#lockdown Nick.Penwarden
#rb none
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MAJOR FEATURES + CHANGES
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Change 3209340 on 2016/11/23 by Ben.Marsh
Convert UE4 codebase to an "include what you use" model - where every header just includes the dependencies it needs, rather than every source file including large monolithic headers like Engine.h and UnrealEd.h.
Measured full rebuild times around 2x faster using XGE on Windows, and improvements of 25% or more for incremental builds and full rebuilds on most other platforms.
* Every header now includes everything it needs to compile.
* There's a CoreMinimal.h header that gets you a set of ubiquitous types from Core (eg. FString, FName, TArray, FVector, etc...). Most headers now include this first.
* There's a CoreTypes.h header that sets up primitive UE4 types and build macros (int32, PLATFORM_WIN64, etc...). All headers in Core include this first, as does CoreMinimal.h.
* Every .cpp file includes its matching .h file first.
* This helps validate that each header is including everything it needs to compile.
* No engine code includes a monolithic header such as Engine.h or UnrealEd.h any more.
* You will get a warning if you try to include one of these from the engine. They still exist for compatibility with game projects and do not produce warnings when included there.
* There have only been minor changes to our internal games down to accommodate these changes. The intent is for this to be as seamless as possible.
* No engine code explicitly includes a precompiled header any more.
* We still use PCHs, but they're force-included on the compiler command line by UnrealBuildTool instead. This lets us tune what they contain without breaking any existing include dependencies.
* PCHs are generated by a tool to get a statistical amount of coverage for the source files using it, and I've seeded the new shared PCHs to contain any header included by > 15% of source files.
Tool used to generate this transform is at Engine\Source\Programs\IncludeTool.
[CL 3209342 by Ben Marsh in Main branch]
UETOOL-332 - Collections 2.0
UETOOL-369 - Want nested collections with collapsing
We now have version 2 collections which maintain a persistent GUID for each collection. Existing collections will be lazily updated to this version when they need to be re-saved.
This GUID is used by child collections to keep track their parents, and the collections view (as well as the quick asset management) now show a tree of collections. Collections in the main collection view tree can be re-parented via drag and drop.
Performing Content Browser searches against a given collection will also test to see if an object exists in child collections, and the asset view will now show you folder entries for child collections when viewing a parent (if folders are enabled in your Content Browser view settings).
[CL 2593321 by Jamie Dale in Main branch]
UE-14641 - Fix PushMenu() to use QueryPopupMethod()
Pretty big refactor
Adds IMenu as way to identify menus. Replaces referring to menus as SWindows.
Lots of uses of PushMenu() fixed up to match new API
#codereview Nick.Atamas
[CL 2579277 by Chris Wood in Main branch]
Improved and unified the folder drag and drop validation in the Content Browser
UE-9025 - User gets green check mark when trying to move class into content folder
The Content Browser folder drag and drop validation had not been updated to handle class folders. This meant that it was possible to crash the editor by dragging class folders around, and also meant that you were given misinformation when trying to copy a class around.
I've unified all the duplicated logic from SPathView, SAssetView, SAssetTreeItem, and SAssetViewItem into utility functions inside a new DragDropHandler in the Content Browser. This class correctly validates that you can only interact with assets and asset paths, but doesn't outright prevent you being able to include classes and class paths in your drag operations (it just warns you about them, and the strips them out of the drop lists).
[CL 2438229 by Matthew Griffin in Main branch]
