catch and report TTS errors

[stephankn]

Purpose / Description

implement onError() to report a Toast with some hints to the user
in case the TTS engine returns an error.

From API 21 upwards we would also have the error code available
for further details on what happened.

Fixes

fixes #5468

Approach

report a Toast

How Has This Been Tested?

Tested on emulator

Checklist

• You have not changed whitespace unnecessarily (it makes diffs hard to read)
• You have a descriptive commit message with a short title (first line, max 50 chars).
• Your code follows the style of the project (e.g. never omit braces in if statements)
• You have commented your code, particularly in hard-to-understand areas
• You have performed a self-review of your own code

[timrae]

Too bad that we don't get the error code. Theoretically it should be available on higher APIs, however when I inspected the Android source code, it seemed that the non-deprecated callback is never called. Maybe I'm just looking in the wrong place? :/

[stephankn]

Too bad that we don't get the error code. Theoretically it should be available on higher APIs, however when I inspected the Android source code, it seemed that the non-deprecated callback is never called. Maybe I'm just looking in the wrong place? :/

I guess I ended up at the same location than you when checking the source code. This was the point when I told to myself "I don't understand the API deprecation concept of Android".
Probably we would have to override the calling code as well, depending on the API level?
I feel uncomfortable doing that change.

The error codes are probably not that important anyways. At this point you already know that the problem happened outside of the scope of Anki. If simply re-installing the TTS does not help, then Android TTS needs to be debugged. Maybe attaching the phone to a PC and reading the logs with ADB is the way to go then. But as said, this is beyond the scope of Anki, as TTS is globally broken.

[stephankn]

please review again. Travis fail does not sound related to my change.

[mikehardy]

agreed re: Travis - that's an area of current work for me, I'm manually shepherding CI status on this PR to both see what flakes on it and make sure it goes green

[mikehardy]

Travis was suffering through a "Major Outage" on their Google Compute Engine services, which is where our builds are routed in their system, complicating matters. CI's green now