Mk2Rev1

various bugfixes and such.
also bookmarks, temp song loaderm and undo overhaul with near complete multiplayer, but menu items disabled. i really wish i could split this into multiple commits, but i don't know how to work unreal.

Plugins/ZipUtility-ue4/Source/ZipUtility/Public/ZipOperation.h

@@ -0,0 +1,42 @@
+#pragma once
+#include "Object.h"
+#include "ZipOperation.generated.h"
+
+class SevenZipCallbackHandler;
+/**
+ * Used to track a zip/unzip operation on the WFULambdaRunnable ThreadPool and allows the ability to terminate the
+ * operation early.
+ */
+UCLASS(BlueprintType)
+class ZIPUTILITY_API UZipOperation : public UObject
+{
+	GENERATED_BODY()
+public:
+	UZipOperation();
+
+	// Stops this zip/unzip if it is still valid. This stop event can occur in two places:
+	// 1. The ThreadPool queue, if it can be stopped here then the operation has not yet started.
+	// 2. The SevenZip layer, once the operation has started, it can be canceled while still running.
+	// Note that calling this carries no guarantees of a successful stop, the end result might be one of:
+	// * The file still got extracted (you were too late)
+	// * The file was never extracted (caught it on time)
+	// * The file was created but is of zero size (oops)
+	// * The file was created, is of non-zero size but is not all there (cut off in the middle)
+	// So, it could be a good idea to do some file housekeeping afterward.
+	UFUNCTION(BlueprintCallable, Category = "Zip Operation")
+	void StopOperation();
+
+	// Set the callback handler
+	void SetCallbackHandler(SevenZipCallbackHandler* Handler);
+
+	// Set the queued work
+	void SetThreadPoolWorker(IQueuedWork* Work);
+	
+private:
+	// A pointer to the callback for this operation. Once the operation completes, this
+	// pointer will become invalid.
+	SevenZipCallbackHandler* CallbackHandler;
+
+	// The work that was queued on the async threadpool in WFULambdaRunnable
+	IQueuedWork* ThreadPoolWork;
+};