Add Knuth–Morris–Pratt to pager

melib/src/text_processing/line_break.rs

@@ -1127,57 +1127,8 @@ easy to take MORE than nothing.'"#;
         println!("{}", l);
     }
     println!("");
-    let text = r#"CHAPTER I. Down the Rabbit-Hole
-
-Alice was beginning to get very tired of sitting by her sister on the 
-bank, and of having nothing to do: once or twice she had peeped into the 
-book her sister was reading, but it had no pictures or conversations in 
-it, ‘and what is the use of a book,’ thought Alice ‘without pictures or 
-conversations?’
-
-So she was considering in her own mind (as well as she could, for the 
-hot day made her feel very sleepy and stupid), whether the pleasure 
-of making a daisy-chain would be worth the trouble of getting up and 
-picking the daisies, when suddenly a White Rabbit with pink eyes ran 
-close by her.
-
->>There was nothing so VERY remarkable in that; nor did Alice think it so 
->>VERY much out of the way to hear the Rabbit say to itself, ‘Oh dear! 
->> Oh dear! I shall be late!’ (when she thought it over afterwards, it 
->>occurred to her that she ought to have wondered at this, but at the time 
->>it all seemed quite natural); but when the Rabbit actually TOOK A WATCH 
-OUT OF ITS WAISTCOAT-POCKET, and looked at it, and then hurried on, 
->>Alice started to her feet, for it flashed across her mind that she had 
->>never before seen a rabbit with either a waistcoat-pocket, or a watch 
->>to take out of it, and burning with curiosity, she ran across the field
-after it, and fortunately was just in time to see it pop down a large 
-rabbit-hole under the hedge.
-
-In another moment down went Alice after it, never once considering how 
-in the world she was to get out again.
-
-The rabbit-hole went straight on like a tunnel for some way, and then 
-dipped suddenly down, so suddenly that Alice had not a moment to think 
-about stopping herself before she found herself falling down a very deep 
-well.
-
-Either the well was very deep, or she fell very slowly, for she had 
-plenty of time as she went down to look about her and to wonder what was 
-going to happen next. First, she tried to look down and make out what 
-she was coming to, but it was too dark to see anything; then she 
-looked at the sides of the well, and noticed that they were filled with 
-cupboards and book-shelves; here and there she saw maps and pictures 
-hung upon pegs. She took down a jar from one of the shelves as 
-she passed; it was labelled ‘ORANGE MARMALADE’, but to her great 
-disappointment it was empty: she did not like to drop the jar for fear 
-of killing somebody, so managed to put it into one of the cupboards as 
-she fell past it.
-
-‘Well!’ thought Alice to herself, ‘after such a fall as this, I shall 
-think nothing of tumbling down stairs! How brave they’ll all think me at 
-home! Why, I wouldn’t say anything about it, even if I fell off the top 
-of the house!’ (Which was very likely true.)"#;
-    for l in split_lines_reflow(text, Reflow::FormatFlowed, Some(72)) {
+    use super::_ALICE_CHAPTER_1;
+    for l in split_lines_reflow(_ALICE_CHAPTER_1, Reflow::FormatFlowed, Some(72)) {
         println!("{}", l);
     }
 }

melib/src/text_processing/mod.rs

@@ -21,6 +21,7 @@
 
 pub mod grapheme_clusters;
 pub mod line_break;
+pub mod search;
 mod tables;
 mod types;
 pub use types::Reflow;
@@ -137,3 +138,54 @@ fn test_globmatch() {
 
