支持纯色背景 (#4184)

HMCLCore/src/main/java/org/jackhuang/hmcl/util/gson/PaintAdapter.java

@@ -0,0 +1,61 @@
+/*
+ * Hello Minecraft! Launcher
+ * Copyright (C) 2025 huangyuhui <huanghongxun2008@126.com> and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package org.jackhuang.hmcl.util.gson;
+
+import com.google.gson.*;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonToken;
+import com.google.gson.stream.JsonWriter;
+import javafx.scene.paint.*;
+
+import java.io.IOException;
+
+public final class PaintAdapter extends TypeAdapter<Paint> {
+
+    @Override
+    public void write(JsonWriter out, Paint value) throws IOException {
+        if (value == null) {
+            out.nullValue();
+            return;
+        }
+
+        if (value instanceof Color) {
+            Color color = (Color) value;
+            int red = (int) Math.round(color.getRed() * 255.);
+            int green = (int) Math.round(color.getGreen() * 255.);
+            int blue = (int) Math.round(color.getBlue() * 255.);
+            int opacity = (int) Math.round(color.getOpacity() * 255.);
+            out.value(String.format("#%02x%02x%02x%02x", red, green, blue, opacity));
+        } else if (value instanceof LinearGradient
+                || value instanceof RadialGradient) {
+            out.value(value.toString());
+        } else {
+            throw new JsonParseException("Unsupported Paint type: " + value.getClass().getName());
+        }
+    }
+
+    @Override
+    public Paint read(JsonReader in) throws IOException {
+        if (in.peek() == JsonToken.NULL) {
+            in.nextNull();
+            return null;
+        }
+        String value = in.nextString();
+        return Paint.valueOf(value);
+    }
+}