bevy_text::input module with no undo

Cargo.toml

@@ -866,6 +866,17 @@ description = "Renders text to multiple windows with different scale factors usi
 category = "2D Rendering"
 wasm = true
 
+[[example]]
+name = "text_input_2d"
+path = "examples/2d/text_input_2d.rs"
+doc-scrape-examples = true
+
+[package.metadata.example.text_input_2d]
+name = "Text Input 2D"
+description = "Text input in 2D"
+category = "2D Rendering"
+wasm = true
+
 [[example]]
 name = "texture_atlas"
 path = "examples/2d/texture_atlas.rs"

crates/bevy_sprite/src/lib.rs

@@ -87,7 +87,8 @@ impl Plugin for SpritePlugin {
                 bevy_text::detect_text_needs_rerender::<Text2d>,
                 update_text2d_layout
                     .after(bevy_camera::CameraUpdateSystems)
-                    .after(bevy_text::remove_dropped_font_atlas_sets),
+                    .after(bevy_text::remove_dropped_font_atlas_sets)
+                    .ambiguous_with(bevy_text::update_placeholder_layouts),
                 calculate_bounds_text2d.in_set(VisibilitySystems::CalculateBounds),
             )
                 .chain()

crates/bevy_sprite/src/sprite.rs

@@ -1,10 +1,13 @@
 use bevy_asset::{Assets, Handle};
-use bevy_camera::visibility::{self, Visibility, VisibilityClass};
+use bevy_camera::{
+    primitives::Aabb,
+    visibility::{self, Visibility, VisibilityClass},
+};
 use bevy_color::Color;
 use bevy_derive::{Deref, DerefMut};
 use bevy_ecs::{component::Component, reflect::ReflectComponent};
 use bevy_image::{Image, TextureAtlas, TextureAtlasLayout};
-use bevy_math::{Rect, UVec2, Vec2};
+use bevy_math::{Rect, UVec2, Vec2, Vec3};
 use bevy_reflect::{std_traits::ReflectDefault, Reflect};
 use bevy_transform::components::Transform;
 
@@ -260,6 +263,16 @@ impl Anchor {
     pub fn as_vec(&self) -> Vec2 {
         self.0
     }
+
+    /// Determine the bounds at the anchor
+    pub fn calculate_bounds(&self, size: Vec2) -> Aabb {
+        let x1 = (Anchor::TOP_LEFT.0.x - self.as_vec().x) * size.x;
+        let x2 = (Anchor::TOP_LEFT.0.x - self.as_vec().x + 1.) * size.x;
+        let y1 = (Anchor::TOP_LEFT.0.y - self.as_vec().y - 1.) * size.y;
+        let y2 = (Anchor::TOP_LEFT.0.y - self.as_vec().y) * size.y;
+
+        Aabb::from_min_max(Vec3::new(x1, y1, 0.), Vec3::new(x2, y2, 0.))
+    }
 }
 
 impl Default for Anchor {

crates/bevy_text/Cargo.toml

@@ -22,6 +22,7 @@ bevy_image = { path = "../bevy_image", version = "0.17.0-dev" }
 bevy_log = { path = "../bevy_log", version = "0.17.0-dev" }
 bevy_math = { path = "../bevy_math", version = "0.17.0-dev" }
 bevy_reflect = { path = "../bevy_reflect", version = "0.17.0-dev" }
+bevy_time = { path = "../bevy_time", version = "0.17.0-dev" }
 bevy_utils = { path = "../bevy_utils", version = "0.17.0-dev" }
 bevy_platform = { path = "../bevy_platform", version = "0.17.0-dev", default-features = false, features = [
   "std",