     assert!(!"INBOX/Lists/".matches_glob("INBOX/Lists/*"));
 }
+
+const _ALICE_CHAPTER_1: &'static str = r#"CHAPTER I. Down the Rabbit-Hole
+
+Alice was beginning to get very tired of sitting by her sister on the 
+bank, and of having nothing to do: once or twice she had peeped into the 
+book her sister was reading, but it had no pictures or conversations in 
+it, ‘and what is the use of a book,’ thought Alice ‘without pictures or 
+conversations?’
+
+So she was considering in her own mind (as well as she could, for the 
+hot day made her feel very sleepy and stupid), whether the pleasure 
+of making a daisy-chain would be worth the trouble of getting up and 
+picking the daisies, when suddenly a White Rabbit with pink eyes ran 
+close by her.
+
+>>There was nothing so VERY remarkable in that; nor did Alice think it so 
+>>VERY much out of the way to hear the Rabbit say to itself, ‘Oh dear! 
+>> Oh dear! I shall be late!’ (when she thought it over afterwards, it 
+>>occurred to her that she ought to have wondered at this, but at the time 
+>>it all seemed quite natural); but when the Rabbit actually TOOK A WATCH 
+OUT OF ITS WAISTCOAT-POCKET, and looked at it, and then hurried on, 
+>>Alice started to her feet, for it flashed across her mind that she had 
+>>never before seen a rabbit with either a waistcoat-pocket, or a watch 
+>>to take out of it, and burning with curiosity, she ran across the field
+after it, and fortunately was just in time to see it pop down a large 
+rabbit-hole under the hedge.
+
+In another moment down went Alice after it, never once considering how 
+in the world she was to get out again.
+
+The rabbit-hole went straight on like a tunnel for some way, and then 
+dipped suddenly down, so suddenly that Alice had not a moment to think 
+about stopping herself before she found herself falling down a very deep 
+well.
+
+Either the well was very deep, or she fell very slowly, for she had 
+plenty of time as she went down to look about her and to wonder what was 
+going to happen next. First, she tried to look down and make out what 
+she was coming to, but it was too dark to see anything; then she 
+looked at the sides of the well, and noticed that they were filled with 
+cupboards and book-shelves; here and there she saw maps and pictures 
+hung upon pegs. She took down a jar from one of the shelves as 
+she passed; it was labelled ‘ORANGE MARMALADE’, but to her great 
+disappointment it was empty: she did not like to drop the jar for fear 
+of killing somebody, so managed to put it into one of the cupboards as 
+she fell past it.
+
+‘Well!’ thought Alice to herself, ‘after such a fall as this, I shall 
+think nothing of tumbling down stairs! How brave they’ll all think me at 
+home! Why, I wouldn’t say anything about it, even if I fell off the top 
+of the house!’ (Which was very likely true.)"#;

melib/src/text_processing/search.rs

@@ -0,0 +1,95 @@
+/*
+ * meli - text_processing mod.
+ *
+ * Copyright 2020 Manos Pitsidianakis
+ *
+ * This file is part of meli.
+ *
+ * meli is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * meli is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with meli. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+use super::TextProcessing;
+
+use smallvec::SmallVec;
+
+pub trait KMP: TextProcessing {
+    fn kmp_search(&self, pattern: &str) -> SmallVec<[usize; 256]> {
+        let w = pattern.split_graphemes();
+        let t = kmp_table(&w);
+        let mut j = 0; // (the position of the current character in text)
+        let mut k = 0; // (the position of the current character in pattern)
+        let mut ret = SmallVec::new();
+
+        let s = self.graphemes_indices();
+        while j < s.len() && k < w.len() as i32 {
+            if w[k as usize] == s[j].1 {
+                j += 1;
+                k += 1;
+                if k as usize == w.len() {
+                    ret.push(s[j - (k as usize)].0);
+                    k = t[k as usize];
+                }
+            } else {
+                k = t[k as usize];
+                if k < 0 {
+                    j += 1;
+                    k += 1;
+                }
+            }
+        }
+        ret
+    }
+}
+
+impl KMP for str {}
+
+fn kmp_table(graphemes: &[&str]) -> SmallVec<[i32; 256]> {
+    let mut ret: SmallVec<_> = SmallVec::with_capacity(graphemes.len() + 1);
+    if graphemes.is_empty() {
+        return ret;
+    }
+    ret.push(-1);
+    for _ in 0..graphemes.len() {
+        ret.push(0);
+    }
+    let mut pos: usize = 1;
+    let mut cnd: i32 = 0;
+    while pos < graphemes.len() {
+        if graphemes[pos] == graphemes[cnd as usize] {
+            ret[pos] = ret[cnd as usize];
+        } else {
+            ret[pos] = cnd;
+            cnd = ret[cnd as usize];
+            while cnd >= 0 && graphemes[pos] != graphemes[cnd as usize] {
+                cnd = ret[cnd as usize];
+            }
+        }
+        pos += 1;
+        cnd += 1;
+    }
+    ret[pos] = cnd;
+    ret
+}
+
+#[test]
+fn test_search() {
+    use super::_ALICE_CHAPTER_1;
+    for ind in _ALICE_CHAPTER_1.kmp_search("Alice") {
+        println!(
+            "{:#?}",
+            &_ALICE_CHAPTER_1
+                [ind.saturating_sub(0)..std::cmp::min(_ALICE_CHAPTER_1.len(), ind + 25)]
+        );
+    }
+}

