performance fixes

dizzle

@@ -1 +1 @@
-Subproject commit b6c1bb5f9400c28de1709df78c18e0d4d5618a15
+Subproject commit 3d04622e4266eac65021da6cd3d378e84a843b87

src/layout/axis.rs

@@ -454,5 +454,5 @@ impl<'a, S: Screen, T: Draw<S>> LayoutPull<'a, S>  for T {}
 impl<'a, S: Screen, T: Draw<S>> LayoutPad<'a, S>   for T {}
 
 pub fn check_layout <'a> (t: impl Draw<Tui>) -> Drawn<u16> {
-    Tui::Layout(XYWH(1u16, 1, 80, 25)).size(None, t)
+    Tui(XYWH(1u16, 1, 80, 25), None).size(None, t)
 }

src/layout/azimuth.rs

@@ -211,22 +211,25 @@ pub fn bar_areas <'a, S: Screen> (
     let XYWH(x0, y0, w0, h0) = to.area();
     Ok(match split {
         Split::South => (
-            to.size(XYWH(x0, y0, w0, n),          a)?,
-            to.size(XYWH(x0, y0 + n, w0, h0 - n), b)?,
+            Some(XYWH(x0, y0, w0, n)),
+            Some(XYWH(x0, y0 + n, w0, h0 - n)),
         ),
         Split::East => (
-            to.size(XYWH(x0, y0, n, h0),          a)?,
-            to.size(XYWH(x0 + n, y0, w0 - n, h0), b)?,
+            Some(XYWH(x0, y0, n, h0)),
+            Some(XYWH(x0 + n, y0, w0 - n, h0)),
         ),
         Split::North => (
-            to.size(XYWH(x0, y0 + h0 - n, w0, n), a)?,
-            to.size(XYWH(x0, y0, w0, h0 - n),     b)?,
+            Some(XYWH(x0, y0 + h0 - n, w0, n)),
+            Some(XYWH(x0, y0, w0, h0 - n)),
         ),
         Split::West => (
-            to.size(XYWH(x0 + w0 - n, y0, n, h0), a)?,
-            to.size(XYWH(x0, y0, w0 - n, h0),     b)?,
+            Some(XYWH(x0 + w0 - n, y0, n, h0)),
+            Some(XYWH(x0, y0, w0 - n, h0)),
+        ),
+        Split::Above | Split::Below => (
+            Some(XYWH(x0, y0, w0, h0)),
+            Some(XYWH(x0, y0, w0, h0)),
         ),
-        _ => todo!()
     })
 }
 
@@ -238,7 +241,7 @@ pub struct Pair<A, B>(Split, A, B);
 /// use ::tengri::*;
 /// use Split::*;
 /// fn size_of <'a, A: Draw<Tui>, B: Draw<Tui>> (stack: &Pair<Tui, A, B>) -> Drawn<S::Unit> {
-///     Tui::Layout(XYWH(0, 0, 80, 25)).size(None, stack)
+///     Tui(XYWH(0, 0, 80, 25), None).size(None, stack)
 /// }
 /// assert_eq!(size_of(&split(East,  "foo", "bar"))?, Some(XYWH(0, 0, 6, 1)));
 /// assert_eq!(size_of(&split(South, "foo", "bar"))?, Some(XYWH(0, 0, 3, 2)));
@@ -293,11 +296,11 @@ fn draw_stacks <'a, S: Screen> (
 /// ```
 /// # use ::tengri::*; fn test_stack_areas () -> Usually<()> {
 /// let area = XYWH(0u16, 0, 80, 25);
-/// assert_eq!(stack_areas(&Split::East, &mut Tui::Layout(area), &"foo", &"bar")?, (
+/// assert_eq!(stack_areas(&Split::East, &mut Tui(area, None), &"foo", &"bar")?, (
 ///     Some(XYWH(0u16, 0, 3, 1)),
 ///     Some(XYWH(3u16, 0, 3, 1)),
 /// ));
-/// assert_eq!(stack_areas(&Split::South, &mut Tui::Layout(area), &"foo", &"bar")?, (
+/// assert_eq!(stack_areas(&Split::South, &mut Tui(area, None), &"foo", &"bar")?, (
 ///     Some(XYWH(0u16, 0, 3, 1)),
 ///     Some(XYWH(0u16, 1, 3, 1)),
 /// ));
@@ -522,7 +525,7 @@ pub const fn below <'a, S: Screen, A: Draw<S>, B: Draw<S>> (a: A, b: B) -> impl
 }
 
