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 wxPython.lib.dialogs import wxScrolledMessageDialog

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
from Thuban.Model.messages import MAPS_CHANGED
from Thuban.Model.layer import RasterLayer
import Thuban.Model.resource

import view
import tree
import mainwindow

from messages import SESSION_REPLACED


class ThubanApplication(wxApp, Publisher):

    """
    Thuban's application class.

    All wxWindows programs have to have an instance of an application
    class derived from wxApp. In Thuban the application class holds
    references to the main window and the session.
    """

    def OnInit(self):
        sys.excepthook = self.ShowExceptionDialog
        self.splash = self.splash_screen()
        if self.splash is not None:
            self.splash.Show()
        self.read_startup_files()
        self.top = self.CreateMainWindow()
        self.SetTopWindow(self.top)
        if self.splash is None:
            self.ShowMainWindow()
        self.session = None
        self.create_session()
        return True

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    def OpenSession(self, filename, db_connection_callback = None):
        """Open the session in the file named filename"""
        # Make sure we deal with an absolute pathname. Otherwise we can
        # get problems when saving because the saving code expects an
        # absolute directory name
        filename = os.path.abspath(filename)
        session = load_session(filename,
                               db_connection_callback = db_connection_callback)
        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 SaveSession(self):
        save_session(self.session, self.session.filename)

    def maps_changed(self, *args):
        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" % exc_value+\
                    "(please report to " \
                    "http://thuban.intevation.org/bugtracker.html)"\
                    "\n\n\n"+\
                    "".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.
            dlg = wxScrolledMessageDialog(None, message,
                                        "Thuban: Internal Error")
            dlg.ShowModal()
            dlg.Destroy()

