Add list widget and improve rendering

.gitignore

@@ -1,2 +1,3 @@
 target
 Cargo.lock
+*.log

Cargo.toml

@@ -7,3 +7,5 @@ authors = ["Florian Dehau <florian.dehau@telecomnancy.net>"]
 termion = "1.1.1"
 bitflags = "0.7"
 cassowary = "0.2.0"
+log = "0.3"
+log4rs = "*"

examples/prototype.rs

@@ -1,4 +1,7 @@
 extern crate tui;
+#[macro_use]
+extern crate log;
+extern crate log4rs;
 extern crate termion;
 
 use std::thread;
@@ -8,25 +11,51 @@ use std::io::{Write, stdin};
 use termion::event;
 use termion::input::TermRead;
 
+use log::LogLevelFilter;
+use log4rs::append::console::ConsoleAppender;
+use log4rs::append::file::FileAppender;
+use log4rs::encode::pattern::PatternEncoder;
+use log4rs::config::{Appender, Config, Logger, Root};
+
 use tui::Terminal;
-use tui::widgets::{Widget, Block, Border};
+use tui::widgets::{Widget, Block, List, Border};
 use tui::layout::{Group, Direction, Alignment, Size};
 
 struct App {
     name: String,
     fetching: bool,
+    items: Vec<String>,
+    selected: usize,
 }
 
 enum Event {
-    Quit,
-    Redraw,
+    Input(event::Key),
 }
 
 fn main() {
 
+    let log = FileAppender::builder()
+        .encoder(Box::new(PatternEncoder::new("{d} - {m}{n}")))
+        .build("prototype.log")
+        .unwrap();
+
+    let config = Config::builder()
+        .appender(Appender::builder().build("log", Box::new(log)))
+        .logger(Logger::builder()
+            .appender("log")
+            .additive(false)
+            .build("log", LogLevelFilter::Info))
+        .build(Root::builder().appender("log").build(LogLevelFilter::Info))
+        .unwrap();
+
+    let handle = log4rs::init_config(config).unwrap();
+    info!("Start");
+
     let mut app = App {
         name: String::from("Test app"),
         fetching: false,
+        items: ["1", "2", "3"].into_iter().map(|e| String::from(*e)).collect(),
+        selected: 0,
     };
     let (tx, rx) = mpsc::channel();
 
@@ -35,29 +64,39 @@ fn main() {
         let stdin = stdin();
         for c in stdin.keys() {
             let evt = c.unwrap();
-            match evt {
-                event::Key::Char('q') => {
-                    tx.send(Event::Quit).unwrap();
-                    break;
-                }
-                event::Key::Char('r') => {
-                    tx.send(Event::Redraw).unwrap();
-                }
-                _ => {}
+            tx.send(Event::Input(evt)).unwrap();
+            if evt == event::Key::Char('q') {
+                break;
             }
         }
     });
+
     let mut terminal = Terminal::new().unwrap();
     terminal.clear();
     terminal.hide_cursor();
+
     loop {
         draw(&mut terminal, &app);
         let evt = rx.recv().unwrap();
         match evt {
-            Event::Quit => {
-                break;
+            Event::Input(input) => {
+                match input {
+                    event::Key::Char('q') => {
+                        break;
+                    }
+                    event::Key::Up => {
+                        if app.selected > 0 {
+                            app.selected -= 1
+                        };
+                    }
+                    event::Key::Down => {
+                        if app.selected < app.items.len() - 1 {
+                            app.selected += 1;
+                        }
+                    }
+                    _ => {}
+                }
             }
-            Event::Redraw => {}
         }
     }
     terminal.show_cursor();
@@ -68,27 +107,34 @@ fn draw(terminal: &mut Terminal, app: &App) {
     let ui = Group::default()
         .direction(Direction::Vertical)
         .alignment(Alignment::Left)
-        .chunks(&[Size::Fixed(3.0), Size::Percent(100.0), Size::Fixed(3.0)])
-        .render(&terminal.area(), |chunks| {
-            vec![Block::default()
-                     .borders(Border::TOP | Border::BOTTOM)
-                     .title("Header")
-                     .render(&chunks[0]),
-                 Group::default()
-                     .direction(Direction::Horizontal)
-                     .alignment(Alignment::Left)
-                     .chunks(&[Size::Percent(50.0), Size::Percent(50.0)])
-                     .render(&chunks[1], |chunks| {
-                    vec![Block::default()
-                             .borders(Border::ALL)
-                             .title("Podcasts")
-                             .render(&chunks[0]),
-                         Block::default()
-                             .borders(Border::ALL)
-                             .title("Episodes")
-                             .render(&chunks[1])]
-                }),
-                 Block::default().borders(Border::ALL).title("Footer").render(&chunks[2])]
+        .chunks(&[Size::Fixed(3), Size::Percent(100), Size::Fixed(3)])
+        .render(&terminal.area(), |chunks, tree| {
+            tree.add(Block::default()
+                .borders(Border::ALL)
+                .title("Header")
+                .render(&chunks[0]));
+            tree.add(Group::default()
+                .direction(Direction::Horizontal)
+                .alignment(Alignment::Left)
+                .chunks(&[Size::Percent(50), Size::Percent(50)])
+                .render(&chunks[1], |chunks, tree| {
+                    tree.add(List::default()
+                        .block(|b| {
+                            b.borders(Border::ALL).title("Podcasts");
+                        })
+                        .items(&app.items)
+                        .select(app.selected)
+                        .formatter(|i, s| {
+                            let prefix = if s { ">" } else { "*" };
+                            format!("{} {}", prefix, i)
+                        })
+                        .render(&chunks[0]));
+                    tree.add(Block::default()
+                        .borders(Border::ALL)
+                        .title("Episodes")
+                        .render(&chunks[1]));
+                }));
+            tree.add(Block::default().borders(Border::ALL).title("Footer").render(&chunks[2]));
         });
-    terminal.render(&ui);
+    terminal.render(ui);
 }

