refactor project structure (start of redoing atomic branch without atomics)

src/widget/text/build.rs

@@ -0,0 +1,128 @@
+use crate::prelude::*;
+use cosmic_text::{Attrs, Family, Metrics};
+use std::marker::Sized;
+
+pub struct TextBuilder<O = TextOutput, H: WidgetOption = ()> {
+    pub content: String,
+    pub attrs: TextAttrs,
+    pub hint: H,
+    pub output: O,
+}
+
+impl<O, H: WidgetOption> TextBuilder<O, H> {
+    pub fn size(mut self, size: impl UiNum) -> Self {
+        self.attrs.font_size = size.to_f32();
+        self.attrs.line_height = self.attrs.font_size * LINE_HEIGHT_MULT;
+        self
+    }
+    pub fn color(mut self, color: UiColor) -> Self {
+        self.attrs.color = color;
+        self
+    }
+    pub fn family(mut self, family: Family<'static>) -> Self {
+        self.attrs.family = family;
+        self
+    }
+    pub fn line_height(mut self, height: f32) -> Self {
+        self.attrs.line_height = height;
+        self
+    }
+    pub fn text_align(mut self, align: impl Into<RegionAlign>) -> Self {
+        self.attrs.align = align.into();
+        self
+    }
+    pub fn center_text(mut self) -> Self {
+        self.attrs.align = Align::CENTER;
+        self
+    }
+    pub fn wrap(mut self, wrap: bool) -> Self {
+        self.attrs.wrap = wrap;
+        self
+    }
+    pub fn editable(self, single_line: bool) -> TextBuilder<TextEditOutput, H> {
+        TextBuilder {
+            content: self.content,
+            attrs: self.attrs,
+            hint: self.hint,
+            output: TextEditOutput { single_line },
+        }
+    }
+}
+
+impl<O> TextBuilder<O> {
+    pub fn hint<W: WidgetLike<Tag>, Tag>(self, hint: W) -> TextBuilder<O, impl WidgetOption> {
+        TextBuilder {
+            content: self.content,
+            attrs: self.attrs,
+            hint: move |ui: &mut Ui| Some(hint.add(ui).any()),
+            output: self.output,
+        }
+    }
+}
+
+pub trait TextBuilderOutput: Sized {
+    type Output;
+    fn run<H: WidgetOption>(ui: &mut Ui, builder: TextBuilder<Self, H>) -> Self::Output;
+}
+
+pub struct TextOutput;
+impl TextBuilderOutput for TextOutput {
+    type Output = Text;
+
+    fn run<H: WidgetOption>(ui: &mut Ui, builder: TextBuilder<Self, H>) -> Self::Output {
+        let mut buf = TextBuffer::new_empty(Metrics::new(
+            builder.attrs.font_size,
+            builder.attrs.line_height,
+        ));
+        let hint = builder.hint.get(ui);
+        let font_system = &mut ui.data.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
+    }
+}
+
+pub struct TextEditOutput {
+    single_line: bool,
+}
+impl TextBuilderOutput for TextEditOutput {
+    type Output = TextEdit;
+
+    fn run<H: WidgetOption>(ui: &mut Ui, builder: TextBuilder<Self, H>) -> Self::Output {
+        let buf = TextBuffer::new_empty(Metrics::new(
+            builder.attrs.font_size,
+            builder.attrs.line_height,
+        ));
+        let mut text = TextEdit::new(
+            TextView::new(buf, builder.attrs, builder.hint.get(ui)),
+            builder.output.single_line,
+        );
+        let font_system = &mut ui.data.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
+    }
+}
+
+impl<O: TextBuilderOutput, H: WidgetOption> FnOnce<(&mut Ui,)> for TextBuilder<O, H> {
+    type Output = O::Output;
+
+    extern "rust-call" fn call_once(self, args: (&mut Ui,)) -> Self::Output {
+        O::run(args.0, self)
+    }
+}
+
+pub fn wtext(content: impl Into<String>) -> TextBuilder {
+    TextBuilder {
+        content: content.into(),
+        attrs: TextAttrs::default(),
+        hint: (),
+        output: TextOutput,
+    }
+}

