More checks against small viewports

Prevents panics when the terminal is resized.

src/views/edit_view.rs

@@ -343,6 +343,7 @@ impl View for EditView {
 
     fn layout(&mut self, size: Vec2) {
         self.last_length = size.x;
+        // println_stderr!("Promised: {}", size.x);
     }
 
     fn take_focus(&mut self, _: Direction) -> bool {

src/views/linear_layout.rs

@@ -26,6 +26,7 @@ struct Child {
 }
 
 impl Child {
+    // Compute and caches the required size.
     fn required_size(&mut self, req: Vec2) -> Vec2 {
         self.size = self.view.required_size(req);
         self.size
@@ -36,6 +37,17 @@ impl Child {
     }
 }
 
+fn cap<'a, I: Iterator<Item = &'a mut usize>>(iter: I, max: usize) {
+    let mut available = max;
+    for item in iter {
+        if *item > available {
+            *item = available;
+        }
+
+        available -= *item;
+    }
+}
+
 impl LinearLayout {
     /// Creates a new layout with the given orientation.
     pub fn new(orientation: direction::Orientation) -> Self {
@@ -197,6 +209,7 @@ impl View for LinearLayout {
         let o = self.orientation;
 
         for child in &mut self.children {
+            // Every item has the same size orthogonal to the layout
             child.size.set_axis_from(o.swap(), &size);
             child.view.layout(size.with_axis_from(o, &child.size));
         }
@@ -225,8 +238,8 @@ impl View for LinearLayout {
             return ideal;
         }
 
-        // Ok, so maybe it didn't.
-        // Budget cuts, everyone.
+        // Ok, so maybe it didn't. Budget cuts, everyone.
+        // Let's pretend we have almost no space in this direction.
         let budget_req = req.with_axis(self.orientation, 1);
         // println_stderr!("Budget req: {:?}", budget_req);
 
@@ -240,8 +253,15 @@ impl View for LinearLayout {
         // println_stderr!("Desperate: {:?}", desperate);
 
         // This is the lowest we'll ever go. It better fit at least.
+        let orientation = self.orientation;
         if !desperate.fits_in(req) {
             // Just give up...
+            // TODO: hard-cut
+            cap(self.children
+                    .iter_mut()
+                    .map(|c| c.size.get_mut(orientation)),
+                *req.get(self.orientation));
+
             // TODO: print some error message or something
             // println_stderr!("Seriously? {:?} > {:?}???", desperate, req);
             // self.cache = Some(SizeCache::build(desperate, req));

src/views/list_view.rs

@@ -6,6 +6,8 @@ use event::{Callback, Event, EventResult, Key};
 
 use std::any::Any;
 use std::rc::Rc;
+
+use unicode_width::UnicodeWidthStr;
 use vec::Vec2;
 use view::ScrollBase;
 use view::Selector;
@@ -132,16 +134,16 @@ impl ListView {
     fn move_focus(&mut self, n: usize, source: direction::Direction)
                   -> EventResult {
         let i = if let Some(i) =
-                       source.relative(direction::Orientation::Vertical)
-            .and_then(|rel| {
-                // The iterator starts at the focused element.
-                // We don't want that one.
-                self.iter_mut(true, rel)
-                    .skip(1)
-                    .filter_map(|p| try_focus(p, source))
-                    .take(n)
-                    .last()
-            }) {
+            source.relative(direction::Orientation::Vertical)
+                .and_then(|rel| {
+                    // The iterator starts at the focused element.
+                    // We don't want that one.
+                    self.iter_mut(true, rel)
+                        .skip(1)
+                        .filter_map(|p| try_focus(p, source))
+                        .take(n)
+                        .last()
+                }) {
             i
         } else {
             return EventResult::Ignored;
@@ -181,28 +183,30 @@ impl View for ListView {
         let offset = self.children
             .iter()
             .map(Child::label)
-            .map(str::len)
+            .map(UnicodeWidthStr::width)
             .max()
             .unwrap_or(0) + 1;
 