crates/bevy_text/src/input/buffer.rs

@@ -0,0 +1,306 @@
+use bevy_asset::{AssetEvent, Assets, Handle};
+use bevy_derive::Deref;
+use bevy_ecs::{
+    change_detection::DetectChanges,
+    component::Component,
+    event::EventReader,
+    lifecycle::HookContext,
+    system::{Query, Res, ResMut},
+    world::{DeferredWorld, Ref},
+};
+use bevy_time::Time;
+use cosmic_text::{Buffer, BufferLine, Edit, Editor, Metrics};
+
+use crate::{
+    load_font_to_fontdb, CosmicFontSystem, CursorBlink, Font, FontSmoothing, Justify, LineBreak,
+    LineHeight, TextCursorBlinkInterval, TextEdit, TextEdits, TextError, TextInputTarget,
+    TextLayoutInfo, TextPipeline,
+};
+
+/// Common text input properties set by the user.
+/// On changes, the text input systems will automatically update the buffer, layout and fonts as required.
+#[derive(Component, Debug, PartialEq)]
+pub struct TextInputAttributes {
+    /// The text input's font, which also applies to any [`crate::Placeholder`] text or password mask.
+    /// A text input's glyphs must all be from the same font.
+    pub font: Handle<Font>,
+    /// The size of the font.
+    /// A text input's glyphs must all be the same size.
+    pub font_size: f32,
+    /// The height of each line.
+    /// A text input's lines must all be the same height.
+    pub line_height: LineHeight,
+    /// Determines how lines will be broken
+    pub line_break: LineBreak,
+    /// The horizontal alignment for all the text in the text input buffer.
+    pub justify: Justify,
+    /// Controls text antialiasing
+    pub font_smoothing: FontSmoothing,
+    /// Maximum number of glyphs the text input buffer can contain.
+    /// Any edits that extend the length above `max_chars` are ignored.
+    /// If set on a buffer longer than `max_chars` the buffer will be truncated.
+    pub max_chars: Option<usize>,
+    /// The maximum number of lines the buffer will display without scrolling.
+    /// * Clamped between zero and target height divided by line height.
+    /// * If None or equal or less than 0, will fill the target space.
+    /// * Only restricts the maximum number of visible lines, places no constraint on the text buffer's length.
+    /// * Supports fractional values, `visible_lines: Some(2.5)` will display two and a half lines of text.
+    pub visible_lines: Option<f32>,
+}
+
+/// Default font size
+pub const DEFAULT_FONT_SIZE: f32 = 20.;
+/// Default line height factor (relative to font size)
+///
+/// `1.2` corresponds to `normal` in `<https://developer.mozilla.org/en-US/docs/Web/CSS/line-height>`
+pub const DEFAULT_LINE_HEIGHT_FACTOR: f32 = 1.2;
+/// Default line height
+pub const DEFAULT_LINE_HEIGHT: f32 = DEFAULT_FONT_SIZE * DEFAULT_LINE_HEIGHT_FACTOR;
+/// Default space advance
+pub const DEFAULT_SPACE_ADVANCE: f32 = 20.;
+
+impl Default for TextInputAttributes {
+    fn default() -> Self {
+        Self {
+            font: Default::default(),
+            font_size: DEFAULT_FONT_SIZE,
+            line_height: LineHeight::RelativeToFont(DEFAULT_LINE_HEIGHT_FACTOR),
+            font_smoothing: Default::default(),
+            justify: Default::default(),
+            line_break: Default::default(),
+            max_chars: None,
+            visible_lines: None,
+        }
+    }
+}
+
+/// Contains the current text in the text input buffer.
+/// Automatically synchronized with the buffer by [`crate::apply_text_edits`] after any edits are applied.
+/// On insertion, replaces the current text in the text buffer.
+#[derive(Component, PartialEq, Debug, Default, Deref)]
+#[component(
+    on_insert = on_insert_text_input_value,
+)]
+pub struct TextInputValue(pub String);
+
+impl TextInputValue {
+    /// New text, when inserted replaces the current text in the text buffer
+    pub fn new(value: impl Into<String>) -> Self {
+        Self(value.into())
+    }
+
+    /// Get the current text
+    pub fn get(&self) -> &str {
+        &self.0
+    }
+}
+
