refact: improve method of launcher helper append variant value

Signed-off-by: ComixHe <heyuming@deepin.org>

apps/app-launch-helper/src/variantValue.h

@@ -0,0 +1,50 @@
+// SPDX-FileCopyrightText: 2023 UnionTech Software Technology Co., Ltd.
+//
+// SPDX-License-Identifier: LGPL-3.0-or-later
+#include "types.h"
+#include <memory>
+
+class VariantValue
+{
+public:
+    explicit VariantValue(msg_ptr &msg)
+        : m_msg(msg)
+    {
+    }
+    virtual ~VariantValue() = default;
+    VariantValue(const VariantValue &) = delete;
+    VariantValue(VariantValue &&) = delete;
+    VariantValue &operator=(const VariantValue &) = delete;
+    VariantValue &operator=(VariantValue &&) = delete;
+
+    virtual int openVariant() noexcept = 0;
+    virtual int closeVariant() noexcept = 0;
+    virtual int appendValue(std::string &&value) noexcept = 0;
+
+    msg_ptr &msgRef() noexcept { return m_msg; }
+
+private:
+    msg_ptr &m_msg;
+};
+
+class StringValue : public VariantValue
+{
+    using VariantValue::VariantValue;
+
+public:
+    int openVariant() noexcept override;
+    int closeVariant() noexcept override;
+    int appendValue(std::string &&value) noexcept override;
+};
+
+class ASValue : public VariantValue
+{
+    using VariantValue::VariantValue;
+
+public:
+    int openVariant() noexcept override;
+    int closeVariant() noexcept override;
+    int appendValue(std::string &&value) noexcept override;
+};
+
+std::unique_ptr<VariantValue> creatValueHandler(msg_ptr &msg, DBusValueType type);