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	bh	2072	# Copyright (C) 2001, 2002, 2003, 2004 by Intevation GmbH
2	bh	6	# Authors:
3			# Jan-Oliver Wagner <[email protected]>
4	bh	189	# Bernhard Herzog <[email protected]>
5	bh	6	#
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	bh	189	import sys, os
16	frank	1133	import os.path
17
18	bh	189	import traceback
19
20	bh	6	from wxPython.wx import *
21
22			from Thuban.Lib.connector import Publisher
23	frank	1150	from Thuban.Lib.fileutil import get_application_dir
24	bh	6
25	jan	374	from Thuban import _
26	bh	6	from Thuban.Model.session import create_empty_session
27			from Thuban.Model.save import save_session
28	bh	1650	from Thuban.Model.load import load_session, LoadCancelled
29	bh	242	from Thuban.Model.messages import MAPS_CHANGED
30	jonathan	1162	from Thuban.Model.layer import RasterLayer
31			import Thuban.Model.resource
32	bh	6
33			import view
34			import tree
35	bh	215	import mainwindow
36	bh	1654	import dbdialog
37	jan	1704	import exceptiondialog
38	bh	6
39	jonathan	503	from messages import SESSION_REPLACED
40	bh	6
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	bh	535	references to the main window and the session.
50	bh	6	"""
51
52			def OnInit(self):
53	jonathan	1518	sys.excepthook = self.ShowExceptionDialog
54	bh	2072
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	bh	401	self.splash = self.splash_screen()
70			if self.splash is not None:
71			self.splash.Show()
72	bh	189	self.read_startup_files()
73	bh	401	self.top = self.CreateMainWindow()
74			self.SetTopWindow(self.top)
75			if self.splash is None:
76			self.ShowMainWindow()
77	bh	2072
78	jonathan	518	return True
79	bh	6
80	bh	251	def OnExit(self):
81			"""Clean up code.
82
83			Extend this in derived classes if needed.
84			"""
85			self.session.Destroy()
86	bh	765	self.session = None
87	bh	251	Publisher.Destroy(self)
88
89	bh	189	def read_startup_files(self):
90			"""Read the startup files."""
91			# for now the startup file is ~/.thuban/thubanstart.py
92	frank	1150	dir = get_application_dir()
93	bh	189	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	jan	374	sys.stderr.write(_("Cannot import the thubanstart"
104	bh	671	" module\n"))
105	bh	189	traceback.print_exc(None, sys.stderr)
106			else:
107			# There's no thubanstart module.
108	jan	374	sys.stderr.write(_("No thubanstart module available\n"))
109	bh	189	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	jan	374	sys.stderr.write(_("Cannot import the thubanstart module\n"))
116	bh	189	traceback.print_exc(None, sys.stderr)
117			else:
118			# There's no .thuban directory
119	jan	374	sys.stderr.write(_("No ~/.thuban directory\n"))
120	bh	189
121	bh	401	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	jonathan	518	self.top.Show(True)
146	bh	535
147	bh	235	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	jan	374	msg = (_("This is the wxPython-based Graphical User Interface"
155			" for exploring geographic data"))
156	bh	535	return mainwindow.MainWindow(NULL, -1, "Thuban", self, None,
157	jonathan	934	initial_message = msg,
158			size = (600, 400))
159	bh	235
160	bh	219	def Session(self):
161			"""Return the application's session object"""
162			return self.session
163
164	bh	6	def SetSession(self, session):
165	bh	219	"""Make session the new session.
166
167	jonathan	503	Issue SESSION_REPLACED after self.session has become the new
168	bh	242	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	bh	219	"""
172	bh	6	oldsession = self.session
173			self.session = session
174	bh	242	self.subscribe_session(self.session)
175	jonathan	503	self.issue(SESSION_REPLACED)
176	bh	242	self.maps_changed()
177	bh	6	if oldsession is not None:
178	bh	242	self.unsubscribe_session(oldsession)
179	bh	6	oldsession.Destroy()
180
181	frank	2051	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	bh	242	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	bh	6	def create_session(self):
208	bh	242	"""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	bh	6	self.SetSession(create_empty_session())
216
217	bh	1648	def OpenSession(self, filename, db_connection_callback = None):
218	bh	592	"""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	bh	1654	if db_connection_callback is None:
224			db_connection_callback = self.run_db_param_dialog
225	bh	1650	try:
226			session = load_session(filename,
227			db_connection_callback=db_connection_callback)
228			except LoadCancelled:
229			return
230	bh	6	session.SetFilename(filename)
231			session.UnsetModified()
232			self.SetSession(session)
233
234	jonathan	1162	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	bh	1566	msg = _("The current session contains Image layers,\n"
239			"but the GDAL library is not available to "
240	jonathan	1162	"draw them.")
241	bh	1566	dlg = wx.wxMessageDialog(None,
242			msg,
243	jonathan	1162	_("Library not available"),
244			wx.wxOK \| wx.wxICON_INFORMATION)
245			print msg
246			dlg.ShowModal()
247			dlg.Destroy()
248			break
249
250	bh	1654	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	bh	6	def SaveSession(self):
258			save_session(self.session, self.session.filename)
259
260	bh	242	def maps_changed(self, *args):
261	bh	1776	"""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	bh	2072	# 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	jonathan	1390
280	jonathan	1518	in_exception_dialog = 0 # flag: are we already inside the exception dialog?
281	jonathan	1390
282	jonathan	1518	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	jonathan	1390
291	jonathan	1518	if self.in_exception_dialog:
292			return
293			self.in_exception_dialog = 1
294			while wxIsBusy():
295			wxEndBusyCursor() # reset the mouse cursor
296	jonathan	1390
297	jonathan	1518	try:
298			lines = traceback.format_exception(exc_type, exc_value,
299			exc_traceback)
300	bh	1874	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	jonathan	1518	print message
305	jonathan	1390
306	jonathan	1518	# 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	jan	1704	exceptiondialog.run_exception_dialog(None, message)
310	jonathan	1390
311	jonathan	1518	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	jonathan	1390
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