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()
        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 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	bh	401	# Copyright (C) 2001, 2002, 2003 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	401	self.splash = self.splash_screen()
55			if self.splash is not None:
56			self.splash.Show()
57	bh	189	self.read_startup_files()
58	bh	401	self.top = self.CreateMainWindow()
59			self.SetTopWindow(self.top)
60			if self.splash is None:
61			self.ShowMainWindow()
62	bh	6	self.session = None
63			self.create_session()
64	jonathan	518	return True
65	bh	6
66	bh	251	def OnExit(self):
67			"""Clean up code.
68
69			Extend this in derived classes if needed.
70			"""
71			self.session.Destroy()
72	bh	765	self.session = None
73	bh	251	Publisher.Destroy(self)
74
75	bh	189	def read_startup_files(self):
76			"""Read the startup files."""
77			# for now the startup file is ~/.thuban/thubanstart.py
78	frank	1150	dir = get_application_dir()
79	bh	189	if os.path.isdir(dir):
80			sys.path.append(dir)
81			try:
82			import thubanstart
83			except ImportError:
84			tb = sys.exc_info()[2]
85			try:
86			if tb.tb_next is not None:
87			# The ImportError exception was raised from
88			# inside the thubanstart module.
89	jan	374	sys.stderr.write(_("Cannot import the thubanstart"
90	bh	671	" module\n"))
91	bh	189	traceback.print_exc(None, sys.stderr)
92			else:
93			# There's no thubanstart module.
94	jan	374	sys.stderr.write(_("No thubanstart module available\n"))
95	bh	189	finally:
96			# make sure we delete the traceback object,
97			# otherwise there's be circular references involving
98			# the current stack frame
99			del tb
100			except:
101	jan	374	sys.stderr.write(_("Cannot import the thubanstart module\n"))
102	bh	189	traceback.print_exc(None, sys.stderr)
103			else:
104			# There's no .thuban directory
105	jan	374	sys.stderr.write(_("No ~/.thuban directory\n"))
106	bh	189
107	bh	401	def splash_screen(self):
108			"""Create and return a splash screen.
109
110			This method is called by OnInit to determine whether the
111			application should have a splashscreen. If the application
112			should display a splash screen override this method in a derived
113			class and have it create and return the wxSplashScreen instance.
114			The implementation of this method in the derived class should
115			also arranged for ShowMainWindow to be called.
116
117			The default implementation simply returns None so that no splash
118			screen is shown and ShowMainWindow will be called automatically.
119			"""
120			return None
121
122			def ShowMainWindow(self):
123			"""Show the main window
124
125			Normally this method is automatically called by OnInit to show
126			the main window. However, if the splash_screen method has
127			returned a splashscreen it is expected that the derived class
128			also arranges for ShowMainWindow to be called at the appropriate
129			time.
130			"""
131	jonathan	518	self.top.Show(True)
132	bh	535
133	bh	235	def CreateMainWindow(self):
134			"""Create and return the main window for the application.
135
136			Override this in subclasses to instantiate the Thuban mainwindow
137			with different parameters or to use a different class for the
138			main window.
139			"""
140	jan	374	msg = (_("This is the wxPython-based Graphical User Interface"
141			" for exploring geographic data"))
142	bh	535	return mainwindow.MainWindow(NULL, -1, "Thuban", self, None,
143	jonathan	934	initial_message = msg,
144			size = (600, 400))
145	bh	235
146	bh	219	def Session(self):
147			"""Return the application's session object"""
148			return self.session
149
150	bh	6	def SetSession(self, session):
151	bh	219	"""Make session the new session.
152
153	jonathan	503	Issue SESSION_REPLACED after self.session has become the new
154	bh	242	session. After the session has been assigned call
155			self.subscribe_session() with the new session and
156			self.unsubscribe_session with the old one.
157	bh	219	"""
158	bh	6	oldsession = self.session
159			self.session = session
160	bh	242	self.subscribe_session(self.session)
161	jonathan	503	self.issue(SESSION_REPLACED)
162	bh	242	self.maps_changed()
163	bh	6	if oldsession is not None:
164	bh	242	self.unsubscribe_session(oldsession)
165	bh	6	oldsession.Destroy()
166
167	bh	242	def subscribe_session(self, session):
168			"""Subscribe to some of the sessions channels.
169
170			Extend this method in derived classes if you need additional
171			channels.
172			"""
173			session.Subscribe(MAPS_CHANGED, self.maps_changed)
174
175			def unsubscribe_session(self, session):
176			"""Unsubscribe from the sessions channels.