 #[cfg(test)] #[test] fn test_align () -> Usually<()> {
-    let mut screen = Tui::Layout(XYWH(0, 0, 80, 25));
+    let mut screen = Tui(XYWH(0, 0, 80, 25), None);
     assert_eq!("FOOBAR\nKILROY".draw(&mut screen)?, Some(XYWH(0, 0, 6, 2)));
     assert_eq!("FOOBAR\nKILROY".align_nw().draw(&mut screen)?, Some(XYWH(0,   0, 6, 2)));
     assert_eq!("FOOBAR\nKILROY".align_n().draw(&mut screen)?,  Some(XYWH(37,  0, 6, 2)));

src/lib.rs

@@ -1792,67 +1792,7 @@ pub trait AsMutOpt<T> { fn as_mut_opt (&mut self) -> Option<&mut T>; }
 }
 
 #[cfg(feature = "text")] pub use self::text::*;
-#[cfg(feature = "text")] mod text {
-    #![allow(unused)]
-
-    pub(crate) use ::unicode_width::*;
-
-    /// Displays an owned [str]-like with fixed maximum width.
-    ///
-    /// Width is computed using [unicode_width].
-    pub struct TrimString<T: AsRef<str>>(pub u16, pub T);
-
-    impl<T: AsRef<str>> AsRef<str> for TrimString<T> {
-        fn as_ref (&self) -> &str {
-            self.1.as_ref()
-        }
-    }
-
-    impl<'a, T: AsRef<str>> TrimString<T> {
-        fn to_ref (&self) -> TrimStr<'_, T> {
-            TrimStr(self.0, &self.1)
-        }
-    }
-
-    /// Displays a borrowed [str]-like with fixed maximum width
-    ///
-    /// Width is computed using [unicode_width].
-    pub struct TrimStr<'a, T: AsRef<str>>(pub u16, pub &'a T);
-
-    impl<T: AsRef<str>> AsRef<str> for TrimStr<'_, T> {
-        fn as_ref (&self) -> &str {
-            self.1.as_ref()
-        }
-    }
-
-    pub(crate) fn width_chars_max (max: u16, text: impl AsRef<str>) -> u16 {
-        let mut width: u16 = 0;
-        let mut chars = text.as_ref().chars();
-        while let Some(c) = chars.next() {
-            width += c.width().unwrap_or(0) as u16;
-            if width >= max {
-                break
-            }
-        }
-        return width
-    }
-
-    /// Trim string with [unicode_width].
-    pub fn trim_string (max_width: usize, input: impl AsRef<str>) -> String {
-        let input = input.as_ref();
-        let mut output = Vec::with_capacity(input.len());
-        let mut width: usize = 1;
-        let mut chars = input.chars();
-        while let Some(c) = chars.next() {
-            if width > max_width {
-                break
-            }
-            output.push(c);
-            width += c.width().unwrap_or(0);
-        }
-        return output.into_iter().collect()
-    }
-}
+#[cfg(feature = "text")] mod text;
 
 #[cfg(feature = "term")] pub use self::term::*;
 #[cfg(feature = "term")] mod term;

src/term.rs

@@ -29,6 +29,7 @@ mod modify; pub use self::modify::*;
 mod phat;   pub use self::phat::*;
 mod repeat; pub use self::repeat::*;
 mod scroll; pub use self::scroll::*;
+#[cfg(feature = "text")] mod text;
 
 #[macro_export] macro_rules! tui_app {
     ($Struct:ident { $($fields:tt)* }) => {
@@ -75,30 +76,44 @@ mod scroll; pub use self::scroll::*;
 }
 
