Allow multi key remappings in config file (#454)

* Use tree like structure to store keymaps

* Allow multi key keymaps in config file

* Allow multi key keymaps in insert mode

* Make keymap state self contained

* Add keymap! macro for ergonomic declaration

* Add descriptions for editor commands

* Allow keymap! to take multiple keys

* Restore infobox display

* Fix keymap merging and add infobox titles

* Fix and add tests for keymaps

* Clean up comments and apply suggestions

* Allow trailing commas in keymap!

* Remove mode suffixes from keymaps

* Preserve order of keys when showing infobox

* Make command descriptions smaller

* Strip infobox title prefix from items

* Strip infobox title prefix from items

3 files changed, 21 insertions, 11 deletions

diff --git a/helix-view/src/editor.rs b/helix-view/src/editor.rs
index cd9d0a92..7ff689df 100644
--- a/helix-view/src/editor.rs
+++ b/helix-view/src/editor.rs
@@ -1,7 +1,6 @@
 use crate::{
     clipboard::{get_clipboard_provider, ClipboardProvider},
     graphics::{CursorKind, Rect},
-    info::Info,
     theme::{self, Theme},
     tree::Tree,
     Document, DocumentId, RegisterSelection, View, ViewId,
@@ -33,7 +32,6 @@ pub struct Editor {
     pub syn_loader: Arc<syntax::Loader>,
     pub theme_loader: Arc<theme::Loader>,
 
-    pub autoinfo: Option<&'static Info>,
     pub status_msg: Option<(String, Severity)>,
 }
 
@@ -67,7 +65,6 @@ impl Editor {
             theme_loader: themes,
             registers: Registers::default(),
             clipboard_provider: get_clipboard_provider(),
-            autoinfo: None,
             status_msg: None,
         }
     }
diff --git a/helix-view/src/info.rs b/helix-view/src/info.rs
index f3df50fe..70e934cd 100644
--- a/helix-view/src/info.rs
+++ b/helix-view/src/info.rs
@@ -5,9 +5,9 @@ use std::fmt::Write;
 #[derive(Debug)]
 /// Info box used in editor. Rendering logic will be in other crate.
 pub struct Info {
-    /// Title kept as static str for now.
-    pub title: &'static str,
-    /// Text body, should contains newline.
+    /// Title shown at top.
+    pub title: String,
+    /// Text body, should contain newlines.
     pub text: String,
     /// Body width.
     pub width: u16,
@@ -16,17 +16,20 @@ pub struct Info {
 }
 
 impl Info {
-    pub fn key(title: &'static str, body: Vec<(&[KeyEvent], &'static str)>) -> Info {
+    // body is a BTreeMap instead of a HashMap because keymaps are represented
+    // with nested hashmaps with no ordering, and each invocation of infobox would
+    // show different orders of items
+    pub fn key(title: &str, body: Vec<(&str, Vec<KeyEvent>)>) -> Info {
         let (lpad, mpad, rpad) = (1, 2, 1);
         let keymaps_width: u16 = body
             .iter()
-            .map(|r| r.0.iter().map(|e| e.width() as u16 + 2).sum::<u16>() - 2)
+            .map(|r| r.1.iter().map(|e| e.width() as u16 + 2).sum::<u16>() - 2)
             .max()
             .unwrap();
         let mut text = String::new();
         let mut width = 0;
         let height = body.len() as u16;
-        for (keyevents, desc) in body {
+        for (desc, keyevents) in body {
             let keyevent = keyevents[0];
             let mut left = keymaps_width - keyevent.width() as u16;
             for _ in 0..lpad {
@@ -48,7 +51,7 @@ impl Info {
             writeln!(text, "{}", desc).ok();
         }
         Info {
-            title,
+            title: title.to_string(),
             text,
             width,
             height,
diff --git a/helix-view/src/input.rs b/helix-view/src/input.rs
index 2847bb69..8d9ee6fb 100644
--- a/helix-view/src/input.rs
+++ b/helix-view/src/input.rs
@@ -14,6 +14,16 @@ pub struct KeyEvent {
     pub modifiers: KeyModifiers,
 }
 
+impl KeyEvent {
+    /// Get only the character involved in this event
+    pub fn char(&self) -> Option<char> {
+        match self.code {
+            KeyCode::Char(ch) => Some(ch),
+            _ => None,
+        }
+    }
+}
+
 pub(crate) mod keys {
     pub(crate) const BACKSPACE: &str = "backspace";
     pub(crate) const ENTER: &str = "ret";
@@ -168,7 +178,7 @@ impl std::str::FromStr for KeyEvent {
             keys::MINUS => KeyCode::Char('-'),
             keys::SEMICOLON => KeyCode::Char(';'),
             keys::PERCENT => KeyCode::Char('%'),
-            single if single.len() == 1 => KeyCode::Char(single.chars().next().unwrap()),
+            single if single.chars().count() == 1 => KeyCode::Char(single.chars().next().unwrap()),
             function if function.len() > 1 && function.starts_with('F') => {
                 let function: String = function.chars().skip(1).collect();
                 let function = str::parse::<u8>(&function)?;