EM_Task/UnrealEd/Public/SComponentClassCombo.h

// Copyright Epic Games, Inc. All Rights Reserved.

#pragma once

#include "CoreMinimal.h"
#include "SlateFwd.h"
#include "Templates/SubclassOf.h"
#include "Components/ActorComponent.h"
#include "Widgets/DeclarativeSyntaxSupport.h"
#include "Widgets/Input/SComboButton.h"
#include "Widgets/Views/STableViewBase.h"
#include "Widgets/Views/STableRow.h"

class FComponentClassComboEntry;
class SToolTip;
class FTextFilterExpressionEvaluator;

typedef TSharedPtr<class FComponentClassComboEntry> FComponentClassComboEntryPtr;

//////////////////////////////////////////////////////////////////////////

namespace EComponentCreateAction
{
enum Type
{
    /** Create a new C++ class based off the specified ActorComponent class and then add it to the tree */
    CreateNewCPPClass,
    /** Create a new blueprint class based off the specified ActorComponent class and then add it to the tree */
    CreateNewBlueprintClass,
    /** Spawn a new instance of the specified ActorComponent class and then add it to the tree */
    SpawnExistingClass,
};
}  // namespace EComponentCreateAction

DECLARE_DELEGATE_OneParam(FOnComponentCreated, UActorComponent*);

DECLARE_DELEGATE_RetVal_ThreeParams(UActorComponent*, FComponentClassSelected, TSubclassOf<UActorComponent>, EComponentCreateAction::Type, UObject*);

struct FComponentEntryCustomizationArgs
{
    /** Specific asset to use instead of the selected asset in the content browser */
    TWeakObjectPtr<UObject> AssetOverride;
    /** Custom name to display */
    FString ComponentNameOverride;
    /** Callback when a new component is created */
    FOnComponentCreated OnComponentCreated;
    /** Brush icon to use instead of the class icon */
    FName IconOverrideBrushName;
    /** Custom sort priority to use (smaller means sorted first) */
    int32 SortPriority;

    FComponentEntryCustomizationArgs()
        : AssetOverride(nullptr), ComponentNameOverride(), OnComponentCreated(), IconOverrideBrushName(NAME_None), SortPriority(0)
    {
    }
};
class FComponentClassComboEntry: public TSharedFromThis<FComponentClassComboEntry>
{
public:
    FComponentClassComboEntry(const FString& InHeadingText, TSubclassOf<UActorComponent> InComponentClass, bool InIncludedInFilter, EComponentCreateAction::Type InComponentCreateAction, FComponentEntryCustomizationArgs InCustomizationArgs = FComponentEntryCustomizationArgs())
        : ComponentClass(InComponentClass), IconClass(InComponentClass), ComponentName(), ComponentPath(), HeadingText(InHeadingText), bIncludedInFilter(InIncludedInFilter), ComponentCreateAction(InComponentCreateAction), CustomizationArgs(InCustomizationArgs)
    {}

    FComponentClassComboEntry(const FString& InHeadingText, const FString& InComponentName, FName InComponentPath, const UClass* InIconClass, bool InIncludedInFilter)
        : ComponentClass(nullptr), IconClass(InIconClass), ComponentName(InComponentName), ComponentPath(InComponentPath), HeadingText(InHeadingText), bIncludedInFilter(InIncludedInFilter), ComponentCreateAction(EComponentCreateAction::SpawnExistingClass)
    {}

    FComponentClassComboEntry(const FString& InHeadingText)
        : ComponentClass(nullptr), IconClass(nullptr), ComponentName(), ComponentPath(), HeadingText(InHeadingText), bIncludedInFilter(false)
    {}

    FComponentClassComboEntry()
        : ComponentClass(nullptr), IconClass(nullptr)
    {}

