Fix notification background image not showing on when the device has a RTL set

[jkasten2]

Description

One Line Summary

Fix notification background image not showing on when the device has a RTL language set and the app's AndroidManifest.xml has RTL support enabled.

Details

Motivation

Setting a custom background image for notifications is a supported feature only through the REST API, is limited in features, and Android 12 has limited customizability. However OneSignal currently supports this feature and it should remind free of common/high impact bugs.

Scope

Only affects the display of notifications when the following is true:

• Sent through the OneSignal REST API
• Includes android_background_layout in the payload.
• The AndroidManifest.xml has android:supportsRtl="true"
• The device has set a RTL language
  • Or Dev options > Drawing > "Force RTL layout direction" is enabled

This PR only affects the background image render. Changes / fixes to the title or body text is out of scope for this PR.

• Keeping this PR as small as possible for a quicker turn around time as possible since it can result in a completely unreadable notification. A fix for rendering text in the in the correct direction for RTL is part of PR Fix notification background image layouts to render text RTL based on the device's language setting #1474.

Android 4.1 (API 16) is out of scope, since android:layoutDirection was introduced in Android API level 17.

• This might be ok, as this issue may not have existed on this version of android anyway.

What was the bug?

When the a notification background image is set and the RTL conditions are meet, notifications becoming a sold color (all known instances have been a white background). The text may or not be visible, but depends on the text color and that the resulting background.

On LTR devices notifications looks like this:

On RTL devices notifications looks like this:

Why the bug was happening?

When RTL is set it moves all elements to the right, not just text elements.

How the bug was fixed?

Set android:layoutDirection="ltr" on the layout used for the background image so it isn't influenced by the language direction.

Testing

Unit testing

N/A, only a visual layout change.

Manual testing

Tested the Example app included in this repo (it has android:supportsRtl="true") and set "Force RTL layout direction" on the device. Also tested w/o "Force RTL layout direction", to make sure it remained working.
Test on:

• LG G7 with Android 9
• Android 10 Emulator
• Android 5.0 Emulator

Screenshot after fix

Android 10 Emulator with English with "Force RTL layout direction" enabled:

• Odd resized image on the 2nd notification was indented, was done as a quick size test
• Text itself didn't change RTL, but not in this scope of this PR.

Affected code checklist

• Notifications
  • Display
  • Open
  • Push Processing
  • Confirm Deliveries
• Outcomes
• Sessions
• In-App Messaging
• REST API requests
• Public API changes

Checklist

Overview

• I have filled out all REQUIRED sections above
• PR does one thing
  • If it is hard to explain how any codes changes are related to each other then it most likely needs to be more than one PR
• Any Public API changes are explained in the PR details and conform to existing APIs

Testing

• I have included test coverage for these changes, or explained why they are not needed
• All automated tests pass, or I explained why that is not possible
• I have personally tested this on my device, or explained why that is not possible

Final pass

• Code is as readable as possible.
  • Simplify with less code, followed by splitting up code into well named functions and variables, followed by adding comments to the code.
• I have reviewed this PR myself, ensuring it meets each checklist item
  • WIP (Work In Progress) is ok, but explain what is still in progress and what you would like feedback on. Start the PR title with "WIP" to indicate this.

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This change is 

[nan-li]

Reviewed 1 of 1 files at r1, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @adamschlesinger and @emawby)

[nan-li]

Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @adamschlesinger and @emawby)