ui: Support wallets unloaded dynamically

src/interfaces/wallet.cpp

@@ -429,6 +429,10 @@ public:
     bool hdEnabled() override { return m_wallet.IsHDEnabled(); }
     OutputType getDefaultAddressType() override { return m_wallet.m_default_address_type; }
     OutputType getDefaultChangeType() override { return m_wallet.m_default_change_type; }
+    std::unique_ptr<Handler> handleUnload(UnloadFn fn) override
+    {
+        return MakeHandler(m_wallet.NotifyUnload.connect(fn));
+    }
     std::unique_ptr<Handler> handleShowProgress(ShowProgressFn fn) override
     {
         return MakeHandler(m_wallet.ShowProgress.connect(fn));

src/interfaces/wallet.h

@@ -242,6 +242,10 @@ public:
     // Get default change type.
     virtual OutputType getDefaultChangeType() = 0;
 
+    //! Register handler for unload message.
+    using UnloadFn = std::function<void()>;
+    virtual std::unique_ptr<Handler> handleUnload(UnloadFn fn) = 0;
+
     //! Register handler for show progress messages.
     using ShowProgressFn = std::function<void(const std::string& title, int progress)>;
     virtual std::unique_ptr<Handler> handleShowProgress(ShowProgressFn fn) = 0;