src/layout.rs

@@ -5,8 +5,11 @@ use cassowary::{Solver, Variable, Constraint};
 use cassowary::WeightedRelation::*;
 use cassowary::strength::{WEAK, MEDIUM, STRONG, REQUIRED};
 
+use util::hash;
 use buffer::Buffer;
+use widgets::WidgetType;
 
+#[derive(Hash)]
 pub enum Alignment {
     Top,
     Left,
@@ -15,12 +18,13 @@ pub enum Alignment {
     Right,
 }
 
+#[derive(Hash)]
 pub enum Direction {
     Horizontal,
     Vertical,
 }
 
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, PartialEq)]
 pub struct Rect {
     pub x: u16,
     pub y: u16,
@@ -98,10 +102,10 @@ impl Rect {
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Hash)]
 pub enum Size {
-    Fixed(f64),
-    Percent(f64),
+    Fixed(u16),
+    Percent(u16),
 }
 
 /// # Examples
@@ -153,9 +157,9 @@ pub fn split(area: &Rect, dir: &Direction, align: &Alignment, sizes: &[Size]) ->
                 let cs = [elements[i].y | EQ(REQUIRED) | area.y as f64,
                           elements[i].height | EQ(REQUIRED) | area.height as f64,
                           match *size {
-                              Size::Fixed(f) => elements[i].width | EQ(REQUIRED) | f,
+                              Size::Fixed(f) => elements[i].width | EQ(REQUIRED) | f as f64,
                               Size::Percent(p) => {
-                                  elements[i].width | EQ(WEAK) | area.width as f64 * p / 100.0
+                                  elements[i].width | EQ(WEAK) | (area.width * p) as f64 / 100.0
                               }
                           }];
                 constraints.extend_from_slice(&cs);
@@ -169,9 +173,9 @@ pub fn split(area: &Rect, dir: &Direction, align: &Alignment, sizes: &[Size]) ->
                 let cs = [elements[i].x | EQ(REQUIRED) | area.x as f64,
                           elements[i].width | EQ(REQUIRED) | area.width as f64,
                           match *size {
-                              Size::Fixed(f) => elements[i].height | EQ(REQUIRED) | f,
+                              Size::Fixed(f) => elements[i].height | EQ(REQUIRED) | f as f64,
                               Size::Percent(p) => {
-                                  elements[i].height | EQ(WEAK) | area.height as f64 * p / 100.0
+                                  elements[i].height | EQ(WEAK) | (area.height * p) as f64 / 100.0
                               }
                           }];
                 constraints.extend_from_slice(&cs);
@@ -218,6 +222,67 @@ impl Element {
     }
 }
 