 /// Terminal output.
-pub enum Tui {
-    /// Draw mode: updates contained [Buffer].
-    Draw (
-        /// Ratatui buffer; area is screen size
-        Buffer,
-        /// Current draw area
-        XYWH<u16>
-    ),
-    /// Discard mode: only computes sizes
-    Layout (
-        /// Draw area; no buffer
-        XYWH<u16>
-    )
+pub struct Tui(
+    /// Current draw area
+    pub(crate) XYWH<u16>,
+    /// Ratatui buffer.
+    ///
+    /// - Area is screen size.
+    /// - If present, we're in draw mode.
+    /// - If absent, we're in layout mode.
+    pub(crate) Option<Buffer>
+);
+
+impl AsRef<XYWH<u16>> for Tui {
+    fn as_ref (&self) -> &XYWH<u16> {
+        &self.0
+    }
+}
+
+impl From<&Tui> for XYWH<u16> {
+    fn from (screen: &Tui) -> XYWH<u16> {
+        screen.0
+    }
+}
+
+impl<'a: 'b, 'b> From<&'a mut Tui> for &'b mut XYWH<u16> {
+    fn from (screen: &'a mut Tui) -> &'b mut XYWH<u16> {
+        &mut screen.0
+    }
 }
 
 impl Screen for Tui {
     type Unit = u16;
     fn area (&self) -> XYWH<Self::Unit> {
-        self.into()
+        self.0
     }
     fn size <'a> (
         &mut self, area: impl Into<Option<XYWH<u16>>>, draw: impl Draw<Self>,
     ) -> Drawn<Self::Unit> {
-        Self::Layout(self.area()).clip(area, &|to|draw.draw(to))
+        Self(self.area(), None).clip(area, &|to|draw.draw(to))
     }
     fn draw <'a> (
         &mut self, area: impl Into<Option<XYWH<u16>>>, draw: impl Draw<Tui>
@@ -111,10 +126,12 @@ impl Screen for Tui {
         let prev = self.area();
         if let Some(area) = area.into() {
             *self.area_mut() = area.into();
+            let result = draw(self);
+            *self.area_mut() = prev;
+            result
+        } else {
+            draw(self)
         }
-        let result = draw(self);
-        *self.area_mut() = prev;
-        result
     }
 }
 
@@ -177,24 +194,28 @@ impl Tui {
         disable_raw_mode().map_err(Into::into)
     }
     pub fn new (width: u16, height: u16) -> Self {
-        Self::Draw(Buffer::empty(Rect { x: 0, y: 0, width, height }), XYWH(0, 0, width, height))
+        Self(
+            XYWH(0, 0, width, height),
+            Some(Buffer::empty(Rect { x: 0, y: 0, width, height }))
+        )
     }
     pub fn resize <W: Write> (&mut self, back: &mut CrosstermBackend<W>, width: u16, height: u16) {
         let size = Rect { x: 0, y: 0, width, height };
-        if let Self::Draw(buffer, ..) = self {
+        self.buffer().map(|buffer|{
             if buffer.area != size {
                 back.clear_region(ClearType::All).unwrap();
                 buffer.resize(size);
                 buffer.reset();
             }
-        }
+        });
     }
     pub fn redraw <'b, W: Write> (
         &'b mut self,
         back: &mut CrosstermBackend<W>,
         next: &'b mut Self
     ) {
-        if let Self::Draw(prev, ..) = self && let Self::Draw(next, ..) = next {
+        if let Some(prev) = self.buffer()
+        && let Some(next) = next.buffer() {
             let updates = prev.diff(&next);
             back.draw(updates.into_iter()).expect("failed to render");
             Backend::flush(back).expect("failed to flush output new");
@@ -204,7 +225,7 @@ impl Tui {
     }
     pub fn update (&mut self, callback: &impl Fn(&mut Cell, u16, u16)) -> XYWH<u16> {
         let XYWH(x0, y0, w, h) = self.area();
-        if let Self::Draw(buffer, ..) = self {
+        if let Some(buffer) = self.buffer() {
             for row in 0..h {
                 let y = y0 + row;
                 for col in 0..w {
@@ -220,7 +241,7 @@ impl Tui {
         self.xywh()
     }
     pub fn blit (&mut self, text: &impl AsRef<str>, x: u16, y: u16, style: Option<Style>) {
-        if let Self::Draw(buffer, ..) = self {
+        if let Some(buffer) = self.buffer() {
             let text = text.as_ref();
             let style = style.unwrap_or(Style::default());
             if x < buffer.area.width && y < buffer.area.height {
@@ -229,7 +250,7 @@ impl Tui {
         }
     }
     pub fn tint_all (&mut self, fg: Color, bg: Color, modifier: Modifier) {
-        if let Self::Draw(buffer, ..) = self {
+        if let Some(buffer) = self.buffer() {
             for cell in buffer.content.iter_mut() {
                 cell.fg = fg;
                 cell.bg = bg;
@@ -303,11 +324,7 @@ impl Tui {
     }
 