177
178			Extend this method in derived classes if you subscribed to
179			additional channels in subscribe_session().
180			"""
181			session.Unsubscribe(MAPS_CHANGED, self.maps_changed)
182
183	bh	6	def create_session(self):
184	bh	242	"""Create a default session.
185
186			Override this method in derived classes to instantiate the
187			session differently or to use a different session class. Don't
188			subscribe to channels here yet. Do that in the
189			subscribe_session() method.
190			"""
191	bh	6	self.SetSession(create_empty_session())
192
193	bh	1648	def OpenSession(self, filename, db_connection_callback = None):
194	bh	592	"""Open the session in the file named filename"""
195			# Make sure we deal with an absolute pathname. Otherwise we can
196			# get problems when saving because the saving code expects an
197			# absolute directory name
198			filename = os.path.abspath(filename)
199	bh	1654	if db_connection_callback is None:
200			db_connection_callback = self.run_db_param_dialog
201	bh	1650	try:
202			session = load_session(filename,
203			db_connection_callback=db_connection_callback)
204			except LoadCancelled:
205			return
206	bh	6	session.SetFilename(filename)
207			session.UnsetModified()
208			self.SetSession(session)
209
210	jonathan	1162	for map in session.Maps():
211			for layer in map.Layers():
212			if isinstance(layer, RasterLayer) \
213			and not Thuban.Model.resource.has_gdal_support():
214	bh	1566	msg = _("The current session contains Image layers,\n"
215			"but the GDAL library is not available to "
216	jonathan	1162	"draw them.")
217	bh	1566	dlg = wx.wxMessageDialog(None,
218			msg,
219	jonathan	1162	_("Library not available"),
220			wx.wxOK \| wx.wxICON_INFORMATION)
221			print msg
222			dlg.ShowModal()
223			dlg.Destroy()
224			break
225
226	bh	1654	def run_db_param_dialog(self, parameters, message):
227			"""Implementation of the db_connection_callback for loading sessions"""
228			dlg = dbdialog.DBDialog(None, _("DB Connection Parameters"),
229			parameters, message)
230			return dlg.RunDialog()
231
232
233	bh	6	def SaveSession(self):
234			save_session(self.session, self.session.filename)
235
236	bh	242	def maps_changed(self, *args):
237	bh	1776	"""Subscribed to the session's MAPS_CHANGED messages.
238
239			Set the toplevel window's map to the map in the session. This is
240			done by calling the window's SetMap method with the map as
241			argument. If the session doesn't have any maps None is used
242			instead.
243
244			Currently Thuban can only really handle at most one map in a
245			sessions so the first map in the session's list of maps as
246			returned by the Maps method is used.
247			"""
248	bh	6	if self.session.HasMaps():
249			self.top.SetMap(self.session.Maps()[0])
250			else:
251			self.top.SetMap(None)
252	jonathan	1390
253	jonathan	1518	in_exception_dialog = 0 # flag: are we already inside the exception dialog?
254	jonathan	1390
255	jonathan	1518	def ShowExceptionDialog(self, exc_type, exc_value, exc_traceback):
256			"""Show a message box with information about an exception.
257
258			The parameters are the usual values describing an exception in
259			Python, the exception type, the value and the traceback.
260
261			This method can be used as a value for the sys.excepthook.
262			"""
263	jonathan	1390
264	jonathan	1518	if self.in_exception_dialog:
265			return
266			self.in_exception_dialog = 1
267			while wxIsBusy():
268			wxEndBusyCursor() # reset the mouse cursor
269	jonathan	1390
270	jonathan	1518	try:
271			lines = traceback.format_exception(exc_type, exc_value,
272			exc_traceback)
273	bh	1874	message = _("An unhandled exception occurred:\n%s\n"
274			"(please report to"
275			" http://thuban.intevation.org/bugtracker.html)"
276			"\n\n%s") % (exc_value, "".join(lines))
277	jonathan	1518	print message
278	jonathan	1390
279	jonathan	1518	# We don't use an explicit parent here because this method might
280			# be called in circumstances where the main window doesn't exist
281			# anymore.
282	jan	1704	exceptiondialog.run_exception_dialog(None, message)
283	jonathan	1390
284	jonathan	1518	finally:
285			self.in_exception_dialog = 0
286			# delete the last exception info that python keeps in
287			# sys.last_* because especially last_traceback keeps
288			# indirect references to all objects bound to local
289			# variables and this might prevent some object from being
290			# collected early enough.
291			sys.last_type = sys.last_value = sys.last_traceback = None
292	jonathan	1390
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svn:keywords	Author Date Id Revision