Remove comments that only restate the text code

# Conflicts:
#	core/src/render/primitive.rs

Cargo.toml

@@ -8,8 +8,7 @@ edition.workspace = true
 [dependencies]
 iris-core = { workspace = true }
 iris-macro = { workspace = true }
-cosmic-text = { workspace = true }
-unicode-segmentation = { workspace = true }
+parley = { workspace = true }
 winit = { workspace = true }
 arboard = { workspace = true, features = ["wayland-data-control"] }
 pollster = { workspace = true }
@@ -28,13 +27,13 @@ version = "0.1.0"
 edition = "2024"
 
 [workspace.dependencies]
-pollster = "1.0.1"
+pollster = "0.4.0"
 winit = "0.30.12"
-wgpu = "30.0.0"
+wgpu = "28.0.0"
 bytemuck = "1.23.1"
 image = "0.25.6"
-cosmic-text = "0.16.0"
-unicode-segmentation = "1.12.0"
+parley = "0.11.1"
+swash = "0.2.10"
 fxhash = "0.2.1"
 arboard = "3.6.1"
 iris-core = { path = "core" }

core/Cargo.toml

@@ -4,9 +4,9 @@ version.workspace = true
 edition.workspace = true
 
 [dependencies]
-winit = { workspace = true }
 wgpu = { workspace = true }
 bytemuck ={ workspace = true }
 image = { workspace = true }
-cosmic-text = { workspace = true }
+parley = { workspace = true }
+swash = { workspace = true }
 fxhash = { workspace = true }

core/src/attr.rs

@@ -1,4 +1,4 @@
-use crate::{UiRsc, WidgetIdFn, WidgetLike, WeakWidget};
+use crate::{UiRsc, WeakWidget, WidgetIdFn, WidgetLike};
 
 pub trait WidgetAttr<Rsc, W: ?Sized> {
     type Input;

core/src/lib.rs

@@ -5,7 +5,6 @@
 #![feature(unboxed_closures)]
 #![feature(fn_traits)]
 #![feature(const_destruct)]
-#![feature(portable_simd)]
 #![feature(associated_type_defaults)]
 #![feature(unsize)]
 #![feature(coerce_unsized)]

core/src/primitive/color.rs

@@ -10,6 +10,12 @@ pub struct Color<T> {
     pub a: T,
 }
 
+impl<T: ColorNum> Default for Color<T> {
+    fn default() -> Self {
+        Self::BLACK
+    }
+}
+
 impl<T: ColorNum> Color<T> {
     pub const BLACK: Self = Self::rgb(T::MIN, T::MIN, T::MIN);
     pub const WHITE: Self = Self::rgb(T::MAX, T::MAX, T::MAX);

core/src/primitive/text.rs

@@ -1,60 +1,63 @@
-use crate::{Align, RegionAlign, TextureHandle, Textures, UiColor, util::Vec2};
-use cosmic_text::{
-    Attrs, AttrsList, Buffer, CacheKey, Color, Family, FontSystem, Metrics, Placement, SwashCache,
-    SwashContent,
+use crate::{Align, GlyphAtlas, GlyphKey, PlacedGlyph, RegionAlign, Textures, UiColor, util::Vec2};
+use parley::{
+    Alignment, AlignmentOptions, FontContext, FontFamily, FontFamilyName, GenericFamily, Layout,
+    LayoutContext, LineHeight, PositionedLayoutItem, StyleProperty,
+};
+use swash::{
+    FontRef,
+    scale::{Render, ScaleContext, Source, StrikeWith},
+    zeno::{Format, Vector},
 };
-use image::{DynamicImage, GenericImageView, RgbaImage};
-use std::simd::{Simd, num::SimdUint};
-
-/// TODO: properly wrap this
-pub mod text_lib {
-    pub use cosmic_text::*;
-}
 
 pub struct TextData {
-    pub font_system: FontSystem,
-    pub swash_cache: SwashCache,
-    glyph_cache: Vec<(Placement, CacheKey, Color)>,
+    pub font_cx: FontContext,
+    pub layout_cx: LayoutContext<UiColor>,
+    scale_cx: ScaleContext,
+    pub atlas: GlyphAtlas,
 }
 
 impl Default for TextData {
     fn default() -> Self {
         Self {
-            font_system: FontSystem::new(),
-            swash_cache: SwashCache::new(),
-            glyph_cache: Default::default(),
+            font_cx: FontContext::new(),
+            layout_cx: LayoutContext::new(),
+            scale_cx: ScaleContext::new(),
+            atlas: GlyphAtlas::default(),
         }
     }
 }
 
-#[derive(Clone, Copy)]
+#[derive(Clone, PartialEq)]
+pub enum Family {
+    SansSerif,
+    Serif,
+    Monospace,
+    Named(String),
+}
+
+impl Family {
+    fn family(&self) -> FontFamily<'_> {
+        let name = match self {
+            Self::SansSerif => FontFamilyName::Generic(GenericFamily::SansSerif),
+            Self::Serif => FontFamilyName::Generic(GenericFamily::Serif),
+            Self::Monospace => FontFamilyName::Generic(GenericFamily::Monospace),
+            Self::Named(name) => FontFamilyName::Named(name.as_str().into()),
+        };
+        FontFamily::Single(name)
+    }
+}
+
+#[derive(Clone, PartialEq)]
 pub struct TextAttrs {
     pub color: UiColor,
     pub font_size: f32,
     pub line_height: f32,
-    pub family: Family<'static>,
+    pub family: Family,
     pub wrap: bool,
-    /// inner alignment of text region (within where it's drawn)
     pub align: RegionAlign,
 }
 
-impl TextAttrs {
-    pub fn apply(&self, font_system: &mut FontSystem, buf: &mut Buffer, width: Option<f32>) {
-        buf.set_metrics_and_size(
-            font_system,
-            Metrics::new(self.font_size, self.line_height),
-            width,
-            None,
-        );
-        let attrs = Attrs::new().family(self.family);
-        let list = AttrsList::new(&attrs);
-        for line in &mut buf.lines {
-            line.set_attrs_list(list.clone());
-        }
-    }
-}
-
-pub type TextBuffer = Buffer;
+pub const LINE_HEIGHT_MULT: f32 = 1.1;
 
 impl Default for TextAttrs {
     fn default() -> Self {
@@ -70,122 +73,178 @@ impl Default for TextAttrs {
     }
 }
 
-pub const LINE_HEIGHT_MULT: f32 = 1.1;
+/// Keeps text and its corresponding layout from getting out of sync.
+pub struct TextBuffer {
+    text: String,
+    layout: Layout<UiColor>,
+    shaped: Option<(TextAttrs, Option<f32>)>,
+}
 
-impl TextData {
-    pub fn draw(
-        &mut self,
-        buffer: &mut TextBuffer,
-        attrs: &TextAttrs,
-        textures: &mut Textures,
-    ) -> RenderedText {
-        // TODO: either this or the layout stuff (or both) is super slow,
-        // should probably do texture packing and things if possible.
-        // very visible if you add just a couple of wrapping texts and resize window
-        // should also be timed to figure out exactly what points need to be sped up
-        // let mut pixels = HashMap::<_, [u8; 4]>::default();
-        let mut min_x = 0;
-        let mut min_y = 0;
-        let mut max_x = 0;
-        let mut max_y = 0;
-        let text_color = {
-            let c = attrs.color;
-            cosmic_text::Color::rgba(c.r, c.g, c.b, c.a)
-        };
-        let mut max_width = 0.0f32;
-        let mut height = 0.0;
-
-        for run in buffer.layout_runs() {
-            for glyph in run.glyphs.iter() {
-                let physical_glyph = glyph.physical((0., 0.), 1.0);
-
-                let glyph_color = match glyph.color_opt {
-                    Some(some) => some,
-                    None => text_color,
-                };
-
-                if let Some(img) = self
-                    .swash_cache
-                    .get_image(&mut self.font_system, physical_glyph.cache_key)
-                {
-                    let mut pos = img.placement;
-                    pos.left += physical_glyph.x;
-                    pos.top = physical_glyph.y + run.line_y as i32 - pos.top;
-                    min_x = min_x.min(pos.left);
-                    min_y = min_y.min(pos.top);
-                    max_x = max_x.max(pos.left + pos.width as i32);
-                    max_y = max_y.max(pos.top + pos.height as i32);
-                    self.glyph_cache
-                        .push((pos, physical_glyph.cache_key, glyph_color));
-                }
-            }
-            max_width = max_width.max(run.line_w);
-            height += run.line_height;
-        }
-        let img_width = (max_x - min_x + 1) as u32;
-        let img_height = (max_y - min_y + 1) as u32;
-        let mut image = RgbaImage::new(img_width, img_height);
-
-        for (pos, key, color) in self.glyph_cache.drain(..) {
-            let img = self
-                .swash_cache
-                .get_image(&mut self.font_system, key)
-                .as_ref()
-                .unwrap();
-            let mut merge = |i, color: [u8; 4]| {
-                let i = i as i32;
-                let x = (i % pos.width as i32 + pos.left - min_x) as u32;
-                let y = (i / pos.width as i32 + pos.top - min_y) as u32;
-                let pixel = &mut image[(x, y)].0;
-                // TODO: no clue if proper alpha blending should be done
-                *pixel = Simd::from(color).saturating_add(Simd::from(*pixel)).into();
-            };
-
-            match img.content {
-                SwashContent::Mask => {
-                    for (i, a) in img.data.iter().enumerate() {
-                        let mut color = color.as_rgba();
-                        color[3] = ((color[3] as u32 * *a as u32) / u8::MAX as u32) as u8;
-                        merge(i, color);
-                    }
-                }
-                SwashContent::SubpixelMask => todo!("subpixel mask text rendering"),
-                SwashContent::Color => {
-                    let (colors, _) = img.data.as_chunks::<4>();
-                    for (i, color) in colors.iter().enumerate() {
-                        merge(i, *color);
-                    }
-                }
-            }
-        }
-
-        let max_dim = 8192;
-        if image.width() > max_dim || image.height() > max_dim {
-            let width = image.width().min(max_dim);
-            let height = image.height().min(max_dim);
-            eprintln!(
-                "WARNING: image of size {:?} cropped to {:?} (texture too big)",
-                image.dimensions(),
-                (width, height)
-            );
-            image = image.view(0, 0, width, height).to_image();
-        }
-
-        RenderedText {
-            handle: textures.add(image),
-            top_left_offset: Vec2::new(min_x as f32, min_y as f32),
-            size: Vec2::new(max_width, height),
+impl TextBuffer {
+    pub fn new(text: impl Into<String>) -> Self {
+        Self {
+            text: text.into(),
+            layout: Layout::new(),
+            shaped: None,
         }
     }
+
+    pub fn new_empty() -> Self {
+        Self::new("")
+    }
+
+    pub fn text(&self) -> &str {
+        &self.text
+    }
+
+    pub fn layout(&self) -> &Layout<UiColor> {
+        &self.layout
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.text.is_empty()
+    }
+
+    pub fn set_text(&mut self, text: impl Into<String>) {
+        let text = text.into();
+        if text != self.text {
+            self.text = text;
+            self.shaped = None;
+        }
+    }
+
+    /// Invalidates the layout and returns the underlying string for editing.
+    pub fn edit(&mut self) -> &mut String {
+        self.shaped = None;
+        &mut self.text
+    }
+
+    pub fn size(&self) -> Vec2 {
+        Vec2::new(self.layout.width(), self.layout.height())
+    }
+
+    pub fn shape(&mut self, data: &mut TextData, attrs: &TextAttrs, width: Option<f32>) {
+        if self.shaped.as_ref() == Some(&(attrs.clone(), width)) {
+            return;
+        }
+        let mut builder = data
+            .layout_cx
+            .ranged_builder(&mut data.font_cx, &self.text, 1.0, true);
+        builder.push_default(StyleProperty::FontFamily(attrs.family.family()));
+        builder.push_default(StyleProperty::FontSize(attrs.font_size));
+        builder.push_default(StyleProperty::LineHeight(LineHeight::Absolute(
+            attrs.line_height,
+        )));
+        builder.push_default(StyleProperty::Brush(attrs.color));
+        builder.build_into(&mut self.layout, &self.text);
+        self.layout.break_all_lines(width);
+        self.layout
+            .align(Alignment::Start, AlignmentOptions::default());
+        self.shaped = Some((attrs.clone(), width));
+    }
+}
+
+impl TextData {
+    pub fn place(&mut self, buffer: &TextBuffer, textures: &mut Textures) -> Vec<PlacedGlyph> {
+        let mut placed = Vec::new();
+        for line in buffer.layout.lines() {
+            for item in line.items() {
+                let PositionedLayoutItem::GlyphRun(run) = item else {
+                    continue;
+                };
+                let font = run.run().font();
+                let font_size = run.run().font_size();
+                let coords = run.run().normalized_coords();
+                let Some(font_ref) = FontRef::from_index(font.data.as_ref(), font.index as usize)
+                else {
+                    continue;
+                };
+                let coords_hash = hash_coords(coords);
+                // `font.data.id()` rather than the pointer, so the same font
+                // loaded twice is still one set of entries.
+                let font_id = font.data.id();
+
+                for glyph in run.positioned_glyphs() {
+                    let subpixel = ((glyph.x.fract() * 4.0).round() as i32).rem_euclid(4) as u8;
+                    let key = GlyphKey {
+                        font: font_id,
+                        glyph: glyph.id,
+                        size: (font_size * 16.0).round() as u32,
+                        subpixel,
+                        coords: coords_hash,
+                    };
+                    let entry = match self.atlas.get(&key) {
+                        Some(entry) => entry,
+                        None => {
+                            let mut scaler = self
+                                .scale_cx
+                                .builder(font_ref)
+                                .size(font_size)
+                                .hint(true)
+                                .normalized_coords(coords)
+                                .build();
+                            let image = Render::new(&[
+                                Source::ColorOutline(0),
+                                Source::ColorBitmap(StrikeWith::BestFit),
+                                Source::Outline,
+                            ])
+                            .format(Format::Alpha)
+                            .offset(Vector::new(subpixel as f32 / 4.0, 0.0))
+                            .render(&mut scaler, glyph.id as u16);
+                            match image {
+                                Some(image) => self.atlas.insert(key, &image, textures),
+                                None => {
+                                    self.atlas.insert_empty(key);
+                                    None
+                                }
+                            }
+                        }
+                    };
+                    let Some(entry) = entry else { continue };
+                    placed.push(PlacedGlyph {
+                        entry,
+                        offset: Vec2::new(
+                            glyph.x.floor() + entry.left as f32,
+                            glyph.y.floor() - entry.top as f32,
+                        ),
+                    });
+                }
+            }
+        }
+        placed
+    }
+}
+
+fn hash_coords(coords: &[i16]) -> u64 {
+    let mut h: u64 = 0xcbf2_9ce4_8422_2325;
+    for c in coords {
+        h ^= *c as u16 as u64;
+        h = h.wrapping_mul(0x1000_0000_01b3);
+    }
+    h
 }
 