     pub fn buffer (&mut self) -> Option<&mut Buffer> {
-        if let Tui::Draw(buffer, _) = self {
-            Some(buffer)
-        } else {
-            None
-        }
+        self.1.as_mut()
     }
 
     pub fn set_char (&mut self, x: u16, y: u16, c: char) {
@@ -325,14 +342,6 @@ impl Tui {
 //impl Deref         for Tui { type Target = Buffer; fn deref (&self) -> &Buffer { &self.0 } }
 //impl DerefMut      for Tui { fn deref_mut (&mut self) -> &mut Buffer { &mut self.0 } }
 //impl AsMut<Buffer> for Tui { fn as_mut (&mut self) -> &mut Buffer { &mut self.0 } }
-impl AsRef<XYWH<u16>> for Tui {
-    fn as_ref (&self) -> &XYWH<u16> {
-        match self {
-            Self::Draw(_, area) => area,
-            Self::Layout(area) => area
-        }
-    }
-}
 
 impl Wide<u16> for Tui {
     fn w (&self) -> u16 { self.as_ref().2 }
@@ -351,24 +360,6 @@ impl HasOrigin for Tui {
     fn origin (&self) -> Azimuth { Azimuth::NW }
 }
 
-impl From<&Tui> for XYWH<u16> {
-    fn from (screen: &Tui) -> XYWH<u16> {
-        match screen {
-            Tui::Draw(_, area) => *area,
-            Tui::Layout(area) => *area,
-        }
-    }
-}
-
-impl<'a: 'b, 'b> From<&'a mut Tui> for &'b mut XYWH<u16> {
-    fn from (screen: &'a mut Tui) -> &'b mut XYWH<u16> {
-        match screen {
-            Tui::Draw(_, area) => area,
-            Tui::Layout(area) => area,
-        }
-    }
-}
-
 pub const fn fill_char <'a> (c: char) -> impl Draw<Tui> {
     draw(move|to: &mut Tui|Ok(Some(to.update(&|cell,_,_|{
         cell.set_char(c);
@@ -407,131 +398,3 @@ impl<'a, T: Draw<Tui>> Draw<Tui> for ShowSizeOf<T> {
         None
     })
 });
-
-//#[cfg(feature = "text")] pub use self::tui_text::*;
-#[cfg(feature = "text")] mod tui_text {
-    use super::*;
-
-    impl Tui {
-        /// Write a line of text
-        ///
-        /// TODO: do a paragraph (handle newlines)
-        pub fn text (&mut self, text: &impl AsRef<str>, x0: u16, y: u16, max_width: u16)
-            -> Perhaps<XYWH<u16>>
-        {
-            let text = text.as_ref();
-            let mut string_width: u16 = 0;
-            for character in text.chars() {
-                let x = x0 + string_width;
-                let character_width = character.width().unwrap_or(0) as u16;
-                string_width += character_width;
-                if string_width > max_width {
-                    break
-                }
-                if let Self::Draw(buffer, ..) = self {
-                    if let Some(cell) = buffer.cell_mut(ratatui::prelude::Position { x, y }) {
-                        cell.set_char(character);
-                    } else {
-                        break
-                    }
-                }
-            }
-            Ok(Some(XYWH(x0, y, string_width, 1)))
-        }
-    }
-
-    impl_draw!(|self: usize, to: Tui|{
-        let XYWH(x0, y0, w0, h0) = to.area();
-        let mut v = *self;
-        let w = (1 + if v > 0 { self.ilog10() } else { 0 }) as u16;
-        let h = 1u16;
-        Ok((w0 >= w && h0 >= h).then(||{
-            if let Tui::Draw(buffer, ..) = to {
-                let mut x = x0 + w - 1;
