FGantryLoadScopeGuard

#include "GantryLoadScopeGuard.h"

C++ helper that opens a load scope when it is created and closes it when it goes out of scope.

Use it in synchronous code with several early returns, where a missed CloseScope would leave a scope open and the loading screen up:

FGantryLoadScopeGuard Guard(TEXT("Bootstrap"), GantryGaugeTags::Load_Scope_Bootstrap);
if (Failed()) { Guard.Fail(); return; }     // still closed, marked Failed

Async work outlives the stack frame. For that, open the scope on FGantryLoadLedger and close it from the completion delegate, or hand the guard's scope over with Release.

In Blueprint, use Begin Load Scope and End Load Scope instead.

FGantryLoadScopeGuard::FGantryLoadScopeGuard(FString DebugName, FGameplayTag ReasonTag, FGantryHandle ParentHandle=FGantryHandle(), bool bUserFacing=true)

Opens a scope on the module ledger, taking the same arguments as FGantryLoadLedger::OpenScope.

If the ledger is unavailable the guard owns nothing and every method is a no-op.

FGantryLoadScopeGuard::~FGantryLoadScopeGuard()

Closes the owned scope as Failed, Cancelled or Completed, unless Release gave it away.

FGantryLoadScopeGuard::FGantryLoadScopeGuard(const FGantryLoadScopeGuard &)=delete

Not copyable: a scope must be closed exactly once.

Move-construct to transfer ownership.

FGantryLoadScopeGuard & FGantryLoadScopeGuard::operator=(const FGantryLoadScopeGuard &)=delete

Not assignable, by copy or by move: a guard keeps the scope it was constructed with.

FGantryLoadScopeGuard::FGantryLoadScopeGuard(FGantryLoadScopeGuard &&Other)

Takes over Other's scope and final state; Other is left owning nothing.

FGantryHandle FGantryLoadScopeGuard::GetHandle() const

Returns the guarded scope's handle, e.g.

to parent child scopes; invalid if none is owned.

void FGantryLoadScopeGuard::AttachHandle(TSharedPtr< FStreamableHandle > StreamableHandle)

Attaches a streamable handle to the guarded scope.

Ignored when the guard owns nothing.

void FGantryLoadScopeGuard::Fail()

Marks the scope failed.

It still closes on destruction.

void FGantryLoadScopeGuard::Cancel()

Marks the scope cancelled.

It still closes on destruction.

FGantryHandle FGantryLoadScopeGuard::Release()

Gives up ownership without closing, for handing the scope to an async continuation.

The caller becomes responsible for closing it.

Returns: The scope's handle, or an invalid handle if the guard owned nothing.