+/// Set the text input with the text from the `TextInputValue` when inserted.
+fn on_insert_text_input_value(mut world: DeferredWorld, context: HookContext) {
+    if let Some(value) = world.get::<TextInputValue>(context.entity) {
+        let value = value.0.clone();
+        if let Some(mut actions) = world.entity_mut(context.entity).get_mut::<TextEdits>() {
+            actions.queue(TextEdit::SetText(value));
+        }
+    }
+}
+
+/// Get the text from a cosmic text buffer
+pub fn get_cosmic_text_buffer_contents(buffer: &Buffer) -> String {
+    buffer
+        .lines
+        .iter()
+        .map(BufferLine::text)
+        .fold(String::new(), |mut out, line| {
+            if !out.is_empty() {
+                out.push('\n');
+            }
+            out.push_str(line);
+            out
+        })
+}
+
+/// The text input buffer.
+/// Primary component that contains the text layout.
+///
+/// The `needs_redraw` method can be used to check if the buffer's contents have changed and need redrawing.
+/// Component change detection is not reliable as the editor buffer needs to be borrowed mutably during updates.
+#[derive(Component, Debug)]
+#[require(TextInputAttributes, TextInputTarget, TextEdits, TextLayoutInfo)]
+pub struct TextInputBuffer {
+    /// The cosmic text editor buffer.
+    pub editor: Editor<'static>,
+    /// Space advance width for the current font, used to determine the width of the cursor when it is at the end of a line
+    /// or when the buffer is empty.
+    pub space_advance: f32,
+}
+
+impl Default for TextInputBuffer {
+    fn default() -> Self {
+        Self {
+            editor: Editor::new(Buffer::new_empty(Metrics::new(
+                DEFAULT_FONT_SIZE,
+                DEFAULT_LINE_HEIGHT,
+            ))),
+            space_advance: DEFAULT_SPACE_ADVANCE,
+        }
+    }
+}
+
+impl TextInputBuffer {
+    /// Use the cosmic text buffer mutably
+    pub fn with_buffer_mut<F, T>(&mut self, f: F) -> T
+    where
+        F: FnOnce(&mut Buffer) -> T,
+    {
+        self.editor.with_buffer_mut(f)
+    }
+
+    /// Use the cosmic text buffer
+    pub fn with_buffer<F, T>(&self, f: F) -> T
+    where
+        F: FnOnce(&Buffer) -> T,
+    {
+        self.editor.with_buffer(f)
+    }
+
+    /// True if the buffer is empty
+    pub fn is_empty(&self) -> bool {
+        self.with_buffer(|buffer| {
+            buffer.lines.is_empty()
+                || (buffer.lines.len() == 1 && buffer.lines[0].text().is_empty())
+        })
+    }
+
+    /// Get the text contained in the text buffer
+    pub fn get_text(&self) -> String {
+        self.editor.with_buffer(get_cosmic_text_buffer_contents)
+    }
+
+    /// Returns true if the buffer's contents have changed and need to be redrawn.
+    pub fn needs_redraw(&self) -> bool {
+        self.editor.redraw()
+    }
+}
+
+/// Updates the text input buffer in response to changes
+/// that require regeneration of the the buffer's
+/// metrics and attributes.
+pub fn update_text_input_buffers(
+    mut text_input_query: Query<(
+        &mut TextInputBuffer,
+        Ref<TextInputTarget>,
+        &TextEdits,
+        Ref<TextInputAttributes>,
+        Option<&mut CursorBlink>,
+    )>,
+    time: Res<Time>,
+    cursor_blink_interval: Res<TextCursorBlinkInterval>,
+    mut font_system: ResMut<CosmicFontSystem>,
+    mut text_pipeline: ResMut<TextPipeline>,
+    fonts: Res<Assets<Font>>,
+    mut font_events: EventReader<AssetEvent<Font>>,
+) {
+    let font_system = &mut font_system.0;
+    let font_id_map = &mut text_pipeline.map_handle_to_font_id;
+    for (mut input_buffer, target, edits, attributes, maybe_cursor_blink) in
+        text_input_query.iter_mut()
+    {
+        let TextInputBuffer {
+            editor,
+            space_advance,
+        } = input_buffer.as_mut();
+
+        if let Some(mut cursor_blink) = maybe_cursor_blink {
+            cursor_blink.cursor_blink_timer = if edits.queue.is_empty() {
