theme: fix gtk3 checkboxes in light mode

fixes #1555

quickshell/scripts/gtk.sh

@@ -1,12 +1,49 @@
 #!/usr/bin/env bash
 
 CONFIG_DIR="$1"
+SHELL_DIR="$3"
 
 if [ -z "$CONFIG_DIR" ]; then
-    echo "Usage: $0 <config_dir>" >&2
+    echo "Usage: $0 <config_dir> [is_light] [shell_dir]" >&2
     exit 1
 fi
 
+# The light template references adw-gtk3 image assets relative to gtk.css
+# (check/radio glyphs, slider knobs); without them checked boxes render as
+# solid blocks.
+link_gtk3_assets() {
+    local gtk3_dir="$1"
+    local assets_link="$gtk3_dir/assets"
+
+    if [ -e "$assets_link" ] && [ ! -L "$assets_link" ]; then
+        echo "Leaving user-managed $assets_link in place"
+        return
+    fi
+
+    local candidates=(
+        "$HOME/.local/share/themes/adw-gtk3/gtk-3.0/assets"
+        "$HOME/.themes/adw-gtk3/gtk-3.0/assets"
+        "/usr/share/themes/adw-gtk3/gtk-3.0/assets"
+        "/usr/local/share/themes/adw-gtk3/gtk-3.0/assets"
+    )
+    local target=""
+    for c in "${candidates[@]}"; do
+        if [ -d "$c" ]; then
+            target="$c"
+            break
+        fi
+    done
+    if [ -z "$target" ] && [ -n "$SHELL_DIR" ] && [ -d "$SHELL_DIR/matugen/gtk3-assets" ]; then
+        target="$SHELL_DIR/matugen/gtk3-assets"
+    fi
+    if [ -z "$target" ]; then
+        return
+    fi
+
+    ln -sfn "$target" "$assets_link"
+    echo "Linked GTK3 assets: $assets_link -> $target"
+}
+
 apply_gtk3_colors() {
     local config_dir="$1"
 
@@ -29,6 +66,8 @@ apply_gtk3_colors() {
 
     ln -s "dank-colors.css" "$gtk_css"
     echo "Created symlink: $gtk_css -> dank-colors.css"
+
+    link_gtk3_assets "$gtk3_dir"
 }
 
 apply_gtk4_colors() {
@@ -58,6 +97,15 @@ apply_gtk4_colors() {
     echo "Updated GTK4 CSS import"
 }
 
+# Repair pass for shells whose gtk.css was linked before asset handling
+# existed; only acts when DMS already manages gtk.css.
+if [ "$4" = "assets-only" ]; then
+    if [ -L "$CONFIG_DIR/gtk-3.0/gtk.css" ]; then
+        link_gtk3_assets "$CONFIG_DIR/gtk-3.0"
+    fi
+    exit 0
+fi
+
 mkdir -p "$CONFIG_DIR/gtk-3.0" "$CONFIG_DIR/gtk-4.0"
 
 apply_gtk3_colors "$CONFIG_DIR"