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Submitter:

Can you please provide a brief text explanation of:

1. What is the summary of the issue you're seeing
2. What is the expected behavior
3. What is the actual behavior
4. What software is showing the bug. What version of software are you reporting it against
5. What operating system are you running (android version, device)
6. If an app integration, what version of emojicompat or emoji2 are you linking against.

Thanks!

Thanks for the report.

On which Android version does canvas.drawText() not support emoji?

Since you mentioned that you switched to AppCompat, I wonder if the issue is: on an older android version, newer emoji does not render via canvas.drawText()?

Hi,

We are using the following version of AppCompat:

implementation 'androidx.appcompat:appcompat:1.4.0-alpha01'

The screenshots are taken from the Android emulator running Android API 30.

Apologies it wasn't from the emulator, it was a Samsung S20 running Android 11.

Let me separate a few concerns here:

• Policy

  • canvas.drawText is platform code, and starting from Android 12 should update to the new emoji automatically and if nothing in the string is changed (i.e. replacement spans for supporting custom emoji) it should work.
  • The policy mentions that "Apps running on Android 12 and above must comply with the latest Unicode version within 4 months of public availability.". Therefore it applies to Android 12 and above.
  • I suspect the drawText function you mentioned does not show new emoji on an older device.

• Being able to render emoji using EmojiCompat on all android versions

  • If the text you pass to drawText is a Spannable that is processed by EmojiCompat and the emoji spans are added, currently canvas.drawText will not be able to draw those since it discards the spans the last time I checked. It might be possible to draw render some spans but there is no support.
  • On the current state, StaticLayout is the one that can draw the Span's. Is it (code wise, or performance wise) possible to use a StaticLayout instead of drawText in your use case?

As a side note: It might be possible to create a compat class/code that will draw at least the known some of the known spans (not the spans such as line height etc).

Thank you. I can confirm that on a device running Android 12 the emojis show correctly using canvas.drawText(). (see android_12_emoji.jpg)

I will look into the methods stated to support the emojis running on older devices.

Can we add emojicompat support to Canvas.drawText().

Short answer: Not directly Longer answer: We would have to do this as a ktx library, which won't allow extensions on Canvas.

How can you draw emoji today on a Canvas

1. EmojiCompat.process(str); add emoji spans
2. Layout result of #1 using StaticLayout directly StaticLayout.Builder
3. Use StaticLayout.draw(canvas) Layout.draw

StaticLayout is required to draw spans correctly, and it looks like the existing drawText overloads don't use it cs

Can we add something to EmojiCompat to do the above?

Yes. What sort of API are you interested in?

Thanks,

Sean

Hi Sean,

I have done some testing and the methodology you've described works well. There was an emojis that rendered incorrectly: 👭 (screenshots attached of what it should look like) but otherwise it looked good.

I'll need to do some research into this EmojiCompat library. I used: EmojiCompat.init(BundledEmojiCompatConfig(context)) so maybe this is why the emoji above didn't render properly. I also called val emojiProcessText = EmojiCompat.get().process(iconLabel) straight after and it kept failing saying that EmojiCompat wasn't initialised so I had to put a Thread.sleep(1000) in between for testing purposes.

I also note that in the documentation it says this BundledEmojiCompatConfig is 10MB so will have to research into an alternative method.

I think for now this method would be fine for me, the current difficulty is around the initialisation and setup of EmojiCompat, which is just spending more time looking at the documentation (time isn't on my side sorry), so an extension to EmojiCompat wouldn't really help me much versus the method you've described.