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	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	bh	2076	# 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	bh	401	self.SetTopWindow(self.top)
78			if self.splash is None:
79			self.ShowMainWindow()
80	bh	2072
81	jonathan	518	return True
82	bh	6
83	bh	251	def OnExit(self):
84			"""Clean up code.
85
86			Extend this in derived classes if needed.
87			"""
88			self.session.Destroy()
89	bh	765	self.session = None
90	bh	251	Publisher.Destroy(self)
91
92	bh	189	def read_startup_files(self):
93			"""Read the startup files."""
94			# for now the startup file is ~/.thuban/thubanstart.py
95	frank	1150	dir = get_application_dir()
96	bh	189	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	jan	374	sys.stderr.write(_("Cannot import the thubanstart"
107	bh	671	" module\n"))
108	bh	189	traceback.print_exc(None, sys.stderr)
109			else:
110			# There's no thubanstart module.
111	jan	374	sys.stderr.write(_("No thubanstart module available\n"))
112	bh	189	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	jan	374	sys.stderr.write(_("Cannot import the thubanstart module\n"))
119	bh	189	traceback.print_exc(None, sys.stderr)
120			else:
121			# There's no .thuban directory
122	jan	374	sys.stderr.write(_("No ~/.thuban directory\n"))
123	bh	189
124	bh	401	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	jonathan	518	self.top.Show(True)
149	bh	535
150	bh	235	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	jan	374	msg = (_("This is the wxPython-based Graphical User Interface"
158			" for exploring geographic data"))
159	bh	535	return mainwindow.MainWindow(NULL, -1, "Thuban", self, None,
160	jonathan	934	initial_message = msg,
161			size = (600, 400))
162	bh	235
163	bh	219	def Session(self):
164			"""Return the application's session object"""
165			return self.session
166
167	bh	6	def SetSession(self, session):
168	bh	219	"""Make session the new session.
169
170	jonathan	503	Issue SESSION_REPLACED after self.session has become the new
171	bh	242	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	bh	219	"""
175	bh	6	oldsession = self.session
176			self.session = session
177	bh	242	self.subscribe_session(self.session)
178	jonathan	503	self.issue(SESSION_REPLACED)
179	bh	242	self.maps_changed()
180	bh	6	if oldsession is not None:
181	bh	242	self.unsubscribe_session(oldsession)
182	bh	6	oldsession.Destroy()
183
184	frank	2051	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	bh	242	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	bh	6	def create_session(self):
211	bh	242	"""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	bh	6	self.SetSession(create_empty_session())
219
220	bh	1648	def OpenSession(self, filename, db_connection_callback = None):
221	bh	592	"""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	bh	1654	if db_connection_callback is None:
227			db_connection_callback = self.run_db_param_dialog
228	bh	1650	try:
229			session = load_session(filename,
230			db_connection_callback=db_connection_callback)
231			except LoadCancelled:
232			return
233	bh	6	session.SetFilename(filename)
234			session.UnsetModified()
235			self.SetSession(session)
236
237	jonathan	1162	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	bh	1566	msg = _("The current session contains Image layers,\n"
242			"but the GDAL library is not available to "
243	jonathan	1162	"draw them.")
244	bh	1566	dlg = wx.wxMessageDialog(None,
245			msg,
246	jonathan	1162	_("Library not available"),
247			wx.wxOK \| wx.wxICON_INFORMATION)
248			print msg
249			dlg.ShowModal()
250			dlg.Destroy()
251			break
252
253	bh	1654	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	bh	6	def SaveSession(self):
261			save_session(self.session, self.session.filename)
262
263	bh	242	def maps_changed(self, *args):
264	bh	1776	"""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	bh	2072	# 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	jonathan	1390
283	jonathan	1518	in_exception_dialog = 0 # flag: are we already inside the exception dialog?
284	jonathan	1390
285	jonathan	1518	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	jonathan	1390
294	jonathan	1518	if self.in_exception_dialog:
295			return
296			self.in_exception_dialog = 1
297			while wxIsBusy():
298			wxEndBusyCursor() # reset the mouse cursor
299	jonathan	1390
300	jonathan	1518	try:
301			lines = traceback.format_exception(exc_type, exc_value,
302			exc_traceback)
303	bh	1874	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	jonathan	1518	print message
308	jonathan	1390
309	jonathan	1518	# 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	jan	1704	exceptiondialog.run_exception_dialog(None, message)
313	jonathan	1390
314	jonathan	1518	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	jonathan	1390
Name	Value
svn:eol-style	native
svn:keywords	Author Date Id Revision