View tree implementation: render multiple split views.

Cursors are still a bit buggy and we should render in focus statusbar
differently than in the other pane.

4 files changed, 21 insertions, 26 deletions

diff --git a/helix-view/Cargo.toml b/helix-view/Cargo.toml
index 0a435811..938f35e5 100644
--- a/helix-view/Cargo.toml
+++ b/helix-view/Cargo.toml
@@ -24,3 +24,5 @@ url = "2"
 
 smol = "1"
 futures-util = "0.3"
+
+slotmap = "1"
diff --git a/helix-view/src/editor.rs b/helix-view/src/editor.rs
index 54a098f9..eb745066 100644
--- a/helix-view/src/editor.rs
+++ b/helix-view/src/editor.rs
@@ -1,45 +1,36 @@
 use crate::theme::Theme;
+use crate::tree::Tree;
 use crate::{Document, View};
+use slotmap::DefaultKey as Key;
 
 use std::path::PathBuf;
 
 use anyhow::Error;
 
 pub struct Editor {
-    pub views: Vec<View>,
-    pub focus: usize,
+    pub tree: Tree,
+    // pub documents: Vec<Document>,
+    pub focus: Key,
     pub should_close: bool,
     pub theme: Theme, // TODO: share one instance
     pub language_servers: helix_lsp::Registry,
 }
 
-impl Default for Editor {
-    fn default() -> Self {
-        Self::new()
-    }
-}
-
 impl Editor {
-    pub fn new() -> Self {
+    pub fn new(area: tui::layout::Rect) -> Self {
         let theme = Theme::default();
         let language_servers = helix_lsp::Registry::new();
 
         Self {
-            views: Vec::new(),
-            focus: 0,
+            tree: Tree::new(area),
+            focus: Key::default(),
             should_close: false,
             theme,
             language_servers,
         }
     }
 
-    pub fn open(
-        &mut self,
-        path: PathBuf,
-        size: (u16, u16),
-        executor: &smol::Executor,
-    ) -> Result<(), Error> {
-        let pos = self.views.len();
+    pub fn open(&mut self, path: PathBuf, executor: &smol::Executor) -> Result<(), Error> {
         let mut doc = Document::load(path, self.theme.scopes())?;
 
         // try to find a language server based on the language name
@@ -60,16 +51,17 @@ impl Editor {
             .unwrap();
         }
 
-        self.views.push(View::new(doc, size)?);
+        let view = View::new(doc)?;
+        let pos = self.tree.insert(view);
         self.focus = pos;
         Ok(())
     }
 
     pub fn view(&self) -> &View {
-        self.views.get(self.focus).unwrap()
+        self.tree.get(self.focus)
     }
 
     pub fn view_mut(&mut self) -> &mut View {
-        self.views.get_mut(self.focus).unwrap()
+        self.tree.get_mut(self.focus)
     }
 }
diff --git a/helix-view/src/lib.rs b/helix-view/src/lib.rs
index f28c8116..05de7e9f 100644
--- a/helix-view/src/lib.rs
+++ b/helix-view/src/lib.rs
@@ -1,6 +1,7 @@
 pub mod document;
 pub mod editor;
 pub mod theme;
+pub mod tree;
 pub mod view;
 
 pub use document::Document;
diff --git a/helix-view/src/view.rs b/helix-view/src/view.rs
index df41e3ae..24b50d81 100644
--- a/helix-view/src/view.rs
+++ b/helix-view/src/view.rs
@@ -17,15 +17,15 @@ pub const PADDING: usize = 5;
 pub struct View {
     pub doc: Document,
     pub first_line: usize,
-    pub size: (u16, u16),
+    pub area: Rect,
 }
 
 impl View {
-    pub fn new(doc: Document, size: (u16, u16)) -> Result<Self, Error> {
+    pub fn new(doc: Document) -> Result<Self, Error> {
         let view = Self {
             doc,
             first_line: 0,
-            size,
+            area: Rect::default(), // will get calculated upon inserting into tree
         };
 
         Ok(view)
@@ -34,7 +34,7 @@ impl View {
     pub fn ensure_cursor_in_view(&mut self) {
         let cursor = self.doc.state.selection().cursor();
         let line = self.doc.text().char_to_line(cursor);
-        let document_end = self.first_line + (self.size.1 as usize).saturating_sub(2);
+        let document_end = self.first_line + (self.area.height as usize).saturating_sub(2);
 
         // TODO: side scroll
 
@@ -50,7 +50,7 @@ impl View {
     /// Calculates the last visible line on screen
     #[inline]
     pub fn last_line(&self) -> usize {
-        let viewport = Rect::new(6, 0, self.size.0, self.size.1 - 2); // - 2 for statusline and prompt
+        let viewport = Rect::new(6, 0, self.area.width, self.area.height - 2); // - 2 for statusline and prompt
         std::cmp::min(
             self.first_line + (viewport.height as usize),
             self.doc.text().len_lines() - 1,