[orca] Use dbus rather than gsettings when checking if accessibility support and screen reader are enabled

[Joanmarie Diggs <joanied src gnome org>]

commit 852bfe5ee6ceab3528a13efdc4118ed49e8376c0
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Fri Feb 10 07:02:58 2012 -0500

    Use dbus rather than gsettings when checking if accessibility support and screen reader are enabled

 configure.ac                 |    2 +-
 src/orca/orca.py             |   16 +++++++++++-----
 src/orca/settings_manager.py |   21 +++++++++++++++------
 3 files changed, 27 insertions(+), 12 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index bfb997f..79c1fe4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -6,7 +6,7 @@ m4_define([orca_version],
 
 m4_define(gtk_required_version, 3.1.91)
 m4_define(pygobject_required_version, 3.0.2)
-m4_define(atspi_required_version, 2.1.92)
+m4_define(atspi_required_version, 2.3.5)
 
 AC_INIT([orca],
         [orca_version],
diff --git a/src/orca/orca.py b/src/orca/orca.py
index 14e5048..9e6d72f 100644
--- a/src/orca/orca.py
+++ b/src/orca/orca.py
@@ -36,8 +36,11 @@ import sys
 import time
 import shutil
 
-from gi.repository.Gio import Settings
-a11yAppSettings = Settings('org.gnome.desktop.a11y.applications')      
+try:
+    from gi.repository.Gio import Settings
+    a11yAppSettings = Settings('org.gnome.desktop.a11y.applications')
+except:
+    a11yAppSettings = None
 
 # We're going to force the name of the app to "orca" so we
 # will end up showing us as "orca" to the AT-SPI.  If we don't
@@ -1452,8 +1455,7 @@ def init(registry):
 
     global _initialized
 
-    if _initialized \
-       and a11yAppSettings.get_boolean('screen-reader-enabled'):
+    if _initialized and _settingsManager.isScreenReaderServiceEnabled():
         return False
 
     # Do not hang on initialization if we can help it.
@@ -1469,7 +1471,11 @@ def init(registry):
         signal.alarm(0)
 
     _initialized = True
-    a11yAppSettings.connect('changed', onEnabledChanged)
+    # In theory, we can do this through dbus. In practice, it fails to
+    # work sometimes. Until we know why, we need to leave this as-is
+    # so that we respond when gnome-control-center is used to stop Orca.
+    if a11yAppSettings:
+        a11yAppSettings.connect('changed', onEnabledChanged)
     return True
 
 def start(registry):
diff --git a/src/orca/settings_manager.py b/src/orca/settings_manager.py
index 68e8bb0..a8cc33f 100644
--- a/src/orca/settings_manager.py
+++ b/src/orca/settings_manager.py
@@ -28,6 +28,7 @@ __date__      = "$Date$"
 __copyright__ = "Copyright (c) 2010 Consorcio Fernando de los Rios."
 __license__   = "LGPL"
 
+import dbus
 import os
 import imp
 from json import load
@@ -37,9 +38,10 @@ from keybindings import KeyBinding
 import settings
 import pronunciation_dict
 
-from gi.repository.Gio import Settings
-a11yAppSettings = Settings('org.gnome.desktop.interface')  
-
+_bus = dbus.SessionBus()
+_proxy = _bus.get_object("org.a11y.Bus", "/org/a11y/bus")
+_desktopProps = \
+    dbus.Interface(_proxy, dbus_interface='org.freedesktop.DBus.Properties')
 
 class SettingsManager(object):
     """Settings backend manager. This class manages orca user's settings
@@ -300,11 +302,18 @@ class SettingsManager(object):
         return not alreadyEnabled
 
     def isAccessibilityEnabled(self):
-        return a11yAppSettings.get_boolean("toolkit-accessibility")
+        return bool(_desktopProps.Get('org.a11y.Status', 'IsEnabled'))
 
     def setAccessibility(self, enable):
-        return a11yAppSettings.set_boolean(
-            "toolkit-accessibility", enable)
+        _desktopProps.Set('org.a11y.Status', 'IsEnabled', enable)
+        return True
+
+    def isScreenReaderServiceEnabled(self):
+        """Returns True if the screen reader service is enabled. Note that
+        this does not necessarily mean that Orca (or any other screen reader)
+        is running at the moment."""
+
+        return bool(_desktopProps.Get('org.a11y.Status', 'ScreenReaderEnabled'))
 
     def setStartingProfile(self, profile=None):
         if profile is None: