MovieSceneCustomBinding.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "MovieSceneSequenceID.h"
#include "MovieSceneBindingProxy.h"
#include "Textures/SlateIcon.h"
#include "MovieSceneCustomBinding.generated.h"
 
namespace UE
{
    namespace MovieScene
    {
        struct FSharedPlaybackState;
    }
}
 
class UMovieSceneSequence;
class UMovieScene;
struct FGuid;
struct FMovieSceneBindingResolveParams;
struct FSlateBrush;
struct FMovieSceneBindingReference;
class UMovieSceneSpawnableBindingBase;
 
USTRUCT(BlueprintType)
struct FMovieSceneBindingResolveResult
{
    GENERATED_BODY()
 
    
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "General")
    TArray<TObjectPtr<UObject>> Objects;
 
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "General", meta = (DeprecatedProperty, DeprecationMessage = "This property is deprecated, please use the array of Objects instead."))
    TObjectPtr<UObject> Object = nullptr;
};
 
/*
* Blueprint-specific resolution context for custom bindings.
*/
USTRUCT(BlueprintType)
struct FMovieSceneBindingResolveContext
{
    GENERATED_BODY()
 
    /* The world context*/
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category="Default")
    TObjectPtr<UObject> WorldContext;
    
    /* Binding for the bound object currently evaluating this condition if applicable (BindingId will be invalid for conditions on global tracks/sections). */
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category="Default")
    FMovieSceneBindingProxy Binding;
};
 
UCLASS(abstract, DefaultToInstanced, EditInlineNew, MinimalAPI)
class UMovieSceneCustomBinding
    : public UObject
{
public:
 
    GENERATED_BODY()
 
    static MOVIESCENE_API const int32 BaseEnginePriority;
    static MOVIESCENE_API const int32 BaseCustomPriority;
 
    UFUNCTION(BlueprintCallable, Category = "Sequencer|Binding")
    static int32 GetBaseEnginePriority() { return BaseEnginePriority; }
 
    UFUNCTION(BlueprintCallable, Category = "Sequencer|Binding")
    static int32 GetBaseCustomPriority() { return BaseCustomPriority; }
 
    /* Must be implemented.
    * Resolve the custom binding based on the passed in context. May return an existing UObject or spawn a new one. 
    */
    virtual FMovieSceneBindingResolveResult ResolveBinding(const FMovieSceneBindingResolveParams& ResolveParams, int32 BindingIndex, TSharedRef<const UE::MovieScene::FSharedPlaybackState> SharedPlaybackState) const PURE_VIRTUAL(UMovieSceneCustomBinding::ResolveBinding, return FMovieSceneBindingResolveResult(););
 
    /* Returns whether this binding type will spawn an object in the current context. This will be true for Spawnables always, and true for Replaceables in Editor.*/
    virtual bool WillSpawnObject(TSharedRef<const UE::MovieScene::FSharedPlaybackState> SharedPlaybackState) const { return false; }
 
 
    virtual int32 GetCustomBindingPriority() const { return BaseEnginePriority; }
 
    /*
    * Must be implemented. Called by Sequencer to determine whether this custom binding type supports binding the given object.
    * If true is returned, a new binding may be created using CreateNewCustomBinding.
    */
    virtual bool SupportsBindingCreationFromObject(const UObject* SourceObject) const PURE_VIRTUAL(UMovieSceneCustomBinding::SupportsBindingCreationFromObject, return false;);
 
    /*
    * Must be implemented.
    * Called by Sequencer on each Custom Binding class CDO if it supports a UObject type to try to create a new instanced custom binding. 
    * If the derived custom spawnable type supports the passed in object type, this should return a new UMovieSceneCustomBinding instance parented to the passed in OwnerMovieScene.
    * See UMovieSceneSpawnableActorBinding for an example of how to implement.
    */
    virtual UMovieSceneCustomBinding* CreateNewCustomBinding(UObject* SourceObject, UMovieScene& OwnerMovieScene) PURE_VIRTUAL(UMovieSceneCustomBinding::CreateNewCustomBinding, return nullptr;);
 