 #[derive(Clone)]
 pub struct RenderedText {
-    pub handle: TextureHandle,
-    pub top_left_offset: Vec2,
+    pub glyphs: std::sync::Arc<Vec<PlacedGlyph>>,
     pub size: Vec2,
+    pub color: UiColor,
 }
 
-pub trait HasTextures {
-    fn add_texture(&mut self, image: DynamicImage) -> TextureHandle;
+impl TextData {
+    pub fn render(
+        &mut self,
+        buffer: &mut TextBuffer,
+        attrs: &TextAttrs,
+        width: Option<f32>,
+        textures: &mut Textures,
+    ) -> RenderedText {
+        buffer.shape(self, attrs, width);
+        let glyphs = self.place(buffer, textures);
+        RenderedText {
+            glyphs: std::sync::Arc::new(glyphs),
+            size: buffer.size(),
+            color: attrs.color,
+        }
+    }
 }

core/src/primitive/texture.rs

@@ -29,14 +29,24 @@ pub struct Textures {
 pub enum TextureUpdate<'a> {
     Push(&'a DynamicImage),
     Set(u32, &'a DynamicImage),
+    Patch(u32, PatchRect, &'a DynamicImage),
     Free(u32),
     PushFree,
     SetFree,
 }
 
+#[derive(Debug, Clone, Copy)]
+pub struct PatchRect {
+    pub x: u32,
+    pub y: u32,
+    pub width: u32,
+    pub height: u32,
+}
+
 enum Update {
     Push(u32),
     Set(u32),
+    Patch(u32, PatchRect),
     Free(u32),
 }
 
@@ -81,6 +91,18 @@ impl Textures {
         }
     }
 
+    pub fn image_mut(&mut self, handle: &TextureHandle) -> &mut DynamicImage {
+        self.images[handle.inner.view_idx as usize]
+            .as_mut()
+            .expect("texture was freed while still held")
+    }
+
+    /// Queue an upload of just `rect`, after writing it with `image_mut`.
+    pub fn patch(&mut self, handle: &TextureHandle, rect: PatchRect) {
+        self.updates
+            .push(Update::Patch(handle.inner.view_idx, rect));
+    }
+
     pub fn free(&mut self) {
         for idx in self.recv.try_iter() {
             self.images[idx as usize] = None;
@@ -99,6 +121,10 @@ impl Textures {
                 .as_ref()
                 .map(|img| TextureUpdate::Set(i, img))
                 .unwrap_or(TextureUpdate::SetFree),
+            Update::Patch(i, rect) => self.images[i as usize]
+                .as_ref()
+                .map(|img| TextureUpdate::Patch(i, rect, img))
+                .unwrap_or(TextureUpdate::SetFree),
             Update::Free(i) => TextureUpdate::Free(i),
         })
     }

core/src/render/atlas.rs

@@ -0,0 +1,200 @@
+use crate::{
+    PatchRect, TextureHandle, Textures,
+    util::{HashMap, Vec2},
+};
+use image::RgbaImage;
+use swash::scale::image::{Content, Image};
+
+const PAGE: u32 = 1024;
+
+/// Transparent margin kept around every glyph, so that sampling one cannot
+/// pick up its neighbour along a shared edge.
+const PAD: u32 = 1;
+
+#[derive(Clone, Copy, PartialEq, Eq, Hash)]
+pub struct GlyphKey {
+    pub font: u64,
+    pub glyph: u32,
+    /// Font size in 1/16 px, so sizes that round to the same pixels share a
+    /// raster instead of filling the atlas with near-duplicates.
+    pub size: u32,
+    /// Horizontal subpixel phase, in 1/4 px.
+    pub subpixel: u8,
+    /// Hash of the variation coordinates; a variable font at two weights is two
+    /// different sets of pixels from one glyph id.
+    pub coords: u64,
+}
+
+#[derive(Clone, Copy)]
+pub struct GlyphEntry {
+    pub uv_min: [f32; 2],
+    pub uv_max: [f32; 2],
+    /// Offset from the glyph's pen position to the top-left of its pixels.
+    pub left: i32,
+    pub top: i32,
+    pub width: u32,
+    pub height: u32,
+    pub is_color: bool,
+    pub view_idx: u32,
+    pub sampler_idx: u32,
+}
+
+struct Page {
+    handle: TextureHandle,
+    x: u32,
+    y: u32,
+    shelf_height: u32,
+}
+
+#[derive(Default)]
+pub struct GlyphAtlas {
+    pages: Vec<Page>,
+    /// `None` for a glyph that rasterised to nothing -- a space, say. Cached
+    /// too, so it is not re-rasterised on every layout.
+    entries: HashMap<GlyphKey, Option<GlyphEntry>>,
+}
+
+impl GlyphAtlas {
+    pub fn get(&self, key: &GlyphKey) -> Option<Option<GlyphEntry>> {
+        self.entries.get(key).copied()
+    }
+
+    pub fn insert(
+        &mut self,
+        key: GlyphKey,
+        image: &Image,
+        textures: &mut Textures,
+    ) -> Option<GlyphEntry> {
+        let w = image.placement.width;
+        let h = image.placement.height;
+        if w == 0 || h == 0 {
+            self.entries.insert(key, None);
+            return None;
+        }
+        if w + PAD * 2 > PAGE || h + PAD * 2 > PAGE {
+            self.entries.insert(key, None);
+            return None;
+        }
+
+        let (page_idx, x, y) = self.allocate(w, h, textures);
+        let page = &self.pages[page_idx];
+
+        let img = textures.image_mut(&page.handle);
+        let rgba = img.as_mut_rgba8().expect("atlas page is rgba8");
+        write_glyph(rgba, image, x, y);
+
+        let handle = page.handle.clone();
+        let rect = PatchRect {
+            x,
+            y,
+            width: w,
+            height: h,
+        };
+        textures.patch(&handle, rect);
+
+        let page = &self.pages[page_idx];
+        let scale = 1.0 / PAGE as f32;
+        let entry = GlyphEntry {
+            uv_min: [x as f32 * scale, y as f32 * scale],
+            uv_max: [(x + w) as f32 * scale, (y + h) as f32 * scale],
+            left: image.placement.left,
+            top: image.placement.top,
+            width: w,
+            height: h,
+            is_color: matches!(image.content, Content::Color),
+            view_idx: page.handle.primitive().view_idx,
+            sampler_idx: page.handle.primitive().sampler_idx,
+        };
+        self.entries.insert(key, Some(entry));
+        Some(entry)
+    }
+
+    fn allocate(&mut self, w: u32, h: u32, textures: &mut Textures) -> (usize, u32, u32) {
+        let need_w = w + PAD;
+        let need_h = h + PAD;
+        if let Some(i) = self.pages.iter().position(|p| fits(p, need_w, need_h)) {
+            let page = &mut self.pages[i];
+            if page.x + need_w > PAGE {
+                page.y += page.shelf_height;
+                page.x = PAD;
+                page.shelf_height = 0;
+            }
+            let (x, y) = (page.x, page.y);
+            page.x += need_w;
+            page.shelf_height = page.shelf_height.max(need_h);
+            return (i, x, y);
+        }
+
+        let handle = textures.add(RgbaImage::new(PAGE, PAGE));
+        self.pages.push(Page {
+            handle,
+            x: PAD + w + PAD,
+            y: PAD,
+            shelf_height: h + PAD,
+        });
+        (self.pages.len() - 1, PAD, PAD)
+    }
+
+    pub fn insert_empty(&mut self, key: GlyphKey) {
+        self.entries.insert(key, None);
+    }
+
+    pub fn page_count(&self) -> usize {
+        self.pages.len()
+    }
+
+    pub fn glyph_count(&self) -> usize {
+        self.entries.len()
+    }
+}
+
+fn fits(page: &Page, need_w: u32, need_h: u32) -> bool {
+    (page.x + need_w <= PAGE && page.y + need_h <= PAGE)
+        || (need_w + PAD <= PAGE && page.y + page.shelf_height + need_h <= PAGE)
+}
+
+/// Mask glyphs keep coverage in alpha so their raster can be tinted at draw time.
+fn write_glyph(page: &mut RgbaImage, image: &Image, x: u32, y: u32) {
+    let w = image.placement.width;
+    let h = image.placement.height;
+    match image.content {
+        Content::Mask => {
+            for row in 0..h {
+                for col in 0..w {
+                    let a = image.data[(row * w + col) as usize];
+                    page.put_pixel(x + col, y + row, image::Rgba([255, 255, 255, a]));
+                }
+            }
+        }
+        Content::Color => {
+            for row in 0..h {
+                for col in 0..w {
+                    let i = ((row * w + col) * 4) as usize;
+                    let px = [
+                        image.data[i],
+                        image.data[i + 1],
+                        image.data[i + 2],
+                        image.data[i + 3],
+                    ];
+                    page.put_pixel(x + col, y + row, image::Rgba(px));
+                }
+            }
+        }
+        Content::SubpixelMask => {
+            // Preserve readable output if the rasterizer returns a subpixel mask.
+            for row in 0..h {
+                for col in 0..w {
+                    let i = ((row * w + col) * 4) as usize;
+                    let a = image.data[i + 1];
+                    page.put_pixel(x + col, y + row, image::Rgba([255, 255, 255, a]));
+                }
+            }
+        }
+    }
+}
+
+#[derive(Clone, Copy)]
+pub struct PlacedGlyph {
+    pub entry: GlyphEntry,
+    pub offset: Vec2,
+}

core/src/render/mod.rs

@@ -3,20 +3,21 @@ use std::num::NonZero;
 use crate::{
     UiData, UiRenderState,
     render::{data::PrimitiveInstance, texture::GpuTextures, util::ArrBuf},
-    util::HashMap,
+    util::{HashMap, Vec2},
 };
 use data::WindowUniform;
 use wgpu::{
     util::{BufferInitDescriptor, DeviceExt},
     *,
 };
-use winit::dpi::PhysicalSize;
 
+mod atlas;
 mod data;
 mod primitive;
 mod texture;
 mod util;
 
+pub use atlas::*;
 pub use data::{Mask, MaskIdx};
 pub use primitive::*;
 
@@ -118,10 +119,11 @@ impl UiRenderNode {
         }
     }
 
-    pub fn resize(&mut self, size: &PhysicalSize<u32>, queue: &Queue) {
+    pub fn resize(&mut self, size: impl Into<Vec2>, queue: &Queue) {
+        let size = size.into();
         let slice = &[WindowUniform {
-            width: size.width as f32,
-            height: size.height as f32,
+            width: size.x,
+            height: size.y,
         }];
         queue.write_buffer(&self.window_buffer, 0, bytemuck::cast_slice(slice));
     }
@@ -137,7 +139,10 @@ impl UiRenderNode {
             source: ShaderSource::Wgsl(SHAPE_SHADER.into()),
         });
 
-        let window_uniform = WindowUniform::default();
+        let window_uniform = WindowUniform {
+            width: config.width as f32,
+            height: config.height as f32,
+        };
         let window_buffer = device.create_buffer_init(&BufferInitDescriptor {
             label: Some("window"),
             contents: bytemuck::cast_slice(&[window_uniform]),
@@ -188,7 +193,7 @@ impl UiRenderNode {
 
         let pipeline_layout = device.create_pipeline_layout(&PipelineLayoutDescriptor {
             label: Some("UI Shape Pipeline Layout"),
-            bind_group_layouts: &[&uniform_layout, &primitive_layout, &rsc_layout].map(Some),
+            bind_group_layouts: &[&uniform_layout, &primitive_layout, &rsc_layout],
             immediate_size: 0,
         });
         let pipeline = device.create_render_pipeline(&RenderPipelineDescriptor {
@@ -197,7 +202,7 @@ impl UiRenderNode {
             vertex: VertexState {
                 module: &shader,
                 entry_point: Some("vs_main"),
-                buffers: &[Some(PrimitiveInstance::desc())],
+                buffers: &[PrimitiveInstance::desc()],
                 compilation_options: Default::default(),
             },
             fragment: Some(FragmentState {

core/src/render/primitive.rs

@@ -93,7 +93,7 @@ macro_rules! primitives {
             }
         )*
     };
-    (@count $t1:tt $($t:tt)+) => { 1 + primitives!(@count $($t),+) };
+    (@count $t1:tt $($t:tt)+) => { 1 + primitives!(@count $($t)+) };
     (@count $t:tt) => { 1 };
 }
 
@@ -201,6 +201,7 @@ impl PrimitiveHandle {
 primitives!(
     rects: RectPrimitive => 0,
     textures: TexturePrimitive => 1,
+    glyphs: GlyphPrimitive => 2,
 );
 