+pub enum Tree {
+    Node(Node),
+    Leaf(Leaf),
+}
+
+impl IntoIterator for Tree {
+    type Item = Leaf;
+    type IntoIter = WidgetIterator;
+
+    fn into_iter(self) -> WidgetIterator {
+        WidgetIterator::new(self)
+    }
+}
+
+pub struct WidgetIterator {
+    stack: Vec<Tree>,
+}
+
+impl WidgetIterator {
+    fn new(tree: Tree) -> WidgetIterator {
+        WidgetIterator { stack: vec![tree] }
+    }
+}
+
+impl Iterator for WidgetIterator {
+    type Item = Leaf;
+    fn next(&mut self) -> Option<Leaf> {
+        match self.stack.pop() {
+            Some(t) => {
+                match t {
+                    Tree::Node(n) => {
+                        let index = self.stack.len();
+                        for c in n.children {
+                            self.stack.insert(index, c);
+                        }
+                        self.next()
+                    }
+                    Tree::Leaf(l) => Some(l),
+                }
+            }
+            None => None,
+        }
+    }
+}
+
+pub struct Node {
+    pub children: Vec<Tree>,
+}
+
+impl Node {
+    pub fn add(&mut self, node: Tree) {
+        self.children.push(node);
+    }
+}
+
+pub struct Leaf {
+    pub widget_type: WidgetType,
+    pub hash: u64,
+    pub buffer: Buffer,
+}
+
 pub struct Group {
     direction: Direction,
     alignment: Alignment,
@@ -249,15 +314,12 @@ impl Group {
         self.chunks = Vec::from(chunks);
         self
     }
-    pub fn render<F>(&self, area: &Rect, f: F) -> Buffer
-        where F: Fn(&[Rect]) -> Vec<Buffer>
+    pub fn render<F>(&self, area: &Rect, f: F) -> Tree
+        where F: Fn(&[Rect], &mut Node)
     {
         let chunks = split(area, &self.direction, &self.alignment, &self.chunks);
-        let results = f(&chunks);
-        let mut result = results[0].clone();
-        for r in results.iter().skip(1) {
-            result.merge(&r);
-        }
-        result
+        let mut node = Node { children: Vec::new() };
+        let results = f(&chunks, &mut node);
+        Tree::Node(node)
     }
 }

src/lib.rs

@@ -1,9 +1,12 @@
 extern crate termion;
 #[macro_use]
 extern crate bitflags;
+#[macro_use]
+extern crate log;
 extern crate cassowary;
 
 mod buffer;
+mod util;
 pub mod terminal;
 pub mod widgets;
 pub mod style;

src/style.rs

@@ -1,6 +1,6 @@
 use termion;
 
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, Hash)]
 pub enum Color {
     Black,
     Red,

src/terminal.rs

@@ -1,17 +1,20 @@
 use std::iter;
 use std::io;
 use std::io::Write;
+use std::collections::HashMap;
 
 use termion;
 use termion::raw::{IntoRawMode, RawTerminal};
 
 use buffer::Buffer;
-use layout::Rect;
+use widgets::WidgetType;
+use layout::{Rect, Tree, Node, Leaf};
 
 pub struct Terminal {
-    stdout: RawTerminal<io::Stdout>,
     width: u16,
     height: u16,
+    stdout: RawTerminal<io::Stdout>,
+    previous: HashMap<(WidgetType, u64), Rect>,
 }
 
 impl Terminal {
@@ -19,9 +22,10 @@ impl Terminal {
         let terminal = try!(termion::terminal_size());
         let stdout = try!(io::stdout().into_raw_mode());
         Ok(Terminal {
-            stdout: stdout,
             width: terminal.0,
             height: terminal.1,
+            stdout: stdout,
+            previous: HashMap::new(),
         })
     }
 
@@ -34,7 +38,31 @@ impl Terminal {
         }
     }
 
-    pub fn render(&mut self, buffer: &Buffer) {
+    pub fn render(&mut self, ui: Tree) {
+        let mut buffers: Vec<Buffer> = Vec::new();
+        let mut previous: HashMap<(WidgetType, u64), Rect> = HashMap::new();
+        for node in ui.into_iter() {
+            let area = *node.buffer.area();
+            match self.previous.remove(&(node.widget_type, node.hash)) {
+                Some(r) => {
+                    if r != area {
+                        buffers.push(node.buffer);
+                    }
+                }
+                None => {
+                    buffers.push(node.buffer);
+                }
+            }
+            previous.insert((node.widget_type, node.hash), area);
+        }
+        for buf in buffers {
+            self.render_buffer(&buf);
+            info!("{:?}", buf.area());
+        }
+        self.previous = previous;
+    }
+
+    pub fn render_buffer(&mut self, buffer: &Buffer) {
         for (i, cell) in buffer.content().iter().enumerate() {
             let (lx, ly) = buffer.pos_of(i);
             let (x, y) = (lx + buffer.area().x, ly + buffer.area().y);
@@ -50,6 +78,7 @@ impl Terminal {
     }
     pub fn clear(&mut self) {
         write!(self.stdout, "{}", termion::clear::All).unwrap();
+        write!(self.stdout, "{}", termion::cursor::Goto(1, 1)).unwrap();
         self.stdout.flush().unwrap();
     }
     pub fn hide_cursor(&mut self) {

src/util.rs

@@ -0,0 +1,7 @@
+use std::hash::{Hash, SipHasher, Hasher};
+
+pub fn hash<T: Hash>(t: &T) -> u64 {
+    let mut s = SipHasher::new();
+    t.hash(&mut s);
+    s.finish()
+}

src/widgets/block.rs

@@ -2,8 +2,9 @@
 use buffer::Buffer;
 use layout::Rect;
 use style::Color;
-use widgets::{Widget, Border, Line, vline, hline};
+use widgets::{Widget, WidgetType, Border, Line, vline, hline};
 
