Thuban/UI/application.py

# Copyright (C) 2001-2005 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

from extensionregistry import ext_registry

import view
import tree
import mainwindow
import dbdialog
import altpathdialog
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":".", "alt_path":""}

        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.init_extensions()
        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 init_extensions(self):
        """Call initialization callbacks for all registered extensions."""
        for ext in ext_registry:
            ext.init_ext()

    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,
                                    shapefile_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
        if shapefile_callback is None:
            shapefile_callback = self.run_alt_path_dialog
        try:
            session = load_session(filename,
                               db_connection_callback=db_connection_callback,
                               shapefile_callback=shapefile_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 = wxMessageDialog(None,
                                             msg,
                                             _("Library not available"),
                                             wxOK | 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()

    # run_alt_path_dialog: Raise a dialog to ask for an alternative path
    # if the shapefile couldn't be found.
    # TODO: 
    #   - Store a list of already used alternative paths and return these 
    #     iteratively (using a generator) 
    #   - How do we interact with the user to tell him we used a different 
    #     shapefile (location), mode "check"? The current approach with the 
    #     file dialog is not that comfortable.
    #
    def run_alt_path_dialog(self, filename, mode = None, second_try = 0):
        """Implemetation of the shapefile_callback while loading sessions.
        
           This implements two modes:
           - search: Search for an alternative path. If available from a 
             list of alrady known paths, else interactivly by file dialog.
             Currently the "second_try" is important since else the user might
             be caught in a loop.
           - check: Ask the user for confirmation, if a path from list has
             been found successful.

           Returns:
           - fname: The full path to the (shape) file.
           - from_list: Flags if the path was taken from list or entered
             manually.
        """

        if mode == "search":
            if self.Path('alt_path') == "" or second_try:
                dlg = altpathdialog.AltPathFileDialog(filename)
                fname = dlg.RunDialog()
                if fname is not None:
                    self.SetPath('alt_path', fname)    
                from_list = 0
            else:
                fname = os.path.join(self.Path('alt_path'),
                                     os.path.basename(filename))
                from_list = 1
        elif mode == "check":
                dlg = altpathdialog.AltPathConfirmDialog(filename)
                fname = dlg.RunDialog()
                if fname is not None:
                    self.SetPath('alt_path', fname)
                from_list = 0
        else:
            fname = None
            from_list = 0
        return fname, from_list


