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