) 2001, 2002, 2003 by Intevation GmbH
2	# Authors:
3	# Jan-Oliver Wagner <[email protected]>
4	# Bernhard Herzog <[email protected]>
5	#
6	# This program is free software under the GPL (>=v2)
7	# Read the file COPYING coming with Thuban for details.
8
9	"""
10	Thuban's application object.
11	"""
12
13	__version__ = "$Revision$"
14
15	import sys, os
16	import os.path
17
18	import traceback
19
20	from wxPython.wx import *
21
22	from Thuban.Lib.connector import Publisher
23	from Thuban.Lib.fileutil import get_application_dir
24
25	from Thuban import _
26	from Thuban.Model.session import create_empty_session
27	from Thuban.Model.save import save_session
28	from Thuban.Model.load import load_session, LoadCancelled
29	from Thuban.Model.messages import MAPS_CHANGED
30	from Thuban.Model.layer import RasterLayer
31	import Thuban.Model.resource
32
33	import view
34	import tree
35	import mainwindow
36	import dbdialog
37	import exceptiondialog
38
39	from messages import SESSION_REPLACED
40
41
42	class ThubanApplication(wxApp, Publisher):
43
44	"""
45	Thuban's application class.
46
47	All wxWindows programs have to have an instance of an application
48	class derived from wxApp. In Thuban the application class holds
49	references to the main window and the session.
50	"""
51
52	def OnInit(self):
53	sys.excepthook = self.ShowExceptionDialog
54	self.splash = self.splash_screen()
55	if self.splash is not None:
56	self.splash.Show()
57	self.read_startup_files()
58	self.top = self.CreateMainWindow()
59	self.SetTopWindow(self.top)
60	if self.splash is None:
61	self.ShowMainWindow()
62	self.session = None
63	self.create_session()
64	return True
65
66	def OnExit(self):
67	"""Clean up code.
68
69	Extend this in derived classes if needed.
70	"""
71	self.session.Destroy()
72	self.session = None
73	Publisher.Destroy(self)
74
75	def read_startup_files(self):
76	"""Read the startup files."""
77	# for now the startup file is ~/.thuban/thubanstart.py
78	dir = get_application_dir()
79	if os.path.isdir(dir):
80	sys.path.append(dir)
81	try:
82	import thubanstart
83	except ImportError:
84	tb = sys.exc_info()[2]
85	try:
86	if tb.tb_next is not None:
87	# The ImportError exception was raised from
88	# inside the thubanstart module.
89	sys.stderr.write(_("Cannot import the thubanstart"
90	" module\n"))
91	traceback.print_exc(None, sys.stderr)
92	else:
93	# There's no thubanstart module.
94	sys.stderr.write(_("No thubanstart module available\n"))
95	finally:
96	# make sure we delete the traceback object,
97	# otherwise there's be circular references involving
98	# the current stack frame
99	del tb
100	except:
101	sys.stderr.write(_("Cannot import the thubanstart module\n"))
102	traceback.print_exc(None, sys.stderr)
103	else:
104	# There's no .thuban directory
105	sys.stderr.write(_("No ~/.thuban directory\n"))
106
107	def splash_screen(self):
108	"""Create and return a splash screen.
109
110	This method is called by OnInit to determine whether the
111	application should have a splashscreen. If the application
112	should display a splash screen override this method in a derived
113	class and have it create and return the wxSplashScreen instance.
114	The implementation of this method in the derived class should
115	also arranged for ShowMainWindow to be called.
116
117	The default implementation simply returns None so that no splash
118	screen is shown and ShowMainWindow will be called automatically.
119	"""
120	return None
121
122	def ShowMainWindow(self):
123	"""Show the main window
124
125	Normally this method is automatically called by OnInit to show
126	the main window. However, if the splash_screen method has
127	returned a splashscreen it is expected that the derived class
128	also arranges for ShowMainWindow to be called at the appropriate
129	time.
130	"""
131	self.top.Show(True)
132
133	def CreateMainWindow(self):
134	"""Create and return the main window for the application.
135
136	Override this in subclasses to instantiate the Thuban mainwindow
137	with different parameters or to use a different class for the
138	main window.
139	"""
140	msg = (_("This is the wxPython-based Graphical User Interface"
141	" for exploring geographic data"))
142	return mainwindow.MainWindow(NULL, -1, "Thuban", self, None,
143	initial_message = msg,
144	size = (600, 400))
145
146	def Session(self):
147	"""Return the application's session object"""
148	return self.session
149
150	def SetSession(self, session):
151	"""Make session the new session.
152
153	Issue SESSION_REPLACED after self.session has become the new
154	session. After the session has been assigned call
155	self.subscribe_session() with the new session and
156	self.unsubscribe_session with the old one.
