Thuban/UI/application.py

# Copyright (C) 2001, 2002, 2003, 2004 by Intevation GmbH
# Authors:
# Jan-Oliver Wagner <[email protected]>
# Bernhard Herzog <[email protected]>
#
# This program is free software under the GPL (>=v2)
# Read the file COPYING coming with Thuban for details.

"""
Thuban's application object.
"""

__version__ = "$Revision$"

import sys, os
import os.path

import traceback

from wxPython.wx import *

from Thuban.Lib.connector import Publisher
from Thuban.Lib.fileutil import get_application_dir

from Thuban import _
from Thuban.Model.session import create_empty_session
from Thuban.Model.save import save_session
from Thuban.Model.load import load_session, LoadCancelled
from Thuban.Model.messages import MAPS_CHANGED
from Thuban.Model.layer import RasterLayer
import Thuban.Model.resource

import view
import tree
import mainwindow
import dbdialog
import 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.top = self.CreateMainWindow()
        # The session was alredy created above and we need to get the
        # map into the mainwindow.  maps_changed does that.
        self.maps_changed()
        self.SetTopWindow(self.top)
        if self.splash is None:
            self.ShowMainWindow()

        return True

    def OnExit(self):
        """Clean up code.

        Extend this in derived classes if needed.
        """
        self.session.Destroy()
        self.session = None
        Publisher.Destroy(self)

    def read_startup_files(self):
        """Read the startup files."""
        # for now the startup file is ~/.thuban/thubanstart.py
        dir = get_application_dir()
        if os.path.isdir(dir):
            sys.path.append(dir)
            try:
                import thubanstart
            except ImportError:
                tb = sys.exc_info()[2]
                try:
                    if tb.tb_next is not None:
                        # The ImportError exception was raised from
                        # inside the thubanstart module.
                        sys.stderr.write(_("Cannot import the thubanstart"
                                         " module\n"))
                        traceback.print_exc(None, sys.stderr)
                    else:
                        # There's no thubanstart module.
                        sys.stderr.write(_("No thubanstart module available\n"))
                finally:
                    # make sure we delete the traceback object,
                    # otherwise there's be circular references involving
                    # the current stack frame
                    del tb
            except:
                sys.stderr.write(_("Cannot import the thubanstart module\n"))
                traceback.print_exc(None, sys.stderr)
        else:
            # There's no .thuban directory
            sys.stderr.write(_("No ~/.thuban directory\n"))

    def splash_screen(self):
        """Create and return a splash screen.

        This method is called by OnInit to determine whether the
        application should have a splashscreen. If the application
        should display a splash screen override this method in a derived
        class and have it create and return the wxSplashScreen instance.
        The implementation of this method in the derived class should
        also arranged for ShowMainWindow to be called.

        The default implementation simply returns None so that no splash
        screen is shown and ShowMainWindow will be called automatically.
        """
        return None

    def ShowMainWindow(self):
        """Show the main window

        Normally this method is automatically called by OnInit to show
        the main window. However, if the splash_screen method has
        returned a splashscreen it is expected that the derived class
        also arranges for ShowMainWindow to be called at the appropriate
        time.
        """
        self.top.Show(True)

    def CreateMainWindow(self):
        """Create and return the main window for the application.

        Override this in subclasses to instantiate the Thuban mainwindow
        with different parameters or to use a different class for the
        main window.
        """
        msg = (_("This is the wxPython-based Graphical User Interface"
               " for exploring geographic data"))
        return mainwindow.MainWindow(NULL, -1, "Thuban", self, None,
                                     initial_message = msg,
                                     size = (600, 400))

    def Session(self):
        """Return the application's session object"""
        return self.session

    def SetSession(self, session):
        """Make session the new session.

        Issue SESSION_REPLACED after self.session has become the new
        session. After the session has been assigned call
        self.subscribe_session() with the new session and
        self.unsubscribe_session with the old one.
        """
        oldsession = self.session
        self.session = session
        self.subscribe_session(self.session)
        self.issue(SESSION_REPLACED)
        self.maps_changed()
        if oldsession is not None:
            self.unsubscribe_session(oldsession)
            oldsession.Destroy()

    def SetPath(self, group, filename):
        """Store the application's default path for file dialogs extracted
        from a given filename.
        """
        self.path[group] = os.path.dirname( filename )

    def Path(self, group):
        """Return the application's default path for file dialogs."""
        return self.path[group]

    def subscribe_session(self, session):
        """Subscribe to some of the sessions channels.

        Extend this method in derived classes if you need additional
        channels.
        """
        session.Subscribe(MAPS_CHANGED, self.maps_changed)

    def unsubscribe_session(self, session):
        """Unsubscribe from the sessions channels.