+#[derive(Hash)]
 pub struct Block<'a> {
     title: Option<&'a str>,
     borders: Border::Flags,
@@ -35,7 +36,7 @@ impl<'a> Block<'a> {
 }
 
 impl<'a> Widget for Block<'a> {
-    fn render(&self, area: &Rect) -> Buffer {
+    fn buffer(&self, area: &Rect) -> Buffer {
 
         let mut buf = Buffer::empty(*area);
 
@@ -91,4 +92,8 @@ impl<'a> Widget for Block<'a> {
         }
         buf
     }
+
+    fn widget_type(&self) -> WidgetType {
+        WidgetType::Block
+    }
 }

src/widgets/list.rs

@@ -0,0 +1,98 @@
+use std::cmp::{min, max};
+use std::fmt::Display;
+use std::hash::{Hash, Hasher};
+
+use buffer::Buffer;
+use widgets::{Widget, WidgetType, Block};
+use style::Color;
+use layout::Rect;
+
+pub struct List<'a, T> {
+    block: Block<'a>,
+    selected: usize,
+    formatter: Box<Fn(&T, bool) -> String>,
+    items: Vec<T>,
+}
+
+impl<'a, T> Hash for List<'a, T>
+    where T: Hash
+{
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.block.hash(state);
+        self.selected.hash(state);
+        self.items.hash(state);
+    }
+}
+
+impl<'a, T> Default for List<'a, T> {
+    fn default() -> List<'a, T> {
+        List {
+            block: Block::default(),
+            selected: 0,
+            formatter: Box::new(|e: &T, selected: bool| String::from("")),
+            items: Vec::new(),
+        }
+    }
+}
+
+impl<'a, T> List<'a, T>
+    where T: Clone
+{
+    pub fn block<F>(&'a mut self, f: F) -> &mut List<'a, T>
+        where F: Fn(&mut Block)
+    {
+        f(&mut self.block);
+        self
+    }
+
+    pub fn formatter<F>(&'a mut self, f: F) -> &mut List<'a, T>
+        where F: 'static + Fn(&T, bool) -> String
+    {
+        self.formatter = Box::new(f);
+        self
+    }
+
+    pub fn items(&'a mut self, items: &'a [T]) -> &mut List<'a, T> {
+        self.items = items.to_vec();
+        self
+    }
+
+    pub fn select(&'a mut self, index: usize) -> &mut List<'a, T> {
+        self.selected = index;
+        self
+    }
+}
+
+impl<'a, T> Widget for List<'a, T>
+    where T: Display + Hash
+{
+    fn buffer(&self, area: &Rect) -> Buffer {
+        let mut buf = self.block.buffer(area);
+        if area.area() == 0 {
+            return buf;
+        }
+
+        let list_length = self.items.len();
+        let list_area = area.inner(1);
+        let list_height = list_area.height as usize;
+        let bound = min(list_height, list_length);
+        let offset = if self.selected > list_height {
+            min(self.selected - list_height, list_length - list_height)
+        } else {
+            0
+        };
+        for i in 0..bound {
+            let index = i + offset;
+            let ref item = self.items[index];
+            let ref formatter = self.formatter;
+            let mut string = formatter(item, self.selected == index);
+            string.truncate(list_area.width as usize);
+            buf.set_string(1, 1 + i as u16, &string);
+        }
+        buf
+    }
+
+    fn widget_type(&self) -> WidgetType {
+        WidgetType::List
+    }
+}

src/widgets/mod.rs

@@ -1,9 +1,13 @@
 mod block;
+mod list;
 
 pub use self::block::Block;
+pub use self::list::List;
+use std::hash::{Hash, SipHasher, Hasher};
 
+use util::hash;
 use buffer::{Buffer, Cell};
-use layout::Rect;
+use layout::{Rect, Tree, Leaf};
 use style::Color;
 
 enum Line {
@@ -77,6 +81,23 @@ fn vline<'a>(x: u16, y: u16, len: u16, fg: Color, bg: Color) -> Buffer {
                    })
 }
 
-pub trait Widget {
-    fn render(&self, area: &Rect) -> Buffer;
+#[derive(Debug, Hash, Eq, PartialEq, Clone, Copy)]
+pub enum WidgetType {
+    Block,
+    List,
+}
+
+pub trait Widget: Hash {
+    fn buffer(&self, area: &Rect) -> Buffer;
+    fn widget_type(&self) -> WidgetType;
+    fn render(&self, area: &Rect) -> Tree {
+        let widget_type = self.widget_type();
+        let hash = hash(&self);
+        let buffer = self.buffer(area);
+        Tree::Leaf(Leaf {
+            widget_type: widget_type,
+            hash: hash,
+            buffer: buffer,
+        })
+    }
 }