157	"""
158	oldsession = self.session
159	self.session = session
160	self.subscribe_session(self.session)
161	self.issue(SESSION_REPLACED)
162	self.maps_changed()
163	if oldsession is not None:
164	self.unsubscribe_session(oldsession)
165	oldsession.Destroy()
166
167	def subscribe_session(self, session):
168	"""Subscribe to some of the sessions channels.
169
170	Extend this method in derived classes if you need additional
171	channels.
172	"""
173	session.Subscribe(MAPS_CHANGED, self.maps_changed)
174
175	def unsubscribe_session(self, session):
176	"""Unsubscribe from the sessions channels.
177
178	Extend this method in derived classes if you subscribed to
179	additional channels in subscribe_session().
180	"""
181	session.Unsubscribe(MAPS_CHANGED, self.maps_changed)
182
183	def create_session(self):
184	"""Create a default session.
185
186	Override this method in derived classes to instantiate the
187	session differently or to use a different session class. Don't
188	subscribe to channels here yet. Do that in the
189	subscribe_session() method.
190	"""
191	self.SetSession(create_empty_session())
192
193	def OpenSession(self, filename, db_connection_callback = None):
194	"""Open the session in the file named filename"""
195	# Make sure we deal with an absolute pathname. Otherwise we can
196	# get problems when saving because the saving code expects an
197	# absolute directory name
198	filename = os.path.abspath(filename)
199	if db_connection_callback is None:
200	db_connection_callback = self.run_db_param_dialog
201	try:
202	session = load_session(filename,
203	db_connection_callback=db_connection_callback)
204	except LoadCancelled:
205	return
206	session.SetFilename(filename)
207	session.UnsetModified()
208	self.SetSession(session)
209
210	for map in session.Maps():
211	for layer in map.Layers():
212	if isinstance(layer, RasterLayer) \
213	and not Thuban.Model.resource.has_gdal_support():
214	msg = _("The current session contains Image layers,\n"
215	"but the GDAL library is not available to "
216	"draw them.")
217	dlg = wx.wxMessageDialog(None,
218	msg,
219	_("Library not available"),
220	wx.wxOK \| wx.wxICON_INFORMATION)
221	print msg
222	dlg.ShowModal()
223	dlg.Destroy()
224	break
225
226	def run_db_param_dialog(self, parameters, message):
227	"""Implementation of the db_connection_callback for loading sessions"""
228	dlg = dbdialog.DBDialog(None, _("DB Connection Parameters"),
229	parameters, message)
230	return dlg.RunDialog()
231
232
233	def SaveSession(self):
234	save_session(self.session, self.session.filename)
235
236	def maps_changed(self, *args):
237	"""Subscribed to the session's MAPS_CHANGED messages.
238
239	Set the toplevel window's map to the map in the session. This is
240	done by calling the window's SetMap method with the map as
241	argument. If the session doesn't have any maps None is used
242	instead.
243
244	Currently Thuban can only really handle at most one map in a
245	sessions so the first map in the session's list of maps as
246	returned by the Maps method is used.
247	"""
248	if self.session.HasMaps():
249	self.top.SetMap(self.session.Maps()[0])
250	else:
251	self.top.SetMap(None)
252
253	in_exception_dialog = 0 # flag: are we already inside the exception dialog?
254
255	def ShowExceptionDialog(self, exc_type, exc_value, exc_traceback):
256	"""Show a message box with information about an exception.
257
258	The parameters are the usual values describing an exception in
259	Python, the exception type, the value and the traceback.
260
261	This method can be used as a value for the sys.excepthook.
262	"""
263
264	if self.in_exception_dialog:
265	return
266	self.in_exception_dialog = 1
267	while wxIsBusy():
268	wxEndBusyCursor() # reset the mouse cursor
269
270	try:
271	lines = traceback.format_exception(exc_type, exc_value,
272	exc_traceback)
273	message = _("An unhandled exception occurred:\n%s\n") % exc_value+\
274	_("(please report to") +\
275	" http://thuban.intevation.org/bugtracker.html)"\
276	"\n\n\n"+\
277	"".join(lines)
278	print message
279
280	# We don't use an explicit parent here because this method might
281	# be called in circumstances where the main window doesn't exist
282	# anymore.
283	exceptiondialog.run_exception_dialog(None, message)
284
285	finally:
286	self.in_exception_dialog = 0
287	# delete the last exception info that python keeps in
288	# sys.last_* because especially last_traceback keeps
289	# indirect references to all objects bound to local
290	# variables and this might prevent some object from being
291	# collected early enough.
292	sys.last_type = sys.last_value = sys.last_traceback = None
293
Name	Value
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svn:keywords	Author Date Id Revision