Support for non-Latin languages

[koutheir]

Is there an existing issue for this?

• [X] I have searched the existing issues.

Is this issue related to iced?

• [X] My hardware is compatible and my graphics drivers are up-to-date.

What happened?

Running the tour package, and typing Arabic text on the Text input page, displays squared interrogation point characters.

$ cargo run --package tour

What is the expected behavior?

Arabic text should be displayed correctly.

Version

master

Operative System

Linux

Do you have any log output?

No response

[ids1024]

I believe with the default_system_font feature enabled, this should at least be able to find a font with the appropriate characters?

Though Arabic text still won't be right without RTL support (https://github.com/iced-rs/iced/issues/250) and text shaping (https://github.com/iced-rs/iced/issues/33).

[koutheir]

I added default_system_font to the iced features in iced/examples/tour/Cargo.toml:

[dependencies]
iced = { path = "../..", features = ["image", "debug", "default_system_font"] }
env_logger = "0.8"

and then run:

$ cargo run --package tour

But no Arabic characters are displayed properly.

[adals]

I added default_system_font to the iced features in iced/examples/tour/Cargo.toml:

i think that your problem is lacking a font that contains the relevant glyphs.

but RTL is still not supported yet

[koutheir]

i think that your problem is lacking a font that contains the relevant glyphs.

I disagree, as I routinely write Arabic text in other applications (libreoffice, kate, etc.) and I don't have any font issues.

[mmstick]

@koutheir Check this out! https://github.com/pop-os/libcosmic/pull/12 Please try out Arabic in the text example and help locate bugs in the rendering.

[ids1024]

i think that your problem is lacking a font that contains the relevant glyphs.

I think Iced isn't implementing fallback font behavior, which is normally used to find a font for a different writing system. So that's why it doesn't find a font with the right gylphs.

Luckily this (as well as text shaping and RTL) is being prototyped in libcosmic as mentioned, and hopefully will be integrated into Iced soon.

[koutheir]

Check this out! https://github.com/pop-os/libcosmic/pull/12 Please try out Arabic in the text example and help locate bugs in the rendering.

Running the following command panics:

$ cargo run --package cosmic
<...>
     Running `target/debug/cosmic`
icon 'go-previous-symbolic' size 24 not found
icon 'window-minimize-symbolic' size 16 not found
icon 'window-maximize-symbolic' size 16 not found
icon 'window-close-symbolic' size 16 not found
icon 'network-wireless' size 20 not found
icon 'preferences-desktop' size 20 not found
icon 'system-software-update' size 20 not found
thread 'main' panicked at 'Downcast on stateless state', /home/koutheir/.cargo/git/checkouts/iced-14fbad96f5d3e3c7/7461b82/native/src/widget/tree.rs:172:28
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Running the following command works:

$ cargo run --package text

The Arabic letters are rendered correctly, and selecting them with the mouse and moving between the characters works as I expect.

However, using the Right and Left keyboard keys works logically, instead of visually, i.e., the Left key moves to the right, and vice versa, and that feels weird. I don't know if that's intended or it is an issue.