IssueTracker

Nona'san can you prioritize this ticket please? I believe we had some ideas about when and how to support this, but I do not know the priority for Anastasia.

Uploaded a CL https://android-review.googlesource.com/c/platform/frameworks/support/+/1289555

This CL just passes down the maxLines parameter to the underlying TextDelegate class. This won't do anything if overflow happens. We need to decide which layer takes responsibility of overflow scrolling since either clipping or ellipsis doesn't work for TextField.

Nona, Siyamed,

I think what we need for FilledTextField is a bit different - here is the ticket b/152973638.

I pushed back the CL since it was not clear the expected behavior. We need to define the behavior first, or even we may drop maxLines from TextField.

I checked the resources Anastasia pointed.

The following are use cases from the material perspective:

• single line Textfield (scrolls horizontally)
• multi-line and growing TextField (grows as text does not fit)
• multi-line fixed height TextField (scrolls)

I want to add the following to this list:

• multi-line growing TextField until a height is reached

I checked CSS a bunch, however the amount of attributes related to line clamp behavior is a lot. Some related attrbutes are

• whitespace
• line-clamp
• max-lines

As far I understood input(type=text) is single line, and textarea is multi line in html

• text-area has rows and cols attribute where rows match to height in terms of lines

One of concerns I have (applies to Text(maxLines) as well) is providing the maximum0 height in terms of line height can be done using a modifier

• option a: by converting max lines or lines to from sp to dp
• option b: by providing a modifier that does it for API user.

If we were to assume that sp will be converted to dp, we will need to make sure that the line height can be identified before the composition.

Some nites: From the perspective of TextField:

• single line is an important configuration since we also have to inform IME about this
• we can provide a "lines" attribute/modifier with the semantics of the visual height will be that many lines
• I am not sure if "lines=1" would be singleLine semantics
• we can provide a "maxLines" attribute/modifier with the semantics of the visual height will be at most that many lines

comment copied from b/167396627

FYI scrolling behaviour WIP CL https://android-review.googlesource.com/c/platform/frameworks/support/+/1394667. It's planned to be moved into CoreTextField or BaseTextField (I couldn't do it earlier because cursor was not in coretextfield). We discussed it a few syncs ago and I mentioned that one frame lag was not an issue in my prototype CL.

Please let me know if you're adding the scrolling behaviour, or whether I should continue working on my CL. As I don't want us to do the duplicate work :)