src/widget/text/edit.rs

@@ -0,0 +1,625 @@
+use std::ops::{Deref, DerefMut};
+
+use crate::prelude::*;
+use cosmic_text::{Affinity, Attrs, Cursor, FontSystem, LayoutRun, Motion};
+use unicode_segmentation::UnicodeSegmentation;
+use winit::{
+    event::KeyEvent,
+    keyboard::{Key, NamedKey},
+};
+
+pub struct TextEdit {
+    view: TextView,
+    selection: TextSelection,
+    history: Vec<(String, TextSelection)>,
+    double_hit: Option<Cursor>,
+    pub single_line: bool,
+}
+
+impl TextEdit {
+    pub fn new(view: TextView, single_line: bool) -> Self {
+        Self {
+            view,
+            selection: Default::default(),
+            history: Default::default(),
+            double_hit: None,
+            single_line,
+        }
+    }
+    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
+        }
+    }
+}
+
+impl Widget for TextEdit {
+    fn draw(&mut self, painter: &mut Painter) {
+        let base = painter.layer;
+        painter.child_layer();
+        self.view.draw(painter);
+        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),
+                    );
+                }
+            }
+        }
+    }
+
+    fn desired_width(&mut self, ctx: &mut SizeCtx) -> Len {
+        self.view.desired_width(ctx)
+    }
+
+    fn desired_height(&mut self, ctx: &mut SizeCtx) -> Len {
+        self.view.desired_height(ctx)
+    }
+}
+
+/// 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
+}
+
+pub struct TextEditCtx<'a> {
+    pub text: &'a mut TextEdit,
+    pub font_system: &'a mut FontSystem,
+}
+
+impl<'a> TextEditCtx<'a> {
+    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();
+        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();
+    }
+
+    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);
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    pub fn replace(&mut self, len: usize, text: &str) {
+        let text = self.string(text);
+        for _ in 0..len {
+            self.delete(false);
+        }
+        self.insert_inner(&text, false);
+    }
+
+    fn string(&self, text: &str) -> String {
+        if self.text.single_line {
+            text.replace('\n', "")
+        } else {
+            text.to_string()
+        }
+    }
+
+    pub fn insert(&mut self, text: &str) {
+        let text = self.string(text);
+        let mut lines = text.split('\n');
+        let Some(first) = lines.next() else {
+            return;
+        };
+        self.insert_inner(first, true);
+        for line in lines {
+            self.newline();
+            self.insert_inner(line, true);
+        }
+    }
+
+    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
+        }
+    }
+
+    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);
+                }
+            }
+        }
+    }
+
+    pub fn newline(&mut self) {
+        if self.text.single_line {
+            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;
+        }
+    }
+
+    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);
+        }
+    }
+
+    pub fn delete(&mut self, word: bool) {
+        if !self.clear_span()
+            && let TextSelection::Pos(cursor) = &mut self.text.selection
+        {
+            if word {
+                let start = *cursor;
+                if let Some(end) = self.buf_motion(start, Motion::RightWord) {
+                    self.delete_between(start, end);
+                }
+            } 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);
+                }
+            }
+        }
+    }
+
+    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)
+    }
+
+    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(&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)
+                }
+            }
+            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);
+        }
+    }
+
+    pub fn deselect(&mut self) {
+        self.text.selection = TextSelection::None;
+    }
+
+    pub fn apply_event(&mut self, event: &KeyEvent, modifiers: &Modifiers) -> TextInputResult {
+        let old = (self.text.content(), 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 {
+            self.text.history.push(old);
+        }
+        res
+    }
+
+    fn apply_event_inner(
+        &mut self,
+        event: &KeyEvent,
+        modifiers: &Modifiers,
+        undo: &mut bool,
+    ) -> TextInputResult {
+        match &event.logical_key {
+            Key::Named(named) => match named {
+                NamedKey::Backspace => self.backspace(modifiers.control),
+                NamedKey::Delete => self.delete(modifiers.control),
+                NamedKey::Space => self.insert(" "),
+                NamedKey::Enter => {
+                    if modifiers.shift {
+                        self.newline();
+                    } else {
+                        return TextInputResult::Submit;
+                    }
+                }
+                NamedKey::ArrowRight => {
+                    if modifiers.control {
+                        self.motion(Motion::RightWord, modifiers.shift)
+                    } else {
+                        self.motion(Motion::Right, modifiers.shift)
+                    }
+                }
+                NamedKey::ArrowLeft => {
+                    if modifiers.control {
+                        self.motion(Motion::LeftWord, modifiers.shift)
+                    } else {
+                        self.motion(Motion::Left, modifiers.shift)
+                    }
+                }
+                NamedKey::ArrowUp => self.motion(Motion::Up, modifiers.shift),
+                NamedKey::ArrowDown => self.motion(Motion::Down, modifiers.shift),
+                NamedKey::Escape => {
+                    self.deselect();
+                    return TextInputResult::Unfocus;
+                }
+                _ => return TextInputResult::Unused,
+            },
+            Key::Character(text) => {
+                if modifiers.control {
+                    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);
+                                return TextInputResult::Copy(content);
+                            }
+                        }
+                        "x" => {
+                            if let TextSelection::Span { start, end } = self.text.selection {
+                                let content = self.text.select_content(start, end);
+                                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;
+                        }
+                        _ => self.insert(text),
+                    }
+                } else {
+                    self.insert(text);
+                }
+            }
+            _ => return TextInputResult::Unused,
+        }
+        TextInputResult::Used
+    }
+}
+
+#[derive(Default)]
+pub struct Modifiers {
+    pub shift: bool,
+    pub control: bool,
+}
+
+impl Modifiers {
+    pub fn clear(&mut self) {
+        self.shift = false;
+        self.control = false;
+    }
+}
+
+pub enum TextInputResult {
+    Used,
+    Unused,
+    Unfocus,
+    Submit,
+    Copy(String),
+    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)
+    }
+}
+
+impl Deref for TextEdit {
+    type Target = TextView;
+
+    fn deref(&self) -> &Self::Target {
+        &self.view
+    }
+}
+
+impl DerefMut for TextEdit {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.view
+    }
+}
+
+pub trait TextEditable {
+    fn edit<'a>(&self, ui: &'a mut Ui) -> TextEditCtx<'a>;
+}
+
+impl<I: IdLike<Widget = TextEdit>> TextEditable for I {
+    fn edit<'a>(&self, ui: &'a mut Ui) -> TextEditCtx<'a> {
+        TextEditCtx {
+            text: ui.data.widgets.get_mut(self).unwrap(),
+            font_system: &mut ui.data.text.font_system,
+        }
+    }
+}