src/components/mail/view.rs

@@ -90,6 +90,7 @@ pub struct MailView {
     pager: Pager,
     subview: Option<Box<dyn Component>>,
     dirty: bool,
+    initialised: bool,
     mode: ViewMode,
     expand_headers: bool,
     headers_no: usize,
@@ -133,6 +134,7 @@ impl MailView {
             pager: pager.unwrap_or_default(),
             subview,
             dirty: true,
+            initialised: false,
             mode: ViewMode::Normal,
             expand_headers: false,
 
@@ -343,6 +345,7 @@ impl MailView {
     pub fn update(&mut self, new_coordinates: (usize, FolderHash, EnvelopeHash)) {
         self.coordinates = new_coordinates;
         self.mode = ViewMode::Normal;
+        self.initialised = false;
         self.set_dirty(true);
     }
 }
@@ -587,7 +590,8 @@ impl Component for MailView {
             }
         };
 
-        if self.dirty {
+        if !self.initialised {
+            self.initialised = true;
             let body = {
                 let account = &mut context.accounts[self.coordinates.0];
                 let envelope: EnvelopeRef = account.collection.get_env(self.coordinates.2);
@@ -595,7 +599,6 @@ impl Component for MailView {
                 match envelope.body(op) {
                     Ok(body) => body,
                     Err(e) => {
-                        self.dirty = false;
                         clear_area(
                             grid,
                             (set_y(upper_left, y), bottom_right),
@@ -626,10 +629,12 @@ impl Component for MailView {
                     let attachment = &body.attachments()[aidx];
                     self.subview = Some(Box::new(HtmlView::new(&attachment, context)));
                     self.mode = ViewMode::Subview;
+                    self.initialised = false;
                 }
                 ViewMode::Normal if body.is_html() => {
                     self.subview = Some(Box::new(HtmlView::new(&body, context)));
                     self.mode = ViewMode::Subview;
+                    self.initialised = false;
                 }
                 ViewMode::Normal
                     if context
@@ -659,6 +664,7 @@ impl Component for MailView {
                         context,
                     )));
                     self.mode = ViewMode::Subview;
+                    self.initialised = false;
                 }
                 ViewMode::Subview | ViewMode::ContactSelector(_) => {}
                 ViewMode::Source(source) => {
@@ -787,6 +793,7 @@ impl Component for MailView {
                     }
                 }
                 self.mode = ViewMode::Normal;
+                self.initialised = false;
                 return true;
             }
             (ViewMode::ContactSelector(ref mut s), _) => {
@@ -879,6 +886,7 @@ impl Component for MailView {
                     context,
                 ));
                 self.dirty = true;
+                self.initialised = false;
                 return true;
             }
             UIEvent::Input(Key::Esc) | UIEvent::Input(Key::Alt(''))
@@ -886,6 +894,7 @@ impl Component for MailView {
             {
                 self.mode = ViewMode::Normal;
                 self.set_dirty(true);
+                self.initialised = false;
                 return true;
             }
             UIEvent::Input(Key::Esc) | UIEvent::Input(Key::Alt('')) if !self.cmd_buf.is_empty() => {
@@ -916,6 +925,7 @@ impl Component for MailView {
                     _ => ViewMode::Source(Source::Decoded),
                 };
                 self.set_dirty(true);
+                self.initialised = false;
                 return true;
             }
             UIEvent::Input(ref key)
@@ -931,6 +941,7 @@ impl Component for MailView {
             {
                 self.mode = ViewMode::Normal;
                 self.set_dirty(true);
+                self.initialised = false;
                 return true;
             }
             UIEvent::Input(ref key)
@@ -1052,6 +1063,7 @@ impl Component for MailView {
 
