Add Tabs widget

src/widgets/tabs.rs

@@ -0,0 +1,94 @@
+use unicode_width::UnicodeWidthStr;
+
+use widgets::{Block, Widget};
+use buffer::Buffer;
+use layout::Rect;
+use style::Color;
+use symbols::line;
+
+pub struct Tabs<'a> {
+    block: Option<Block<'a>>,
+    titles: &'a [&'a str],
+    selected: usize,
+    highlight_color: Color,
+    color: Color,
+}
+
+impl<'a> Default for Tabs<'a> {
+    fn default() -> Tabs<'a> {
+        Tabs {
+            block: None,
+            titles: &[],
+            selected: 0,
+            highlight_color: Color::Reset,
+            color: Color::Reset,
+        }
+    }
+}
+
+impl<'a> Tabs<'a> {
+    pub fn block(&mut self, block: Block<'a>) -> &mut Tabs<'a> {
+        self.block = Some(block);
+        self
+    }
+
+    pub fn titles(&mut self, titles: &'a [&'a str]) -> &mut Tabs<'a> {
+        self.titles = titles;
+        self
+    }
+
+    pub fn select(&mut self, selected: usize) -> &mut Tabs<'a> {
+        self.selected = selected;
+        self
+    }
+
+    pub fn color(&mut self, color: Color) -> &mut Tabs<'a> {
+        self.color = color;
+        self
+    }
+
+    pub fn highlight_color(&mut self, color: Color) -> &mut Tabs<'a> {
+        self.highlight_color = color;
+        self
+    }
+}
+
+impl<'a> Widget for Tabs<'a> {
+    fn buffer(&self, area: &Rect, buf: &mut Buffer) {
+        let tabs_area = match self.block {
+            Some(b) => {
+                b.buffer(area, buf);
+                b.inner(area)
+            }
+            None => *area,
+        };
+        if tabs_area.height < 1 {
+            return;
+        }
+
+        let mut x = tabs_area.left();
+        for (title, color) in self.titles.iter().enumerate().map(|(i, t)| if i == self.selected {
+            (t, self.highlight_color)
+        } else {
+            (t, self.color)
+        }) {
+            x += 1;
+            if x > tabs_area.right() {
+                break;
+            } else {
+                buf.set_string(x, tabs_area.top(), title, color, Color::Reset);
+                x += title.width() as u16 + 1;
+                if x > tabs_area.right() {
+                    break;
+                } else {
+                    buf.set_cell(x,
+                                 tabs_area.top(),
+                                 line::VERTICAL,
+                                 Color::Reset,
+                                 Color::Reset);
+                    x += 1;
+                }
+            }
+        }
+    }
+}