[SuperEditor] - Fix selection highlight alignment for RTL languages

[mohamadlounnas]

before:

after the fix:

[matthew-carroll]

@mohamadlounnas I see that you added a Positioned widget, but I have no idea why that fixed anything.

Can you please describe the root of the problem, and why a Positioned widget solves it?

[mohamadlounnas]

@mohamadlounnas I see that you added a Positioned widget, but I have no idea why that fixed anything.

Can you please describe the root of the problem, and why a Positioned widget solves it?

Hey @matthew-carroll,

The issue occurs when selecting RTL text ,the highlight is flipped because RTL text itself is mirrored, causing the highlight to start from -100%:

You can try it yourself. I fixed it by forcing the highlight layer to stay within the positive area of the stack, as shown in the image:

[matthew-carroll]

@angelosilvestre can you check on the root cause for this? I'm skeptical that the correct solution is to add a Positioned widget, but I'm still not sure what the root cause of this really is.

[mohamadlounnas]

@angelosilvestre can you check on the root cause for this? I'm skeptical that the correct solution is to add a Positioned widget, but I'm still not sure what the root cause of this really is.

The main issue is that CustomPainter starts drawing from left to right only, and currently has no inherent size (0,0). In RTL mode, this causes it to stick to the top right and begin drawing from there towards the right.

To fix this, we can use Positioned (as i did) to enforce constraints on its children or wrap the CustomPainter with a SizedBox set to width: double.infinity to ensure it receives constraints

[mohamadlounnas]

Since the issue originates from super_text_layout (and it may also be used in other projects), I think it's better to fix it within that package.

For now, wrapping it with SizedBox.shrink seems to resolve the problem.
new pull request: #2638