    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	# Copyright (C) 2001-2005 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	from extensionregistry import ext_registry
34
35	import view
36	import tree
37	import mainwindow
38	import dbdialog
39	import altpathdialog
40	import exceptiondialog
41
42	from messages import SESSION_REPLACED
43
44
45	class ThubanApplication(wxApp, Publisher):
46
47	"""
48	Thuban's application class.
49
50	All wxWindows programs have to have an instance of an application
51	class derived from wxApp. In Thuban the application class holds
52	references to the main window and the session.
53	"""
54
55	def OnInit(self):
56	sys.excepthook = self.ShowExceptionDialog
57
58	# Initialize instance variables before trying to create any
59	# windows. Creating windows can start an event loop if
60	# e.g. message boxes are popped up for some reason, and event
61	# handlers, especially EVT_UPDATE_UI may want to access things
62	# from the application.
63
64	# Defaults for the directories used in file dialogs
65	self.path={"data":".", "projection":".", "alt_path":""}
66
67	self.session = None
68	self.top = None
69	self.create_session()
70
71	# Create an optional splash screen and then the mainwindow
72	self.splash = self.splash_screen()
73	if self.splash is not None:
74	self.splash.Show()
75	self.read_startup_files()
76	self.init_extensions()
77	self.top = self.CreateMainWindow()
78	# The session was alredy created above and we need to get the
79	# map into the mainwindow. maps_changed does that.
80	self.maps_changed()
81	self.SetTopWindow(self.top)
82	if self.splash is None:
83	self.ShowMainWindow()
84
85	return True
86
87	def OnExit(self):
88	"""Clean up code.
89
90	Extend this in derived classes if needed.
91	"""
92	self.session.Destroy()
93	self.session = None
94	Publisher.Destroy(self)
95
96	def read_startup_files(self):
97	"""Read the startup files."""
98	# for now the startup file is ~/.thuban/thubanstart.py
99	dir = get_application_dir()
100	if os.path.isdir(dir):
101	sys.path.append(dir)
102	try:
103	import thubanstart
104	except ImportError:
105	tb = sys.exc_info()[2]
106	try:
107	if tb.tb_next is not None:
108	# The ImportError exception was raised from
109	# inside the thubanstart module.
110	sys.stderr.write(_("Cannot import the thubanstart"
111	" module\n"))
112	traceback.print_exc(None, sys.stderr)
113	else:
114	# There's no thubanstart module.
115	sys.stderr.write(_("No thubanstart module available\n"))
116	finally:
117	# make sure we delete the traceback object,
118	# otherwise there's be circular references involving
119	# the current stack frame
120	del tb
121	except:
122	sys.stderr.write(_("Cannot import the thubanstart module\n"))
123	traceback.print_exc(None, sys.stderr)
124	else:
125	# There's no .thuban directory
126	sys.stderr.write(_("No ~/.thuban directory\n"))
127
128	def init_extensions(self):
129	"""Call initialization callbacks for all registered extensions."""
130	for ext in ext_registry:
131	ext.init_ext()
132
133	def splash_screen(self):
134	"""Create and return a splash screen.
135
136	This method is called by OnInit to determine whether the
137	application should have a splashscreen. If the application
138	should display a splash screen override this method in a derived
139	class and have it create and return the wxSplashScreen instance.
140	The implementation of this method in the derived class should
141	also arranged for ShowMainWindow to be called.
142
143	The default implementation simply returns None so that no splash
144	screen is shown and ShowMainWindow will be called automatically.
145	"""
146	return None
147
148	def ShowMainWindow(self):
149	"""Show the main window
150
151	Normally this method is automatically called by OnInit to show
152	the main window. However, if the splash_screen method has
153	returned a splashscreen it is expected that the derived class
154	also arranges for ShowMainWindow to be called at the appropriate
155	time.
156	"""
157	self.top.Show(True)
158
159	def CreateMainWindow(self):
160	"""Create and return the main window for the application.
161
162	Override this in subclasses to instantiate the Thuban mainwindow
163	with different parameters or to use a different class for the
164	main window.
165	"""
166	msg = (_("This is the wxPython-based Graphical User Interface"
167	" for exploring geographic data"))
168	return mainwindow.MainWindow(NULL, -1, "Thuban", self, None,
169	initial_message = msg,
170	size = (600, 400))
171
172	def Session(self):
173	"""Return the application's session object"""
174	return self.session
175
176	def SetSession(self, session):
177	"""Make session the new session.
178
179	Issue SESSION_REPLACED after self.session has become the new
180	session. After the session has been assigned call
181	self.subscribe_session() with the new session and
182	self.unsubscribe_session with the old one.
183	"""
184	oldsession = self.session
185	self.session = session
186	self.subscribe_session(self.session)
187	self.issue(SESSION_REPLACED)
188	self.maps_changed()
189	if oldsession is not None:
190	self.unsubscribe_session(oldsession)
191	oldsession.Destroy()
192
193	def SetPath(self, group, filename):
194	"""Store the application's default path for file dialogs extracted
195	from a given filename.
196	"""
197	self.path[group] = os.path.dirname( filename )
198
199	def Path(self, group):
200	"""Return the application's default path for file dialogs."""
201	return self.path[group]
202
203	def subscribe_session(self, session):
204	"""Subscribe to some of the sessions channels.
205
206	Extend this method in derived classes if you need additional
207	channels.
208	"""
209	session.Subscribe(MAPS_CHANGED, self.maps_changed)
210
211	def unsubscribe_session(self, session):
212	"""Unsubscribe from the sessions channels.
213
214	Extend this method in derived classes if you subscribed to
215	additional channels in subscribe_session().
216	"""
217	session.Unsubscribe(MAPS_CHANGED, self.maps_changed)
