Merge pull request #3 from helix-editor/goto-implementation

Goto mode implementation

8 files changed, 1133 insertions, 20 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 7253b7fd..68870ef6 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -225,6 +225,7 @@ checksum = "4bd1061998a501ee7d4b6d449020df3266ca3124b941ec56cf2005c3779ca142"
 dependencies = [
  "bitflags",
  "indexmap",
+ "lazy_static",
  "os_str_bytes",
  "textwrap",
  "unicode-width",
diff --git a/helix-core/src/state.rs b/helix-core/src/state.rs
index 36ca221c..047ff83d 100644
--- a/helix-core/src/state.rs
+++ b/helix-core/src/state.rs
@@ -9,6 +9,7 @@ use std::path::PathBuf;
 pub enum Mode {
     Normal,
     Insert,
+    Goto,
 }
 
 /// A state represents the current editor state of a single buffer.
@@ -287,9 +288,6 @@ impl State {
     }
 }
 
-/// Coordinates are a 0-indexed line and column pair.
-pub type Coords = (usize, usize); // line, col
-
 /// Convert a character index to (line, column) coordinates.
 pub fn coords_at_pos(text: &RopeSlice, pos: usize) -> Position {
     let line = text.char_to_line(pos);
diff --git a/helix-core/src/syntax.rs b/helix-core/src/syntax.rs
index 638ec8ee..3e5927e5 100644
--- a/helix-core/src/syntax.rs
+++ b/helix-core/src/syntax.rs
@@ -312,7 +312,7 @@ pub struct LanguageLayer {
     tree: Option<Tree>,
 }
 
-use crate::state::{coords_at_pos, Coords};
+use crate::state::coords_at_pos;
 use crate::transaction::{ChangeSet, Operation};
 use crate::Tendril;
 
diff --git a/helix-term/src/editor.rs b/helix-term/src/editor.rs
index 70b5758e..09d66c5a 100644
--- a/helix-term/src/editor.rs
+++ b/helix-term/src/editor.rs
@@ -87,7 +87,7 @@ impl Editor {
                 // TODO: inefficient, should feed chunks.iter() to tree_sitter.parse_with(|offset, pos|)
                 let source_code = view.state.doc().to_string();
 
-                let last_line = view.last_line(viewport);
+                let last_line = view.last_line();
 
                 let range = {
                     // calculate viewport byte ranges
@@ -219,7 +219,7 @@ impl Editor {
                 }
 
                 let style: Style = view.theme.get("ui.linenr");
-                for (i, line) in (view.first_line..(last_line as u16)).enumerate() {
+                for (i, line) in (view.first_line..last_line).enumerate() {
                     self.surface
                         .set_stringn(0, i as u16, format!("{:>5}", line + 1), 5, style);
                     // lavender
@@ -254,6 +254,7 @@ impl Editor {
                 let mode = match view.state.mode() {
                     Mode::Insert => "INS",
                     Mode::Normal => "NOR",
+                    Mode::Goto => "GOTO",
                 };
                 self.surface.set_style(
                     Rect::new(0, self.size.1 - 1, self.size.0, 1),
@@ -278,13 +279,14 @@ impl Editor {
                 match view.state.mode() {
                     Mode::Insert => write!(stdout, "\x1B[6 q"),
                     Mode::Normal => write!(stdout, "\x1B[2 q"),
+                    Mode::Goto => write!(stdout, "\x1B[2 q"),
                 };
 
                 // render the cursor
                 let pos = view.state.selection().cursor();
 
                 let pos = view
-                    .screen_coords_at_pos(&view.state.doc().slice(..), pos, area)
+                    .screen_coords_at_pos(&view.state.doc().slice(..), pos)
                     .expect("Cursor is out of bounds.");
 
