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 = 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()

    # 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	jan	2581	# Copyright (C) 2001-2005 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	jan	2581	from extensionregistry import ext_registry
34
35	bh	6	import view
36			import tree
37	bh	215	import mainwindow
38	bh	1654	import dbdialog
39	frank	2446	import altpathdialog
40	jan	1704	import exceptiondialog
41	bh	6
42	jonathan	503	from messages import SESSION_REPLACED
43	bh	6
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	bh	535	references to the main window and the session.
53	bh	6	"""
54
55			def OnInit(self):
56	jonathan	1518	sys.excepthook = self.ShowExceptionDialog
57	bh	2072
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	frank	2446	self.path={"data":".", "projection":".", "alt_path":""}
66	bh	2072
67			self.session = None
68			self.top = None
69			self.create_session()
70
71			# Create an optional splash screen and then the mainwindow
72	bh	401	self.splash = self.splash_screen()
73			if self.splash is not None:
74			self.splash.Show()
75	bh	189	self.read_startup_files()
76	jan	2581	self.init_extensions()
77	bh	401	self.top = self.CreateMainWindow()
78	bh	2076	# 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	bh	401	self.SetTopWindow(self.top)
82			if self.splash is None:
83			self.ShowMainWindow()
84	bh	2072
85	jonathan	518	return True
86	bh	6
87	bh	251	def OnExit(self):
88			"""Clean up code.
89
90			Extend this in derived classes if needed.
91			"""
92			self.session.Destroy()
93	bh	765	self.session = None
94	bh	251	Publisher.Destroy(self)
95
96	bh	189	def read_startup_files(self):
97			"""Read the startup files."""
98			# for now the startup file is ~/.thuban/thubanstart.py
99	frank	1150	dir = get_application_dir()
100	bh	189	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	jan	374	sys.stderr.write(_("Cannot import the thubanstart"
111	bh	671	" module\n"))
112	bh	189	traceback.print_exc(None, sys.stderr)
113			else:
114			# There's no thubanstart module.
115	jan	374	sys.stderr.write(_("No thubanstart module available\n"))
116	bh	189	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	jan	374	sys.stderr.write(_("Cannot import the thubanstart module\n"))
123	bh	189	traceback.print_exc(None, sys.stderr)
124			else:
125			# There's no .thuban directory
126	jan	374	sys.stderr.write(_("No ~/.thuban directory\n"))
127	bh	189
128	jan	2581	def init_extensions(self):
129			"""Call initialization callbacks for all registered extensions."""
130			for ext in ext_registry:
131			ext.init_ext()
132
133	bh	401	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	jonathan	518	self.top.Show(True)
158	bh	535
159	bh	235	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	jan	374	msg = (_("This is the wxPython-based Graphical User Interface"
167			" for exploring geographic data"))
168	bh	535	return mainwindow.MainWindow(NULL, -1, "Thuban", self, None,
169	jonathan	934	initial_message = msg,
170			size = (600, 400))
171	bh	235
172	bh	219	def Session(self):
173			"""Return the application's session object"""
174			return self.session
175
176	bh	6	def SetSession(self, session):
177	bh	219	"""Make session the new session.
178
179	jonathan	503	Issue SESSION_REPLACED after self.session has become the new
180	bh	242	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	bh	219	"""
184	bh	6	oldsession = self.session
185			self.session = session
186	bh	242	self.subscribe_session(self.session)
187	jonathan	503	self.issue(SESSION_REPLACED)
188	bh	242	self.maps_changed()
189	bh	6	if oldsession is not None:
190	bh	242	self.unsubscribe_session(oldsession)
191	bh	6	oldsession.Destroy()
192
193	frank	2051	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	bh	242	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	bh	6	def create_session(self):
220	bh	242	"""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	bh	6	self.SetSession(create_empty_session())
228
229	frank	2446	def OpenSession(self, filename, db_connection_callback = None,
230			shapefile_callback = None):
231	bh	592	"""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	bh	1654	if db_connection_callback is None:
237			db_connection_callback = self.run_db_param_dialog
238	frank	2446	if shapefile_callback is None:
239			shapefile_callback = self.run_alt_path_dialog
240	bh	1650	try:
241			session = load_session(filename,
242	frank	2446	db_connection_callback=db_connection_callback,
243			shapefile_callback=shapefile_callback)
244	bh	1650	except LoadCancelled:
245			return
246	bh	6	session.SetFilename(filename)
247			session.UnsetModified()
248			self.SetSession(session)
249
250	jonathan	1162	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	bh	1566	msg = _("The current session contains Image layers,\n"
255			"but the GDAL library is not available to "
256	jonathan	1162	"draw them.")
257	bh	1566	dlg = wx.wxMessageDialog(None,
258			msg,
259	jonathan	1162	_("Library not available"),
260			wx.wxOK \| wx.wxICON_INFORMATION)
261			print msg
262			dlg.ShowModal()
263			dlg.Destroy()
264			break
265
266	bh	1654	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	frank	2446	# 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	bh	1654
292	frank	2446	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	bh	6	def SaveSession(self):
322			save_session(self.session, self.session.filename)
323
324	bh	242	def maps_changed(self, *args):
325	bh	1776	"""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	bh	2072	# 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	jonathan	1390
344	jonathan	1518	in_exception_dialog = 0 # flag: are we already inside the exception dialog?
345	jonathan	1390
346	jonathan	1518	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	jonathan	1390
355	jonathan	1518	if self.in_exception_dialog:
356			return
357			self.in_exception_dialog = 1
358			while wxIsBusy():
359			wxEndBusyCursor() # reset the mouse cursor
360	jonathan	1390
361	jonathan	1518	try:
362			lines = traceback.format_exception(exc_type, exc_value,
363			exc_traceback)
364	bh	1874	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	jonathan	1518	print message
369	jonathan	1390
370	jonathan	1518	# 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	jan	1704	exceptiondialog.run_exception_dialog(None, message)
374	jonathan	1390
375	jonathan	1518	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	jonathan	1390
Name	Value
svn:eol-style	native
svn:keywords	Author Date Id Revision