iris: add positioned text overflow

core/src/primitive/text.rs

@@ -1,5 +1,5 @@
 use crate::{
-    Align, GlyphAtlas, GlyphKey, PaintId, PlacedGlyph, RegionAlign, Textures, WidgetId,
+    Align, GlyphAtlas, GlyphKey, Len, PaintId, PlacedGlyph, RegionAlign, Textures, WidgetId,
     util::{Resources, RscHandle, StrongRscId, Vec2, WeakRscId},
 };
 use parley::{
@@ -584,10 +584,39 @@ pub struct TextAttrs {
     pub font_size: f32,
     pub line_height: f32,
     pub family: String,
-    pub wrap: bool,
+    pub overflow: TextOverflow,
+    pub overflow_position: Len,
     pub align: RegionAlign,
 }
 
+#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
+pub enum TextOverflow {
+    #[default]
+    Visible,
+    Wrap,
+    Hidden,
+    Ellipsis,
+}
+
+#[derive(Clone, PartialEq)]
+struct TextShapeAttrs {
+    color: PaintId,
+    font_size: f32,
+    line_height: f32,
+    family: String,
+}
+
+impl From<&TextAttrs> for TextShapeAttrs {
+    fn from(attrs: &TextAttrs) -> Self {
+        Self {
+            color: attrs.color.clone(),
+            font_size: attrs.font_size,
+            line_height: attrs.line_height,
+            family: attrs.family.clone(),
+        }
+    }
+}
+
 pub const LINE_HEIGHT_MULT: f32 = 1.1;
 
 impl Default for TextAttrs {
@@ -598,7 +627,8 @@ impl Default for TextAttrs {
             font_size: size,
             line_height: size * LINE_HEIGHT_MULT,
             family: SANS_SERIF.to_owned(),
-            wrap: false,
+            overflow: TextOverflow::Visible,
+            overflow_position: Len::ZERO,
             align: Align::CENTER_LEFT,
         }
     }
@@ -611,7 +641,7 @@ pub struct TextBuffer {
     text: String,
     layout: Layout<PaintId>,
     spans: Vec<SpanStyle>,
-    shaped: Option<(TextAttrs, Option<f32>, f32)>,
+    shaped: Option<(TextShapeAttrs, Option<f32>, f32)>,
 }
 
 impl TextBuffer {
@@ -671,7 +701,8 @@ impl TextBuffer {
         width: Option<f32>,
         density: f32,
     ) {
-        if self.shaped.as_ref() == Some(&(attrs.clone(), width, density)) {
+        let shape_attrs = TextShapeAttrs::from(attrs);
+        if self.shaped.as_ref() == Some(&(shape_attrs.clone(), width, density)) {
             return;
         }
         let base_family = data.resolve_family(&attrs.family);
@@ -719,7 +750,7 @@ impl TextBuffer {
         self.layout.break_all_lines(width);
         self.layout
             .align(Alignment::Start, AlignmentOptions::default());
-        self.shaped = Some((attrs.clone(), width, density));
+        self.shaped = Some((shape_attrs, width, density));
     }
 
     fn invalidate(&mut self) {
@@ -762,8 +793,10 @@ pub struct RenderedText {
 
 pub struct TextRsc {
     buffer: TextBuffer,
+    ellipsis_buffer: TextBuffer,
     attrs: TextAttrs,
     rendered: Option<RenderedText>,
+    ellipsis_rendered: Option<(TextShapeAttrs, f32, RenderedText)>,
     width: Option<f32>,
     density: f32,
     owner: Option<WidgetId>,
@@ -773,8 +806,10 @@ impl TextRsc {
     fn new(buffer: TextBuffer, attrs: TextAttrs) -> Self {
         Self {
             buffer,
+            ellipsis_buffer: TextBuffer::new("…"),
             attrs,
             rendered: None,
+            ellipsis_rendered: None,
             width: None,
             density: 0.0,
             owner: None,
@@ -784,6 +819,8 @@ impl TextRsc {
     fn invalidate(&mut self) {
         self.buffer.invalidate();
         self.rendered = None;
+        self.ellipsis_buffer.invalidate();
+        self.ellipsis_rendered = None;
     }
 }
 
@@ -885,6 +922,34 @@ impl TextResources {
         resource.rendered = Some(rendered.clone());
         (rendered, true)
     }
+
+    fn render_ellipsis(
+        &mut self,
+        resource: &mut TextRsc,
+        owner: WidgetId,
+        textures: &mut Textures,
+        density: f32,
+    ) -> (RenderedText, bool) {
+        let shape_attrs = TextShapeAttrs::from(&resource.attrs);
+        let atlas_generation = self.data.atlas.generation();
+        resource.owner = Some(owner);
+        if let Some((cached_attrs, cached_density, rendered)) = &resource.ellipsis_rendered
+            && cached_attrs == &shape_attrs
+            && *cached_density == density
+            && rendered.generation == atlas_generation
+        {
+            return (rendered.clone(), false);
+        }
+        let rendered = self.data.render(
+            &mut resource.ellipsis_buffer,
+            &resource.attrs,
+            None,
+            textures,
+            density,
+        );
+        resource.ellipsis_rendered = Some((shape_attrs, density, rendered.clone()));
+        (rendered, true)
+    }
 }
 
 impl Default for TextResources {
@@ -961,6 +1026,14 @@ impl TextHandle {
         RefMut::map(resource, |resource| &mut resource.attrs)
     }
 
+    pub fn set_overflow_position(&mut self, position: Len) {
+        self.rsc.get_mut().attrs.overflow_position = position;
+    }
+
+    pub fn set_overflow(&mut self, overflow: TextOverflow) {
+        self.rsc.get_mut().attrs.overflow = overflow;
+    }
+
     pub fn rendered(&self) -> Option<RenderedText> {
         self.rsc.get().rendered.clone()
     }
@@ -996,6 +1069,17 @@ impl TextHandle {
         let mut resource = self.rsc.get_mut_shared();
         resources.render(&mut resource, width, owner, textures, density)
     }
+
+    pub fn render_ellipsis(
+        &self,
+        owner: WidgetId,
+        textures: &mut Textures,
+        density: f32,
+    ) -> (RenderedText, bool) {
+        let mut resources = self.resources.borrow_mut();
+        let mut resource = self.rsc.get_mut_shared();
+        resources.render_ellipsis(&mut resource, owner, textures, density)
+    }
 }
 
 #[cfg(test)]