-                while x >= x0 {
-                    if let Some(cell) = buffer.cell_mut(Position { x, y: y0 }) {
-                        cell.set_char([
-                            '0', '1', '2', '3', '4', '5', '6', '7', '8', '9'
-                        ][(v % 10) as usize]);
-                    }
-                    x -= 1;
-                    v = v / 10;
-                }
-            }
-            XYWH(x0, y0, w, h)
-        }))
-    });
-
-    impl_draw!(|self: String, to: Tui|{
-        self.as_str().draw(to)
-    });
-
-    impl_draw!(|self: std::sync::Arc<str>, to: Tui|{
-        self.as_ref().draw(to)
-    });
-
-    impl_draw!(<T: AsRef<str>,>|self: TrimString<T>, to: Tui|{
-        self.as_ref().draw(to)
-    });
-
-    impl<'a> Draw<Tui> for &str {
-        fn draw (&self, to: &mut Tui) -> Drawn<u16> {
-            let XYWH(x, y, w, h) = to.area();
-            let mut max_w = 0u16;
-            let mut max_h = 0u16;
-            for (index, line) in self.split("\n").enumerate() {
-                let length = width_chars_max(w, line) as u16;
-                max_w = max_w.max(length);
-                max_h += 1;
-                if let Tui::Draw(..) = to {
-                    let _ = to.text(&line, x, y + index as u16, length)?;
-                }
-                if max_h >= h {
-                    break;
-                }
-            }
-            Ok(Some(XYWH(x, y, max_w, max_h)))
-        }
-    }
-
-    impl<'a, T: AsRef<str>> Draw<Tui> for TrimStr<'a, T> {
-        fn draw (&self, to: &mut Tui) -> Drawn<u16> {
-            let text = self.1.as_ref();
-            let area = layout_text_u16(text, to.area())?.unwrap();
-            let XYWH(x, y, w, ..) = to.area();
-            let mut width: u16 = 1;
-            let mut chars = text.chars();
-            while let Some(c) = chars.next() {
-                if width > self.0 || width > w {
-                    break
-                }
-                if let Tui::Draw(..) = to {
-                    to.set_char(x + width - 1, y, c);
-                }
-                width += c.width().unwrap_or(0) as u16;
-            }
-            let XYWH(x, y, w, ..) = XYWH(
-                to.x(), to.y(), to.w().min(self.0).min(self.1.as_ref().width() as u16), to.h()
-            );
-            to.text(&self.as_ref(), x, y, w)
-        }
-    }
-
-    fn layout_text_u16 (text: &str, area: XYWH<u16>) -> Perhaps<XYWH<u16>> {
-        let XYWH(x, y, w, h) = area;
-        let mut max_w = 0u16;
-        let mut max_h = 0u16;
-        for line in text.split("\n") {
-            max_h += 1;
-            max_w = max_w.max(line.len() as u16);
-        }
-        Ok(Some(XYWH(x, y, w.min(max_w), h.min(max_h))))
-    }
-
-    #[cfg(test)] #[test] fn test_layout_text_u16 () -> Usually<()> {
-        assert_eq!(layout_text_u16("foo", XYWH(5, 6, 10, 10))?, Some(XYWH(5, 6, 3, 1)));
-        assert_eq!(layout_text_u16("foo\nbarz", XYWH(5, 6, 10, 10))?, Some(XYWH(5, 6, 4, 2)));
-        Ok(())
-    }
-
-}

src/term/modify.rs

@@ -113,12 +113,13 @@ pub const fn modify <'a> (on: bool, modifier: Modifier, item: impl Draw<Tui>)
 }
 