        Extend this method in derived classes if you subscribed to
        additional channels in subscribe_session().
        """
        session.Unsubscribe(MAPS_CHANGED, self.maps_changed)

    def create_session(self):
        """Create a default session.

        Override this method in derived classes to instantiate the
        session differently or to use a different session class. Don't
        subscribe to channels here yet. Do that in the
        subscribe_session() method.
        """
        self.SetSession(create_empty_session())

    def OpenSession(self, filename, db_connection_callback = None,
                                    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	bh	2072	# Copyright (C) 2001, 2002, 2003, 2004 by Intevation GmbH
2	bh	6	# Authors:
3			# Jan-Oliver Wagner <[email protected]>
4	bh	189	# Bernhard Herzog <[email protected]>
5	bh	6	#
6			# This program is free software under the GPL (>=v2)
7			# Read the file COPYING coming with Thuban for details.
8
9			"""
10			Thuban's application object.
11			"""
12
13			__version__ = "$Revision$"
14
15	bh	189	import sys, os
16	frank	1133	import os.path
17
18	bh	189	import traceback
19
20	bh	6	from wxPython.wx import *
21
22			from Thuban.Lib.connector import Publisher
23	frank	1150	from Thuban.Lib.fileutil import get_application_dir
24	bh	6
25	jan	374	from Thuban import _
26	bh	6	from Thuban.Model.session import create_empty_session
27			from Thuban.Model.save import save_session
28	bh	1650	from Thuban.Model.load import load_session, LoadCancelled
29	bh	242	from Thuban.Model.messages import MAPS_CHANGED
30	jonathan	1162	from Thuban.Model.layer import RasterLayer
31			import Thuban.Model.resource
32	bh	6
33			import view
34			import tree
35	bh	215	import mainwindow
36	bh	1654	import dbdialog
37	frank	2446	import altpathdialog
38	jan	1704	import exceptiondialog
39	bh	6
40	jonathan	503	from messages import SESSION_REPLACED
41	bh	6
42
43			class ThubanApplication(wxApp, Publisher):
44
45			"""
46			Thuban's application class.
47
48			All wxWindows programs have to have an instance of an application
49			class derived from wxApp. In Thuban the application class holds
50	bh	535	references to the main window and the session.
51	bh	6	"""
52
53			def OnInit(self):
54	jonathan	1518	sys.excepthook = self.ShowExceptionDialog
55	bh	2072
56			# Initialize instance variables before trying to create any
57			# windows. Creating windows can start an event loop if
58			# e.g. message boxes are popped up for some reason, and event
59			# handlers, especially EVT_UPDATE_UI may want to access things
60			# from the application.
61
62			# Defaults for the directories used in file dialogs
63	frank	2446	self.path={"data":".", "projection":".", "alt_path":""}
64	bh	2072
65			self.session = None
66			self.top = None
67			self.create_session()
68
69			# Create an optional splash screen and then the mainwindow
70	bh	401	self.splash = self.splash_screen()
71			if self.splash is not None:
72			self.splash.Show()
73	bh	189	self.read_startup_files()
74	bh	401	self.top = self.CreateMainWindow()
75	bh	2076	# The session was alredy created above and we need to get the
76			# map into the mainwindow. maps_changed does that.
77			self.maps_changed()
78	bh	401	self.SetTopWindow(self.top)
79			if self.splash is None:
80			self.ShowMainWindow()
81	bh	2072
82	jonathan	518	return True
83	bh	6
84	bh	251	def OnExit(self):
85			"""Clean up code.
86
87			Extend this in derived classes if needed.
88			"""
89			self.session.Destroy()
90	bh	765	self.session = None
91	bh	251	Publisher.Destroy(self)
92
93	bh	189	def read_startup_files(self):
94			"""Read the startup files."""
95			# for now the startup file is ~/.thuban/thubanstart.py
96	frank	1150	dir = get_application_dir()
97	bh	189	if os.path.isdir(dir):
98			sys.path.append(dir)
99			try:
100			import thubanstart
101			except ImportError:
102			tb = sys.exc_info()[2]
103			try:
104			if tb.tb_next is not None:
105			# The ImportError exception was raised from
106			# inside the thubanstart module.
107	jan	374	sys.stderr.write(_("Cannot import the thubanstart"
108	bh	671	" module\n"))
109	bh	189	traceback.print_exc(None, sys.stderr)
110			else:
111			# There's no thubanstart module.
112	jan	374	sys.stderr.write(_("No thubanstart module available\n"))
113	bh	189	finally:
114			# make sure we delete the traceback object,
115			# otherwise there's be circular references involving
116			# the current stack frame
117			del tb
118			except:
119	jan	374	sys.stderr.write(_("Cannot import the thubanstart module\n"))
120	bh	189	traceback.print_exc(None, sys.stderr)
121			else:
122			# There's no .thuban directory
123	jan	374	sys.stderr.write(_("No ~/.thuban directory\n"))
124	bh	189
125	bh	401	def splash_screen(self):
126			"""Create and return a splash screen.
127