+                (cursor_blink.cursor_blink_timer + time.delta_secs())
+                    .rem_euclid(cursor_blink_interval.0.as_secs_f32() * 2.)
+            } else {
+                0.
+            };
+        }
+
+        let _ = editor.with_buffer_mut(|buffer| {
+            if target.is_changed()
+                || attributes.is_changed()
+                || font_events.read().any(|event| match event {
+                    AssetEvent::Added { id } | AssetEvent::Modified { id } => {
+                        *id == attributes.font.id()
+                    }
+                    _ => false,
+                })
+            {
+                let line_height = attributes.line_height.eval(attributes.font_size);
+                let metrics =
+                    Metrics::new(attributes.font_size, line_height).scale(target.scale_factor);
+                buffer.set_metrics(font_system, metrics);
+
+                buffer.set_wrap(font_system, attributes.line_break.into());
+
+                if !fonts.contains(attributes.font.id()) {
+                    return Err(TextError::NoSuchFont);
+                }
+
+                let face_info =
+                    load_font_to_fontdb(attributes.font.clone(), font_system, font_id_map, &fonts);
+
+                let attrs = cosmic_text::Attrs::new()
+                    .metadata(0)
+                    .family(cosmic_text::Family::Name(&face_info.family_name))
+                    .stretch(face_info.stretch)
+                    .style(face_info.style)
+                    .weight(face_info.weight);
+
+                let mut text = buffer.lines.iter().map(BufferLine::text).fold(
+                    String::new(),
+                    |mut out, line| {
+                        if !out.is_empty() {
+                            out.push('\n');
+                        }
+                        out.push_str(line);
+                        out
+                    },
+                );
+
+                if let Some(max_chars) = attributes.max_chars {
+                    text.truncate(max_chars);
+                }
+
+                buffer.set_text(font_system, &text, &attrs, cosmic_text::Shaping::Advanced);
+                let align = Some(attributes.justify.into());
+                for buffer_line in buffer.lines.iter_mut() {
+                    buffer_line.set_align(align);
+                }
+
+                *space_advance = font_id_map
+                    .get(&attributes.font.id())
+                    .and_then(|(id, ..)| font_system.get_font(*id))
+                    .and_then(|font| {
+                        let face = font.rustybuzz();
+                        face.glyph_index(' ')
+                            .and_then(|gid| face.glyph_hor_advance(gid))
+                            .map(|advance| advance as f32 / face.units_per_em() as f32)
+                    })
+                    .unwrap_or(0.0)
+                    * buffer.metrics().font_size;
+
+                let height =
+                    if let Some(lines) = attributes.visible_lines.filter(|lines| 0. < *lines) {
+                        (metrics.line_height * lines).max(target.size.y)
+                    } else {
+                        target.size.y
+                    };
+
+                buffer.set_size(
+                    font_system,
+                    Some(target.size.x - *space_advance),
+                    Some(height),
+                );
+
+                buffer.set_redraw(true);
+            }
+
+            Ok(())
+        });
+    }
+}

crates/bevy_text/src/input/clipboard.rs

@@ -0,0 +1,8 @@
+use bevy_ecs::resource::Resource;
+
+/// Basic clipboard implementation that only works within the bevy app.
+///
+/// This is written to in the [`crate::apply_text_edits`] system when
+/// [`crate::TextEdit::Copy`], [`crate::TextEdit::Cut`] or [`crate::TextEdit::Paste`] edits are applied.
+#[derive(Resource, Default)]
+pub struct Clipboard(pub String);