Resolve FontSources on changes

crates/bevy_text/src/font.rs

@@ -1,16 +1,16 @@
-use crate::ComputedTextBlock;
 use crate::FontCx;
+use crate::FontSource;
+use crate::TextFont;
 use bevy_asset::Asset;
 use bevy_asset::AssetId;
 use bevy_asset::Assets;
+use bevy_ecs::change_detection::DetectChangesMut;
 use bevy_ecs::system::Local;
 use bevy_ecs::system::Query;
-use bevy_ecs::system::Res;
 use bevy_ecs::system::ResMut;
 use bevy_platform::collections::HashSet;
 use bevy_reflect::TypePath;
 use parley::fontique::Blob;
-use parley::fontique::FontInfoOverride;
 use smol_str::SmolStr;
 
 /// An [`Asset`] that contains the data for a loaded font, if loaded as an asset.
@@ -29,8 +29,9 @@ use smol_str::SmolStr;
 pub struct Font {
     /// Content of a font file as bytes
     pub data: Blob<u8>,
-    /// Font family name.
-    /// If the font file is a collection with multiple families, the first family name from the last font is used.
+    /// Font family name used to resolve this asset when referenced by handle.
+    /// If the font file is a collection with multiple families, this is the family name from the
+    /// first font face in the collection.
     pub family_name: SmolStr,
 }
 
@@ -46,32 +47,76 @@ impl Font {
 
 /// Add new font assets to the internal font collection.
 pub fn load_font_assets_into_font_collection(
-    fonts: Res<Assets<Font>>,
+    mut fonts: ResMut<Assets<Font>>,
     mut loaded_fonts: Local<HashSet<AssetId<Font>>>,
     mut font_cx: ResMut<FontCx>,
-    mut text_block_query: Query<&mut ComputedTextBlock>,
+    mut text_font_query: Query<&mut TextFont>,
 ) {
-    let mut new_fonts_added = false;
-
     loaded_fonts.retain(|id| fonts.contains(*id));
 
-    for (id, font) in fonts.iter() {
-        if loaded_fonts.insert(id) {
-            font_cx.0.collection.register_fonts(
-                font.data.clone(),
-                Some(FontInfoOverride {
-                    family_name: Some(font.family_name.as_str()),
-                    ..Default::default()
-                }),
-            );
-            new_fonts_added = true;
+    let new_asset_ids: Vec<_> = fonts.ids().filter(|id| loaded_fonts.insert(*id)).collect();
+
+    if new_asset_ids.is_empty() {
+        return;
+    }
+
+    let mut new_family_ids = Vec::new();
+    for asset_id in new_asset_ids.iter() {
+        let font_data = fonts
+            .get(*asset_id)
+            .expect("AssetId should have a corresponding asset")
+            .data
+            .clone();
+
+        let new_fonts = font_cx.collection.register_fonts(font_data, None);
+
+        if let Some((_, family_id)) = new_fonts
+            .iter()
+            .flat_map(|(family_id, fonts)| {
+                fonts
+                    .iter()
+                    .map(move |font_info| (font_info.index(), *family_id))
+            })
+            .min_by_key(|(index, _)| *index)
+            && let Some(family_name) = font_cx.0.collection.family_name(family_id)
+            && let Some(font) = fonts.get_mut_untracked(*asset_id)
+        {
+            font.family_name = family_name.into();
+            new_family_ids.extend(new_fonts.iter().map(|(family_id, _)| *family_id));
         }
     }
 
-    // Whenever new fonts are added, update all text blocks so they use the new fonts.
-    if new_fonts_added {
-        for mut block in text_block_query.iter_mut() {
-            block.needs_rerender = true;
+    for mut text_font in text_font_query.iter_mut() {
+        if match &text_font.font {
+            FontSource::Handle(handle) => new_asset_ids.contains(&handle.id()),
+            FontSource::Family(name) => font_cx
+                .collection
+                .family_id(name)
+                .is_some_and(|id| new_family_ids.contains(&id)),
+            generic_source => {
+                let generic_family = match generic_source {
+                    FontSource::Handle(_) | FontSource::Family(_) => unreachable!(),
+                    FontSource::Serif => parley::GenericFamily::Serif,
+                    FontSource::SansSerif => parley::GenericFamily::SansSerif,
+                    FontSource::Cursive => parley::GenericFamily::Cursive,
+                    FontSource::Fantasy => parley::GenericFamily::Fantasy,
+                    FontSource::Monospace => parley::GenericFamily::Monospace,
+                    FontSource::SystemUi => parley::GenericFamily::SystemUi,
+                    FontSource::UiSerif => parley::GenericFamily::UiSerif,
+                    FontSource::UiSansSerif => parley::GenericFamily::UiSansSerif,
+                    FontSource::UiMonospace => parley::GenericFamily::UiMonospace,
+                    FontSource::UiRounded => parley::GenericFamily::UiRounded,
+                    FontSource::Emoji => parley::GenericFamily::Emoji,
+                    FontSource::Math => parley::GenericFamily::Math,
+                    FontSource::FangSong => parley::GenericFamily::FangSong,
+                };
+                font_cx
+                    .collection
+                    .generic_families(generic_family)
+                    .any(|id| new_family_ids.contains(&id))
+            }
+        } {
+            text_font.set_changed();
         }
     }
 }

crates/bevy_ui/src/widget/text_input_layout.rs

@@ -78,7 +78,6 @@ pub fn update_editable_text_content_size(
             || text_font.is_changed()
             || line_height.is_changed()
             || target.is_changed()
-            || fonts.is_changed()
             || rem_size.is_changed())
         {
             continue;
@@ -170,10 +169,8 @@ pub fn update_editable_text_styles(
     for (mut editable_text, text_font, line_height, target, text_layout) in
         editable_text_query.iter_mut()
     {
-        let editor = editable_text.editor_mut();
-
-        if f32::EPSILON < (target.scale_factor() - editor.get_scale()).abs() {
-            editor.set_scale(target.scale_factor());
+        if f32::EPSILON < (target.scale_factor() - editable_text.editor.get_scale()).abs() {
+            editable_text.editor.set_scale(target.scale_factor());
         }
 
         if text_font.is_changed()
@@ -183,9 +180,12 @@ pub fn update_editable_text_styles(
                 FontSize::Vw(_) | FontSize::Vh(_) | FontSize::VMin(_) | FontSize::VMax(_)
             ) && target.is_changed()
         {
-            editor.edit_styles().insert(StyleProperty::FontSize(
-                text_font.font_size.eval(target.logical_size(), rem_size.0),
-            ));
+            editable_text
+                .editor
+                .edit_styles()
+                .insert(StyleProperty::FontSize(
+                    text_font.font_size.eval(target.logical_size(), rem_size.0),
+                ));
         }
 
         if text_font.is_changed() {