                 execute!(
@@ -326,6 +328,7 @@ impl Editor {
                 }))) => {
                     break;
                 }
+
                 Some(Ok(Event::Key(event))) => {
                     if let Some(view) = &mut self.view {
                         match view.state.mode() {
@@ -359,6 +362,19 @@ impl Editor {
                                     self.render();
                                 }
                             }
+                            Mode::Goto => {
+                                // TODO: handle modes and sequences (`gg`)
+                                let keys = vec![event];
+                                if let Some(command) = keymap[&Mode::Goto].get(&keys) {
+                                    // TODO: handle count other than 1
+                                    command(view, 1);
+
+                                    // TODO: simplistic ensure cursor in view for now
+                                    view.ensure_cursor_in_view();
+
+                                    self.render();
+                                }
+                            }
                         }
                     }
                 }
diff --git a/helix-term/test.txt b/helix-term/test.txt
new file mode 100644
index 00000000..11798245
--- /dev/null
+++ b/helix-term/test.txt
@@ -0,0 +1,1000 @@
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diff --git a/helix-view/src/commands.rs b/helix-view/src/commands.rs
index 6dd1101c..19853c37 100644
--- a/helix-view/src/commands.rs
+++ b/helix-view/src/commands.rs
@@ -13,6 +13,8 @@ use crate::view::View;
 /// state (usually by creating and applying a transaction).
 pub type Command = fn(view: &mut View, count: usize);
 
+const PADDING: usize = 5;
+
 pub fn move_char_left(view: &mut View, count: usize) {
     // TODO: use a transaction
     let selection = view
@@ -117,6 +119,74 @@ pub fn move_next_word_end(view: &mut View, count: usize) {
     view.state.selection = Selection::single(pos, pos);
 }
 
+pub fn move_file_start(view: &mut View, _count: usize) {
+    // TODO: use a transaction
+    view.state.selection = Selection::single(0, 0);
+
+    view.state.mode = Mode::Normal;
+}
+
+pub fn move_file_end(view: &mut View, _count: usize) {
+    // TODO: use a transaction
+    let text = &view.state.doc;
+    let last_line = text.line_to_char(text.len_lines().saturating_sub(2));
+    view.state.selection = Selection::single(last_line, last_line);
+
+    view.state.mode = Mode::Normal;
+}
+
+pub fn check_cursor_in_view(view: &mut View) -> bool {
+    let cursor = view.state.selection().cursor();
+    let line = view.state.doc().char_to_line(cursor);
+    let document_end = view.first_line + view.size.1.saturating_sub(1) as usize;
+
+    if (line > document_end.saturating_sub(PADDING)) | (line < view.first_line + PADDING) {
+        return false;
+    }
+    true
+}
+
+pub fn page_up(view: &mut View, _count: usize) {
+    view.first_line = view.first_line.saturating_sub(view.size.1 as usize);
+
+    if !check_cursor_in_view(view) {
+        let text = view.state.doc();
+        let pos = text.line_to_char(view.last_line().saturating_sub(PADDING as usize));
+        view.state.selection = Selection::single(pos, pos);
+    }
+}
+
+pub fn page_down(view: &mut View, _count: usize) {
+    view.first_line += view.size.1 as usize + PADDING;
+
+    if view.first_line < view.state.doc().len_lines() {
+        let text = view.state.doc();
+        let pos = text.line_to_char(view.first_line as usize);
+        view.state.selection = Selection::single(pos, pos);
+    }
+}
+
+pub fn half_page_up(view: &mut View, _count: usize) {
+    view.first_line = view.first_line.saturating_sub(view.size.1 as usize / 2);
+
+    if !check_cursor_in_view(view) {
+        let text = &view.state.doc;
+        let pos = text.line_to_char(view.last_line() - PADDING as usize);
+        view.state.selection = Selection::single(pos, pos);
+    }
+}
+
+pub fn half_page_down(view: &mut View, _count: usize) {
+    let lines = view.state.doc().len_lines();
+    if view.first_line < lines.saturating_sub(view.size.1 as usize) {
+        view.first_line += view.size.1 as usize / 2;
+    }
+    if !check_cursor_in_view(view) {
+        let text = view.state.doc();
+        let pos = text.line_to_char(view.first_line as usize);
+        view.state.selection = Selection::single(pos, pos);
+    }
+}
 // avoid select by default by having a visual mode switch that makes movements into selects
 
 pub fn extend_char_left(view: &mut View, count: usize) {
@@ -292,6 +362,10 @@ pub fn normal_mode(view: &mut View, _count: usize) {
     }
 }
 
+pub fn goto_mode(view: &mut View, _count: usize) {
+    view.state.mode = Mode::Goto;
+}
+
 // TODO: insert means add text just before cursor, on exit we should be on the last letter.
 pub fn insert_char(view: &mut View, c: char) {
     let c = Tendril::from_char(c);
diff --git a/helix-view/src/keymap.rs b/helix-view/src/keymap.rs
index ef23ff2a..72fc0e79 100644
--- a/helix-view/src/keymap.rs
+++ b/helix-view/src/keymap.rs
@@ -108,6 +108,15 @@ macro_rules! shift {
     };
 }
 
