support dark mode for images with alpha channel

2 files changed, 40 insertions, 2 deletions

diff --git a/engine/Skin.php b/engine/Skin.php
index 917eef7..a8924d4 100644
--- a/engine/Skin.php
+++ b/engine/Skin.php
@@ -23,8 +23,8 @@ class Skin {
         else
             $js = null;
 
-        $theme = ($_COOKIE['theme'] ?? 'auto');
-        if (!in_array($theme, ['auto', 'dark', 'light']))
+        $theme = themes::getUserTheme();
+        if ($theme != 'auto' && !themes::themeExists($theme))
             $theme = 'auto';
 
         $layout_ctx = new SkinContext('\\skin\\base');
diff --git a/engine/themes.php b/engine/themes.php
new file mode 100644
index 0000000..839377f
--- /dev/null
+++ b/engine/themes.php
@@ -0,0 +1,38 @@
+<?php
+
+class themes {
+
+    public static array $Themes = [
+        'dark' => [
+            'bg' => 0x222222,
+            // 'alpha' => 0x303132,
+            'alpha' => 0x222222,
+        ],
+        'light' => [
+            'bg' => 0xffffff,
+            // 'alpha' => 0xf2f2f2,
+            'alpha' => 0xffffff,
+        ]
+    ];
+
+    public static function getThemes(): array {
+        return array_keys(self::$Themes);
+    }
+
+    public static function themeExists(string $name): bool {
+        return array_key_exists($name, self::$Themes);
+    }
+
+    public static function getThemeAlphaColorAsRGB(string $name): array {
+        $color = self::$Themes[$name]['alpha'];
+        $r = ($color >> 16) & 0xff;
+        $g = ($color >> 8) & 0xff;
+        $b = $color & 0xff;
+        return [$r, $g, $b];
+    }
+
+    public static function getUserTheme(): string {
+        return ($_COOKIE['theme'] ?? 'auto');
+    }
+
+}
\ No newline at end of file