 #[repr(C)]
@@ -230,6 +231,21 @@ pub struct TexturePrimitive {
     pub sampler_idx: u32,
 }
 
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct GlyphPrimitive {
+    pub uv_min: [f32; 2],
+    pub uv_max: [f32; 2],
+    pub view_idx: u32,
+    pub sampler_idx: u32,
+    pub color: Color<u8>,
+    pub flags: u32,
+}
+
+impl GlyphPrimitive {
+    pub const IS_COLOR: u32 = 1;
+}
+
 pub struct PrimitiveVec<T> {
     vec: Vec<T>,
     free: Vec<usize>,

core/src/render/shader.wgsl

@@ -1,7 +1,6 @@
-enable wgpu_binding_array;
-
 const RECT: u32 = 0u;
 const TEXTURE: u32 = 1u;
+const GLYPH: u32 = 2u;
 
 @group(0) @binding(0)
 var<uniform> window: WindowUniform;
@@ -9,6 +8,8 @@ var<uniform> window: WindowUniform;
 var<storage> rects: array<Rect>;
 @group(1) @binding(TEXTURE)
 var<storage> textures: array<TextureInfo>;
+@group(1) @binding(GLYPH)
+var<storage> glyphs: array<GlyphInfo>;
 
 struct Rect {
     color: u32,
@@ -22,6 +23,15 @@ struct TextureInfo {
     sampler_idx: u32,
 }
 
+struct GlyphInfo {
+    uv_min: vec2<f32>,
+    uv_max: vec2<f32>,
+    view_idx: u32,
+    sampler_idx: u32,
+    color: u32,
+    flags: u32,
+}
+
 struct Mask {
     x: UiSpan,
     y: UiSpan,
@@ -67,9 +77,9 @@ struct VertexOutput {
     @location(0) top_left: vec2<f32>,
     @location(1) bot_right: vec2<f32>,
     @location(2) uv: vec2<f32>,
-    @location(3) @interpolate(flat) binding: u32,
-    @location(4) @interpolate(flat) idx: u32,
-    @location(5) @interpolate(flat) mask_idx: u32,
+    @location(3) binding: u32,
+    @location(4) idx: u32,
+    @location(5) mask_idx: u32,
     @builtin(position) clip_position: vec4<f32>,
 };
 
@@ -127,6 +137,9 @@ fn fs_main(
         case TEXTURE: {
             color = draw_texture(region, textures[i]);
         }
+        case GLYPH: {
+            color = draw_glyph(region, glyphs[i]);
+        }
         default: {
             color = vec4(1.0, 0.0, 1.0, 1.0);
         }
@@ -150,6 +163,17 @@ fn draw_texture(region: Region, info: TextureInfo) -> vec4<f32> {
     return textureSample(views[info.view_idx], samplers[info.sampler_idx], region.uv);
 }
 
+fn draw_glyph(region: Region, g: GlyphInfo) -> vec4<f32> {
+    let uv = mix(g.uv_min, g.uv_max, region.uv);
+    let texel = textureSample(views[g.view_idx], samplers[g.sampler_idx], uv);
+    if (g.flags & 1u) != 0u {
+        return texel;
+    }
+    var color = unpack4x8unorm(g.color);
+    color.a *= texel.a;
+    return color;
+}
+
 fn draw_rounded_rect(region: Region, rect: Rect) -> vec4<f32> {
     var color = unpack4x8unorm(rect.color);
 

core/src/render/texture.rs

@@ -1,11 +1,13 @@
-use image::{DynamicImage, EncodableLayout};
+use image::{DynamicImage, EncodableLayout, GenericImageView};
 use wgpu::{util::DeviceExt, *};
 
-use crate::{TextureUpdate, Textures};
+use crate::{PatchRect, TextureUpdate, Textures};
 
 pub struct GpuTextures {
     device: Device,
     queue: Queue,
+    /// Parallel to `views`; patches require textures rather than views.
+    textures: Vec<Option<Texture>>,
     views: Vec<TextureView>,
     view_count: usize,
     samplers: Vec<Sampler>,
@@ -17,37 +19,95 @@ impl GpuTextures {
     pub fn update(&mut self, textures: &mut Textures) -> bool {
         let mut changed = false;
         for update in textures.updates() {
-            changed = true;
             match update {
-                TextureUpdate::Push(image) => self.push(image),
-                TextureUpdate::Set(i, image) => self.set(i, image),
-                TextureUpdate::SetFree => self.view_count += 1,
-                TextureUpdate::Free(i) => self.free(i),
-                TextureUpdate::PushFree => self.push_free(),
+                TextureUpdate::Push(image) => {
+                    self.push(image);
+                    changed = true;
+                }
+                TextureUpdate::Set(i, image) => {
+                    self.set(i, image);
+                    changed = true;
+                }
+                TextureUpdate::Patch(i, rect, image) => {
+                    // Patching contents leaves the binding array unchanged.
+                    self.patch(i, rect, image);
+                }
+                TextureUpdate::SetFree => {
+                    self.view_count += 1;
+                    changed = true;
+                }
+                TextureUpdate::Free(i) => {
+                    self.free(i);
+                    changed = true;
+                }
+                TextureUpdate::PushFree => {
+                    self.push_free();
+                    changed = true;
+                }
             }
         }
         changed
     }
     fn set(&mut self, i: u32, image: &DynamicImage) {
         self.view_count += 1;
-        let view = self.create_view(image);
+        let (texture, view) = self.create(image);
+        self.textures[i as usize] = Some(texture);
         self.views[i as usize] = view;
     }
     fn free(&mut self, i: u32) {
         self.view_count -= 1;
+        self.textures[i as usize] = None;
         self.views[i as usize] = self.null_view.clone();
     }
     fn push(&mut self, image: &DynamicImage) {
         self.view_count += 1;
-        let view = self.create_view(image);
+        let (texture, view) = self.create(image);
+        self.textures.push(Some(texture));
         self.views.push(view);
     }
     fn push_free(&mut self) {
         self.view_count += 1;
+        self.textures.push(None);
         self.views.push(self.null_view.clone());
     }
 
-    fn create_view(&self, image: &DynamicImage) -> TextureView {
+    fn patch(&mut self, i: u32, rect: PatchRect, image: &DynamicImage) {
+        let Some(texture) = &self.textures[i as usize] else {
+            return;
+        };
+        if rect.width == 0 || rect.height == 0 {
+            return;
+        }
+        // `write_texture` requires tightly packed rows, unlike the atlas image.
+        let sub = image
+            .view(rect.x, rect.y, rect.width, rect.height)
+            .to_image();
+        self.queue.write_texture(
+            TexelCopyTextureInfo {
+                texture,
+                mip_level: 0,
+                origin: Origin3d {
+                    x: rect.x,
+                    y: rect.y,
+                    z: 0,
+                },
+                aspect: TextureAspect::All,
+            },
+            sub.as_bytes(),
+            TexelCopyBufferLayout {
+                offset: 0,
+                bytes_per_row: Some(rect.width * 4),
+                rows_per_image: Some(rect.height),
+            },
+            Extent3d {
+                width: rect.width,
+                height: rect.height,
+                depth_or_array_layers: 1,
+            },
+        );
+    }
+
+    fn create(&self, image: &DynamicImage) -> (Texture, TextureView) {
         let image = image.to_rgba8();
         let (width, height) = image.dimensions();
         let texture = self.device.create_texture_with_data(
@@ -63,13 +123,14 @@ impl GpuTextures {
                 sample_count: 1,
                 dimension: TextureDimension::D2,
                 format: TextureFormat::Rgba8Unorm,
-                usage: TextureUsages::TEXTURE_BINDING,
+                usage: TextureUsages::TEXTURE_BINDING | TextureUsages::COPY_DST,
                 view_formats: &[],
             },
             wgt::TextureDataOrder::MipMajor,
             image.as_bytes(),
         );
-        texture.create_view(&TextureViewDescriptor::default())
+        let view = texture.create_view(&TextureViewDescriptor::default());
+        (texture, view)
     }
 
     pub fn new(device: &Device, queue: &Queue) -> Self {
@@ -77,6 +138,7 @@ impl GpuTextures {
         Self {
             device: device.clone(),
             queue: queue.clone(),
+            textures: Vec::new(),
             views: Vec::new(),
             samplers: vec![default_sampler(device)],
             no_views: vec![null_view.clone()],

core/src/ui/mod.rs

@@ -28,7 +28,7 @@ pub trait UiRsc {
     #[allow(unused_variables)]
     fn on_remove(&mut self, id: WidgetId) {}
     #[allow(unused_variables)]
-    fn on_draw(&mut self, active: &ActiveData, redrawn: bool) {}
+    fn on_draw(&mut self, active: &ActiveData) {}
     #[allow(unused_variables)]
     fn on_undraw(&mut self, active: &ActiveData) {}
 

core/src/ui/painter.rs

@@ -1,7 +1,7 @@
 use crate::{
     Axis, Len, RenderedText, Size, SizeCtx, StrongWidget, TextAttrs, TextBuffer, TextData,
-    TextureHandle, UiRegion, UiRenderState, UiRsc, Widget, WidgetId,
-    render::{Mask, MaskIdx, Primitive, PrimitiveHandle, PrimitiveInst},
+    TextureHandle, UiRegion, UiRenderState, UiRsc, UiScalar, UiVec2, Widget, WidgetId,
+    render::{GlyphPrimitive, Mask, MaskIdx, Primitive, PrimitiveHandle, PrimitiveInst},
     util::Vec2,
 };
 
@@ -90,10 +90,43 @@ impl<'a> Painter<'a> {
         self.primitive_at(handle.primitive(), region);
     }
 
-    /// returns (handle, offset from top left)
-    pub fn render_text(&mut self, buffer: &mut TextBuffer, attrs: &TextAttrs) -> RenderedText {
+    pub fn render_text(
+        &mut self,
+        buffer: &mut TextBuffer,
+        attrs: &TextAttrs,
+        width: Option<f32>,
+    ) -> RenderedText {
         let ui = self.rsc.ui_mut();
-        ui.text.draw(buffer, attrs, &mut ui.textures)
+        ui.text.render(buffer, attrs, width, &mut ui.textures)
+    }
+
+    pub fn glyphs(&mut self, text: &RenderedText, origin: UiRegion) {
+        let flags_for = |is_color| {
+            if is_color {
+                GlyphPrimitive::IS_COLOR
+            } else {
+                0
+            }
+        };
+        for glyph in text.glyphs.iter() {
+            let mut region = origin;
+            region.x.end = region.x.start;
+            region.y.end = region.y.start;
+            let mut region = region.offset(UiVec2::abs(glyph.offset));
+            region.x.end = region.x.start + UiScalar::abs(glyph.entry.width as f32);
+            region.y.end = region.y.start + UiScalar::abs(glyph.entry.height as f32);
+            self.primitive_at(
+                GlyphPrimitive {
+                    uv_min: glyph.entry.uv_min,
+                    uv_max: glyph.entry.uv_max,
+                    view_idx: glyph.entry.view_idx,
+                    sampler_idx: glyph.entry.sampler_idx,
+                    color: text.color,
+                    flags: flags_for(glyph.entry.is_color),
+                },
+                region,
+            );
+        }
     }
 
     pub fn region(&self) -> UiRegion {

core/src/ui/render_state.rs

@@ -52,7 +52,7 @@ impl UiRenderState {
             );
         }
         let root = root.into();
-        if self.root_changed(root) || self.resized {
+        if self.needs_full_redraw(root) {
             self.redraw_all(root, rsc);
             self.old_root = root.map(|r| r.id());
             self.resized = false;
@@ -81,12 +81,10 @@ impl UiRenderState {
         old_children: Option<Vec<WidgetId>>,
         rsc: &mut dyn UiRsc,
     ) {
-        let mut redrawn = old_children.is_some();
         let mut old_children = old_children.unwrap_or_default();
         if let Some(active) = self.active.get_mut(&id)
             && !rsc.widgets().needs_redraw.contains(&id)
         {
-            redrawn = true;
             // check to see if we can skip drawing first
             if active.region == region {
                 return;
@@ -151,7 +149,7 @@ impl UiRenderState {
             }
         }
 
-        rsc.on_draw(&active, redrawn);
+        rsc.on_draw(&active);
         self.active.insert(id, active);
     }
 
@@ -220,12 +218,17 @@ impl UiRenderState {
         root.into().map(|r| r.id()) != self.old_root
     }
 
+    // Scheduling and drawing must use the same full-redraw predicate.
+    fn needs_full_redraw<'a>(&self, root: impl Into<Option<&'a StrongWidget>>) -> bool {
+        self.root_changed(root) || self.resized
+    }
+
     pub fn needs_redraw<'a>(
         &self,
         root: impl Into<Option<&'a StrongWidget>>,
         widgets: &Widgets,
     ) -> bool {
-        self.root_changed(root) || widgets.has_updates()
+        self.needs_full_redraw(root) || widgets.has_updates()
     }
 
     pub fn active_widgets(&self) -> usize {

core/src/ui/size.rs

@@ -76,8 +76,13 @@ impl SizeCtx<'_> {
         self.output_size
     }
 
-    pub fn draw_text(&mut self, buffer: &mut TextBuffer, attrs: &TextAttrs) -> RenderedText {
-        self.text.draw(buffer, attrs, self.textures)
+    pub fn draw_text(
+        &mut self,
+        buffer: &mut TextBuffer,
+        attrs: &TextAttrs,
+        width: Option<f32>,
+    ) -> RenderedText {
+        self.text.render(buffer, attrs, width, self.textures)
     }
 
     pub fn label(&self, id: WidgetId) -> &String {

core/src/util/mod.rs

@@ -16,7 +16,7 @@ pub use id::*;
 pub use math::*;
 pub use refcount::*;
 pub use slot::*;
-pub use trust::*;
+pub(crate) use trust::*;
 pub use typemap::*;
 pub use vec2::*;
 

core/src/util/trust.rs

@@ -1,15 +1,15 @@
 #[allow(clippy::missing_safety_doc)]
-pub unsafe fn forget_ref<'a, T>(x: &T) -> &'a T {
+pub(crate) unsafe fn forget_ref<'a, T>(x: &T) -> &'a T {
     unsafe { std::mem::transmute::<&T, &T>(x) }
 }
 