        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	jonathan	1390	from wxPython.lib.dialogs import wxScrolledMessageDialog
22	bh	6
23			from Thuban.Lib.connector import Publisher
24	frank	1150	from Thuban.Lib.fileutil import get_application_dir
25	bh	6
26	jan	374	from Thuban import _
27	bh	6	from Thuban.Model.session import create_empty_session
28			from Thuban.Model.save import save_session
29			from Thuban.Model.load import load_session
30	bh	242	from Thuban.Model.messages import MAPS_CHANGED
31	jonathan	1162	from Thuban.Model.layer import RasterLayer
32			import Thuban.Model.resource
33	bh	6
34			import view
35			import tree
36	bh	215	import mainwindow
37	bh	6
38	jonathan	503	from messages import SESSION_REPLACED
39	bh	6
40
41			class ThubanApplication(wxApp, Publisher):
42
43			"""
44			Thuban's application class.
45
46			All wxWindows programs have to have an instance of an application
47			class derived from wxApp. In Thuban the application class holds
48	bh	535	references to the main window and the session.
49	bh	6	"""
50
51			def OnInit(self):
52	jonathan	1518	sys.excepthook = self.ShowExceptionDialog
53	bh	401	self.splash = self.splash_screen()
54			if self.splash is not None:
55			self.splash.Show()
56	bh	189	self.read_startup_files()
57	bh	401	self.top = self.CreateMainWindow()
58			self.SetTopWindow(self.top)
59			if self.splash is None:
60			self.ShowMainWindow()
61	bh	6	self.session = None
62			self.create_session()
63	jonathan	518	return True
64	bh	6
65	bh	251	def OnExit(self):
66			"""Clean up code.
67
68			Extend this in derived classes if needed.
69			"""
70			self.session.Destroy()
71	bh	765	self.session = None
72	bh	251	Publisher.Destroy(self)
73
74	bh	189	def read_startup_files(self):
75			"""Read the startup files."""
76			# for now the startup file is ~/.thuban/thubanstart.py
77	frank	1150	dir = get_application_dir()
78	bh	189	if os.path.isdir(dir):
79			sys.path.append(dir)
80			try:
81			import thubanstart
82			except ImportError:
83			tb = sys.exc_info()[2]
84			try:
85			if tb.tb_next is not None:
86			# The ImportError exception was raised from
87			# inside the thubanstart module.
88	jan	374	sys.stderr.write(_("Cannot import the thubanstart"
89	bh	671	" module\n"))
90	bh	189	traceback.print_exc(None, sys.stderr)
91			else:
92			# There's no thubanstart module.
93	jan	374	sys.stderr.write(_("No thubanstart module available\n"))
94	bh	189	finally:
95			# make sure we delete the traceback object,
96			# otherwise there's be circular references involving
97			# the current stack frame
98			del tb
99			except:
100	jan	374	sys.stderr.write(_("Cannot import the thubanstart module\n"))
101	bh	189	traceback.print_exc(None, sys.stderr)
102			else:
103			# There's no .thuban directory
104	jan	374	sys.stderr.write(_("No ~/.thuban directory\n"))
105	bh	189
106	bh	401	def splash_screen(self):
107			"""Create and return a splash screen.
108
109			This method is called by OnInit to determine whether the
110			application should have a splashscreen. If the application
111			should display a splash screen override this method in a derived
112			class and have it create and return the wxSplashScreen instance.
113			The implementation of this method in the derived class should
114			also arranged for ShowMainWindow to be called.
115
116			The default implementation simply returns None so that no splash
117			screen is shown and ShowMainWindow will be called automatically.
118			"""
119			return None
120
121			def ShowMainWindow(self):
122			"""Show the main window
123
124			Normally this method is automatically called by OnInit to show
125			the main window. However, if the splash_screen method has
126			returned a splashscreen it is expected that the derived class
127			also arranges for ShowMainWindow to be called at the appropriate
128			time.
129			"""
130	jonathan	518	self.top.Show(True)
131	bh	535
132	bh	235	def CreateMainWindow(self):
133			"""Create and return the main window for the application.
134
135			Override this in subclasses to instantiate the Thuban mainwindow
136			with different parameters or to use a different class for the
137			main window.
138			"""
139	jan	374	msg = (_("This is the wxPython-based Graphical User Interface"
140			" for exploring geographic data"))
141	bh	535	return mainwindow.MainWindow(NULL, -1, "Thuban", self, None,
142	jonathan	934	initial_message = msg,
143			size = (600, 400))
144	bh	235
145	bh	219	def Session(self):
146			"""Return the application's session object"""
147			return self.session
148
149	bh	6	def SetSession(self, session):
150	bh	219	"""Make session the new session.
151
152	jonathan	503	Issue SESSION_REPLACED after self.session has become the new
153	bh	242	session. After the session has been assigned call
154			self.subscribe_session() with the new session and
155			self.unsubscribe_session with the old one.
156	bh	219	"""
157	bh	6	oldsession = self.session
158			self.session = session
159	bh	242	self.subscribe_session(self.session)
160	jonathan	503	self.issue(SESSION_REPLACED)
161	bh	242	self.maps_changed()
162	bh	6	if oldsession is not None:
163	bh	242	self.unsubscribe_session(oldsession)
164	bh	6	oldsession.Destroy()
165
166	bh	242	def subscribe_session(self, session):
167			"""Subscribe to some of the sessions channels.
168
169			Extend this method in derived classes if you need additional
170			channels.
171			"""
172			session.Subscribe(MAPS_CHANGED, self.maps_changed)
173
174			def unsubscribe_session(self, session):
175			"""Unsubscribe from the sessions channels.
176
177			Extend this method in derived classes if you subscribed to
178			additional channels in subscribe_session().
179			"""
180			session.Unsubscribe(MAPS_CHANGED, self.maps_changed)
181
182	bh	6	def create_session(self):
183	bh	242	"""Create a default session.
184
185			Override this method in derived classes to instantiate the
186			session differently or to use a different session class. Don't
187			subscribe to channels here yet. Do that in the
188			subscribe_session() method.
189			"""
190	bh	6	self.SetSession(create_empty_session())
191
192	bh	1648	def OpenSession(self, filename, db_connection_callback = None):
193	bh	592	"""Open the session in the file named filename"""
194			# Make sure we deal with an absolute pathname. Otherwise we can
195			# get problems when saving because the saving code expects an
196			# absolute directory name
197			filename = os.path.abspath(filename)
198	bh	1648	session = load_session(filename,
199			db_connection_callback = db_connection_callback)
200	bh	6	session.SetFilename(filename)
201			session.UnsetModified()
202			self.SetSession(session)
203
204	jonathan	1162	for map in session.Maps():
205			for layer in map.Layers():
206			if isinstance(layer, RasterLayer) \
207			and not Thuban.Model.resource.has_gdal_support():
208	bh	1566	msg = _("The current session contains Image layers,\n"
209			"but the GDAL library is not available to "
210	jonathan	1162	"draw them.")
211	bh	1566	dlg = wx.wxMessageDialog(None,
212			msg,
213	jonathan	1162	_("Library not available"),
214			wx.wxOK \| wx.wxICON_INFORMATION)
215			print msg
216			dlg.ShowModal()
217			dlg.Destroy()
218			break
219
220	bh	6	def SaveSession(self):
221			save_session(self.session, self.session.filename)
222
223	bh	242	def maps_changed(self, *args):
224	bh	6	if self.session.HasMaps():
225			self.top.SetMap(self.session.Maps()[0])
226			else:
227			self.top.SetMap(None)
228	jonathan	1390
229	jonathan	1518	in_exception_dialog = 0 # flag: are we already inside the exception dialog?
230	jonathan	1390
231	jonathan	1518	def ShowExceptionDialog(self, exc_type, exc_value, exc_traceback):
232			"""Show a message box with information about an exception.
233
234			The parameters are the usual values describing an exception in
235			Python, the exception type, the value and the traceback.
236
237			This method can be used as a value for the sys.excepthook.
238			"""
239	jonathan	1390
240	jonathan	1518	if self.in_exception_dialog:
241			return
242			self.in_exception_dialog = 1
243			while wxIsBusy():
244			wxEndBusyCursor() # reset the mouse cursor
245	jonathan	1390
246	jonathan	1518	try:
247			lines = traceback.format_exception(exc_type, exc_value,
248			exc_traceback)
249			message = "An unhandled exception occurred:\n%s\n" % exc_value+\
250			"(please report to " \
251			"http://thuban.intevation.org/bugtracker.html)"\
252			"\n\n\n"+\
253			"".join(lines)
254			print message
255	jonathan	1390
256	jonathan	1518	# We don't use an explicit parent here because this method might
257			# be called in circumstances where the main window doesn't exist
258			# anymore.
259			dlg = wxScrolledMessageDialog(None, message,
260			"Thuban: Internal Error")
261			dlg.ShowModal()
262			dlg.Destroy()
263	jonathan	1390
264	jonathan	1518	finally:
265			self.in_exception_dialog = 0
266			# delete the last exception info that python keeps in
267			# sys.last_* because especially last_traceback keeps
268			# indirect references to all objects bound to local
269			# variables and this might prevent some object from being
270			# collected early enough.
271			sys.last_type = sys.last_value = sys.last_traceback = None
272	jonathan	1390
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svn:keywords	Author Date Id Revision