Add Emoji support to chat

[thechauffeur]

Android ppl send nice emojis and I can't see them. That makes me sad ;-(

[enkore]

I can see them. Perhaps a font issue? (#520 is probably also a font issue).

Bundle the GUI fonts with the app to avoid platform inconsistencies?

[audax]

It is just a font thing. Also, desktop keyboards usually don't have emoji buttons, so that's definitly something we should address.

[enkore]

Spike: Check if fallback font is possible.

Choose new font (po).

[enkore]

Note: this is still required even with our move to double-dot emojis (Qabel/qabel-android#759), because Android users can still send UTF-8 emoijs

[julianseeger]

FTR.: this does not happen when using the desktop client with ubuntu

[enkore]

The missing emojis or #520? (nb both have the same image)

[julianseeger]

The emojis. It doesn't even happen if launched from the IDE while using Windows. I think we just need to get the encoding of dropmessages right by always using explicit encoding when transforming Byte Arrays to Strings

[julianseeger]

emojis are fully working on the testdevice btw:

[julianseeger]

Do we still have any device that doesn't handle emojis? Need to reproduce what ever goes wrong, without that it could be anything.

[julianseeger]

To answer the original question: I couldn't get a fallback font working for single characters. In my tests, it either picked the first font or used the system fallback font (Segoe UI on Windows and Lucida Grande on MacOS with the addition that colored / image based fonts like Segoe UI Emoji can't be rendered). So we either have to rely on not using MacOS or on a emoji supporting default font like OpenSansEmoji (currently we are using Source Sans Pro which doesn't seem to contain emojis). Or we don't care and just replace them with images.

From left to right: OpenSansEmoji with Source Sans Pro as fallback font none defined (javafx windows default) Source Sans Pro with OpenSansEmoji as fallback font