    /*
    * Optional method that can be overridden to return a desired name for the binding. This may be used by sequencer to name the possessable containing the binding.
    */
    virtual FString GetDesiredBindingName() const { return FString(); }
 
    /*
    * For custom bindings inheriting from UMovieSceneSpawnableBindingBase, returns this object cast to UMovieSceneSpawnableBindingBase.
    * For custom bindings inheriting from UMovieSceneReplaceableBinding, returns the inner UMovieSceneSpawnableBindingBase* in editor, or nullptr in runtime.
    */
    virtual const UMovieSceneSpawnableBindingBase* AsSpawnable(TSharedRef<const UE::MovieScene::FSharedPlaybackState> SharedPlaybackState) const { return nullptr; }
 
    /*
    * For custom bindings inheriting from UMovieSceneSpawnableBindingBase, returns this object cast to UMovieSceneSpawnableBindingBase.
    * For custom bindings inheriting from UMovieSceneReplaceableBinding, returns the inner UMovieSceneSpawnableBindingBase* in editor, or nullptr in runtime.
    */
    UMovieSceneSpawnableBindingBase* AsSpawnable(TSharedRef<const UE::MovieScene::FSharedPlaybackState> SharedPlaybackState) { return const_cast<UMovieSceneSpawnableBindingBase*>(const_cast<const UMovieSceneCustomBinding*>(this)->AsSpawnable(SharedPlaybackState)); }
 
    /*
    * Must be implemented.
    * Should return the most specific relevant class of the bound object. Used to populate the FMovieScenePossessable bound object class.
    */
    virtual UClass* GetBoundObjectClass() const PURE_VIRTUAL(UMovieSceneCustomBinding::GetBoundObjectClass, return UObject::StaticClass(););
 
 
#if WITH_EDITOR
 
    /*
    * Called by Sequencer upon creating a new custom binding or converting a binding to use this type. Can be used by custom binding types to add required track types, etc.
    */
    virtual void SetupDefaults(UObject* SpawnedObject, FGuid ObjectBindingId, UMovieScene& OwnerMovieScene) {}
    
    /*
    * Allows the custom binding to optionally provide a custom icon overlay for the object binding track.
    */
    virtual FSlateIcon GetBindingTrackCustomIconOverlay() const { return FSlateIcon(); }
 
    /*
    * Allows the custom binding to optionally provide a custom tooltip to show when hovering over the icon area in the object binding track.
    */
    virtual FText GetBindingTrackIconTooltip() const { return FText(); }
 
    /*
    * Called by UI code to see if this custom binding type supports conversions from the presented binding, including any current bound or spawned object as reference.
    */
    virtual bool SupportsConversionFromBinding(const FMovieSceneBindingReference& BindingReference, const UObject* SourceObject) const { return false; }
 
    /*
    * Called during binding conversion to create a new binding of this type from a selected binding, if supported.
    */
    virtual UMovieSceneCustomBinding* CreateCustomBindingFromBinding(const FMovieSceneBindingReference& BindingReference, UObject* SourceObject, UMovieScene& OwnerMovieScene) { return nullptr; }
 
    /*
    * Must be implemented. Used by the UI to describe this binding type during conversions, etc.
    */
    virtual FText GetBindingTypePrettyName() const PURE_VIRTUAL(UMovieSceneCustomBinding::GetBindingTypePrettyName, return FText(););
 
 
    /*
    * Called by UI code to see if this custom binding supports converting to a possessable.
    */
    virtual bool CanConvertToPossessable(const FGuid& Guid, FMovieSceneSequenceIDRef TemplateID, TSharedRef<const UE::MovieScene::FSharedPlaybackState> SharedPlaybackState) const { return true; }
 
    /*
    * Called by UI code when the binding has recently been added or modified in the case anything needs to be initialized or modified based on this. 
    */
    virtual void OnBindingAddedOrChanged(UMovieScene& OwnerMovieScene) {}
 
#endif
 
};