+macro_rules! ctrl {
+    ($ch:expr) => {
+        Key {
+            code: KeyCode::Char($ch),
+            modifiers: Modifiers::CONTROL,
+        }
+    };
+}
+
 pub fn default() -> Keymaps {
     hashmap!(
         state::Mode::Normal =>
@@ -126,6 +135,7 @@ pub fn default() -> Keymaps {
                 vec![key!('w')] => commands::move_next_word_start,
                 vec![key!('b')] => commands::move_prev_word_start,
                 vec![key!('e')] => commands::move_next_word_end,
+                vec![key!('g')] => commands::goto_mode,
                 vec![key!('i')] => commands::insert_mode,
                 vec![shift!('I')] => commands::prepend_to_line,
                 vec![key!('a')] => commands::append_mode,
@@ -139,6 +149,16 @@ pub fn default() -> Keymaps {
                     code: KeyCode::Esc,
                     modifiers: Modifiers::NONE
                 }] => commands::normal_mode,
+                vec![Key {
+                    code: KeyCode::PageUp,
+                    modifiers: Modifiers::NONE
+                }] => commands::page_up,
+                vec![Key {
+                    code: KeyCode::PageDown,
+                    modifiers: Modifiers::NONE
+                }] => commands::page_down,
+                vec![ctrl!('u')] => commands::half_page_up,
+                vec![ctrl!('d')] => commands::half_page_down,
             ),
             state::Mode::Insert => hashmap!(
                 vec![Key {
@@ -161,6 +181,14 @@ pub fn default() -> Keymaps {
                     code: KeyCode::Tab,
                     modifiers: Modifiers::NONE
                 }] => commands::insert_tab,
+            ),
+            state::Mode::Goto => hashmap!(
+                vec![Key {
+                    code: KeyCode::Esc,
+                    modifiers: Modifiers::NONE
+                }] => commands::normal_mode as Command,
+                vec![key!('g')] => commands::move_file_start as Command,
+                vec![key!('e')] => commands::move_file_end as Command,
             )
     )
 }
diff --git a/helix-view/src/view.rs b/helix-view/src/view.rs
index 09cd4c65..887c45a2 100644
--- a/helix-view/src/view.rs
+++ b/helix-view/src/view.rs
@@ -11,7 +11,7 @@ use tui::layout::Rect;
 
 pub struct View {
     pub state: State,
-    pub first_line: u16,
+    pub first_line: usize,
     pub size: (u16, u16),
     pub theme: Theme, // TODO: share one instance
 }
@@ -33,10 +33,10 @@ impl View {
 
     pub fn ensure_cursor_in_view(&mut self) {
         let cursor = self.state.selection().cursor();
-        let line = self.state.doc().char_to_line(cursor) as u16;
-        let document_end = self.first_line + self.size.1.saturating_sub(1) - 1;
+        let line = self.state.doc().char_to_line(cursor);
+        let document_end = self.first_line + (self.size.1 as usize).saturating_sub(1);
 
-        let padding = 5u16;
+        let padding = 5usize;
 
         // TODO: side scroll
 
@@ -51,9 +51,10 @@ impl View {
 
     /// Calculates the last visible line on screen
     #[inline]
-    pub fn last_line(&self, viewport: Rect) -> usize {
+    pub fn last_line(&self) -> usize {
+        let viewport = Rect::new(6, 0, self.size.0, self.size.1 - 1); // - 1 for statusline
         std::cmp::min(
-            (self.first_line + viewport.height) as usize,
+            self.first_line + (viewport.height as usize),
             self.state.doc().len_lines() - 1,
         )
     }
@@ -61,15 +62,10 @@ impl View {
     /// Translates a document position to an absolute position in the terminal.
     /// Returns a (line, col) position if the position is visible on screen.
     // TODO: Could return width as well for the character width at cursor.
-    pub fn screen_coords_at_pos(
-        &self,
-        text: &RopeSlice,
-        pos: usize,
-        viewport: Rect,
-    ) -> Option<Position> {
+    pub fn screen_coords_at_pos(&self, text: &RopeSlice, pos: usize) -> Option<Position> {
         let line = text.char_to_line(pos);
 
-        if line < self.first_line as usize || line > self.last_line(viewport) {
+        if line < self.first_line as usize || line > self.last_line() {
             // Line is not visible on screen
             return None;
         }