-        self.scrollbase.draw(printer, |printer, i| {
-            match self.children[i] {
-                Child::Row(ref label, ref view) => {
-                    printer.print((0, 0), label);
-                    view.draw(&printer.offset((offset, 0), i == self.focus));
-                }
-                Child::Delimiter => (),
+        // println_stderr!("Offset: {}", offset);
+
+        self.scrollbase.draw(printer, |printer, i| match self.children[i] {
+            Child::Row(ref label, ref view) => {
+                printer.print((0, 0), label);
+                view.draw(&printer.offset((offset, 0), i == self.focus));
             }
+            Child::Delimiter => (),
         });
     }
 
     fn required_size(&mut self, req: Vec2) -> Vec2 {
-        let label_size = self.children
+        // We'll show 2 columns: the labels, and the views.
+        let label_width = self.children
             .iter()
             .map(Child::label)
-            .map(str::len)
+            .map(UnicodeWidthStr::width)
             .max()
             .unwrap_or(0);
+
         let view_size = self.children
             .iter_mut()
             .filter_map(Child::view)
@@ -211,26 +215,34 @@ impl View for ListView {
             .unwrap_or(0);
 
         if self.children.len() > req.y {
-            Vec2::new(label_size + 1 + view_size + 2, req.y)
+            Vec2::new(label_width + 1 + view_size + 2, req.y)
         } else {
-            Vec2::new(label_size + 1 + view_size, self.children.len())
+            Vec2::new(label_width + 1 + view_size, self.children.len())
         }
     }
 
     fn layout(&mut self, size: Vec2) {
         self.scrollbase.set_heights(size.y, self.children.len());
 
-        let label_size = self.children
+        // We'll show 2 columns: the labels, and the views.
+        let label_width = self.children
             .iter()
             .map(Child::label)
-            .map(str::len)
+            .map(UnicodeWidthStr::width)
             .max()
             .unwrap_or(0);
-        let mut available = size.x - label_size - 1;
 
-        if self.children.len() > size.y {
-            available -= 2;
-        }
+        let spacing = 1;
+        let scrollbar_width = if self.children.len() > size.y { 2 } else { 0 };
+
+        let available = if label_width + spacing + scrollbar_width > size.x {
+            // We have no space for the kids! :(
+            0
+        } else {
+            size.x - label_width - spacing - scrollbar_width
+        };
+
+        // println_stderr!("Available: {}", available);
 
         for child in self.children.iter_mut().filter_map(Child::view) {
             child.layout(Vec2::new(available, 1));

src/views/select_view.rs

@@ -340,6 +340,9 @@ impl<T: 'static> View for SelectView<T> {
                 ColorStyle::Highlight
             };
             let x = printer.size.x;
+            if x == 0 {
+                return;
+            }
 
 
             printer.with_color(style, |printer| {

src/xy.rs

@@ -45,6 +45,14 @@ impl<T> XY<T> {
         }
     }
 
+    /// Returns a mutable reference to the value on the given axis.
+    pub fn get_mut(&mut self, o: Orientation) -> &mut T {
+        match o {
+            Orientation::Horizontal => &mut self.x,
+            Orientation::Vertical => &mut self.y,
+        }
+    }
+
     /// Returns a new `XY` of tuples made by zipping `self` and `other`.
     pub fn zip<U>(self, other: XY<U>) -> XY<(T, U)> {
         XY::new((self.x, other.x), (self.y, other.y))
@@ -56,7 +64,7 @@ impl<T> XY<T> {
     }
 }
 
-impl <T: Clone> XY<T> {
+impl<T: Clone> XY<T> {
     /// Returns a new `XY` with the axis `o` set to `value`.
     pub fn with_axis(&self, o: Orientation, value: T) -> Self {
         let mut new = self.clone();