 #[allow(clippy::missing_safety_doc)]
-pub unsafe fn forget_mut<'a, T>(x: &mut T) -> &'a mut T {
+pub(crate) unsafe fn forget_mut<'a, T>(x: &mut T) -> &'a mut T {
     unsafe { std::mem::transmute::<&mut T, &mut T>(x) }
 }
 
 #[allow(clippy::mut_from_ref, clippy::missing_safety_doc)]
-pub unsafe fn to_mut<T>(x: &T) -> &mut T {
+pub(crate) unsafe fn to_mut<T>(x: &T) -> &mut T {
     #[allow(mutable_transmutes)]
     unsafe {
         std::mem::transmute::<&T, &mut T>(x)

core/src/widget/like.rs

@@ -34,7 +34,7 @@ pub trait HasRoot {
 
 pub trait WidgetArrLike<Rsc, const LEN: usize, Tag> {
     #[track_caller]
-    fn add(self, rsc: &mut Rsc) -> WidgetArr<LEN>;
+    fn add(self, state: &mut Rsc) -> WidgetArr<LEN>;
 }
 
 impl<Rsc, const LEN: usize> WidgetArrLike<Rsc, LEN, ArrTag> for WidgetArr<LEN> {
@@ -58,13 +58,6 @@ macro_rules! impl_widget_arr {
                 )
             }
         }
-        impl<Rsc: UiRsc, $($W: WidgetLike<Rsc, $Tag>,$Tag,)*> IntoWidgetVec<Rsc, ($($Tag,)*), ArrTag> for ($($W,)*) {
-            fn into_vec(self, rsc: &mut Rsc) -> Vec<StrongWidget> {
-                #[allow(non_snake_case)]
-                let ($($W,)*) = self;
-                vec![$($W.add(rsc).upgrade(rsc),)*]
-            }
-        }
     };
 }
 

core/src/widget/mod.rs

@@ -1,4 +1,4 @@
-use crate::{Axis, AxisT, Len, Painter, SizeCtx, UiRsc};
+use crate::{Axis, AxisT, Len, Painter, SizeCtx};
 use std::any::Any;
 
 mod data;
@@ -85,16 +85,3 @@ impl<State, F: FnOnce(&mut State) -> Option<StrongWidget>> WidgetOption<State> f
         self(state)
     }
 }
-
-pub trait IntoWidgetVec<Rsc, WTag, GTag> {
-    fn into_vec(self, rsc: &mut Rsc) -> Vec<StrongWidget>;
-}
-
-impl<Rsc: UiRsc, I: IntoIterator, Tag> IntoWidgetVec<Rsc, Tag, IterTag> for I
-where
-    I::Item: WidgetLike<Rsc, Tag>,
-{
-    fn into_vec(self, rsc: &mut Rsc) -> Vec<StrongWidget> {
-        self.into_iter().map(|w| w.add_strong(rsc).any()).collect()
-    }
-}

core/src/widget/tag.rs

@@ -62,4 +62,3 @@ impl<Rsc: UiRsc, V: WidgetView> WidgetLike<Rsc, ViewTag> for V {
 }
 
 pub struct ArrTag;
-pub struct IterTag;

examples/minimal.rs

@@ -10,7 +10,11 @@ struct State {
 }
 
 impl DefaultAppState for State {
-    fn new(mut ui_state: DefaultUiState, rsc: &mut DefaultRsc<Self>) -> Self {
+    fn new(
+        mut ui_state: DefaultUiState,
+        rsc: &mut DefaultRsc<Self>,
+        _: Proxy<Self::Event>,
+    ) -> Self {
         rect(Color::RED).set_root(rsc, &mut ui_state);
         Self { ui_state }
     }

examples/tabs/main.rs

@@ -1,4 +1,3 @@
-use cosmic_text::Family;
 use std::{cell::RefCell, rc::Rc};
 use winit::event::WindowEvent;
 
@@ -16,7 +15,11 @@ pub struct Client {
 }
 
 impl DefaultAppState for Client {
-    fn new(mut ui_state: DefaultUiState, rsc: &mut DefaultRsc<Self>) -> Self {
+    fn new(
+        mut ui_state: DefaultUiState,
+        rsc: &mut DefaultRsc<Self>,
+        _: Proxy<Self::Event>,
+    ) -> Self {
         let rrect = rect(Color::WHITE).radius(20);
         let pad_test = (
             rrect.color(Color::BLUE),
@@ -144,7 +147,7 @@ impl DefaultAppState for Client {
             .span(Dir::DOWN)
             .add(rsc);
 
-        let main = WidgetPtr::empty().add(rsc);
+        let main = WidgetPtr::new().add(rsc);
 
         let vals = Rc::new(RefCell::new((0, Vec::new())));
         let mut switch_button = |color, to: WeakWidget, label| {

examples/task.rs

@@ -11,7 +11,11 @@ struct State {
 }
 
 impl DefaultAppState for State {
-    fn new(mut ui_state: DefaultUiState, rsc: &mut DefaultRsc<Self>) -> Self {
+    fn new(
+        mut ui_state: DefaultUiState,
+        rsc: &mut DefaultRsc<Self>,
+        _: Proxy<Self::Event>,
+    ) -> Self {
         let rect = rect(Color::RED).add(rsc);
         rect.task_on(CursorSense::click(), async move |mut ctx| {
             tokio::time::sleep(Duration::from_secs(1)).await;

examples/view.rs

@@ -36,7 +36,11 @@ impl Test {
 }
 
 impl DefaultAppState for State {
-    fn new(mut ui_state: DefaultUiState, rsc: &mut DefaultRsc<Self>) -> Self {
+    fn new(
+        mut ui_state: DefaultUiState,
+        rsc: &mut DefaultRsc<Self>,
+        _: Proxy<Self::Event>,
+    ) -> Self {
         let test = Test::new(rsc);
 
         test.on(CursorSense::click(), move |_, rsc| {

macro/Cargo.toml

@@ -6,7 +6,7 @@ edition.workspace = true
 [dependencies]
 proc-macro2 = "1.0.103"
 quote = "1.0.42"
-syn = { version = "3.0.3", features = ["full"] }
+syn = { version = "2.0.111", features = ["full"] }
 
 [lib]
 proc-macro = true

rust-toolchain.toml

@@ -0,0 +1,3 @@
+[toolchain]
+channel = "nightly"
+components = ["clippy", "rustfmt"]

src/default/event.rs

@@ -7,11 +7,3 @@ impl Event for Submit {}
 #[derive(Eq, PartialEq, Hash, Clone)]
 pub struct Edited;
 impl Event for Edited {}
-
-#[derive(Eq, PartialEq, Hash, Clone)]
-pub struct Draw;
-impl Event for Draw {}
-
-#[derive(Eq, PartialEq, Hash, Clone)]
-pub struct Undraw;
-impl Event for Undraw {}

src/default/mod.rs

@@ -29,26 +29,7 @@ pub use sense::*;
 pub use state::*;
 pub use task::*;
 
-pub struct EventSender<State: DefaultAppState> {
-    proxy: EventLoopProxy<UiMainEvent<State>>,
-}
-
-impl<State: DefaultAppState> Clone for EventSender<State> {
-    fn clone(&self) -> Self {
-        Self {
-            proxy: self.proxy.clone(),
-        }
-    }
-}
-
-impl<State: DefaultAppState> EventSender<State> {
-    pub fn send(&self, event: State::Event) {
-        let _ = self.proxy.send_event(UiMainEvent::App(event));
-    }
-    pub fn run(&self, f: impl MainCallback<State>) {
-        let _ = self.proxy.send_event(UiMainEvent::Callback(Box::new(f)));
-    }
-}
+pub type Proxy<Event> = EventLoopProxy<Event>;
 
 pub struct DefaultUiState {
     pub root: Option<StrongWidget>,
@@ -89,8 +70,9 @@ pub trait HasDefaultUiState: Sized + 'static {
 }
 
 pub trait DefaultAppState: HasDefaultUiState {
-    type Event: Send = ();
-    fn new(ui_state: DefaultUiState, rsc: &mut DefaultRsc<Self>) -> Self;
+    type Event = ();
+    fn new(ui_state: DefaultUiState, rsc: &mut DefaultRsc<Self>, proxy: Proxy<Self::Event>)
+    -> Self;
     #[allow(unused_variables)]
     fn event(
         &mut self,
@@ -114,54 +96,23 @@ pub trait DefaultAppState: HasDefaultUiState {
     }
 }
 
-pub struct DefaultRsc<State: 'static + DefaultAppState> {
+pub struct DefaultRsc<State: 'static> {
     pub ui: UiData,
     pub events: EventManager<Self>,
     pub tasks: Tasks<Self>,
     pub state: WidgetState,
-    pub widget_events: Vec<WidgetEvent>,
-    pub window_event: EventSender<State>,
     _state: PhantomData<State>,
 }
 
-pub struct WidgetEvent {
-    id: WidgetId,
-    ty: WidgetEventType,
-}
-
-pub enum WidgetEventType {
-    Draw,
-    Undraw,
-    Remove,
-}
-
-pub trait MainCallback<State>: FnOnce(&mut DefaultRsc<State>) + Sync + Send + 'static {}
-impl<F: FnOnce(&mut DefaultRsc<State>) + Sync + Send + 'static, State> MainCallback<State> for F {}
-
-pub enum UiMainEvent<State: DefaultAppState> {
-    RequestUpdate,
-    Callback(Box<dyn MainCallback<State>>),
-    App(State::Event),
-}
-
-impl<State: DefaultAppState> DefaultRsc<State> {
-    fn init(proxy: EventLoopProxy<UiMainEvent<State>>) -> (Self, TaskMsgReceiver<Self>) {
-        let window_event = EventSender {
-            proxy: proxy.clone(),
-        };
-        let (tasks, recv) = Tasks::init(move || {
-            if proxy.send_event(UiMainEvent::RequestUpdate).is_err() {
-                panic!("main thread blew up or smth");
-            }
-        });
+impl<State> DefaultRsc<State> {
+    fn init(window: Arc<Window>) -> (Self, TaskMsgReceiver<Self>) {
+        let (tasks, recv) = Tasks::init(window);
         (
             Self {
                 ui: Default::default(),
                 events: Default::default(),
                 tasks,
-                widget_events: Default::default(),
                 state: Default::default(),
-                window_event,
                 _state: Default::default(),
             },
             recv,
@@ -173,7 +124,7 @@ impl<State: DefaultAppState> DefaultRsc<State> {
     }
 }
 
-impl<State: DefaultAppState> UiRsc for DefaultRsc<State> {
+impl<State> UiRsc for DefaultRsc<State> {
     fn ui(&self) -> &UiData {
         &self.ui
     }
@@ -182,39 +133,25 @@ impl<State: DefaultAppState> UiRsc for DefaultRsc<State> {
         &mut self.ui
     }
 
-    fn on_draw(&mut self, active: &ActiveData, redrawn: bool) {
+    fn on_draw(&mut self, active: &ActiveData) {
         self.events.draw(active);
-        if !redrawn {
-            self.widget_events.push(WidgetEvent {
-                id: active.id,
-                ty: WidgetEventType::Draw,
-            });
-        }
     }
 
     fn on_undraw(&mut self, active: &ActiveData) {
         self.events.undraw(active);
-        self.widget_events.push(WidgetEvent {
-            id: active.id,
-            ty: WidgetEventType::Undraw,
-        });
     }
 
     fn on_remove(&mut self, id: WidgetId) {
         self.events.remove(id);
         self.state.remove(id);
-        self.widget_events.push(WidgetEvent {
-            id,
-            ty: WidgetEventType::Remove,
-        });
     }
 }
 
-impl<State: 'static + DefaultAppState> HasState for DefaultRsc<State> {
+impl<State: 'static> HasState for DefaultRsc<State> {
     type State = State;
 }
 
-impl<State: 'static + DefaultAppState> HasEvents for DefaultRsc<State> {
+impl<State: 'static> HasEvents for DefaultRsc<State> {
     fn events(&self) -> &EventManager<Self> {
         &self.events
     }
@@ -224,13 +161,13 @@ impl<State: 'static + DefaultAppState> HasEvents for DefaultRsc<State> {
     }
 }
 
-impl<State: 'static + DefaultAppState> HasTasks for DefaultRsc<State> {
+impl<State: 'static> HasTasks for DefaultRsc<State> {
     fn tasks_mut(&mut self) -> &mut Tasks<Self> {
         &mut self.tasks
     }
 }
 
