From 5bd297ba273d93aefa075b8d123a54efcb5d3c3b Mon Sep 17 00:00:00 2001
From: "Timothy J. Warren" <tim@timshomepage.net>
Date: Fri, 12 Mar 2021 12:17:32 -0500
Subject: [PATCH] Search forward

---
 src/document.rs | 10 ++++++---
 src/editor.rs   | 57 +++++++++++++++++++++++++++++++++----------------
 src/row.rs      | 10 +++++----
 3 files changed, 52 insertions(+), 25 deletions(-)

diff --git a/src/document.rs b/src/document.rs
index f65062e..08564f6 100644
--- a/src/document.rs
+++ b/src/document.rs
@@ -103,11 +103,15 @@ impl Document {
         self.dirty
     }
 
-    pub fn find(&self, query: &str) -> Option<Position> {
-        for (y, row) in self.rows.iter().enumerate() {
-            if let Some(x) = row.find(query) {
+    pub fn find(&self, query: &str, after: &Position) -> Option<Position> {
+        let mut x = after.x;
+
+        for (y, row) in self.rows.iter().enumerate().skip(after.y) {
+            if let Some(x) = row.find(query, x) {
                 return Some(Position { x, y })
             }
+
+            x = 0;
         }
 
         None
diff --git a/src/editor.rs b/src/editor.rs
index 1b866b3..04ab07b 100644
--- a/src/editor.rs
+++ b/src/editor.rs
@@ -12,7 +12,7 @@ const STATUS_BG_COLOR: color::Rgb = color::Rgb(239, 239, 239);
 const VERSION: &str = env!("CARGO_PKG_VERSION");
 const QUIT_TIMES: u8 = 3;
 
-#[derive(Default)]
+#[derive(Default, Clone)]
 pub struct Position {
     pub x: usize,
     pub y: usize,
@@ -177,6 +177,43 @@ impl Editor {
         }
     }
 
+    fn search(&mut self) {
+        let old_position = self.cursor_position.clone();
+
+        if let Some(query) = self
+            .prompt(
+                "Search (ESC to cancel, arrows to navigate): ",
+                |editor, key, query| {
+                    let mut moved = false;
+
+                    match key {
+                        Key::Right | Key::Down => {
+                            editor.move_cursor(Key::Right);
+                            moved = true;
+                        }
+                        _ => (),
+                    }
+
+                if let Some(position) = editor.document.find(&query, &editor.cursor_position) {
+                    editor.cursor_position = position;
+                    editor.scroll();
+                } else {
+                    editor.move_cursor(Key::Left);
+                }
+            })
+            .unwrap_or(None)
+        {
+            if let Some(position) = self.document.find(&query[..], &old_position) {
+                self.cursor_position = position;
+            } else {
+                self.status_message = StatusMessage::from(format!("Not found: {}", query));
+            }
+        } else {
+            self.cursor_position = old_position;
+            self.scroll();
+        }
+    }
+
     fn process_keypress(&mut self) -> Result<(), std::io::Error> {
         let pressed_key = Terminal::read_key()?;
         match pressed_key {
@@ -195,23 +232,7 @@ impl Editor {
                 self.should_quit = true
             },
             Key::Ctrl('s') => self.save(),
-            Key::Ctrl('f') => {
-                if let Some(query) = self
-                    .prompt("Search: ", |editor, _, query| {
-                        if let Some(position) = editor.document.find(&query) {
-                            editor.cursor_position = position;
-                            editor.scroll();
-                        }
-                    })
-                    .unwrap_or(None)
-                {
-                    if let Some(position) = self.document.find(&query[..]) {
-                        self.cursor_position = position;
-                    } else {
-                        self.status_message = StatusMessage::from(format!("Not found: {}", query));
-                    }
-                }
-            }
+            Key::Ctrl('f') => self.search(),
             Key::Char(c) => {
                 self.document.insert(&self.cursor_position, c);
                 self.move_cursor(Key::Right);
diff --git a/src/row.rs b/src/row.rs
index cb04a19..9794252 100644
--- a/src/row.rs
+++ b/src/row.rs
@@ -127,14 +127,16 @@ impl Row {
         self.string.as_bytes()
     }
 
-    pub fn find(&self, query: &str) -> Option<usize> {
-        let matching_byte_index = self.string.find(query);
+    pub fn find(&self, query: &str, after: usize) -> Option<usize> {
+        let substring: String = self.string[..].graphemes(true).skip(after).collect();
+        let matching_byte_index = substring.find(query);
+
         if let Some(matching_byte_index) = matching_byte_index {
             for (grapheme_index, (byte_index, _)) in
-                self.string[..].grapheme_indices(true).enumerate()
+                substring[..].grapheme_indices(true).enumerate()
             {
                 if matching_byte_index == byte_index {
-                    return Some(grapheme_index);
+                    return Some(after + grapheme_index);
                 }
             }
         }