src/widget/text/mod.rs

@@ -0,0 +1,202 @@
+mod build;
+mod edit;
+
+pub use build::*;
+pub use edit::*;
+
+use crate::{prelude::*, util::MutDetect};
+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,
+}
+
+pub struct TextView {
+    pub attrs: MutDetect<TextAttrs>,
+    pub buf: MutDetect<TextBuffer>,
+    // cache
+    tex: Option<RenderedText>,
+    width: Option<f32>,
+    pub hint: Option<WidgetId>,
+}
+
+impl TextView {
+    pub fn new(buf: TextBuffer, attrs: TextAttrs, hint: Option<WidgetId>) -> Self {
+        Self {
+            attrs: attrs.into(),
+            buf: buf.into(),
+            tex: None,
+            width: None,
+            hint,
+        }
+    }
+
+    /// region where the text should be draw
+    /// does not include extra height or width from weird unicode
+    pub fn region(&self) -> UiRegion {
+        self.tex()
+            .map(|t| t.size)
+            .unwrap_or(Vec2::ZERO)
+            .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)
+        } else {
+            None
+        };
+        if width == self.width
+            && let Some(tex) = &self.tex
+            && !self.attrs.changed
+            && !self.buf.changed
+        {
+            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);
+        self.tex = Some(tex.clone());
+        self.attrs.changed = false;
+        self.buf.changed = false;
+        tex
+    }
+    pub fn tex(&self) -> Option<&RenderedText> {
+        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()
+        {
+            ctx.width(hint)
+        } else {
+            Len::abs(self.render(ctx).size.x)
+        }
+    }
+    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()
+        {
+            ctx.height(hint)
+        } else {
+            Len::abs(self.render(ctx).size.y)
+        }
+    }
+    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()
+        {
+            painter.widget(hint);
+        } else {
+            painter.texture_within(&tex.handle, region);
+        }
+        region
+    }
+
+    pub fn content(&self) -> String {
+        self.buf
+            .lines
+            .iter()
+            .map(|l| l.text())
+            .collect::<Vec<_>>()
+            .join("\n")
+    }
+}
+
+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));
+        Self {
+            content: content.into().into(),
+            view: TextView::new(buf, attrs, None),
+        }
+    }
+    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,
+            );
+        }
+    }
+}
+
+impl Widget for Text {
+    fn draw(&mut self, painter: &mut Painter) {
+        self.update_buf(&mut painter.size_ctx());
+        self.view.draw(painter);
+    }
+
+    fn desired_width(&mut self, ctx: &mut SizeCtx) -> Len {
+        self.update_buf(ctx);
+        self.view.desired_width(ctx)
+    }
+
+    fn desired_height(&mut self, ctx: &mut SizeCtx) -> Len {
+        self.update_buf(ctx);
+        self.view.desired_height(ctx)
+    }
+}
+
+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;
+
+    fn deref(&self) -> &Self::Target {
+        &self.view
+    }
+}
+
+impl DerefMut for Text {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.view
+    }
+}
+
+impl Deref for TextView {
+    type Target = TextAttrs;
+
+    fn deref(&self) -> &Self::Target {
+        &self.attrs
+    }
+}
+
+impl DerefMut for TextView {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.attrs
+    }
+}