From 176a813fb9c793348b88135bfb4626d14f8da7e2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bel=C3=A9n=20Albeza?= <belen.albeza@kaleidos.net>
Date: Fri, 10 Jul 2026 12:02:30 +0200
Subject: [PATCH] :bug: Fix selected text background color in light theme
 (#10614)

---
 .../app/main/ui/workspace/viewport_wasm.cljs  | 11 +++++++
 frontend/src/app/render_wasm/api.cljs         |  1 +
 frontend/src/app/render_wasm/text_editor.cljs | 30 ++++++++++++++++++-
 frontend/src/app/util/color.cljs              | 17 +++++++++++
 4 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/frontend/src/app/main/ui/workspace/viewport_wasm.cljs b/frontend/src/app/main/ui/workspace/viewport_wasm.cljs
index 1c4384f1e6..4a0c4a80b2 100644
--- a/frontend/src/app/main/ui/workspace/viewport_wasm.cljs
+++ b/frontend/src/app/main/ui/workspace/viewport_wasm.cljs
@@ -575,6 +575,17 @@
            (wasm.api/push-ruler-theme-colors!)
            (wasm.api/request-render "rulers-colors-theme")))))
 
+    ;; Text-editor-wasm: push the theme colors (selection background, caret)
+    ;; into the WASM text editor so the selection follows the design tokens per
+    ;; theme (purple on light, teal on dark) instead of a hardcoded default.
+    (mf/with-effect [@canvas-init?]
+      (when @canvas-init?
+        (wasm.api/text-editor-apply-theme)
+        (theme/add-color-scheme-listener!
+         (fn []
+           (wasm.api/text-editor-apply-theme)
+           (wasm.api/request-render "text-editor-colors-theme")))))
+
     ;; Ruler overlay updates below only change the UI surface, not the shapes.
     ;; They use `render-from-cache!` (cached tiles + UI, atomic) instead of a full
     ;; `request-render`, which would kick off a progressive tile-by-tile shape
diff --git a/frontend/src/app/render_wasm/api.cljs b/frontend/src/app/render_wasm/api.cljs
index cea8256980..e4be664616 100644
--- a/frontend/src/app/render_wasm/api.cljs
+++ b/frontend/src/app/render_wasm/api.cljs
@@ -273,6 +273,7 @@
 (def draw-thumbnail-to-canvas webgl/draw-thumbnail-to-canvas)
 
 ;; Re-export public text editor functions
+(def text-editor-apply-theme text-editor/text-editor-apply-theme)
 (def text-editor-focus text-editor/text-editor-focus)
 (def text-editor-blur text-editor/text-editor-blur)
 (def text-editor-set-cursor-from-offset text-editor/text-editor-set-cursor-from-offset)
diff --git a/frontend/src/app/render_wasm/text_editor.cljs b/frontend/src/app/render_wasm/text_editor.cljs
index 5dba3e675c..d630346159 100644
--- a/frontend/src/app/render_wasm/text_editor.cljs
+++ b/frontend/src/app/render_wasm/text_editor.cljs
@@ -15,7 +15,10 @@
    [app.render-wasm.helpers :as h]
    [app.render-wasm.mem :as mem]
    [app.render-wasm.serializers :as sr]
-   [app.render-wasm.wasm :as wasm]))
+   [app.render-wasm.serializers.color :as sr-clr]
+   [app.render-wasm.wasm :as wasm]
+   [app.util.color :as uc]
+   [app.util.dom :as dom]))
 
 (def multiple-state-multiple (sr/translate-multiple-state :multiple))
 
@@ -124,6 +127,31 @@
 
       nil)))
 
+(def ^:private selection-color-css-var "--text-editor-selection-background-color")
+(def ^:private caret-color-css-var "--text-editor-caret-color")
+
+(defn- resolve-theme-color
+  "Resolve a themed CSS color variable (read from the document body) into a
+   32-bit argb value for the WASM text editor, preserving the variable's alpha
+   channel."
+  [css-var]
+  (when-let [{:keys [color opacity]}
+             (uc/parse-css-color-opacity
+              (dom/get-css-variable css-var js/document.body))]
+    (sr-clr/hex->u32argb color opacity)))
+
+(defn text-editor-apply-theme
+  "Push the current theme's selection and caret colors (read from the CSS
+   custom properties on the document body) into the WASM text editor. The
+   editor theme is a persistent singleton, so call once after init and again
+   on every color-scheme change."
+  []
+  (when wasm/context-initialized?
+    (let [selection (resolve-theme-color selection-color-css-var)
+          caret     (resolve-theme-color caret-color-css-var)]
+      (when (and selection caret)
+        (h/call wasm/internal-module "_text_editor_apply_theme" selection caret)))))
+
 (defn text-editor-focus
   [id]
   (when wasm/context-initialized?
diff --git a/frontend/src/app/util/color.cljs b/frontend/src/app/util/color.cljs
index 58cd64beb7..d28c3ccfb6 100644
--- a/frontend/src/app/util/color.cljs
+++ b/frontend/src/app/util/color.cljs
@@ -104,3 +104,20 @@
         (cc/valid-hex-color? s)
         (-> (subs s 1) cc/expand-hex cc/prepend-hash)
         :else (some-> (cc/parse-rgb s) cc/rgb->hex)))))
+
+(def ^:private rgba-color-re
+  #"rgba?\(\s*(\d{1,3})\s*,\s*(\d{1,3})\s*,\s*(\d{1,3})\s*(?:,\s*([0-9]*\.?[0-9]+)\s*)?\)")
+
+(defn parse-css-color-opacity
+  "Like `parse-css-color` but also extracts the alpha channel, returning a
+   `{:color \"#rrggbb\" :opacity <0..1>}` map (opacity defaults to 1 when the
+   source has none). Handles #rrggbb, #rgb, rgb() and rgba(). Returns nil when
+   the string cannot be parsed."
+  [raw]
+  (let [s (some-> raw str/trim)]
+    (when (and (string? s) (seq s))
+      (if (cc/valid-hex-color? s)
+        {:color (-> (subs s 1) cc/expand-hex cc/prepend-hash) :opacity 1}
+        (when-let [[_ r g b a] (re-matches rgba-color-re s)]
+          {:color (cc/rgb->hex [(js/parseInt r 10) (js/parseInt g 10) (js/parseInt b 10)])
+           :opacity (if a (js/parseFloat a) 1)})))))