Fix margins in ListView

[patryk84a]

General items:

• I have updated the relevant documentation files under docs/
• My code follows the:
  • Google Java style guide (for .java files)
  • Google JavaScript style guide (for .js files)
• ant tests passes on my machine

If your code changes how something works on the device (i.e., it affects the companion):

• I branched from ucr
• My pull request has ucr as the base

Further, if you've changed the blocks language or another user-facing designer/blocks API (added a SimpleProperty, etc.):

• I have updated the corresponding version number in YaVersion.java
• I have updated the corresponding upgrader in YoungAndroidFormUpgrader.java (components only)
• I have updated the corresponding entries in versioning.js

For all other changes:

• I branched from master
• My pull request has master as the base

What does this PR accomplish?

Description

There was no implementation for setting margins in the horizontal layout of ListView. Therefore, the horizontal layout displayed margins incorrectly, adjusting them as for the vertical layout.

[AppInventorWorkerBee]

Can one of the admins verify this patch?

[patryk84a]

Why do I have 3 additional commits in this PR?

• I synced my fork's ucr branch with mit ucr
• I created a fix_margins branch from my fork ucr
• I made changes to the file and committed them to my fork's fix_margins
• then I created a PR

Did something go wrong or is this how it should be?

[ewpatton]

@AppInventorWorkerBee ok to test

[ewpatton]

@patryk84a It looks like because you used the Github-based merge (which creates a merge commit by default), your ucr branch got a bit out of sync with ours. Don't worry about this as we will squash merge this PR into a single commit once approved.

[patryk84a]

What do I need to do to revert my fork's ucr branch to its original state for future reference? Because now it shows me it's in sync.

[ewpatton]

@patryk84a Assuming you have origin set up to be your fork and upstream set up to be mit-cml's repo (this one):

git checkout ucr  # switch to your local ucr branch
git fetch upstream  # gets the latest MIT version
git reset --hard upstream/ucr  # makes your local ucr point to the same commit as our ucr
git push -f origin ucr  # force-push to reset the fork to match MIT and local

Note that the use of the force push is only really necessary because they aren't in sync. If you keep the branches clean, then you can do:

git checkout ucr
git pull --ff-only upstream ucr
git push  # assuming your local ucr is set to track origin/ucr
git push origin ucr  # otherwise...

[ewpatton]

So one issue with doing this here is that it seems to make the elements unbalanced. Here are two screen shots with the first and last elements of the list in horizontal layout mode. Note how the last element is flush with the edge whereas the first element isn't.

[patryk84a]

Yes, I focused on margins, not paying attention to element widths. To fix this we need to set the element width. I also added a screen orientation listener to update widths after screen rotation. I also simplified the code for setting margins for vertical layout, removing lines of code that I had tested with Grid layout before.

[patryk84a]

Now is good: