User Guide: Indicate incompatibility of screen curtain with inverted colors in the Magnifier

[CyrilleB79]

Link to issue number:

Partial fix for #10545

Summary of the issue:

Screen curtain cannot be activated while Windows Magnifier is running with inverted screen colors.
An error message can be heard when trying to activate the screen curtain.
Though, this incompatibility is not documented in the User Guide.

Description of user facing changes

Update the User Guide.

Description of development approach

N/A

Testing strategy:

Check User Guide.

Known issues with pull request:

None

Code Review Checklist:

• Documentation:
  • Change log entry
  • User Documentation
  • Developer / Technical Documentation
  • Context sensitive help for GUI changes
• Testing:
  • Unit tests
  • System (end to end) tests
  • Manual testing
• UX of all users considered:
  • Speech
  • Braille
  • Low Vision
  • Different web browsers
  • Localization in other languages / culture than English
• API is compatible with existing add-ons.
• Security precautions taken.

[seanbudd]

I don't think this should close #10545. While its good to document this behaviour, I think #12701 is needed to close #10545. Thoughts?

[seanbudd]

Is there a UX message or just an error sound when screen curtain fails to activate?

[Qchristensen]

When trying to enable screen curtain with Magnifier on (windows+numpad plus) and set to invert colours (control+alt+i), NVDA speaks "Could not enable screen curtain". No error dialog is presented. The follow log fragment is generated:

IO - inputCore.InputManager.executeGesture (11:42:00.359) - winInputHook (14740):
Input: kb(desktop):control+NVDA+escape
DEBUG - visionEnhancementProviders.screenCurtain.ScreenCurtainProvider.init (11:42:00.361) - MainThread (5216):
Starting ScreenCurtain
WARNING - vision.visionHandler.VisionHandler.initializeProvider (11:42:00.361) - MainThread (5216):
Error initialising screenCurtain. Disabling in config.
ERROR - globalCommands._enableScreenCurtain (11:42:00.361) - MainThread (5216):
Screen curtain initialization error
Traceback (most recent call last):
File "globalCommands.pyc", line 4332, in _enableScreenCurtain
File "vision\visionHandler.pyc", line 261, in initializeProvider
File "vision\visionHandler.pyc", line 256, in initializeProvider
File "visionEnhancementProviders\screenCurtain.pyc", line 354, in init
File "visionEnhancementProviders\screenCurtain.pyc", line 350, in init
File "visionEnhancementProviders\screenCurtain.pyc", line 42, in _errCheck
OSError: [WinError 87] The parameter is incorrect.
IO - speech.speech.speak (11:42:00.378) - MainThread (5216):
Speaking [LangChangeCommand ('en_GB'), 'Could not enable screen curtain']

[Qchristensen]

User guide text reads well

[CyrilleB79]

There are 4 ways to activate screen curtain:

• using the gesture (now NVDA+control+escape): a ui.message reports "Could not enable screen curtain"
• checking the checkbox in Vision settings: an error dialog box is displayed
• triggered by profile switching: nothing is reported; only error ding can be heard in test builds
• when starting NVDA: nothing is reported; only error ding can be heard in test builds

I agree that #10545 should remain open until something is reported in these four cases. #12701 may be a solution but another solution based on error catching in the two last cases is also acceptable IMO; What do you think?

In any case, I have updated the initial description to remove the auto-closing word so that the documentation update can already be merged.