128			This method is called by OnInit to determine whether the
129			application should have a splashscreen. If the application
130			should display a splash screen override this method in a derived
131			class and have it create and return the wxSplashScreen instance.
132			The implementation of this method in the derived class should
133			also arranged for ShowMainWindow to be called.
134
135			The default implementation simply returns None so that no splash
136			screen is shown and ShowMainWindow will be called automatically.
137			"""
138			return None
139
140			def ShowMainWindow(self):
141			"""Show the main window
142
143			Normally this method is automatically called by OnInit to show
144			the main window. However, if the splash_screen method has
145			returned a splashscreen it is expected that the derived class
146			also arranges for ShowMainWindow to be called at the appropriate
147			time.
148			"""
149	jonathan	518	self.top.Show(True)
150	bh	535
151	bh	235	def CreateMainWindow(self):
152			"""Create and return the main window for the application.
153
154			Override this in subclasses to instantiate the Thuban mainwindow
155			with different parameters or to use a different class for the
156			main window.
157			"""
158	jan	374	msg = (_("This is the wxPython-based Graphical User Interface"
159			" for exploring geographic data"))
160	bh	535	return mainwindow.MainWindow(NULL, -1, "Thuban", self, None,
161	jonathan	934	initial_message = msg,
162			size = (600, 400))
163	bh	235
164	bh	219	def Session(self):
165			"""Return the application's session object"""
166			return self.session
167
168	bh	6	def SetSession(self, session):
169	bh	219	"""Make session the new session.
170
171	jonathan	503	Issue SESSION_REPLACED after self.session has become the new
172	bh	242	session. After the session has been assigned call
173			self.subscribe_session() with the new session and
174			self.unsubscribe_session with the old one.
175	bh	219	"""
176	bh	6	oldsession = self.session
177			self.session = session
178	bh	242	self.subscribe_session(self.session)
179	jonathan	503	self.issue(SESSION_REPLACED)
180	bh	242	self.maps_changed()
181	bh	6	if oldsession is not None:
182	bh	242	self.unsubscribe_session(oldsession)
183	bh	6	oldsession.Destroy()
184
185	frank	2051	def SetPath(self, group, filename):
186			"""Store the application's default path for file dialogs extracted
187			from a given filename.
188			"""
189			self.path[group] = os.path.dirname( filename )
190
191			def Path(self, group):
192			"""Return the application's default path for file dialogs."""
193			return self.path[group]
194
195	bh	242	def subscribe_session(self, session):
196			"""Subscribe to some of the sessions channels.
197
198			Extend this method in derived classes if you need additional
199			channels.
200			"""
201			session.Subscribe(MAPS_CHANGED, self.maps_changed)
202
203			def unsubscribe_session(self, session):
204			"""Unsubscribe from the sessions channels.
205
206			Extend this method in derived classes if you subscribed to
207			additional channels in subscribe_session().
208			"""
209			session.Unsubscribe(MAPS_CHANGED, self.maps_changed)
210
211	bh	6	def create_session(self):
212	bh	242	"""Create a default session.
213
214			Override this method in derived classes to instantiate the
215			session differently or to use a different session class. Don't
216			subscribe to channels here yet. Do that in the
217			subscribe_session() method.
218			"""
219	bh	6	self.SetSession(create_empty_session())
220
221	frank	2446	def OpenSession(self, filename, db_connection_callback = None,
222			shapefile_callback = None):
223	bh	592	"""Open the session in the file named filename"""
224			# Make sure we deal with an absolute pathname. Otherwise we can
225			# get problems when saving because the saving code expects an
226			# absolute directory name
227			filename = os.path.abspath(filename)
228	bh	1654	if db_connection_callback is None:
229			db_connection_callback = self.run_db_param_dialog
230	frank	2446	if shapefile_callback is None:
231			shapefile_callback = self.run_alt_path_dialog
232	bh	1650	try:
233			session = load_session(filename,
234	frank	2446	db_connection_callback=db_connection_callback,
235			shapefile_callback=shapefile_callback)
236	bh	1650	except LoadCancelled:
237			return
238	bh	6	session.SetFilename(filename)
239			session.UnsetModified()
240			self.SetSession(session)
241
242	jonathan	1162	for map in session.Maps():
243			for layer in map.Layers():
244			if isinstance(layer, RasterLayer) \
245			and not Thuban.Model.resource.has_gdal_support():
246	bh	1566	msg = _("The current session contains Image layers,\n"
247			"but the GDAL library is not available to "
248	jonathan	1162	"draw them.")
249	bh	1566	dlg = wx.wxMessageDialog(None,
250			msg,
251	jonathan	1162	_("Library not available"),
