Thuban/UI/application.py

# Copyright (C) 2001, 2002, 2003, 2004 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

        # Initialize instance variables before trying to create any
        # windows.  Creating windows can start an event loop if
        # e.g. message boxes are popped up for some reason, and event
        # handlers, especially EVT_UPDATE_UI may want to access things
        # from the application.

        # Defaults for the directories used in file dialogs
        self.path={"data":".", "projection":"."}

        self.session = None
        self.top = None
        self.create_session()

        # Create an optional splash screen and then the mainwindow
        self.splash = self.splash_screen()
        if self.splash is not None:
            self.splash.Show()
        self.read_startup_files()
        self.top = self.CreateMainWindow()
        # The session was alredy created above and we need to get the
        # map into the mainwindow.  maps_changed does that.
        self.maps_changed()
        self.SetTopWindow(self.top)
        if self.splash is None:
            self.ShowMainWindow()

        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 SetPath(self, group, filename):
        """Store the application's default path for file dialogs extracted
        from a given filename.
        """
        self.path[group] = os.path.dirname( filename )

    def Path(self, group):
        """Return the application's default path for file dialogs."""
        return self.path[group]

    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.
        """
        # The mainwindow may not have been created yet, so check whether
        # it has been created before calling any of its methods
        if self.top is not None:
            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"
                        "(please report to"
                        " http://thuban.intevation.org/bugtracker.html)"
                        "\n\n%s") % (exc_value, "".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, 2004 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
55	# Initialize instance variables before trying to create any
56	# windows. Creating windows can start an event loop if
57	# e.g. message boxes are popped up for some reason, and event
58	# handlers, especially EVT_UPDATE_UI may want to access things
59	# from the application.
60
61	# Defaults for the directories used in file dialogs
62	self.path={"data":".", "projection":"."}
63
64	self.session = None
65	self.top = None
66	self.create_session()
67
68	# Create an optional splash screen and then the mainwindow
69	self.splash = self.splash_screen()
70	if self.splash is not None:
71	self.splash.Show()
72	self.read_startup_files()
73	self.top = self.CreateMainWindow()
74	# The session was alredy created above and we need to get the
75	# map into the mainwindow. maps_changed does that.
76	self.maps_changed()
77	self.SetTopWindow(self.top)
78	if self.splash is None:
79	self.ShowMainWindow()
80
81	return True
82
83	def OnExit(self):
84	"""Clean up code.
85
86	Extend this in derived classes if needed.
87	"""
88	self.session.Destroy()
89	self.session = None
90	Publisher.Destroy(self)
91
92	def read_startup_files(self):
93	"""Read the startup files."""
94	# for now the startup file is ~/.thuban/thubanstart.py
95	dir = get_application_dir()
96	if os.path.isdir(dir):
97	sys.path.append(dir)
98	try:
99	import thubanstart
100	except ImportError:
101	tb = sys.exc_info()[2]
102	try:
103	if tb.tb_next is not None:
104	# The ImportError exception was raised from
105	# inside the thubanstart module.
106	sys.stderr.write(_("Cannot import the thubanstart"
107	" module\n"))
108	traceback.print_exc(None, sys.stderr)
109	else:
110	# There's no thubanstart module.
111	sys.stderr.write(_("No thubanstart module available\n"))
112	finally:
113	# make sure we delete the traceback object,
114	# otherwise there's be circular references involving
115	# the current stack frame
116	del tb
117	except:
118	sys.stderr.write(_("Cannot import the thubanstart module\n"))
119	traceback.print_exc(None, sys.stderr)
120	else:
121	# There's no .thuban directory
122	sys.stderr.write(_("No ~/.thuban directory\n"))
123
124	def splash_screen(self):
125	"""Create and return a splash screen.
126
127	This method is called by OnInit to determine whether the
128	application should have a splashscreen. If the application
129	should display a splash screen override this method in a derived
130	class and have it create and return the wxSplashScreen instance.
131	The implementation of this method in the derived class should
132	also arranged for ShowMainWindow to be called.
133
134	The default implementation simply returns None so that no splash
135	screen is shown and ShowMainWindow will be called automatically.
136	"""
137	return None
138
139	def ShowMainWindow(self):
140	"""Show the main window
141
142	Normally this method is automatically called by OnInit to show
143	the main window. However, if the splash_screen method has
144	returned a splashscreen it is expected that the derived class
145	also arranges for ShowMainWindow to be called at the appropriate
146	time.
147	"""
148	self.top.Show(True)
149
150	def CreateMainWindow(self):
151	"""Create and return the main window for the application.
152
153	Override this in subclasses to instantiate the Thuban mainwindow
154	with different parameters or to use a different class for the
155	main window.
156	"""
157	msg = (_("This is the wxPython-based Graphical User Interface"
158	" for exploring geographic data"))
159	return mainwindow.MainWindow(NULL, -1, "Thuban", self, None,
