Allow preformatted background alpha and tidying to be set from child classes

[marecar3]

Fix

This PR adds a method that can change preformatted background alpha color from the child class
and also adds method which can control tidying in AztecParser (we want to avoid tidying for preblock.

Related PR's:
Gutenberg PR: WordPress/gutenberg#18777
Gutenberg-mobile PR: wordpress-mobile/gutenberg-mobile#1615
WPAndroid PR: wordpress-mobile/WordPress-Android#10868

Test

Test 1:

1. Run AztecEditor Demo app and check that background color isn't changed (should have 75% of alpha)
2. Run AztecEditor Demo app and check that <br> tags on the end of the text are removed from pre after app is started.

Test 2:

1. Run Gutenberg mobile PR: 1264 - Activate Preformatted block gutenberg-mobile#1442
   where value is set to 0, and see that background is transparent.
2. Run Gutenberg mobile PR: 1264 - Activate Preformatted block gutenberg-mobile#1442
   with pre block with multiple <br> tags on the end of the text and check that they aren't removed.

Review

@daniloercoli

Make sure strings will be translated:

• If there are new strings that have to be translated, I have added them to the client's strings.xml as a part of the integration PR.

[daniloercoli]

I hope I have tested the right hashes :) but i'm still seeing problems with the BR tags at the end of the PRE block.
I see that some of those BR tags are removed when opened in GB-Mobile. Below is a test Preformatted block i was using during tests:

<!-- wp:preformatted -->
<pre class="wp-block-preformatted">This is a prefortmatted block
not a new 


but not that old








d









</pre>
<!-- /wp:preformatted -->

and when loading it in GB-mobile i see the following (sorry for the low-res picture):

[daniloercoli]

Adding another thing i found on the problem reported above.

If i set the caret beside the d letter on the last line of text, last line before the empty line, and tap Enter.Key I see the caret going down and then back immediately beside the d letter.

[marecar3]

Adding another thing i found on the problem reported above.

If i set the caret beside the d letter on the last line of text, last line before the empty line, and tap Enter.Key I see the caret going down and then back immediately beside the d letter.

Hey Danilo, me and @mchowning have experienced a similar problem with quote block on the latest develop: wordpress-mobile/gutenberg-mobile#1555
Not 100% sure if the root cause is a same?

[marecar3]

I hope I have tested the right hashes :) but i'm still seeing problems with the BR tags at the end of the PRE block.
I see that some of those BR tags are removed when opened in GB-Mobile. Below is a test Preformatted block i was using during tests:

<!-- wp:preformatted -->
<pre class="wp-block-preformatted">This is a prefortmatted block
not a new 


but not that old








d









</pre>
<!-- /wp:preformatted -->

and when loading it in GB-mobile i see the following (sorry for the low-res picture):

Hey @daniloercoli, I have tested with your example:

and I didn't find that BR tags are removed when GB-mobile is loaded

[hypest]

Tried with WPAndroid and noticed an issue with these steps:

0. Start a post on the web with:

<!-- wp:preformatted -->
<pre class="wp-block-preformatted">just a text<br>line2<br></pre>
<!-- /wp:preformatted -->

1. Open the post in the mobile editor
2. Place the caret at the end of "line2"
3. Exit the editor without any actual editing
4. Notice the post marked as "Local changes"
5. Open the post again, it looks OK.
6. Switch to html and notice the <br>s are not there
   6b. Open the post on the web and notice a new autosave available. Check the revision viewer and notice that the <br>s have been replaced with newlines.

Is that <br> replacement expected?

[daniloercoli]

You are totally right @marecar3 - it was a problem on my side with me not updating the Aztec hash on WP-Android. I guess i messed up with things when pointing to your branches. Sorry about that.

I've also found another problem when merging an empty para block with the PRE block above.
See the video here: https://cloudup.com/cWRJW-rtDLm

Steps to repro:

1. Create a preformatted block with empty lines in it
2. Create new paragraph below it
3. Tap Backspace to merge those
4. You will see a preformatted paragraph with all the new lines/ br tags got removed

Edited: It seems the web is affected by the issue mentioned above. So not a problem introduced in this PR.

[SergioEstevao]

You are totally right @marecar3 - it was a problem on my side with me not updating the Aztec hash on WP-Android. I guess i messed up with things when pointing to your branches. Sorry about that.

I've also found another problem when merging an empty para block with the PRE block above.
See the video here: https://cloudup.com/cWRJW-rtDLm

Steps to repro:

1. Create a preformatted block with empty lines in it
2. Create new paragraph below it
3. Tap Backspace to merge those
4. You will see a preformatted paragraph with all the new lines/ br tags got removed

This is a problem in Gutenberg code base it also happens on the web.

[daniloercoli]

Oh yes, we have mentioned that on Slack on Friday, but forgot to update the description here.

At this point, if the parent PR passes testing phase we can merge this one.

[hypest]

I tried #869 (comment) again but now I see that if I re-open the post the editor red-screens with block validation error.

[marecar3]

👋 @hypest, if there are no new requests from your side, maybe we can merge this PR and start with a new tag release for Aztec Android?

[hypest]

LGTM Marko! Feel free to merge, create a release and update the WPAndroid and gutenberg-mobile PRs, thanks!

[hypest]

Oh, can you also link to the related WPAndroid and gutenberg-mobile PRs in the description @marecar3 ? Thanks!

[marecar3]

Oh, can you also link to the related WPAndroid and gutenberg-mobile PRs in the description @marecar3 ? Thanks!

Thanks for the hint. Now they are added.