-impl<State: 'static + DefaultAppState> HasWidgetState for DefaultRsc<State> {
+impl<State: 'static> HasWidgetState for DefaultRsc<State> {
     fn widget_state(&self) -> &WidgetState {
         &self.state
     }
@@ -248,15 +185,15 @@ pub struct DefaultApp<State: DefaultAppState> {
 }
 
 impl<State: DefaultAppState> AppState for DefaultApp<State> {
-    type Event = UiMainEvent<State>;
+    type Event = State::Event;
 
     fn new(event_loop: &ActiveEventLoop, proxy: EventLoopProxy<Self::Event>) -> Self {
         let window = event_loop
             .create_window(State::window_attributes())
             .unwrap();
         let default_state = DefaultUiState::new(window);
-        let (mut rsc, task_recv) = DefaultRsc::init(proxy);
-        let state = State::new(default_state, &mut rsc);
+        let (mut rsc, task_recv) = DefaultRsc::init(default_state.window.clone());
+        let state = State::new(default_state, &mut rsc, proxy);
         let render = UiRenderState::new();
         Self {
             rsc,
@@ -267,39 +204,38 @@ impl<State: DefaultAppState> AppState for DefaultApp<State> {
     }
 
     fn event(&mut self, event: Self::Event, _: &ActiveEventLoop) {
-        match event {
-            UiMainEvent::RequestUpdate => {
-                self.check_updates();
-            }
-            UiMainEvent::App(event) => {
-                self.state.event(event, &mut self.rsc, &mut self.render);
-            }
-            UiMainEvent::Callback(f) => f(&mut self.rsc),
-        }
+        self.state.event(event, &mut self.rsc, &mut self.render);
     }
 
     fn window_event(&mut self, event: WindowEvent, event_loop: &ActiveEventLoop) {
         let Self {
-            rsc, render, state, ..
+            rsc,
+            render,
+            state,
+            task_recv,
         } = self;
 
-        // input handling
+        for update in task_recv.try_iter() {
+            update(state, rsc);
+        }
+
         let ui_state = state.default_state_mut();
-        if ui_state.input.event(&event) {
-            let cursor_state = ui_state.cursor_state().clone();
-            let old = ui_state.focus;
-            if cursor_state.buttons.left.is_start() {
-                ui_state.focus = None;
-            }
+        let input_changed = ui_state.input.event(&event);
+        let cursor_state = ui_state.cursor_state().clone();
+        let old = ui_state.focus;
+        if cursor_state.buttons.left.is_start() {
+            ui_state.focus = None;
+        }
+        if input_changed {
             let window_size = ui_state.window_size();
             render.run_sensors(rsc, state, cursor_state, window_size);
-            if old != state.default_state().focus
-                && let Some(old) = old
-            {
-                old.edit(rsc).deselect();
-            }
         }
         let ui_state = state.default_state_mut();
+        if old != ui_state.focus
+            && let Some(old) = old
+        {
+            old.edit(rsc).deselect();
+        }
         match &event {
             WindowEvent::CloseRequested => event_loop.exit(),
             WindowEvent::RedrawRequested => {
@@ -361,9 +297,11 @@ impl<State: DefaultAppState> AppState for DefaultApp<State> {
             _ => (),
         }
         state.window_event(event, rsc, render);
-
-        self.check_updates();
-        self.state.default_state_mut().input.end_frame();
+        let ui_state = self.state.default_state_mut();
+        if render.needs_redraw(&ui_state.root, rsc.widgets()) {
+            ui_state.renderer.window().request_redraw();
+        }
+        ui_state.input.end_frame();
     }
 
     fn exit(&mut self) {
@@ -371,49 +309,13 @@ impl<State: DefaultAppState> AppState for DefaultApp<State> {
     }
 }
 
-impl<State: DefaultAppState> DefaultApp<State> {
-    pub fn check_updates(&mut self) {
-        let Self {
-            rsc,
-            render,
-            state,
-            task_recv,
-        } = self;
-
-        for update in task_recv.try_iter() {
-            update(state, rsc);
-        }
-
-        let mut events = std::mem::take(&mut rsc.widget_events);
-        for event in events.drain(..) {
-            match event.ty {
-                WidgetEventType::Draw => {
-                    rsc.run_event::<Draw>(event.id, (), state);
-                }
-                WidgetEventType::Undraw => {
-                    rsc.run_event::<Undraw>(event.id, (), state);
-                }
-                _ => (),
-            }
-        }
-        rsc.widget_events = events;
-
-        let ui_state = state.default_state();
-        if render.needs_redraw(&ui_state.root, rsc.widgets()) {
-            ui_state.renderer.window().request_redraw();
-        }
-    }
-}
-
 pub trait RscIdx<Rsc> {
     type Output;
     fn get(self, rsc: &Rsc) -> &Self::Output;
     fn get_mut(self, rsc: &mut Rsc) -> &mut Self::Output;
 }
 
-impl<State: 'static + DefaultAppState, I: RscIdx<DefaultRsc<State>>> std::ops::Index<I>
-    for DefaultRsc<State>
-{
+impl<State: 'static, I: RscIdx<DefaultRsc<State>>> std::ops::Index<I> for DefaultRsc<State> {
     type Output = I::Output;
 
     fn index(&self, index: I) -> &Self::Output {
@@ -421,9 +323,7 @@ impl<State: 'static + DefaultAppState, I: RscIdx<DefaultRsc<State>>> std::ops::I
     }
 }
 
-impl<State: 'static + DefaultAppState, I: RscIdx<DefaultRsc<State>>> std::ops::IndexMut<I>
-    for DefaultRsc<State>
-{
+impl<State: 'static, I: RscIdx<DefaultRsc<State>>> std::ops::IndexMut<I> for DefaultRsc<State> {
     fn index_mut(&mut self, index: I) -> &mut Self::Output {
         index.get_mut(self)
     }

src/default/render.rs

@@ -22,11 +22,7 @@ impl UiRenderer {
     }
 
     pub fn draw(&mut self) {
-        let output = match self.surface.get_current_texture() {
-            CurrentSurfaceTexture::Success(v) => v,
-            CurrentSurfaceTexture::Suboptimal(v) => v,
-            _ => panic!("failed"),
-        };
+        let output = self.surface.get_current_texture().unwrap();
         let view = output
             .texture
             .create_view(&TextureViewDescriptor::default());
@@ -49,14 +45,15 @@ impl UiRenderer {
         }
 
         self.queue.submit(std::iter::once(encoder.finish()));
-        self.queue.present(output);
+        self.window.pre_present_notify();
+        output.present();
     }
 
     pub fn resize(&mut self, size: &PhysicalSize<u32>) {
         self.config.width = size.width;
         self.config.height = size.height;
         self.surface.configure(&self.device, &self.config);
-        self.ui.resize(size, &self.queue);
+        self.ui.resize((size.width, size.height), &self.queue);
     }
 
     fn create_encoder(device: &Device) -> CommandEncoder {
@@ -68,12 +65,9 @@ impl UiRenderer {
     pub fn new(window: Arc<Window>) -> Self {
         let size = window.inner_size();
 
-        let instance = Instance::new(InstanceDescriptor {
+        let instance = Instance::new(&InstanceDescriptor {
             backends: Backends::PRIMARY,
-            flags: Default::default(),
-            memory_budget_thresholds: Default::default(),
-            backend_options: Default::default(),
-            display: None,
+            ..Default::default()
         });
 
         let surface = instance
@@ -85,7 +79,6 @@ impl UiRenderer {
                 power_preference: PowerPreference::default(),
                 compatible_surface: Some(&surface),
                 force_fallback_adapter: false,
-                apply_limit_buckets: false,
             })
             .block_on()
             .expect("Could not get adapter!");
@@ -123,11 +116,10 @@ impl UiRenderer {
             format: surface_format,
             width: size.width,
             height: size.height,
-            present_mode: PresentMode::AutoNoVsync,
+            present_mode: PresentMode::AutoVsync,
             alpha_mode: surface_caps.alpha_modes[0],
             desired_maximum_frame_latency: 2,
             view_formats: vec![],
-            color_space: Default::default(),
         };
 
         surface.configure(&device, &config);

src/default/task.rs

@@ -13,6 +13,7 @@ use tokio::{
         unbounded_channel as async_channel,
     },
 };
+use winit::window::Window;
 
 pub type TaskMsgSender<Rsc> = SyncSender<Box<dyn TaskUpdate<Rsc>>>;
 pub type TaskMsgReceiver<Rsc> = SyncReceiver<Box<dyn TaskUpdate<Rsc>>>;
@@ -22,7 +23,7 @@ impl<F: FnOnce(&mut Rsc::State, &mut Rsc) + Send, Rsc: HasState> TaskUpdate<Rsc>
 
 pub struct Tasks<Rsc: HasState> {
     start: AsyncSender<BoxTask>,
-    request_update: Arc<dyn Fn() + Send + Sync>,
+    window: Arc<Window>,
     msg_send: SyncSender<Box<dyn TaskUpdate<Rsc>>>,
 }
 
@@ -44,7 +45,7 @@ impl<Rsc: HasState + 'static> TaskCtx<Rsc> {
 type BoxTask = Pin<Box<dyn Future<Output = ()> + Send>>;
 
 impl<Rsc: HasState> Tasks<Rsc> {
-    pub fn init(request_update: impl Fn() + 'static + Send + Sync) -> (Self, TaskMsgReceiver<Rsc>) {
+    pub fn init(window: Arc<Window>) -> (Self, TaskMsgReceiver<Rsc>) {
         let (start, start_recv) = async_channel();
         let (msgs, msgs_recv) = sync_channel();
         std::thread::spawn(|| {
@@ -55,7 +56,7 @@ impl<Rsc: HasState> Tasks<Rsc> {
             Self {
                 start,
                 msg_send: msgs,
-                request_update: Arc::new(request_update),
+                window,
             },
             msgs_recv,
         )
@@ -66,10 +67,10 @@ impl<Rsc: HasState> Tasks<Rsc> {
         F::CallOnceFuture: Send,
     {
         let send = self.msg_send.clone();
-        let request_update = self.request_update.clone();
+        let window = self.window.clone();
         let _ = self.start.send(Box::pin(async move {
             task(TaskCtx::new(send)).await;
-            request_update();
+            window.request_redraw();
         }));
     }
 }

src/lib.rs

@@ -1,6 +1,5 @@
 #![feature(unboxed_closures)]
 #![feature(fn_traits)]
-#![feature(gen_blocks)]
 #![feature(associated_type_defaults)]
 #![feature(unsize)]
 #![feature(option_into_flat_iter)]

src/widget/mod.rs

@@ -5,7 +5,6 @@ mod ptr;
 mod rect;
 mod text;
 mod trait_fns;
-mod selector;
 
 pub use image::*;
 pub use mask::*;
@@ -14,4 +13,3 @@ pub use ptr::*;
 pub use rect::*;
 pub use text::*;
 pub use trait_fns::*;
-pub use selector::*;

src/widget/position/span.rs

@@ -152,32 +152,32 @@ impl Span {
     }
 }
 
-pub struct SpanBuilder<Children, Rsc, Tag, GTag> {
-    pub children: Children,
+pub struct SpanBuilder<State, const LEN: usize, Wa: WidgetArrLike<State, LEN, Tag>, Tag> {
+    pub children: Wa,
     pub dir: Dir,
     pub gap: f32,
-    _pd: PhantomData<(Rsc, Tag, GTag)>,
+    _pd: PhantomData<(State, Tag)>,
 }
 
-impl<Children: IntoWidgetVec<Rsc, Tag, GTag>, Rsc, Tag, GTag> WidgetFnTrait<Rsc>
-    for SpanBuilder<Children, Rsc, Tag, GTag>
+impl<Rsc, const LEN: usize, Wa: WidgetArrLike<Rsc, LEN, Tag>, Tag> WidgetFnTrait<Rsc>
+    for SpanBuilder<Rsc, LEN, Wa, Tag>
 {
     type Widget = Span;
 
     #[track_caller]
     fn run(self, rsc: &mut Rsc) -> Self::Widget {
         Span {
-            children: self.children.into_vec(rsc),
+            children: self.children.add(rsc).arr.into_iter().collect(),
             dir: self.dir,
             gap: self.gap,
         }
     }
 }
 
-impl<Children: IntoWidgetVec<Rsc, Tag, GTag>, Rsc, Tag, GTag>
-    SpanBuilder<Children, Rsc, Tag, GTag>
+impl<State, const LEN: usize, Wa: WidgetArrLike<State, LEN, Tag>, Tag>
+    SpanBuilder<State, LEN, Wa, Tag>
 {
-    pub fn new(children: Children, dir: Dir) -> Self {
+    pub fn new(children: Wa, dir: Dir) -> Self {
         Self {
             children,
             dir,

src/widget/position/stack.rs

@@ -42,28 +42,30 @@ pub enum StackSize {
     Child(usize),
 }
 
-pub struct StackBuilder<Children, Rsc, Tag, GTag> {
-    pub children: Children,
+pub struct StackBuilder<State, const LEN: usize, Wa: WidgetArrLike<State, LEN, Tag>, Tag> {
+    pub children: Wa,
     pub size: StackSize,
-    _pd: PhantomData<(Rsc, Tag, GTag)>,
+    _pd: PhantomData<(State, Tag)>,
 }
 
-impl<Children: IntoWidgetVec<Rsc, Tag, GTag>, Rsc, Tag, GTag> WidgetFnTrait<Rsc>
-    for StackBuilder<Children, Rsc, Tag, GTag>
+impl<Rsc, const LEN: usize, Wa: WidgetArrLike<Rsc, LEN, Tag>, Tag> WidgetFnTrait<Rsc>
+    for StackBuilder<Rsc, LEN, Wa, Tag>
 {
     type Widget = Stack;
 
     #[track_caller]
     fn run(self, rsc: &mut Rsc) -> Self::Widget {
         Stack {
-            children: self.children.into_vec(rsc),
+            children: self.children.add(rsc).arr.into_iter().collect(),
             size: self.size,
         }
     }
 }
 