    TSubclassOf<UActorComponent> GetComponentClass() const { return ComponentClass; }

    const UClass* GetIconClass() const { return IconClass; }

    const FString& GetHeadingText() const { return HeadingText; }

    bool IsHeading() const
    {
        return ((ComponentClass == NULL && ComponentName == FString()) && !HeadingText.IsEmpty());
    }
    bool IsSeparator() const
    {
        return ((ComponentClass == NULL && ComponentName == FString()) && HeadingText.IsEmpty());
    }

    bool IsClass() const
    {
        return (ComponentClass != NULL || ComponentName != FString());
    }

    bool IsIncludedInFilter() const
    {
        return bIncludedInFilter;
    }

    const FString& GetComponentNameOverride() const
    {
        return CustomizationArgs.ComponentNameOverride;
    }

    EComponentCreateAction::Type GetComponentCreateAction() const
    {
        return ComponentCreateAction;
    }

    FOnComponentCreated& GetOnComponentCreated()
    {
        return CustomizationArgs.OnComponentCreated;
    }
    FString GetClassName() const;
    FString GetComponentPath() const { return ComponentPath.ToString(); }

    UObject* GetAssetOverride()
    {
        return CustomizationArgs.AssetOverride.Get();
    }

    FName GetIconOverrideBrushName() const { return CustomizationArgs.IconOverrideBrushName; }

    int32 GetSortPriority() const { return CustomizationArgs.SortPriority; }

    void AddReferencedObjects(FReferenceCollector& Collector);

private:
    TSubclassOf<UActorComponent> ComponentClass;
    const UClass* IconClass;
    // For components that are not loaded we just keep the name of the component,
    // loading occurs when the blueprint is spawned, which should also trigger a refresh
    // of the component list:
    FString ComponentName;
    FName ComponentPath;
    FString HeadingText;
    bool bIncludedInFilter;
    EComponentCreateAction::Type ComponentCreateAction;
    FComponentEntryCustomizationArgs CustomizationArgs;
};

//////////////////////////////////////////////////////////////////////////

class UNREALED_API SComponentClassCombo: public SComboButton
{
public:
    SLATE_BEGIN_ARGS(SComponentClassCombo)
        : _IncludeText(true)
    {}

    SLATE_ATTRIBUTE(bool, IncludeText)
    SLATE_EVENT(FComponentClassSelected, OnComponentClassSelected)

    SLATE_END_ARGS()

    void Construct(const FArguments& InArgs);

    ~SComponentClassCombo();

    /** Clear the current combo list selection */
    void ClearSelection();

    /**
     * Updates the filtered list of component names.
     */
    void GenerateFilteredComponentList();

    FText GetCurrentSearchString() const;

    /**
     * Called when the user changes the text in the search box.
     * @param InSearchText The new search string.
     */
    void OnSearchBoxTextChanged(const FText& InSearchText);

    /** Callback when the user commits the text in the searchbox */
    void OnSearchBoxTextCommitted(const FText& NewText, ETextCommit::Type CommitInfo);

    void OnAddComponentSelectionChanged(FComponentClassComboEntryPtr InItem, ESelectInfo::Type SelectInfo);

    TSharedRef<ITableRow> GenerateAddComponentRow(FComponentClassComboEntryPtr Entry, const TSharedRef<STableViewBase>& OwnerTable) const;

    /** Update list of component classes */
    void UpdateComponentClassList();

    /** Returns a component name without the substring "Component" and sanitized for display */
    static FString GetSanitizedComponentName(FComponentClassComboEntryPtr Entry);

private:
    FText GetFriendlyComponentName(FComponentClassComboEntryPtr Entry) const;

    TSharedRef<SToolTip> GetComponentToolTip(FComponentClassComboEntryPtr Entry) const;

    FComponentClassSelected OnComponentClassSelected;

    /** List of component class names used by combo box */
    TArray<FComponentClassComboEntryPtr>* ComponentClassList;

    /** List of component class names, filtered by the current search string */
    TArray<FComponentClassComboEntryPtr> FilteredComponentClassList;

    /** The current search string */
    TSharedPtr<FTextFilterExpressionEvaluator> TextFilter;

    /** The search box control - part of the combo drop down */
    TSharedPtr<SSearchBox> SearchBox;

    /** The component list control - part of the combo drop down */
    TSharedPtr<SListView<FComponentClassComboEntryPtr>> ComponentClassListView;

    /** Cached selection index used to skip over unselectable items */
    int32 PrevSelectedIndex;
};