Add title to views::Panel

src/views/panel.rs

@@ -1,22 +1,91 @@
+use align::*;
 use event::{Event, EventResult};
 use rect::Rect;
+use theme::ColorStyle;
+use unicode_width::UnicodeWidthStr;
 use vec::Vec2;
 use view::{View, ViewWrapper};
 use Printer;
+use With;
 
 /// Draws a border around a wrapped view.
 #[derive(Debug)]
 pub struct Panel<V: View> {
+    // Inner view
     view: V,
+
+    // Possibly empty title.
+    title: String,
+
+    // Where to put the title position
+    title_position: HAlign,
+
+    // `true` when we needs to relayout
+    invalidated: bool,
 }
 
 impl<V: View> Panel<V> {
     /// Creates a new panel around the given view.
     pub fn new(view: V) -> Self {
-        Panel { view }
+        Panel {
+            view,
+            title: String::new(),
+            title_position: HAlign::Center,
+            invalidated: true,
+        }
     }
 
     inner_getters!(self.view: V);
+
+    /// Sets the title of the dialog.
+    ///
+    /// If not empty, it will be visible at the top.
+    pub fn title<S: Into<String>>(self, label: S) -> Self {
+        self.with(|s| s.set_title(label))
+    }
+
+    /// Sets the title of the dialog.
+    pub fn set_title<S: Into<String>>(&mut self, label: S) {
+        self.title = label.into();
+        self.invalidate();
+    }
+
+    /// Sets the horizontal position of the title in the dialog.
+    /// The default position is `HAlign::Center`
+    pub fn title_position(self, align: HAlign) -> Self {
+        self.with(|s| s.set_title_position(align))
+    }
+
+    /// Sets the horizontal position of the title in the dialog.
+    /// The default position is `HAlign::Center`
+    pub fn set_title_position(&mut self, align: HAlign) {
+        self.title_position = align;
+    }
+
+    fn draw_title(&self, printer: &Printer) {
+        if !self.title.is_empty() {
+            let len = self.title.width();
+            if len + 4 > printer.size.x {
+                return;
+            }
+            let spacing = 3; //minimum distance to borders
+            let x = spacing + self
+                .title_position
+                .get_offset(len, printer.size.x - 2 * spacing);
+            printer.with_high_border(false, |printer| {
+                printer.print((x - 2, 0), "┤ ");
+                printer.print((x + len, 0), " ├");
+            });
+
+            printer.with_color(ColorStyle::title_primary(), |p| {
+                p.print((x, 0), &self.title)
+            });
+        }
+    }
+
+    fn invalidate(&mut self) {
+        self.invalidated = true;
+    }
 }
 
 impl<V: View> ViewWrapper for Panel<V> {
@@ -35,6 +104,8 @@ impl<V: View> ViewWrapper for Panel<V> {
 
     fn wrap_draw(&self, printer: &Printer) {
         printer.print_box((0, 0), printer.size, true);
+        self.draw_title(&printer);
+
         let printer = printer.offset((1, 1)).shrinked((1, 1));
         self.view.draw(&printer);
     }
@@ -47,4 +118,9 @@ impl<V: View> ViewWrapper for Panel<V> {
         let inner_size = size.saturating_sub((2, 2));
         self.view.important_area(inner_size) + (1, 1)
     }
+
+    fn wrap_needs_relayout(&self) -> bool {
+        self.invalidated
+            || self.with_view(|v| v.needs_relayout()).unwrap_or(true)
+    }
 }