 pub const fn fill_mod <'a> (on: bool, modifier: Modifier) -> impl Draw<Tui> {
+    let modify = if on {
+        Modifier::insert
+    } else {
+        Modifier::remove
+    };
     draw(move|to: &mut Tui|Ok(Some({
-        if on {
-            to.update(&|cell,_,_|cell.modifier.insert(modifier))
-        } else {
-            to.update(&|cell,_,_|cell.modifier.remove(modifier))
-        }
+        to.update(&|cell,_,_|modify(&mut cell.modifier, modifier))
     })))
 }
 

src/term/repeat.rs

@@ -4,13 +4,13 @@ use ratatui::{prelude::{Position}};
 pub const fn x_repeat (c: &str) -> impl Draw<Tui> {
     draw(move|to: &mut Tui|{
         let XYWH(x, y, w, _h) = to.xywh();
-        for x in x..x+w {
-            if let Tui::Draw(buf, ..) = to {
+        to.buffer().map(|buf|{
+            for x in x..x+w {
                 if let Some(cell) = buf.cell_mut(Position::from((x, y))) {
                     cell.set_symbol(&c);
                 }
             }
-        }
+        });
         Ok(Some(XYWH(x, y, w, 1)))
     })
 }
@@ -18,13 +18,13 @@ pub const fn x_repeat (c: &str) -> impl Draw<Tui> {
 pub const fn y_repeat (c: &str) -> impl Draw<Tui> {
     draw(move|to: &mut Tui|{
         let XYWH(x, y, _w, h) = to.xywh();
-        for y in y..y+h {
-            if let Tui::Draw(buf, ..) = to {
+        to.buffer().map(|buf|{
+            for y in y..y+h {
                 if let Some(cell) = buf.cell_mut(Position::from((x, y))) {
                     cell.set_symbol(&c);
                 }
             }
-        }
+        });
         Ok(Some(XYWH(x, y, 1, h)))
     })
 }
@@ -33,16 +33,16 @@ pub const fn xy_repeat (c: &str) -> impl Draw<Tui> {
     draw(move|to: &mut Tui|{
         let XYWH(x, y, w, h) = to.xywh();
         let a = c.len();
-        for (_v, y) in (y..y+h).enumerate() {
-            for (u, x) in (x..x+w).enumerate() {
-                if let Tui::Draw(buf, ..) = to {
+        to.buffer().map(|buf|{
+            for (_v, y) in (y..y+h).enumerate() {
+                for (u, x) in (x..x+w).enumerate() {
                     if let Some(cell) = buf.cell_mut(Position::from((x, y))) {
                         let u = u % a;
                         cell.set_symbol(&c[u..u+1]);
                     }
                 }
             }
-        }
+        });
         Ok(Some(XYWH(x, y, w, h)))
     })
 }

src/term/scroll.rs

@@ -11,7 +11,7 @@ pub fn x_scroll <'a> () -> impl Draw<Tui> {
         let XYWH(x1, y1, w, _h) = to.area();
         let x2 = x1 + w;
         for (i, x) in (x1..=x2).enumerate() {
-            if let Tui::Draw(buf, ..) = to {
+            to.buffer().map(|buf|{
                 if let Some(cell) = buf.cell_mut(Position::from((x, y1))) {
                     if i < (ICON_DEC_H.len()) {
                         cell.set_fg(Rgb(255, 255, 255));
@@ -31,7 +31,7 @@ pub fn x_scroll <'a> () -> impl Draw<Tui> {
                         cell.set_char('╌');
                     }
                 }
-            }
+            });
         }
         Ok(Some(XYWH(x1, y1, w, 1)))
     })
@@ -42,7 +42,7 @@ pub fn y_scroll <'a> () -> impl Draw<Tui> {
         let XYWH(x1, y1, _w, h) = to.area();
         let y2 = y1 + h;
         for (i, y) in (y1..=y2).enumerate() {
-            if let Tui::Draw(buf, ..) = to {
+            to.buffer().map(|buf|{
                 if let Some(cell) = buf.cell_mut(Position::from((x1, y))) {
                     if (i as usize) < (ICON_DEC_V.len()) {
                         cell.set_fg(Rgb(255, 255, 255));
@@ -62,7 +62,7 @@ pub fn y_scroll <'a> () -> impl Draw<Tui> {
                         cell.set_char('╎'); // ━
                     }
                 }
-            }
+            });
         }
         Ok(Some(XYWH(x1, y1, 1, h)))
     })

