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	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	frank	2051	self.path={"data":".", "projection":"."}
65	jonathan	518	return True
66	bh	6
67	bh	251	def OnExit(self):
68			"""Clean up code.
69
70			Extend this in derived classes if needed.
71			"""
72			self.session.Destroy()
73	bh	765	self.session = None
74	bh	251	Publisher.Destroy(self)
75
76	bh	189	def read_startup_files(self):
77			"""Read the startup files."""
78			# for now the startup file is ~/.thuban/thubanstart.py
79	frank	1150	dir = get_application_dir()
80	bh	189	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	jan	374	sys.stderr.write(_("Cannot import the thubanstart"
91	bh	671	" module\n"))
92	bh	189	traceback.print_exc(None, sys.stderr)
93			else:
94			# There's no thubanstart module.
95	jan	374	sys.stderr.write(_("No thubanstart module available\n"))
96	bh	189	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	jan	374	sys.stderr.write(_("Cannot import the thubanstart module\n"))
103	bh	189	traceback.print_exc(None, sys.stderr)
104			else:
105			# There's no .thuban directory
106	jan	374	sys.stderr.write(_("No ~/.thuban directory\n"))
107	bh	189
108	bh	401	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	jonathan	518	self.top.Show(True)
133	bh	535
134	bh	235	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	jan	374	msg = (_("This is the wxPython-based Graphical User Interface"
142			" for exploring geographic data"))
143	bh	535	return mainwindow.MainWindow(NULL, -1, "Thuban", self, None,
144	jonathan	934	initial_message = msg,
145			size = (600, 400))
146	bh	235
147	bh	219	def Session(self):
148			"""Return the application's session object"""
149			return self.session
150
151	bh	6	def SetSession(self, session):
152	bh	219	"""Make session the new session.
153
154	jonathan	503	Issue SESSION_REPLACED after self.session has become the new
155	bh	242	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	bh	219	"""
159	bh	6	oldsession = self.session
160			self.session = session
161	bh	242	self.subscribe_session(self.session)
162	jonathan	503	self.issue(SESSION_REPLACED)
163	bh	242	self.maps_changed()
164	bh	6	if oldsession is not None:
165	bh	242	self.unsubscribe_session(oldsession)
166	bh	6	oldsession.Destroy()
167
168	frank	2051	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	bh	242	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	bh	6	def create_session(self):
195	bh	242	"""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	bh	6	self.SetSession(create_empty_session())
203
204	bh	1648	def OpenSession(self, filename, db_connection_callback = None):
205	bh	592	"""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	bh	1654	if db_connection_callback is None:
211			db_connection_callback = self.run_db_param_dialog
212	bh	1650	try:
213			session = load_session(filename,
214			db_connection_callback=db_connection_callback)
215			except LoadCancelled:
216			return
217	bh	6	session.SetFilename(filename)
218			session.UnsetModified()
219			self.SetSession(session)
220
221	jonathan	1162	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	bh	1566	msg = _("The current session contains Image layers,\n"
226			"but the GDAL library is not available to "
227	jonathan	1162	"draw them.")
228	bh	1566	dlg = wx.wxMessageDialog(None,
229			msg,
230	jonathan	1162	_("Library not available"),
231			wx.wxOK \| wx.wxICON_INFORMATION)
232			print msg
233			dlg.ShowModal()
234			dlg.Destroy()
235			break
236
237	bh	1654	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	bh	6	def SaveSession(self):
245			save_session(self.session, self.session.filename)
246
247	bh	242	def maps_changed(self, *args):
248	bh	1776	"""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	bh	6	if self.session.HasMaps():
260			self.top.SetMap(self.session.Maps()[0])
261			else:
262			self.top.SetMap(None)
263	jonathan	1390
264	jonathan	1518	in_exception_dialog = 0 # flag: are we already inside the exception dialog?
265	jonathan	1390
266	jonathan	1518	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	jonathan	1390
275	jonathan	1518	if self.in_exception_dialog:
276			return
277			self.in_exception_dialog = 1
278			while wxIsBusy():
279			wxEndBusyCursor() # reset the mouse cursor
280	jonathan	1390
281	jonathan	1518	try:
282			lines = traceback.format_exception(exc_type, exc_value,
283			exc_traceback)
284	bh	1874	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	jonathan	1518	print message
289	jonathan	1390
290	jonathan	1518	# 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	jan	1704	exceptiondialog.run_exception_dialog(None, message)
294	jonathan	1390
295	jonathan	1518	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	jonathan	1390
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svn:eol-style	native
svn:keywords	Author Date Id Revision