160	initial_message = msg,
161	size = (600, 400))
162
163	def Session(self):
164	"""Return the application's session object"""
165	return self.session
166
167	def SetSession(self, session):
168	"""Make session the new session.
169
170	Issue SESSION_REPLACED after self.session has become the new
171	session. After the session has been assigned call
172	self.subscribe_session() with the new session and
173	self.unsubscribe_session with the old one.
174	"""
175	oldsession = self.session
176	self.session = session
177	self.subscribe_session(self.session)
178	self.issue(SESSION_REPLACED)
179	self.maps_changed()
180	if oldsession is not None:
181	self.unsubscribe_session(oldsession)
182	oldsession.Destroy()
183
184	def SetPath(self, group, filename):
185	"""Store the application's default path for file dialogs extracted
186	from a given filename.
187	"""
188	self.path[group] = os.path.dirname( filename )
189
190	def Path(self, group):
191	"""Return the application's default path for file dialogs."""
192	return self.path[group]
193
194	def subscribe_session(self, session):
195	"""Subscribe to some of the sessions channels.
196
197	Extend this method in derived classes if you need additional
198	channels.
199	"""
200	session.Subscribe(MAPS_CHANGED, self.maps_changed)
201
202	def unsubscribe_session(self, session):
203	"""Unsubscribe from the sessions channels.
204
205	Extend this method in derived classes if you subscribed to
206	additional channels in subscribe_session().
207	"""
208	session.Unsubscribe(MAPS_CHANGED, self.maps_changed)
209
210	def create_session(self):
211	"""Create a default session.
212
213	Override this method in derived classes to instantiate the
214	session differently or to use a different session class. Don't
215	subscribe to channels here yet. Do that in the
216	subscribe_session() method.
217	"""
218	self.SetSession(create_empty_session())
219
220	def OpenSession(self, filename, db_connection_callback = None):
221	"""Open the session in the file named filename"""
222	# Make sure we deal with an absolute pathname. Otherwise we can
223	# get problems when saving because the saving code expects an
224	# absolute directory name
225	filename = os.path.abspath(filename)
226	if db_connection_callback is None:
227	db_connection_callback = self.run_db_param_dialog
228	try:
229	session = load_session(filename,
230	db_connection_callback=db_connection_callback)
231	except LoadCancelled:
232	return
233	session.SetFilename(filename)
234	session.UnsetModified()
235	self.SetSession(session)
236
237	for map in session.Maps():
238	for layer in map.Layers():
239	if isinstance(layer, RasterLayer) \
240	and not Thuban.Model.resource.has_gdal_support():
241	msg = _("The current session contains Image layers,\n"
242	"but the GDAL library is not available to "
243	"draw them.")
244	dlg = wx.wxMessageDialog(None,
245	msg,
246	_("Library not available"),
247	wx.wxOK \| wx.wxICON_INFORMATION)
248	print msg
249	dlg.ShowModal()
250	dlg.Destroy()
251	break
252
253	def run_db_param_dialog(self, parameters, message):
254	"""Implementation of the db_connection_callback for loading sessions"""
255	dlg = dbdialog.DBDialog(None, _("DB Connection Parameters"),
256	parameters, message)
257	return dlg.RunDialog()
258
259
260	def SaveSession(self):
261	save_session(self.session, self.session.filename)
262
263	def maps_changed(self, *args):
264	"""Subscribed to the session's MAPS_CHANGED messages.
265
266	Set the toplevel window's map to the map in the session. This is
267	done by calling the window's SetMap method with the map as
268	argument. If the session doesn't have any maps None is used
269	instead.
270
271	Currently Thuban can only really handle at most one map in a
272	sessions so the first map in the session's list of maps as
273	returned by the Maps method is used.
274	"""
275	# The mainwindow may not have been created yet, so check whether
276	# it has been created before calling any of its methods
277	if self.top is not None:
278	if self.session.HasMaps():
279	self.top.SetMap(self.session.Maps()[0])
280	else:
281	self.top.SetMap(None)
282
283	in_exception_dialog = 0 # flag: are we already inside the exception dialog?
284
285	def ShowExceptionDialog(self, exc_type, exc_value, exc_traceback):
286	"""Show a message box with information about an exception.
287
288	The parameters are the usual values describing an exception in
289	Python, the exception type, the value and the traceback.
290
291	This method can be used as a value for the sys.excepthook.
292	"""
293
294	if self.in_exception_dialog:
295	return
296	self.in_exception_dialog = 1
297	while wxIsBusy():
298	wxEndBusyCursor() # reset the mouse cursor
299
300	try:
301	lines = traceback.format_exception(exc_type, exc_value,
302	exc_traceback)
303	message = _("An unhandled exception occurred:\n%s\n"
304	"(please report to"
305	" http://thuban.intevation.org/bugtracker.html)"
306	"\n\n%s") % (exc_value, "".join(lines))
307	print message
308
309	# We don't use an explicit parent here because this method might
310	# be called in circumstances where the main window doesn't exist
311	# anymore.
312	exceptiondialog.run_exception_dialog(None, message)
313
314	finally:
315	self.in_exception_dialog = 0
316	# delete the last exception info that python keeps in
317	# sys.last_* because especially last_traceback keeps
318	# indirect references to all objects bound to local
319	# variables and this might prevent some object from being
320	# collected early enough.
321	sys.last_type = sys.last_value = sys.last_traceback = None
322
Name	Value
svn:eol-style	native
svn:keywords	Author Date Id Revision