Vi-style editor and other editor improvements (#40)

* WIP VI wrapper for editor

* WIP: block cursor

* Create Edit trait, run CI on all feature options

* Add prints describing build steps to ci.sh

* Custom rendering for Vi editor

* Clippy fixes

* More clippy fixes

* Show clippy results in CI

* Fix for Redox

* Fix clippy lint

* Add vi feature to enable vi-style editor

* Add escape to libcosmic text box

src/font/mod.rs

@@ -1,12 +1,54 @@
 // SPDX-License-Identifier: MIT OR Apache-2.0
 
-pub(crate) mod fallback;
+use core::ops::Deref;
 
-pub(crate) use self::font::*;
-mod font;
+pub(crate) mod fallback;
 
 pub use self::matches::*;
 mod matches;
 
 pub use self::system::*;
 mod system;
+
+pub struct Font<'a> {
+    pub info: &'a fontdb::FaceInfo,
+    pub data: &'a [u8],
+    pub rustybuzz: rustybuzz::Face<'a>,
+    #[cfg(feature = "swash")]
+    pub swash: (u32, swash::CacheKey),
+}
+
+impl<'a> Font<'a> {
+    pub fn new(info: &'a fontdb::FaceInfo) -> Option<Self> {
+        let data = match &info.source {
+            fontdb::Source::Binary(data) => data.deref().as_ref(),
+            #[cfg(feature = "std")]
+            fontdb::Source::File(path) => {
+                log::warn!("Unsupported fontdb Source::File('{}')", path.display());
+                return None;
+            }
+            #[cfg(feature = "std")]
+            fontdb::Source::SharedFile(_path, data) => data.deref().as_ref(),
+        };
+
+        Some(Self {
+            info,
+            data,
+            rustybuzz: rustybuzz::Face::from_slice(data, info.index)?,
+            #[cfg(feature = "swash")]
+            swash: {
+                let swash = swash::FontRef::from_index(data, info.index as usize)?;
+                (swash.offset, swash.key)
+            },
+        })
+    }
+
+    #[cfg(feature = "swash")]
+    pub fn as_swash(&self) -> swash::FontRef {
+        swash::FontRef {
+            data: self.data,
+            offset: self.swash.0,
+            key: self.swash.1,
+        }
+    }
+}