-impl<Children: IntoWidgetVec<Rsc, Tag, GTag>, Rsc, Tag, GTag> StackBuilder<Children, Rsc, Tag, GTag> {
-    pub fn new(children: Children) -> Self {
+impl<State, const LEN: usize, Wa: WidgetArrLike<State, LEN, Tag>, Tag>
+    StackBuilder<State, LEN, Wa, Tag>
+{
+    pub fn new(children: Wa) -> Self {
         Self {
             children,
             size: StackSize::default(),

src/widget/ptr.rs

@@ -30,10 +30,8 @@ impl Widget for WidgetPtr {
 }
 
 impl WidgetPtr {
-    pub fn new(widget: StrongWidget) -> Self {
-        Self {
-            inner: Some(widget),
-        }
+    pub fn new() -> Self {
+        Self::default()
     }
     pub fn empty() -> Self {
         Self {

src/widget/selector.rs

@@ -1,48 +0,0 @@
-use std::hash::Hash;
-
-use iris_core::util::HashMap;
-
-use crate::prelude::*;
-
-pub struct WidgetSelector<T> {
-    current: (T, StrongWidget),
-    map: HashMap<T, StrongWidget>,
-}
-
-impl<T: Hash + Eq> WidgetSelector<T> {
-    pub fn new(key: T, widget: StrongWidget) -> Self {
-        Self {
-            current: (key, widget),
-            map: Default::default(),
-        }
-    }
-
-    pub fn set(&mut self, key: T, widget: StrongWidget) {
-        self.map.insert(key, widget);
-    }
-
-    pub fn select(&mut self, key: T) -> bool {
-        if let Some(val) = self.map.remove(&key) {
-            let mut new = (key, val);
-            std::mem::swap(&mut new, &mut self.current);
-            self.map.insert(new.0, new.1);
-            true
-        } else {
-            false
-        }
-    }
-}
-
-impl<T: 'static> Widget for WidgetSelector<T> {
-    fn draw(&mut self, painter: &mut Painter) {
-        painter.widget(&self.current.1);
-    }
-
-    fn desired_width(&mut self, ctx: &mut SizeCtx) -> Len {
-        ctx.width(&self.current.1)
-    }
-
-    fn desired_height(&mut self, ctx: &mut SizeCtx) -> Len {
-        ctx.height(&self.current.1)
-    }
-}

src/widget/text/build.rs

@@ -1,5 +1,4 @@
 use crate::prelude::*;
-use cosmic_text::{Attrs, Family, Metrics};
 use std::marker::{PhantomData, Sized};
 
 pub struct TextBuilder<State, O = TextOutput, H: WidgetOption<State> = ()> {
@@ -20,7 +19,7 @@ impl<State, O, H: WidgetOption<State>> TextBuilder<State, O, H> {
         self.attrs.color = color;
         self
     }
-    pub fn family(mut self, family: Family<'static>) -> Self {
+    pub fn family(mut self, family: Family) -> Self {
         self.attrs.family = family;
         self
     }
@@ -82,19 +81,13 @@ impl<Rsc: UiRsc> TextBuilderOutput<Rsc> for TextOutput {
         state: &mut Rsc,
         builder: TextBuilder<Rsc, Self, H>,
     ) -> Self::Output {
-        let mut buf = TextBuffer::new_empty(Metrics::new(
-            builder.attrs.font_size,
-            builder.attrs.line_height,
-        ));
+        let buf = TextBuffer::new(&builder.content);
         let hint = builder.hint.get(state);
-        let font_system = &mut state.ui_mut().text.font_system;
-        buf.set_text(font_system, &builder.content, &Attrs::new(), SHAPING, None);
         let mut text = Text {
             content: builder.content.into(),
             view: TextView::new(buf, builder.attrs, hint),
         };
         text.content.changed = false;
-        builder.attrs.apply(font_system, &mut text.view.buf, None);
         text
     }
 }
@@ -110,19 +103,11 @@ impl<State: UiRsc> TextBuilderOutput<State> for TextEditOutput {
         state: &mut State,
         builder: TextBuilder<State, Self, H>,
     ) -> Self::Output {
-        let buf = TextBuffer::new_empty(Metrics::new(
-            builder.attrs.font_size,
-            builder.attrs.line_height,
-        ));
-        let mut text = TextEdit::new(
+        let buf = TextBuffer::new(&builder.content);
+        TextEdit::new(
             TextView::new(buf, builder.attrs, builder.hint.get(state)),
             builder.output.mode,
-        );
-        let font_system = &mut state.ui_mut().text.font_system;
-        text.buf
-            .set_text(font_system, &builder.content, &Attrs::new(), SHAPING, None);
-        builder.attrs.apply(font_system, &mut text.buf, None);
-        text
+        )
     }
 }
 

src/widget/text/edit.rs

@@ -1,17 +1,30 @@
 use crate::prelude::*;
-use cosmic_text::{Affinity, Attrs, Cursor, FontSystem, LayoutRun, Motion};
+use iris_core::{TextData, UiColor};
+use parley::{Affinity, Layout, Selection};
 use std::ops::{Deref, DerefMut};
-use unicode_segmentation::UnicodeSegmentation;
 use winit::{
     event::KeyEvent,
     keyboard::{Key, NamedKey},
 };
 
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+pub enum Motion {
+    Left,
+    Right,
+    LeftWord,
+    RightWord,
+    Up,
+    Down,
+    LineStart,
+    LineEnd,
+}
+
 pub struct TextEdit {
     view: TextView,
-    selection: TextSelection,
-    history: Vec<(String, TextSelection)>,
-    double_hit: Option<Cursor>,
+    /// `None` represents unfocused, which Parley's `Selection` cannot express.
+    selection: Option<Selection>,
+    history: Vec<(String, Option<Selection>)>,
+    double_hit: Option<usize>,
     pub mode: EditMode,
 }
 
@@ -25,27 +38,19 @@ impl TextEdit {
     pub fn new(view: TextView, mode: EditMode) -> Self {
         Self {
             view,
-            selection: Default::default(),
+            selection: None,
             history: Default::default(),
             double_hit: None,
             mode,
         }
     }
-    pub fn select_content(&self, start: Cursor, end: Cursor) -> String {
-        let (start, end) = sort_cursors(start, end);
-        let mut iter = self.buf.lines.iter().skip(start.line);
-        let first = iter.next().unwrap();
-        if start.line == end.line {
-            first.text()[start.index..end.index].to_string()
-        } else {
-            let mut str = first.text()[start.index..].to_string();
-            for _ in (start.line + 1)..end.line {
-                str = str + "\n" + iter.next().unwrap().text();
-            }
-            let last = iter.next().unwrap();
-            str = str + "\n" + &last.text()[..end.index];
-            str
+
+    pub fn selected_text(&self) -> Option<String> {
+        let sel = self.selection?;
+        if sel.is_collapsed() {
+            return None;
         }
+        Some(self.buf.text()[sel.text_range()].to_string())
     }
 }
 
@@ -57,39 +62,29 @@ impl Widget for TextEdit {
         painter.layer = base;
         let region = self.region();
 
-        let size = vec2(1, self.attrs.line_height);
-        match self.selection {
-            TextSelection::None => (),
-            TextSelection::Pos(cursor) => {
-                if let Some(offset) = cursor_pos(cursor, &self.buf) {
-                    painter.primitive_within(
-                        RectPrimitive::color(Color::WHITE),
-                        size.align(Align::TOP_LEFT).offset(offset).within(&region),
-                    );
-                }
-            }
-            TextSelection::Span { start, end } => {
-                let (start, end) = sort_cursors(start, end);
-                for (l, x, width) in iter_layout_lines(start, end, &self.buf) {
-                    let top_left = vec2(x, self.attrs.line_height * l as f32);
-                    painter.primitive_within(
-                        RectPrimitive::color(Color::SKY),
-                        size.with_x(width)
-                            .align(Align::TOP_LEFT)
-                            .offset(top_left)
-                            .within(&region),
-                    );
-                }
-                if let Some(end_offset) = cursor_pos(end, &self.buf) {
-                    painter.primitive_within(
-                        RectPrimitive::color(Color::WHITE),
-                        size.align(Align::TOP_LEFT)
-                            .offset(end_offset)
-                            .within(&region),
-                    );
-                }
-            }
+        let Some(selection) = self.selection else {
+            return;
+        };
+        let layout = self.view.buf.layout();
+
+        // parley reports selection as boxes in layout space, so bidi and
+        // wrapped lines come out right without this code knowing about either.
+        for (rect, _) in selection.geometry(layout) {
+            let size = vec2(rect.width() as f32, rect.height() as f32);
+            let top_left = vec2(rect.x0 as f32, rect.y0 as f32);
+            painter.primitive_within(
+                RectPrimitive::color(Color::SKY),
+                size.align(Align::TOP_LEFT).offset(top_left).within(&region),
+            );
         }
+
+        let caret = selection.focus().geometry(layout, CARET_WIDTH);
+        let size = vec2(caret.width() as f32, caret.height() as f32);
+        let top_left = vec2(caret.x0 as f32, caret.y0 as f32);
+        painter.primitive_within(
+            RectPrimitive::color(Color::WHITE),
+            size.align(Align::TOP_LEFT).offset(top_left).within(&region),
+        );
     }
 
     fn desired_width(&mut self, ctx: &mut SizeCtx) -> Len {
@@ -101,154 +96,58 @@ impl Widget for TextEdit {
     }
 }
 
-/// provides top left + width
-fn iter_layout_lines(
-    start: Cursor,
-    end: Cursor,
-    buf: &TextBuffer,
-) -> impl Iterator<Item = (usize, f32, f32)> {
-    gen move {
-        let mut iter = buf.layout_runs().enumerate();
-        for (i, line) in iter.by_ref() {
-            if line.line_i == start.line
-                && let Some(start_x) = index_x(&line, start.index)
-            {
-                if start.line == end.line
-                    && let Some(end_x) = index_x(&line, end.index)
-                {
-                    yield (i, start_x, end_x - start_x);
-                    return;
-                }
-                yield (i, start_x, line.line_w - start_x);
-                break;
-            }
-        }
-        for (i, line) in iter {
-            if line.line_i > end.line {
-                return;
-            }
-            if line.line_i == end.line
-                && let Some(end_x) = index_x(&line, end.index)
-            {
-                yield (i, 0.0, end_x);
-                return;
-            }
-            yield (i, 0.0, line.line_w);
-        }
-    }
-}
-
-/// copied & modified from fn found in Editor in cosmic_text
-/// returns x pos of a (non layout) index within an layout run
-fn index_x(run: &LayoutRun, index: usize) -> Option<f32> {
-    for glyph in run.glyphs.iter() {
-        if index == glyph.start {
-            return Some(glyph.x);
-        } else if index > glyph.start && index < glyph.end {
-            // Guess x offset based on characters
-            let mut before = 0;
-            let mut total = 0;
-
-            let cluster = &run.text[glyph.start..glyph.end];
-            for (i, _) in cluster.grapheme_indices(true) {
-                if glyph.start + i < index {
-                    before += 1;
-                }
-                total += 1;
-            }
-
-            let offset = glyph.w * (before as f32) / (total as f32);
-            return Some(glyph.x + offset);
-        }
-    }
-    None
-}
-
-/// returns top of line segment where cursor should visually select
-fn cursor_pos(cursor: Cursor, buf: &TextBuffer) -> Option<Vec2> {
-    let mut prev = None;
-    for run in buf
-        .layout_runs()
-        .skip_while(|r| r.line_i < cursor.line)
-        .take_while(|r| r.line_i == cursor.line)
-    {
-        prev = Some(vec2(run.line_w, run.line_top));
-        if let Some(pos) = index_x(&run, cursor.index) {
-            return Some(vec2(pos, run.line_top));
-        }
-    }
-    prev
-}
+const CARET_WIDTH: f32 = 1.0;
 
 pub struct TextEditCtx<'a> {
     pub text: &'a mut TextEdit,
-    pub font_system: &'a mut FontSystem,
+    pub data: &'a mut TextData,
 }
 
 impl<'a> TextEditCtx<'a> {
+    fn layout(&mut self) -> &Layout<UiColor> {
+        let attrs = self.text.view.attrs.clone();
+        let width = self.text.view.wrap_width();
+        self.text.view.buf.shape(self.data, &attrs, width);
+        self.text.view.buf.layout()
+    }
+
+    fn refresh(&mut self) {
+        if let Some(sel) = self.text.selection {
+            let layout = self.layout();
+            self.text.selection = Some(sel.refresh(layout));
+        }
+    }
+
     pub fn take(&mut self) -> String {
-        let text = self
-            .text
-            .buf
-            .lines
-            .drain(..)
-            .map(|l| l.into_text())
-            .collect::<Vec<_>>()
-            .join("\n");
-        self.text
-            .buf
-            .set_text(self.font_system, "", &Attrs::new(), SHAPING, None);
-        self.text.selection.clear();
+        let text = self.text.view.buf.text().to_string();
+        self.set("");
         text
     }
 
     pub fn set(&mut self, text: &str) {
         let text = self.string(text);
-        self.text
-            .buf
-            .set_text(self.font_system, &text, &Attrs::new(), SHAPING, None);
-        self.text.selection.clear();
+        self.text.view.buf.set_text(text);
+        self.text.view.buf.changed = true;
+        self.text.selection = None;
     }
 
     pub fn motion(&mut self, motion: Motion, select: bool) {
-        if let TextSelection::Pos(cursor) = self.text.selection
-            && let Some(new) = self.buf_motion(cursor, motion)
-        {
-            if select {
-                self.text.selection = TextSelection::Span {
-                    start: cursor,
-                    end: new,
-                };
-            } else {
-                self.text.selection = TextSelection::Pos(new);
-            }
-        } else if let TextSelection::Span { start, end } = self.text.selection {
-            if select {
-                if let Some(cursor) = self.buf_motion(end, motion) {
-                    self.text.selection = TextSelection::Span { start, end: cursor };
-                }
-            } else {
-                let (start, end) = sort_cursors(start, end);
-                let sel = &mut self.text.selection;
-                match motion {
-                    Motion::Left | Motion::LeftWord => *sel = TextSelection::Pos(start),
-                    Motion::Right | Motion::RightWord => *sel = TextSelection::Pos(end),
-                    _ => {
-                        if let Some(cursor) = self.buf_motion(end, motion) {
-                            self.text.selection = TextSelection::Pos(cursor);
-                        }
-                    }
-                }
-            }
-        }
+        let Some(sel) = self.text.selection else {
+            return;
+        };
+        let layout = self.layout();
+        let sel = apply_motion(sel, layout, motion, select);
+        self.text.selection = Some(sel);
     }
 