                             ContentType::Text { .. } | ContentType::PGPSignature => {
                                 self.mode = ViewMode::Attachment(lidx);
+                                self.initialised = false;
                                 self.dirty = true;
                             }
                             ContentType::Multipart { .. } => {
@@ -1091,6 +1103,7 @@ impl Component for MailView {
                                             {
                                                 let raw_buf = RawBuffer::new(buf, name_opt);
                                                 self.mode = ViewMode::Ansi(raw_buf);
+                                                self.initialised = false;
                                                 self.dirty = true;
                                                 return true;
                                             }
@@ -1227,6 +1240,7 @@ impl Component for MailView {
                     ViewMode::Url => self.mode = ViewMode::Normal,
                     _ => {}
                 }
+                self.initialised = false;
                 self.dirty = true;
                 return true;
             }

src/components/utilities.rs

@@ -276,6 +276,14 @@ pub enum PageMovement {
     End,
 }
 
+#[derive(Default, Debug, Clone)]
+pub struct SearchPattern {
+    pattern: String,
+    positions: Vec<(usize, usize)>,
+    cursor: usize,
+    movement: Option<PageMovement>,
+}
+
 /// A pager for text.
 /// `Pager` holds its own content in its own `CellBuffer` and when `draw` is called, it draws the
 /// current view of the text. It is responsible for scrolling etc.
@@ -287,6 +295,7 @@ pub struct Pager {
     height: usize,
     width: usize,
     minimum_width: usize,
+    search: Option<SearchPattern>,
     dirty: bool,
 
     colors: ThemeAttribute,
@@ -530,7 +539,40 @@ impl Component for Pager {
             empty_cell.set_bg(self.colors.bg);
             let mut content = CellBuffer::new(width, height, empty_cell);
             content.set_ascii_drawing(self.content.ascii_drawing);
+            if let Some(ref mut search) = self.search {
+                use melib::text_processing::search::KMP;
+                search.positions.clear();
+                for (y, l) in lines.iter().enumerate() {
+                    search.positions.extend(
+                        l.kmp_search(&search.pattern)
+                            .into_iter()
+                            .map(|offset| (y, offset)),
+                    );
+                }
+            }
             Pager::print_string(&mut content, lines, self.colors);
+            if let Some(ref mut search) = self.search {
+                let results_attr = crate::conf::value(context, "pager.highlight_search");
+                let results_current_attr =
+                    crate::conf::value(context, "pager.highlight_search_current");
+                search.cursor =
+                    std::cmp::min(search.positions.len().saturating_sub(1), search.cursor);
+                for (i, (y, x)) in search.positions.iter().enumerate() {
+                    for c in content.row_iter(*x..*x + search.pattern.grapheme_len(), *y) {
+                        if i == search.cursor {
+                            content[c]
+                                .set_fg(results_current_attr.fg)
+                                .set_bg(results_current_attr.bg)
+                                .set_attrs(results_current_attr.attrs);
+                        } else {
+                            content[c]
+                                .set_fg(results_attr.fg)
+                                .set_bg(results_attr.bg)
+                                .set_attrs(results_attr.attrs);
+                        }
+                    }
+                }
+            }
             self.content = content;
             self.height = height;
             self.width = width;
@@ -580,6 +622,25 @@ impl Component for Pager {
         if self.height == 0 || self.width == 0 {
             return;
         }
+        if let Some(ref mut search) = self.search {
+            if !search.positions.is_empty() {
+                if let Some(mvm) = search.movement.take() {
+                    match mvm {
+                        PageMovement::Up(_) => {
+                            if self.cursor.1 > search.positions[search.cursor].0 {
+                                self.cursor.1 = search.positions[search.cursor].0;
+                            }
+                        }
+                        PageMovement::Down(_) => {
+                            if self.cursor.1 + height < search.positions[search.cursor].0 {
+                                self.cursor.1 = search.positions[search.cursor].0;
+                            }
+                        }
+                        _ => {}
+                    }
+                }
+            }
+        }
 