src/term/text.rs

@@ -0,0 +1 @@
+use crate::*;

src/text.rs

@@ -0,0 +1,213 @@
+use crate::*;
+pub(crate) use ::unicode_width::*;
+
+/// Displays a multi-line text string.
+pub struct Text<T: AsRef<str>>(T);
+
+/// Displays an owned [str]-like with fixed maximum width.
+///
+/// Width is computed using [unicode_width].
+pub struct TrimString<T: AsRef<str>>(pub u16, pub T);
+
+/// Displays a borrowed [str]-like with fixed maximum width
+///
+/// Width is computed using [unicode_width].
+pub struct TrimStr<'a, T: AsRef<str>>(pub u16, pub &'a T);
+
+impl<T: AsRef<str>> AsRef<str> for TrimString<T> {
+    fn as_ref (&self) -> &str {
+        self.1.as_ref()
+    }
+}
+
+impl<'a, T: AsRef<str>> TrimString<T> {
+    fn to_ref (&self) -> TrimStr<'_, T> {
+        TrimStr(self.0, &self.1)
+    }
+}
+
+impl<T: AsRef<str>> AsRef<str> for TrimStr<'_, T> {
+    fn as_ref (&self) -> &str {
+        self.1.as_ref()
+    }
+}
+
+pub(crate) fn width_chars_max (max: u16, text: impl AsRef<str>) -> u16 {
+    let mut width: u16 = 0;
+    let mut chars = text.as_ref().chars();
+    while let Some(c) = chars.next() {
+        width += c.width().unwrap_or(0) as u16;
+        if width >= max {
+            break
+        }
+    }
+    return width
+}
+
+/// Trim string with [unicode_width].
+pub fn trim_string (max_width: usize, input: impl AsRef<str>) -> String {
+    let input = input.as_ref();
+    let mut output = Vec::with_capacity(input.len());
+    let mut width: usize = 1;
+    let mut chars = input.chars();
+    while let Some(c) = chars.next() {
+        if width > max_width {
+            break
+        }
+        output.push(c);
+        width += c.width().unwrap_or(0);
+    }
+    return output.into_iter().collect()
+}
+
+#[cfg(feature = "term")]
+mod text_term {
+    use crate::*;
+
+    impl Tui {
+        /// Write a line of text
+        ///
+        /// TODO: do a paragraph (handle newlines)
+        pub fn text (&mut self, text: &impl AsRef<str>, x0: u16, y: u16, max_width: u16)
+            -> Perhaps<XYWH<u16>>
+        {
+            let text = text.as_ref();
+            let mut string_width: u16 = 0;
+            for character in text.chars() {
+                let x = x0 + string_width;
+                let character_width = character.width().unwrap_or(0) as u16;
+                string_width += character_width;
+                if string_width > max_width {
+                    break
+                }
+                if Some(true) == self.buffer().map(|buffer|{
+                    if let Some(cell) = buffer.cell_mut(ratatui::prelude::Position { x, y }) {
+                        cell.set_char(character);
+                        false
+                    } else {
+                        true
+                    }
+                }) {
+                    break
+                }
+            }
+            Ok(Some(XYWH(x0, y, string_width, 1)))
+        }
+    }
+
+    impl_draw!(|self: usize, to: Tui|{
+        let XYWH(x0, y0, w0, h0) = to.area();
+        let mut v = *self;
+        let w = (1 + if v > 0 { self.ilog10() } else { 0 }) as u16;
+        let h = 1u16;
+        Ok((w0 >= w && h0 >= h).then(||{
+            to.buffer().map(|buffer|{
+                let mut x = x0 + w - 1;
+                while x >= x0 {
+                    if let Some(cell) = buffer.cell_mut(Position { x, y: y0 }) {
+                        cell.set_char([
+                            '0', '1', '2', '3', '4', '5', '6', '7', '8', '9'
+                        ][(v % 10) as usize]);
