1 files changed, 38 insertions, 0 deletions
diff --git a/map/displacement_mode_manager.hpp b/map/displacement_mode_manager.hpp
new file mode 100644
index 0000000000..a86f7846a6
--- /dev/null
+++ b/map/displacement_mode_manager.hpp
@@ -0,0 +1,38 @@
+#pragma once
+
+#include "std/cstdint.hpp"
+#include "std/function.hpp"
+#include "std/mutex.hpp"
+
+// This class should be used as a single point to control whether
+// hotels displacement mode should be activated or not.
+//
+// *NOTE* as the class is thread-safe, the callback should be
+// very-very lightweight and it should be guaranteed that callback or
+// its callees do not call DisplacementModeManager API. Otherwise,
+// deadlock or exception may happen.
+class DisplacementModeManager
+{
+public:
+  using TCallback = function<void(bool show)>;
+
+  enum Slot
+  {
+    SLOT_INTERACTIVE_SEARCH,
+    SLOT_MAP_SELECTION,
+    SLOT_DEBUG,
+    SLOT_COUNT
+  };
+
+  DisplacementModeManager(TCallback && callback);
+
+  void Set(Slot slot, bool show);
+
+private:
+  TCallback m_callback;
+
+  mutex m_mu;
+  uint32_t m_mask;
+
+  static_assert(SLOT_COUNT <= sizeof(m_mask) * CHAR_BIT, "Number of slots is too large");
+};