Add retained paints and shared text selection

core/src/primitive/text.rs

@@ -1,4 +1,4 @@
-use crate::{Align, GlyphAtlas, GlyphKey, PlacedGlyph, RegionAlign, Textures, UiColor, util::Vec2};
+use crate::{Align, GlyphAtlas, GlyphKey, PaintId, PlacedGlyph, RegionAlign, Textures, util::Vec2};
 use parley::{
     Alignment, AlignmentOptions, FontContext, FontFamily, FontFamilyName, FontStyle, FontWeight,
     GenericFamily, Layout, LayoutContext, LineHeight, PositionedLayoutItem, StyleProperty,
@@ -32,7 +32,7 @@ pub struct FontDiagnostics {
 
 pub struct TextData {
     pub font_cx: FontContext,
-    pub layout_cx: LayoutContext<UiColor>,
+    pub layout_cx: LayoutContext<PaintId>,
     scale_cx: ScaleContext,
     pub atlas: GlyphAtlas,
     /// Physical pixels per dp -- a second copy of
@@ -240,8 +240,13 @@ impl TextData {
         }
     }
 
-    pub fn place(&mut self, buffer: &TextBuffer, textures: &mut Textures) -> Vec<PlacedGlyph> {
+    pub fn place(
+        &mut self,
+        buffer: &TextBuffer,
+        textures: &mut Textures,
+    ) -> (Vec<PlacedGlyph>, Vec<PaintId>) {
         let mut placed = Vec::new();
+        let mut paints = Vec::new();
         for line in buffer.layout.lines() {
             for item in line.items() {
                 let PositionedLayoutItem::GlyphRun(run) = item else {
@@ -250,7 +255,10 @@ impl TextData {
                 let font = run.run().font();
                 let font_size = run.run().font_size();
                 let coords = run.run().normalized_coords();
-                let run_color = run.style().brush;
+                let run_color = run.style().brush.clone();
+                if !paints.contains(&run_color) {
+                    paints.push(run_color.clone());
+                }
                 let Some(font_ref) = FontRef::from_index(font.data.as_ref(), font.index as usize)
                 else {
                     continue;
@@ -301,12 +309,12 @@ impl TextData {
                             glyph.x.floor() + entry.left as f32,
                             glyph.y.floor() - entry.top as f32,
                         ),
-                        color: run_color,
+                        paint: run_color.slot(),
                     });
                 }
             }
         }
-        placed
+        (placed, paints)
     }
 
     pub fn render(
@@ -318,11 +326,12 @@ impl TextData {
         density: f32,
     ) -> RenderedText {
         buffer.shape(self, attrs, width, density);
-        let glyphs = self.place(buffer, textures);
+        let (glyphs, paints) = self.place(buffer, textures);
         RenderedText {
             glyphs: std::sync::Arc::new(glyphs),
+            paints: std::sync::Arc::new(paints),
             size: buffer.size(),
-            color: attrs.color,
+            color: attrs.color.clone(),
             generation: self.atlas.generation(),
         }
     }
@@ -359,7 +368,7 @@ impl Family {
 #[derive(Clone, PartialEq)]
 pub struct SpanStyle {
     pub range: Range<usize>,
-    pub color: Option<UiColor>,
+    pub color: Option<PaintId>,
     pub family: Option<Family>,
     pub font_size: Option<f32>,
     pub bold: bool,
@@ -379,7 +388,7 @@ impl SpanStyle {
             underline: false,
         }
     }
-    pub fn color(mut self, color: UiColor) -> Self {
+    pub fn color(mut self, color: PaintId) -> Self {
         self.color = Some(color);
         self
     }
@@ -407,7 +416,7 @@ impl SpanStyle {
 
 #[derive(Clone, PartialEq)]
 pub struct TextAttrs {
-    pub color: UiColor,
+    pub color: PaintId,
     pub font_size: f32,
     pub line_height: f32,
     pub family: Family,
@@ -421,7 +430,7 @@ impl Default for TextAttrs {
     fn default() -> Self {
         let size = 16.0;
         Self {
-            color: UiColor::WHITE,
+            color: PaintId::WHITE,
             font_size: size,
             line_height: size * LINE_HEIGHT_MULT,
             family: Family::SansSerif,
@@ -436,7 +445,7 @@ impl Default for TextAttrs {
 /// them apart is how they get out of step.
 pub struct TextBuffer {
     text: String,
-    layout: Layout<UiColor>,
+    layout: Layout<PaintId>,
     spans: Vec<SpanStyle>,
     shaped: Option<(TextAttrs, Option<f32>, f32)>,
 }
@@ -464,7 +473,7 @@ impl TextBuffer {
         &self.text
     }
 
-    pub fn layout(&self) -> &Layout<UiColor> {
+    pub fn layout(&self) -> &Layout<PaintId> {
         &self.layout
     }
 
@@ -515,11 +524,11 @@ impl TextBuffer {
         builder.push_default(StyleProperty::LineHeight(LineHeight::Absolute(
             attrs.line_height * density,
         )));
-        builder.push_default(StyleProperty::Brush(attrs.color));
+        builder.push_default(StyleProperty::Brush(attrs.color.clone()));
         for (span, family) in self.spans.iter().zip(&span_families) {
             let range = span.range.clone();
-            if let Some(color) = span.color {
-                builder.push(StyleProperty::Brush(color), range.clone());
+            if let Some(color) = &span.color {
+                builder.push(StyleProperty::Brush(color.clone()), range.clone());
             }
             if let Some(family) = family {
                 builder.push(StyleProperty::FontFamily(family.family()), range.clone());
@@ -563,8 +572,10 @@ fn hash_coords(coords: &[i16]) -> u64 {
 #[derive(Clone)]
 pub struct RenderedText {
     pub glyphs: std::sync::Arc<Vec<PlacedGlyph>>,
+    /// The unique handles whose compact slots the glyphs above carry.
+    pub paints: std::sync::Arc<Vec<PaintId>>,
     pub size: Vec2,
-    pub color: UiColor,
+    pub color: PaintId,
     /// The [`GlyphAtlas::generation`] the glyphs above were placed against.
     /// A holder must re-render rather than re-emit these quads once the
     /// atlas has moved on (`GlyphAtlas::clear`'s doc says what happens