         clear_area(grid, area, crate::conf::value(context, "theme_default"));
         let (width, height) = self.content.size();
@@ -694,6 +755,49 @@ impl Component for Pager {
                     ))));
                 return true;
             }
+            UIEvent::Action(Action::Listing(ListingAction::Filter(pattern))) => {
+                self.search = Some(SearchPattern {
+                    pattern: pattern.to_string(),
+                    positions: vec![],
+                    cursor: 0,
+                    movement: None,
+                });
+                self.initialised = false;
+                self.dirty = true;
+                return true;
+            }
+            UIEvent::Input(Key::Char('n')) if self.search.is_some() => {
+                if let Some(ref mut search) = self.search {
+                    search.movement = Some(PageMovement::Down(1));
+                    search.cursor += 1;
+                } else {
+                    unsafe {
+                        std::hint::unreachable_unchecked();
+                    }
+                }
+                self.initialised = false;
+                self.dirty = true;
+                return true;
+            }
+            UIEvent::Input(Key::Char('N')) if self.search.is_some() => {
+                if let Some(ref mut search) = self.search {
+                    search.movement = Some(PageMovement::Up(1));
+                    search.cursor = search.cursor.saturating_sub(1);
+                } else {
+                    unsafe {
+                        std::hint::unreachable_unchecked();
+                    }
+                }
+                self.initialised = false;
+                self.dirty = true;
+                return true;
+            }
+            UIEvent::Input(Key::Esc) if self.search.is_some() => {
+                self.search = None;
+                self.initialised = false;
+                self.dirty = true;
+                return true;
+            }
             UIEvent::Resize => {
                 self.initialised = false;
                 self.dirty = true;

src/conf/themes.rs

@@ -195,6 +195,8 @@ const DEFAULT_KEYS: &'static [&'static str] = &[
     "mail.view.body",
     "mail.listing.attachment_flag",
     "mail.listing.thread_snooze_flag",
+    "pager.highlight_search",
+    "pager.highlight_search_current",
 ];
 
 /// `ThemeAttributeInner` but with the links resolved.
@@ -717,6 +719,8 @@ impl Default for Theme {
             }
         );
 
+        add!("pager.highlight_search", light = { fg: Color::White, bg: Color::Byte(6) /* Teal */, attrs: Attr::Bold }, dark = { fg: Color::White, bg: Color::Byte(6) /* Teal */, attrs: Attr::Bold });
+        add!("pager.highlight_search_current", light = { fg: Color::White, bg: Color::Byte(17) /* NavyBlue */, attrs: Attr::Bold }, dark = { fg: Color::White, bg: Color::Byte(17) /* NavyBlue */, attrs: Attr::Bold });
         Theme {
             light,
             dark,