From 9a516e0663bb3844ff449ede3fc0b00eea05450f Mon Sep 17 00:00:00 2001
From: Manos Pitsidianakis <el13635@mail.ntua.gr>
Date: Mon, 25 Nov 2019 14:47:58 +0200
Subject: [PATCH] ui/text_editing: add Ctrl-{f,b,u} readline shortcuts

---
 ui/src/components/utilities/widgets.rs | 39 +++++++++++++++++++++++++-
 ui/src/terminal/text_editing.rs        | 19 +++++++++++++
 2 files changed, 57 insertions(+), 1 deletion(-)

diff --git a/ui/src/components/utilities/widgets.rs b/ui/src/components/utilities/widgets.rs
index 29538b2b..48a6883d 100644
--- a/ui/src/components/utilities/widgets.rs
+++ b/ui/src/components/utilities/widgets.rs
@@ -128,7 +128,7 @@ impl Component for Field {
             if let UIEvent::InsertInput(Key::Char('\t')) = event {
                 if let Some(suggestion) = auto_complete.get_suggestion() {
                     *s = UText::new(suggestion);
-                    let len = s.as_str().len().saturating_sub(1);
+                    let len = s.as_str().len();
                     s.set_cursor(len);
                     return true;
                 }
@@ -199,6 +199,43 @@ impl Component for Field {
                     s.set_cursor(0);
                 }
             }
+            UIEvent::InsertInput(Key::Ctrl('b')) => {
+                /* Backward one character */
+                if let Text(ref mut s, _) = self {
+                    s.cursor_dec();
+                }
+            }
+            UIEvent::InsertInput(Key::Ctrl('f')) => {
+                /* Forward one character */
+                if let Text(ref mut s, _) = self {
+                    s.cursor_inc();
+                }
+            }
+            UIEvent::InsertInput(Key::Ctrl('w')) => {
+                // FIXME: Use Unicode word-breaking algorithm.
+                /* Cut previous word */
+                if let Text(ref mut s, _) = self {
+                    while s.as_str()[..s.cursor_pos()]
+                        .last_grapheme()
+                        .map(|(_, graph)| !graph.is_empty() && graph.trim().is_empty())
+                        .unwrap_or(false)
+                    {
+                        s.backspace();
+                    }
+                    while s.as_str()[..s.cursor_pos()]
+                        .last_grapheme()
+                        .map(|(_, graph)| !graph.is_empty() && !graph.trim().is_empty())
+                        .unwrap_or(false)
+                    {
+                        s.backspace();
+                    }
+                }
+            }
+            UIEvent::InsertInput(Key::Ctrl('u')) => {
+                if let Text(ref mut s, _) = self {
+                    s.cut_left()
+                }
+            }
             UIEvent::InsertInput(Key::Ctrl('e')) => {
                 if let Text(ref mut s, _) = self {
                     s.set_cursor(s.as_str().len());
diff --git a/ui/src/terminal/text_editing.rs b/ui/src/terminal/text_editing.rs
index f46c11e1..7821928f 100644
--- a/ui/src/terminal/text_editing.rs
+++ b/ui/src/terminal/text_editing.rs
@@ -89,6 +89,10 @@ impl UText {
      *                       self.cursor_pos
      */
     pub fn insert_char(&mut self, k: char) {
+        if k.is_control() {
+            return;
+        }
+
         self.content.insert(self.cursor_pos, k);
         self.cursor_pos += k.len_utf8();
         self.grapheme_cursor_pos += 1;
@@ -132,4 +136,19 @@ impl UText {
 
         self.content.drain(offset..offset + graph_len).count();
     }
+
+    pub fn cut_left(&mut self) {
+        if self.content.is_empty() {
+            return;
+        }
+        let offset = {
+            let (left, _) = self.content.split_at(self.cursor_pos);
+            left.last_grapheme()
+                .map(|(offset, graph)| offset + graph.len())
+                .unwrap_or(0)
+        };
+        self.cursor_pos = 0;
+        self.grapheme_cursor_pos = 0;
+        self.content.drain(..offset).count();
+    }
 }