218
219	def create_session(self):
220	"""Create a default session.
221
222	Override this method in derived classes to instantiate the
223	session differently or to use a different session class. Don't
224	subscribe to channels here yet. Do that in the
225	subscribe_session() method.
226	"""
227	self.SetSession(create_empty_session())
228
229	def OpenSession(self, filename, db_connection_callback = None,
230	shapefile_callback = None):
231	"""Open the session in the file named filename"""
232	# Make sure we deal with an absolute pathname. Otherwise we can
233	# get problems when saving because the saving code expects an
234	# absolute directory name
235	filename = os.path.abspath(filename)
236	if db_connection_callback is None:
237	db_connection_callback = self.run_db_param_dialog
238	if shapefile_callback is None:
239	shapefile_callback = self.run_alt_path_dialog
240	try:
241	session = load_session(filename,
242	db_connection_callback=db_connection_callback,
243	shapefile_callback=shapefile_callback)
244	except LoadCancelled:
245	return
246	session.SetFilename(filename)
247	session.UnsetModified()
248	self.SetSession(session)
249
250	for map in session.Maps():
251	for layer in map.Layers():
252	if isinstance(layer, RasterLayer) \
253	and not Thuban.Model.resource.has_gdal_support():
254	msg = _("The current session contains Image layers,\n"
255	"but the GDAL library is not available to "
256	"draw them.")
257	dlg = wxMessageDialog(None,
258	msg,
259	_("Library not available"),
260	wxOK \| wxICON_INFORMATION)
261	print msg
262	dlg.ShowModal()
263	dlg.Destroy()
264	break
265
266	def run_db_param_dialog(self, parameters, message):
267	"""Implementation of the db_connection_callback for loading sessions"""
268	dlg = dbdialog.DBDialog(None, _("DB Connection Parameters"),
269	parameters, message)
270	return dlg.RunDialog()
271
272	# run_alt_path_dialog: Raise a dialog to ask for an alternative path
273	# if the shapefile couldn't be found.
274	# TODO:
275	# - Store a list of already used alternative paths and return these
276	# iteratively (using a generator)
277	# - How do we interact with the user to tell him we used a different
278	# shapefile (location), mode "check"? The current approach with the
279	# file dialog is not that comfortable.
280	#
281	def run_alt_path_dialog(self, filename, mode = None, second_try = 0):
282	"""Implemetation of the shapefile_callback while loading sessions.
283
284	This implements two modes:
285	- search: Search for an alternative path. If available from a
286	list of alrady known paths, else interactivly by file dialog.
287	Currently the "second_try" is important since else the user might
288	be caught in a loop.
289	- check: Ask the user for confirmation, if a path from list has
290	been found successful.
291
292	Returns:
293	- fname: The full path to the (shape) file.
294	- from_list: Flags if the path was taken from list or entered
295	manually.
296	"""
297
298	if mode == "search":
299	if self.Path('alt_path') == "" or second_try:
300	dlg = altpathdialog.AltPathFileDialog(filename)
301	fname = dlg.RunDialog()
302	if fname is not None:
303	self.SetPath('alt_path', fname)
304	from_list = 0
305	else:
306	fname = os.path.join(self.Path('alt_path'),
307	os.path.basename(filename))
308	from_list = 1
309	elif mode == "check":
310	dlg = altpathdialog.AltPathConfirmDialog(filename)
311	fname = dlg.RunDialog()
312	if fname is not None:
313	self.SetPath('alt_path', fname)
314	from_list = 0
315	else:
316	fname = None
317	from_list = 0
318	return fname, from_list
319
320
321	def SaveSession(self):
322	save_session(self.session, self.session.filename)
323
324	def maps_changed(self, *args):
325	"""Subscribed to the session's MAPS_CHANGED messages.
326
327	Set the toplevel window's map to the map in the session. This is
328	done by calling the window's SetMap method with the map as
329	argument. If the session doesn't have any maps None is used
330	instead.
331
332	Currently Thuban can only really handle at most one map in a
333	sessions so the first map in the session's list of maps as
334	returned by the Maps method is used.
335	"""
336	# The mainwindow may not have been created yet, so check whether
337	# it has been created before calling any of its methods
338	if self.top is not None:
339	if self.session.HasMaps():
340	self.top.SetMap(self.session.Maps()[0])
341	else:
342	self.top.SetMap(None)
343
344	in_exception_dialog = 0 # flag: are we already inside the exception dialog?
345
346	def ShowExceptionDialog(self, exc_type, exc_value, exc_traceback):
347	"""Show a message box with information about an exception.
348
349	The parameters are the usual values describing an exception in
350	Python, the exception type, the value and the traceback.
351
352	This method can be used as a value for the sys.excepthook.
353	"""
354
355	if self.in_exception_dialog:
356	return
357	self.in_exception_dialog = 1
358	while wxIsBusy():
359	wxEndBusyCursor() # reset the mouse cursor
360
361	try:
362	lines = traceback.format_exception(exc_type, exc_value,
363	exc_traceback)
364	message = _("An unhandled exception occurred:\n%s\n"
365	"(please report to"
366	" http://thuban.intevation.org/bugtracker.html)"
367	"\n\n%s") % (exc_value, "".join(lines))
368	print message
369
370	# We don't use an explicit parent here because this method might
371	# be called in circumstances where the main window doesn't exist
372	# anymore.
373	exceptiondialog.run_exception_dialog(None, message)
374
375	finally:
376	self.in_exception_dialog = 0
377	# delete the last exception info that python keeps in
378	# sys.last_* because especially last_traceback keeps
379	# indirect references to all objects bound to local
380	# variables and this might prevent some object from being
381	# collected early enough.
382	sys.last_type = sys.last_value = sys.last_traceback = None
383
Name	Value
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svn:keywords	Author Date Id Revision