+    /// Replace the `len` characters before the caret. This is the IME's
+    /// preedit path: it re-sends the whole composition each time.
     pub fn replace(&mut self, len: usize, text: &str) {
         let text = self.string(text);
         for _ in 0..len {
-            self.delete(false);
+            self.backspace(false);
         }
-        self.insert_inner(&text, false);
+        self.insert_str(&text);
     }
 
     fn string(&self, text: &str) -> String {
@@ -261,202 +160,183 @@ impl<'a> TextEditCtx<'a> {
 
     pub fn insert(&mut self, text: &str) {
         let text = self.string(text);
-        let mut lines = text.split('\n');
-        let Some(first) = lines.next() else {
+        self.insert_str(&text);
+    }
+
+    fn insert_str(&mut self, text: &str) {
+        if text.is_empty() {
             return;
-        };
-        self.insert_inner(first, true);
-        for line in lines {
-            self.newline();
-            self.insert_inner(line, true);
         }
+        self.clear_span();
+        let at = match self.text.selection {
+            Some(sel) => sel.focus().index(),
+            None => return,
+        };
+        let at = at.min(self.text.view.buf.text().len());
+        self.text.view.buf.edit().insert_str(at, text);
+        self.text.view.buf.changed = true;
+        self.set_caret(at + text.len());
     }
 
     pub fn clear_span(&mut self) -> bool {
-        if let TextSelection::Span { start, end } = self.text.selection {
-            self.delete_between(start, end);
-            let (start, _) = sort_cursors(start, end);
-            self.text.selection = TextSelection::Pos(start);
-            true
-        } else {
-            false
+        let Some(sel) = self.text.selection else {
+            return false;
+        };
+        if sel.is_collapsed() {
+            return false;
         }
+        let range = sel.text_range();
+        self.text.view.buf.edit().replace_range(range.clone(), "");
+        self.text.view.buf.changed = true;
+        self.set_caret(range.start);
+        true
     }
 
-    pub fn delete_between(&mut self, start: Cursor, end: Cursor) {
-        let lines = &mut self.text.view.buf.lines;
-        let (start, end) = sort_cursors(start, end);
-        if start.line == end.line {
-            let line = &mut lines[start.line];
-            let text = line.text();
-            let text = text[..start.index].to_string() + &text[end.index..];
-            edit_line(line, text);
-        } else {
-            // start
-            let start_text = lines[start.line].text()[..start.index].to_string();
-            let end_text = &lines[end.line].text()[end.index..];
-            let text = start_text + end_text;
-            edit_line(&mut lines[start.line], text);
-        }
-        // between
-        let range = (start.line + 1)..=end.line;
-        if !range.is_empty() {
-            lines.splice(range, None);
-        }
-    }
-
-    fn insert_inner(&mut self, text: &str, mov: bool) {
-        self.clear_span();
-        if let TextSelection::Pos(cursor) = &mut self.text.selection {
-            let line = &mut self.text.view.buf.lines[cursor.line];
-            let mut line_text = line.text().to_string();
-            line_text.insert_str(cursor.index, text);
-            edit_line(line, line_text);
-            if mov {
-                for _ in 0..text.chars().count() {
-                    self.motion(Motion::Right, false);
-                }
-            }
-        }
+    fn set_caret(&mut self, index: usize) {
+        let index = index.min(self.text.view.buf.text().len());
+        let layout = self.layout();
+        self.text.selection = Some(Selection::from_byte_index(
+            layout,
+            index,
+            Affinity::default(),
+        ));
     }
 
     pub fn newline(&mut self) {
-        if self.text.mode == EditMode::SingleLine {
-            return;
-        }
-        self.clear_span();
-        if let TextSelection::Pos(cursor) = &mut self.text.selection {
-            let lines = &mut self.text.view.buf.lines;
-            let line = &mut lines[cursor.line];
-            let new = line.split_off(cursor.index);
-            cursor.line += 1;
-            lines.insert(cursor.line, new);
-            cursor.index = 0;
+        if self.text.mode == EditMode::MultiLine {
+            self.insert_str("\n");
         }
     }
 
     pub fn backspace(&mut self, word: bool) {
-        if !self.clear_span()
-            && let TextSelection::Pos(cursor) = &mut self.text.selection
-            && (cursor.index != 0 || cursor.line != 0)
-        {
-            self.motion(if word { Motion::LeftWord } else { Motion::Left }, false);
-            self.delete(word);
+        if self.clear_span() {
+            return;
         }
+        let Some(sel) = self.text.selection else {
+            return;
+        };
+        let end = sel.focus().index();
+        if end == 0 {
+            return;
+        }
+        let start = {
+            let layout = self.layout();
+            if word {
+                sel.focus().previous_logical_word(layout).index()
+            } else {
+                let Some(cluster) = sel.focus().logical_clusters(layout)[0] else {
+                    return;
+                };
+                let range = cluster.text_range();
+                if cluster.is_hard_line_break() || cluster.is_emoji() {
+                    range.start
+                } else {
+                    self.text.view.buf.text()[..range.end]
+                        .char_indices()
+                        .next_back()
+                        .map_or(range.start, |(start, _)| start)
+                }
+            }
+        };
+        self.delete_range(start, end);
     }
 
     pub fn delete(&mut self, word: bool) {
-        if !self.clear_span()
-            && let TextSelection::Pos(cursor) = &mut self.text.selection
-        {
+        if self.clear_span() {
+            return;
+        }
+        let Some(sel) = self.text.selection else {
+            return;
+        };
+        let start = sel.focus().index();
+        if start >= self.text.view.buf.text().len() {
+            return;
+        }
+        let end = {
+            let layout = self.layout();
             if word {
-                let start = *cursor;
-                if let Some(end) = self.buf_motion(start, Motion::RightWord) {
-                    self.delete_between(start, end);
-                }
+                sel.focus().next_logical_word(layout).index()
             } else {
-                let lines = &mut self.text.view.buf.lines;
-                let line = &mut lines[cursor.line];
-                if cursor.index == line.text().len() {
-                    if cursor.line == lines.len() - 1 {
-                        return;
-                    }
-                    let add = lines.remove(cursor.line + 1).into_text();
-                    let line = &mut lines[cursor.line];
-                    let mut cur = line.text().to_string();
-                    cur.push_str(&add);
-                    edit_line(line, cur);
-                } else {
-                    let mut text = line.text().to_string();
-                    text.remove(cursor.index);
-                    edit_line(line, text);
-                }
+                let clusters = sel.focus().logical_clusters(layout);
+                let Some(cluster) = clusters[1].as_ref() else {
+                    return;
+                };
+                cluster.text_range().end
             }
-        }
+        };
+        self.delete_range(start, end);
     }
 
-    fn buf_motion(&mut self, cursor: Cursor, motion: Motion) -> Option<Cursor> {
-        self.text
-            .buf
-            .cursor_motion(self.font_system, cursor, None, motion)
-            .map(|r| r.0)
+    fn delete_range(&mut self, start: usize, end: usize) {
+        let len = self.text.view.buf.text().len();
+        let (start, end) = (start.min(end).min(len), start.max(end).min(len));
+        if start == end {
+            return;
+        }
+        self.text.view.buf.edit().replace_range(start..end, "");
+        self.text.view.buf.changed = true;
+        self.set_caret(start);
     }
 
-    pub fn select_word_at(&mut self, cursor: Cursor) {
-        if let (Some(start), Some(end)) = (
-            self.buf_motion(cursor, Motion::LeftWord),
-            self.buf_motion(cursor, Motion::RightWord),
-        ) {
-            self.text.selection = TextSelection::Span { start, end };
-        }
-    }
-
-    pub fn select_line_at(&mut self, cursor: Cursor) {
-        let end = self.text.buf.lines[cursor.line].text().len();
-        self.text.selection = TextSelection::Span {
-            start: Cursor::new(cursor.line, 0),
-            end: Cursor::new(cursor.line, end),
+    pub fn select_all(&mut self) {
+        let len = self.text.view.buf.text().len();
+        if len == 0 {
+            return;
         }
+        let layout = self.layout();
+        let anchor = parley::Cursor::from_byte_index(layout, 0, Affinity::default());
+        let focus = parley::Cursor::from_byte_index(layout, len, Affinity::default());
+        self.text.selection = Some(Selection::new(anchor, focus));
     }
 
     pub fn select(&mut self, pos: Vec2, size: Vec2, drag: bool, recent: bool) {
         let pos = pos - self.text.region().top_left().to_abs(size);
-        let hit = self.text.buf.hit(pos.x, pos.y);
-        let sel = &mut self.text.selection;
-        match sel {
-            TextSelection::None => {
-                if !drag && let Some(hit) = hit {
-                    *sel = TextSelection::Pos(hit)
-                }
+        let prev_sel = self.text.selection;
+        let prev_hit = self.text.double_hit;
+
+        let outcome = {
+            let layout = self.layout();
+            if drag {
+                prev_sel.map(|sel| (Some(sel.extend_to_point(layout, pos.x, pos.y)), prev_hit))
+            } else {
+                let hit = Selection::from_point(layout, pos.x, pos.y);
+                let index = hit.focus().index();
+                // Successive clicks at one index select the word, then the line.
+                Some(if recent && prev_hit == Some(index) {
+                    (Some(Selection::line_from_point(layout, pos.x, pos.y)), None)
+                } else if recent && prev_sel.map(|s| s.focus().index()) == Some(index) {
+                    (
+                        Some(Selection::word_from_point(layout, pos.x, pos.y)),
+                        Some(index),
+                    )
+                } else {
+                    (Some(hit), None)
+                })
             }
-            TextSelection::Pos(pos) => match (hit, drag) {
-                (None, false) => *sel = TextSelection::None,
-                (None, true) => (),
-                (Some(hit), false) => {
-                    if recent && hit == *pos {
-                        self.text.double_hit = Some(hit);
-                        return self.select_word_at(hit);
-                    } else {
-                        *pos = hit
-                    }
-                }
-                (Some(end), true) => *sel = TextSelection::Span { start: *pos, end },
-            },
-            TextSelection::Span { start, end } => match (hit, drag) {
-                (None, false) => *sel = TextSelection::None,
-                (None, true) => *sel = TextSelection::Pos(*start),
-                (Some(hit), false) => {
-                    if recent
-                        && let Some(double) = self.text.double_hit
-                        && double == hit
-                    {
-                        return self.select_line_at(hit);
-                    } else {
-                        *sel = TextSelection::Pos(hit)
-                    }
-                }
-                (Some(hit), true) => *end = hit,
-            },
-        }
-        if let TextSelection::Span { start, end } = sel
-            && start == end
-        {
-            *sel = TextSelection::Pos(*start);
+        };
+
+        if let Some((selection, double_hit)) = outcome {
+            self.text.selection = selection;
+            self.text.double_hit = double_hit;
         }
     }
 
     pub fn deselect(&mut self) {
-        self.text.selection = TextSelection::None;
+        self.text.selection = None;
+        self.text.double_hit = None;
     }
 
     pub fn apply_event(&mut self, event: &KeyEvent, modifiers: &Modifiers) -> TextInputResult {
-        let old = (self.text.content(), self.text.selection);
+        let old = (self.text.view.buf.text().to_string(), self.text.selection);
         let mut undo = false;
         let res = self.apply_event_inner(event, modifiers, &mut undo);
-        if undo && let Some((old, selection)) = self.text.history.pop() {
-            self.set(&old);
-            self.text.selection = selection;
-        } else if self.text.content() != old.0 {
+        if undo {
+            if let Some((old, selection)) = self.text.history.pop() {
+                self.set(&old);
+                self.text.selection = selection;
+                self.refresh();
+            }
+        } else if self.text.view.buf.text() != old.0 {
             self.text.history.push(old);
         }
         res
@@ -481,21 +361,25 @@ impl<'a> TextEditCtx<'a> {
                     }
                 }
                 NamedKey::ArrowRight => {
-                    if modifiers.control {
-                        self.motion(Motion::RightWord, modifiers.shift)
+                    let motion = if modifiers.control {
+                        Motion::RightWord
                     } else {
-                        self.motion(Motion::Right, modifiers.shift)
-                    }
+                        Motion::Right
+                    };
+                    self.motion(motion, modifiers.shift);
                 }
                 NamedKey::ArrowLeft => {
-                    if modifiers.control {
-                        self.motion(Motion::LeftWord, modifiers.shift)
+                    let motion = if modifiers.control {
+                        Motion::LeftWord
                     } else {
-                        self.motion(Motion::Left, modifiers.shift)
-                    }
+                        Motion::Left
+                    };
+                    self.motion(motion, modifiers.shift);
                 }
                 NamedKey::ArrowUp => self.motion(Motion::Up, modifiers.shift),
                 NamedKey::ArrowDown => self.motion(Motion::Down, modifiers.shift),
+                NamedKey::Home => self.motion(Motion::LineStart, modifiers.shift),
+                NamedKey::End => self.motion(Motion::LineEnd, modifiers.shift),
                 NamedKey::Escape => {
                     self.deselect();
                     return TextInputResult::Unfocus;
@@ -507,34 +391,18 @@ impl<'a> TextEditCtx<'a> {
                     match text.as_str() {
                         "v" => return TextInputResult::Paste,
                         "c" => {
-                            if let TextSelection::Span { start, end } = self.text.selection {
-                                let content = self.text.select_content(start, end);
+                            if let Some(content) = self.text.selected_text() {
                                 return TextInputResult::Copy(content);
                             }
                         }
                         "x" => {
-                            if let TextSelection::Span { start, end } = self.text.selection {
-                                let content = self.text.select_content(start, end);
+                            if let Some(content) = self.text.selected_text() {
                                 self.clear_span();
                                 return TextInputResult::Copy(content);
                             }
                         }
-                        "a" => {
-                            if !self.text.buf.lines[0].text().is_empty()
-                                || self.text.buf.lines.len() > 1
-                            {
-                                let lines = &self.text.buf.lines;
-                                let last_line = lines.len() - 1;
-                                let last_idx = lines[last_line].text().len();
-                                self.text.selection = TextSelection::Span {
-                                    start: Cursor::new(0, 0),
-                                    end: Cursor::new(last_line, last_idx),
-                                };
-                            }
-                        }
-                        "z" => {
-                            *undo = true;
-                        }
+                        "a" => self.select_all(),
+                        "z" => *undo = true,
                         _ => self.insert(text),
                     }
                 } else {
@@ -547,6 +415,24 @@ impl<'a> TextEditCtx<'a> {
     }
 }
 
