Merge ubiquity:sil2100/screen-reader-target-system into ubiquity:master

[Łukasz Zemczak]

Make sure the screen-reader-enabled setting gets passed to the target system - by setting UBIQUITY_A11Y_PROFILE so that the casper accessibility hook can pick it up

Make sure the screen-reader-enabled setting gets passed to the target system - by setting UBIQUITY_A11Y_PROFILE so that he casper accessibility hook can pick it up.

Previously, when we had unity and lightdm, there was a listener taking care of setting UBIQUITY_A11Y_PROFILE on screen-reader switch-on. Since long this is no longer valid, so it never worked. Setting of the env variable then gets forwarded to the
30accessibility hook from casper.

[Michael Hudson-Doyle (mwhudson)]

This seems fine, I guess. There's a typo in the commit message (he->the).

[Michael Hudson-Doyle (mwhudson)]

review: Approve

[Mathieu Trudel-Lapierre (cyphermox)]

review: Approve

[Łukasz Zemczak (sil2100)]

Fixed the commit message, thanks! As for your inline comment: the environment variable is only used for this very purpose (only for the screen reader), it's an env that's only shared between ubiquity and the casper hook. So I guessed that if orca is not installed, it anyway makes no sense to make the hook do anything. There is no risk of us disabling something that was supposed to be enabled.
Let me merge it then!

diff --git a/ubiquity/frontend/gtk_ui.py b/ubiquity/frontend/gtk_ui.py
index 61df505..a04e3a5 100644
--- a/ubiquity/frontend/gtk_ui.py
+++ b/ubiquity/frontend/gtk_ui.py
@@ -162,9 +162,16 @@ class Controller(ubiquity.frontend.base.Controller):
 
 def on_screen_reader_enabled_changed(gsettings, key):
     # handle starting orca only, it exits itself when the key is false
-    if (key == "screen-reader-enabled" and gsettings.get_boolean(key) and
-       osextras.find_on_path('orca')):
-        subprocess.Popen(['orca'], preexec_fn=misc.drop_all_privileges)
+    if key == "screen-reader-enabled":
+        # Besides starting orca, also make sure the screen-reader-enabled
+        # setting gets passed to the target system.
+        if (gsettings.get_boolean(key) and osextras.find_on_path('orca')):
+            # Enable
+            subprocess.Popen(['orca'], preexec_fn=misc.drop_all_privileges)
+            os.environ['UBIQUITY_A11Y_PROFILE'] = 'screen-reader'
+        elif 'UBIQUITY_A11Y_PROFILE' in os.environ:
+            # Disable
+            del os.environ['UBIQUITY_A11Y_PROFILE']
 
 
 class Wizard(BaseFrontend):