+                    }
+                    x -= 1;
+                    v = v / 10;
+                }
+            });
+            XYWH(x0, y0, w, h)
+        }))
+    });
+
+    impl_draw!(|self: String, to: Tui|{
+        self.as_str().draw(to)
+    });
+
+    impl_draw!(|self: std::sync::Arc<str>, to: Tui|{
+        self.as_ref().draw(to)
+    });
+
+    impl_draw!(<T: AsRef<str>,>|self: TrimString<T>, to: Tui|{
+        self.as_ref().draw(to)
+    });
+
+    impl<'a> Draw<Tui> for &str {
+        fn draw (&self, to: &mut Tui) -> Drawn<u16> {
+            let XYWH(x, y, w, h) = to.area();
+            if h > 0 {
+                to.buffer().map(|buf|buf.set_stringn(x, y, self, w as usize, Style::default()));
+                Ok(Some(XYWH(x, y, w.min(self.len() as u16), 1)))
+            } else {
+                Ok(Some(XYWH(x, y, 0, 0)))
+            }
+        }
+    }
+
+    impl<T: AsRef<str>> Draw<Tui> for Text<T> {
+        fn draw (&self, to: &mut Tui) -> Drawn<u16> {
+            let XYWH(x, y, w, h) = to.area();
+            let mut max_w = 0u16;
+            let mut max_h = 0u16;
+            if to.buffer().is_some() {
+                for (index, line) in self.0.as_ref().split("\n").enumerate() {
+                    let length = width_chars_max(w, line) as u16;
+                    max_w = max_w.max(length);
+                    max_h += 1;
+                    let _ = to.text(&line, x, y + index as u16, length)?;
+                    if max_h >= h {
+                        break;
+                    }
+                }
+            } else {
+                for line in self.0.as_ref().split("\n") {
+                    let length = width_chars_max(w, line) as u16;
+                    max_w = max_w.max(length);
+                    max_h += 1;
+                    if max_h >= h {
+                        break;
+                    }
+                }
+            }
+            Ok(Some(XYWH(x, y, max_w, max_h)))
+        }
+    }
+
+    impl<'a, T: AsRef<str>> Draw<Tui> for TrimStr<'a, T> {
+        fn draw (&self, to: &mut Tui) -> Drawn<u16> {
+            let text = self.1.as_ref();
+            //let area = layout_text_u16(text, to.area())?.unwrap();
+            let XYWH(x, y, w, ..) = to.area();
+            let mut width: u16 = 1;
+            let mut chars = text.chars();
+            while let Some(c) = chars.next() {
+                if width > self.0 || width > w {
+                    break
+                }
+                if to.buffer().is_some() {
+                    to.set_char(x + width - 1, y, c);
+                }
+                width += c.width().unwrap_or(0) as u16;
+            }
+            let XYWH(x, y, w, ..) = XYWH(
+                to.x(), to.y(), to.w().min(self.0).min(self.1.as_ref().width() as u16), to.h()
+            );
+            to.text(&self.as_ref(), x, y, w)
+        }
+    }
+
+    fn layout_text_u16 (text: &str, area: XYWH<u16>) -> Perhaps<XYWH<u16>> {
+        let XYWH(x, y, w, h) = area;
+        let mut max_w = 0u16;
+        let mut max_h = 0u16;
+        for line in text.split("\n") {
+            max_h += 1;
+            max_w = max_w.max(line.len() as u16);
+        }
+        Ok(Some(XYWH(x, y, w.min(max_w), h.min(max_h))))
+    }
+
+    #[cfg(test)] #[test] fn test_layout_text_u16 () -> Usually<()> {
+        assert_eq!(layout_text_u16("foo", XYWH(5, 6, 10, 10))?, Some(XYWH(5, 6, 3, 1)));
+        assert_eq!(layout_text_u16("foo\nbarz", XYWH(5, 6, 10, 10))?, Some(XYWH(5, 6, 4, 2)));
+        Ok(())
+    }
+
+}