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