+fn apply_motion(
+    sel: Selection,
+    layout: &Layout<UiColor>,
+    motion: Motion,
+    extend: bool,
+) -> Selection {
+    match motion {
+        Motion::Left => sel.previous_visual(layout, extend),
+        Motion::Right => sel.next_visual(layout, extend),
+        Motion::LeftWord => sel.previous_visual_word(layout, extend),
+        Motion::RightWord => sel.next_visual_word(layout, extend),
+        Motion::Up => sel.previous_line(layout, extend),
+        Motion::Down => sel.next_line(layout, extend),
+        Motion::LineStart => sel.line_start(layout, extend),
+        Motion::LineEnd => sel.line_end(layout, extend),
+    }
+}
+
 #[derive(Default)]
 pub struct Modifiers {
     pub shift: bool,
@@ -569,33 +455,6 @@ pub enum TextInputResult {
     Paste,
 }
 
-#[derive(Debug, Default, Clone, Copy)]
-pub enum TextSelection {
-    #[default]
-    None,
-    Pos(Cursor),
-    Span {
-        start: Cursor,
-        end: Cursor,
-    },
-}
-
-impl TextSelection {
-    pub fn clear(&mut self) {
-        match self {
-            TextSelection::None => (),
-            TextSelection::Pos(cursor) => {
-                cursor.line = 0;
-                cursor.index = 0;
-                cursor.affinity = Affinity::default();
-            }
-            TextSelection::Span { start: _, end: _ } => {
-                *self = TextSelection::None;
-            }
-        }
-    }
-}
-
 impl TextInputResult {
     pub fn unfocus(&self) -> bool {
         matches!(self, TextInputResult::Unfocus)
@@ -625,7 +484,7 @@ impl<I: IdLike<Widget = TextEdit>> TextEditable for I {
         let ui = ui.ui_mut();
         TextEditCtx {
             text: ui.widgets.get_mut(self).unwrap(),
-            font_system: &mut ui.text.font_system,
+            data: &mut ui.text,
         }
     }
 }

src/widget/text/mod.rs

@@ -6,11 +6,8 @@ pub use edit::*;
 use iris_core::util::MutDetect;
 
 use crate::prelude::*;
-use cosmic_text::{Attrs, BufferLine, Cursor, Metrics, Shaping};
 use std::ops::{Deref, DerefMut};
 
-pub const SHAPING: Shaping = Shaping::Advanced;
-
 pub struct Text {
     pub content: MutDetect<String>,
     view: TextView,
@@ -25,6 +22,16 @@ pub struct TextView {
     pub hint: Option<StrongWidget>,
 }
 
+impl TextView {
+    fn is_blank(&self) -> bool {
+        self.buf.is_empty()
+    }
+
+    pub fn wrap_width(&self) -> Option<f32> {
+        self.width
+    }
+}
+
 impl TextView {
     pub fn new(buf: TextBuffer, attrs: TextAttrs, hint: Option<StrongWidget>) -> Self {
         Self {
@@ -45,15 +52,6 @@ impl TextView {
             .align(self.align)
     }
 
-    fn tex_region(&self, tex: &RenderedText) -> UiRegion {
-        let region = tex.size.align(self.align);
-        let dims = tex.handle.size();
-        let mut region = region.offset(tex.top_left_offset);
-        region.x.end = region.x.start + UiScalar::abs(dims.x);
-        region.y.end = region.y.start + UiScalar::abs(dims.y);
-        region
-    }
-
     fn render(&mut self, ctx: &mut SizeCtx) -> RenderedText {
         let width = if self.attrs.wrap {
             Some(ctx.px_size().x)
@@ -68,10 +66,7 @@ impl TextView {
             return tex.clone();
         }
         self.width = width;
-        let font_system = &mut ctx.text.font_system;
-        self.attrs.apply(font_system, &mut self.buf, width);
-        self.buf.shape_until_scroll(font_system, false);
-        let tex = ctx.draw_text(&mut self.buf, &self.attrs);
+        let tex = ctx.draw_text(&mut self.buf, &self.attrs, width);
         self.tex = Some(tex.clone());
         self.attrs.changed = false;
         self.buf.changed = false;
@@ -81,9 +76,8 @@ impl TextView {
         self.tex.as_ref()
     }
     pub fn desired_width(&mut self, ctx: &mut SizeCtx) -> Len {
-        if let Some(hint) = &self.hint
-            && let [line] = &self.buf.lines[..]
-            && line.text().is_empty()
+        if self.is_blank()
+            && let Some(hint) = &self.hint
         {
             ctx.width(hint)
         } else {
@@ -91,9 +85,8 @@ impl TextView {
         }
     }
     pub fn desired_height(&mut self, ctx: &mut SizeCtx) -> Len {
-        if let Some(hint) = &self.hint
-            && let [line] = &self.buf.lines[..]
-            && line.text().is_empty()
+        if self.is_blank()
+            && let Some(hint) = &self.hint
         {
             ctx.height(hint)
         } else {
@@ -102,47 +95,35 @@ impl TextView {
     }
     pub fn draw(&mut self, painter: &mut Painter) -> UiRegion {
         let tex = self.render(&mut painter.size_ctx());
-        let region = self.tex_region(&tex);
-        if let Some(hint) = &self.hint
-            && let [line] = &self.buf.lines[..]
-            && line.text().is_empty()
+        let region = tex.size.align(self.align);
+        if self.is_blank()
+            && let Some(hint) = &self.hint
         {
             painter.widget(hint);
         } else {
-            painter.texture_within(&tex.handle, region);
+            let within = region.within(&painter.region());
+            painter.glyphs(&tex, within);
         }
         region
     }
 
     pub fn content(&self) -> String {
-        self.buf
-            .lines
-            .iter()
-            .map(|l| l.text())
-            .collect::<Vec<_>>()
-            .join("\n")
+        self.buf.text().to_string()
     }
 }
 
 impl Text {
     pub fn new(content: impl Into<String>) -> Self {
-        let attrs = TextAttrs::default();
-        let buf = TextBuffer::new_empty(Metrics::new(attrs.font_size, attrs.line_height));
+        let content: String = content.into();
         Self {
-            content: content.into().into(),
-            view: TextView::new(buf, attrs, None),
+            view: TextView::new(TextBuffer::new(&content), TextAttrs::default(), None),
+            content: content.into(),
         }
     }
-    fn update_buf(&mut self, ctx: &mut SizeCtx) {
+    fn update_buf(&mut self, _ctx: &mut SizeCtx) {
         if self.content.changed {
             self.content.changed = false;
-            self.view.buf.set_text(
-                &mut ctx.text.font_system,
-                &self.content,
-                &Attrs::new().family(self.view.attrs.family),
-                SHAPING,
-                None,
-            );
+            self.view.buf.set_text(self.content.as_str());
         }
     }
 }
@@ -164,16 +145,6 @@ impl Widget for Text {
     }
 }
 
-pub fn sort_cursors(a: Cursor, b: Cursor) -> (Cursor, Cursor) {
-    let start = a.min(b);
-    let end = a.max(b);
-    (start, end)
-}
-
-pub fn edit_line(line: &mut BufferLine, text: String) {
-    line.set_text(text, line.ending(), line.attrs_list().clone());
-}
-
 impl Deref for Text {
     type Target = TextAttrs;
 

src/widget/trait_fns.rs

@@ -131,61 +131,18 @@ widget_trait! {
     }
 }
 
-pub trait CoreWidgetArr<Children, Rsc, Tag, GTag> {
-    fn span(self, dir: Dir) -> SpanBuilder<Children, Rsc, Tag, GTag>;
-    fn stack(self) -> StackBuilder<Children, Rsc, Tag, GTag>;
+pub trait CoreWidgetArr<Rsc, const LEN: usize, Wa: WidgetArrLike<Rsc, LEN, Tag>, Tag> {
+    fn span(self, dir: Dir) -> SpanBuilder<Rsc, LEN, Wa, Tag>;
+    fn stack(self) -> StackBuilder<Rsc, LEN, Wa, Tag>;
 }
 
-impl<Children: IntoWidgetVec<Rsc, Tag, GTag>, Rsc, Tag, GTag>
-    CoreWidgetArr<Children, Rsc, Tag, GTag> for Children
+impl<State, const LEN: usize, Wa: WidgetArrLike<State, LEN, Tag>, Tag>
+    CoreWidgetArr<State, LEN, Wa, Tag> for Wa
 {
-    fn span(self, dir: Dir) -> SpanBuilder<Children, Rsc, Tag, GTag> {
+    fn span(self, dir: Dir) -> SpanBuilder<State, LEN, Wa, Tag> {
         SpanBuilder::new(self, dir)
     }
-    fn stack(self) -> StackBuilder<Children, Rsc, Tag, GTag> {
+    fn stack(self) -> StackBuilder<State, LEN, Wa, Tag> {
         StackBuilder::new(self)
     }
 }
-
-pub trait RscFnMap<Rsc> {
-    type Input;
-    fn rsc_map<O>(
-        self,
-        f: impl Fn(Self::Input, &mut Rsc) -> O + Clone,
-    ) -> impl Iterator<Item = impl FnOnce(&mut Rsc) -> O>;
-}
-
-impl<I: IntoIterator, Rsc> RscFnMap<Rsc> for I {
-    type Input = I::Item;
-    fn rsc_map<O>(
-        self,
-        f: impl Fn(Self::Input, &mut Rsc) -> O + Clone,
-    ) -> impl Iterator<Item = impl FnOnce(&mut Rsc) -> O> {
-        self.into_iter().map(move |i| {
-            let f = f.clone();
-            move |rsc: &mut Rsc| f(i, rsc)
-        })
-    }
-}
-
-pub trait WidgetFnMap<Rsc: UiRsc> {
-    fn widget_map<O: WidgetLike<Rsc, Tag>, Tag>(
-        self,
-        f: impl Fn(WeakWidget) -> O + Clone,
-    ) -> impl Iterator<Item = impl FnOnce(&mut Rsc) -> WeakWidget>;
-}
-
-impl<I: IntoIterator, Rsc: UiRsc> WidgetFnMap<Rsc> for I
-where
-    I::Item: WidgetIdFn<Rsc>,
-{
-    fn widget_map<O: WidgetLike<Rsc, Tag>, Tag>(
-        self,
-        f: impl Fn(WeakWidget) -> O + Clone,
-    ) -> impl Iterator<Item = impl FnOnce(&mut Rsc) -> WeakWidget> {
-        self.into_iter().map(move |f2| {
-            let f = f.clone();
-            move |rsc: &mut Rsc| f(f2(rsc)).add(rsc) as WeakWidget
-        })
-    }
-}

tests/text_edit.rs

@@ -0,0 +1,67 @@
+use iris::prelude::*;
+
+fn editor(text: &str, mode: EditMode) -> (TextEdit, TextData) {
+    let view = TextView::new(TextBuffer::new(text), TextAttrs::default(), None);
+    (TextEdit::new(view, mode), TextData::default())
+}
+
+fn press(edit: &mut TextEditCtx<'_>, x: f32) {
+    edit.select(vec2(x, 10.0), vec2(400.0, 200.0), false, false);
+}
+
+#[test]
+fn pressing_an_empty_field_places_input() {
+    let (mut text, mut data) = editor("", EditMode::SingleLine);
+    let mut edit = TextEditCtx {
+        text: &mut text,
+        data: &mut data,
+    };
+
+    press(&mut edit, 40.0);
+    edit.insert("hello");
+
+    assert_eq!(edit.text.content(), "hello");
+}
+
+#[test]
+fn preedit_replaces_the_previous_composition() {
+    let (mut text, mut data) = editor("", EditMode::SingleLine);
+    let mut edit = TextEditCtx {
+        text: &mut text,
+        data: &mut data,
+    };
+
+    press(&mut edit, 0.0);
+    edit.replace(0, "に");
+    edit.replace(1, "日本");
+
+    assert_eq!(edit.text.content(), "日本");
+}
+
+#[test]
+fn backspace_respects_utf8_boundaries() {
+    let (mut text, mut data) = editor("aé", EditMode::SingleLine);
+    let mut edit = TextEditCtx {
+        text: &mut text,
+        data: &mut data,
+    };
+
+    press(&mut edit, f32::MAX);
+    edit.backspace(false);
+
+    assert_eq!(edit.text.content(), "a");
+}
+
+#[test]
+fn typing_replaces_the_selection() {
+    let (mut text, mut data) = editor("hello", EditMode::SingleLine);
+    let mut edit = TextEditCtx {
+        text: &mut text,
+        data: &mut data,
+    };
+
+    edit.select_all();
+    edit.insert("goodbye");
+
+    assert_eq!(edit.text.content(), "goodbye");
+}