#5440: Add FileOverwriteConfirmation message. An unhandled message wi…

…ll cancel the save process.

include/imessagebus.h

@@ -49,6 +49,7 @@ class IMessage
         Notification,
         TextureChanged,
         ApplicationIsActiveQuery,
+        FileOverwriteConfirmation,
 
         UserDefinedMessagesGoHigherThanThis = 999,
     };

libs/messages/FileOverwriteConfirmation.h

@@ -0,0 +1,70 @@
+#pragma once
+
+#include <stdexcept>
+#include "imessagebus.h"
+#include "iradiant.h"
+
+namespace radiant
+{
+
+/**
+ * Message sent when the backend code wants the user to
+ * confirm overwriting a file. 
+ * Senders: If this message stays unresponded no overwrite should occur.
+ */
+class FileOverwriteConfirmation :
+    public radiant::IMessage
+{
+private:
+    std::string _title;
+    std::string _message;
+
+    bool _confirmed;
+
+public:
+    FileOverwriteConfirmation(const std::string& title, const std::string& message) :
+        _title(title),
+        _message(message)
+    {}
+
+    const std::string& getTitle() const
+    {
+        return _title;
+    }
+
+    bool hasTitle() const
+    {
+        return !_title.empty();
+    }
+
+    const std::string& getMessage() const
+    {
+        return _message;
+    }
+
+    std::size_t getId() const override
+    {
+        return IMessage::Type::FileOverwriteConfirmation;
+    }
+
+    void confirmOverwrite(bool confirmed = true)
+    {
+        _confirmed = confirmed;
+    }
+
+    bool overwriteConfirmed()
+    {
+        return isHandled() && _confirmed;
+    }
+
+    // Convenience method, creating an instance and dispatching it to the message bus, returning the answer
+    static bool SendAndReceiveAnswer(const std::string& message, const std::string& title = std::string())
+    {
+        FileOverwriteConfirmation msg(title, message);
+        GlobalRadiantCore().getMessageBus().sendMessage(msg);
+
+        return msg.overwriteConfirmed();
+    }
+};
+
+}

radiantcore/map/Map.cpp

@@ -43,6 +43,7 @@
 #include "model/export/ModelScalePreserver.h"
 #include "map/algorithm/Skins.h"
 #include "messages/ScopedLongRunningOperation.h"
+#include "messages/FileOverwriteConfirmation.h"
 #include "selection/algorithm/Primitives.h"
 #include "selection/algorithm/Group.h"
 #include "scene/Group.h"
@@ -346,9 +347,10 @@ bool Map::save(const MapFormatPtr& mapFormat)
     }
 
     // Check if the map file has been modified in the meantime
-    if (_resource->fileHasBeenModifiedSinceLastSave())
+    if (_resource->fileHasBeenModifiedSinceLastSave() && !radiant::FileOverwriteConfirmation::SendAndReceiveAnswer(
+            fmt::format(_("The file {0} has been modified since it was last saved,\nperhaps by another application. "
+                "Do you really want to overwrite the file?"), _mapName), _("File modification detected")))
     {
-        radiant::NotificationMessage::SendError("File has been modified in the meantime");
         return false;
     }
 

tools/msvc/libs.vcxproj

@@ -163,6 +163,7 @@
     <ClInclude Include="..\..\libs\messages\ApplicationShutdownRequest.h" />
     <ClInclude Include="..\..\libs\messages\AutomaticMapSaveRequest.h" />
     <ClInclude Include="..\..\libs\messages\CommandExecutionFailed.h" />
+    <ClInclude Include="..\..\libs\messages\FileOverwriteConfirmation.h" />
     <ClInclude Include="..\..\libs\messages\FileSelectionRequest.h" />
     <ClInclude Include="..\..\libs\messages\GameConfigNeededMessage.h" />
     <ClInclude Include="..\..\libs\messages\LongRunningOperationMessage.h" />

tools/msvc/libs.vcxproj.filters

@@ -274,6 +274,9 @@
     <ClInclude Include="..\..\libs\patch\PatchIterators.h">
       <Filter>patch</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\libs\messages\FileOverwriteConfirmation.h">
+      <Filter>messages</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <Filter Include="util">