252			wx.wxOK \| wx.wxICON_INFORMATION)
253			print msg
254			dlg.ShowModal()
255			dlg.Destroy()
256			break
257
258	bh	1654	def run_db_param_dialog(self, parameters, message):
259			"""Implementation of the db_connection_callback for loading sessions"""
260			dlg = dbdialog.DBDialog(None, _("DB Connection Parameters"),
261			parameters, message)
262			return dlg.RunDialog()
263
264	frank	2446	# run_alt_path_dialog: Raise a dialog to ask for an alternative path
265			# if the shapefile couldn't be found.
266			# TODO:
267			# - Store a list of already used alternative paths and return these
268			# iteratively (using a generator)
269			# - How do we interact with the user to tell him we used a different
270			# shapefile (location), mode "check"? The current approach with the
271			# file dialog is not that comfortable.
272			#
273			def run_alt_path_dialog(self, filename, mode = None, second_try = 0):
274			"""Implemetation of the shapefile_callback while loading sessions.
275
276			This implements two modes:
277			- search: Search for an alternative path. If available from a
278			list of alrady known paths, else interactivly by file dialog.
279			Currently the "second_try" is important since else the user might
280			be caught in a loop.
281			- check: Ask the user for confirmation, if a path from list has
282			been found successful.
283	bh	1654
284	frank	2446	Returns:
285			- fname: The full path to the (shape) file.
286			- from_list: Flags if the path was taken from list or entered
287			manually.
288			"""
289
290			if mode == "search":
291			if self.Path('alt_path') == "" or second_try:
292			dlg = altpathdialog.AltPathFileDialog(filename)
293			fname = dlg.RunDialog()
294			if fname is not None:
295			self.SetPath('alt_path', fname)
296			from_list = 0
297			else:
298			fname = os.path.join(self.Path('alt_path'),
299			os.path.basename(filename))
300			from_list = 1
301			elif mode == "check":
302			dlg = altpathdialog.AltPathConfirmDialog(filename)
303			fname = dlg.RunDialog()
304			if fname is not None:
305			self.SetPath('alt_path', fname)
306			from_list = 0
307			else:
308			fname = None
309			from_list = 0
310			return fname, from_list
311
312
313	bh	6	def SaveSession(self):
314			save_session(self.session, self.session.filename)
315
316	bh	242	def maps_changed(self, *args):
317	bh	1776	"""Subscribed to the session's MAPS_CHANGED messages.
318
319			Set the toplevel window's map to the map in the session. This is
320			done by calling the window's SetMap method with the map as
321			argument. If the session doesn't have any maps None is used
322			instead.
323
324			Currently Thuban can only really handle at most one map in a
325			sessions so the first map in the session's list of maps as
326			returned by the Maps method is used.
327			"""
328	bh	2072	# The mainwindow may not have been created yet, so check whether
329			# it has been created before calling any of its methods
330			if self.top is not None:
331			if self.session.HasMaps():
332			self.top.SetMap(self.session.Maps()[0])
333			else:
334			self.top.SetMap(None)
335	jonathan	1390
336	jonathan	1518	in_exception_dialog = 0 # flag: are we already inside the exception dialog?
337	jonathan	1390
338	jonathan	1518	def ShowExceptionDialog(self, exc_type, exc_value, exc_traceback):
339			"""Show a message box with information about an exception.
340
341			The parameters are the usual values describing an exception in
342			Python, the exception type, the value and the traceback.
343
344			This method can be used as a value for the sys.excepthook.
345			"""
346	jonathan	1390
347	jonathan	1518	if self.in_exception_dialog:
348			return
349			self.in_exception_dialog = 1
350			while wxIsBusy():
351			wxEndBusyCursor() # reset the mouse cursor
352	jonathan	1390
353	jonathan	1518	try:
354			lines = traceback.format_exception(exc_type, exc_value,
355			exc_traceback)
356	bh	1874	message = _("An unhandled exception occurred:\n%s\n"
357			"(please report to"
358			" http://thuban.intevation.org/bugtracker.html)"
359			"\n\n%s") % (exc_value, "".join(lines))
360	jonathan	1518	print message
361	jonathan	1390
362	jonathan	1518	# We don't use an explicit parent here because this method might
363			# be called in circumstances where the main window doesn't exist
364			# anymore.
365	jan	1704	exceptiondialog.run_exception_dialog(None, message)
366	jonathan	1390
367	jonathan	1518	finally:
368			self.in_exception_dialog = 0
369			# delete the last exception info that python keeps in
370			# sys.last_* because especially last_traceback keeps
371			# indirect references to all objects bound to local
372			# variables and this might prevent some object from being
373			# collected early enough.
374			sys.last_type = sys.last_value = sys.last_traceback = None
375	jonathan	1390
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