SMenuAnchor.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "CoreMinimal.h"
#include "Misc/Attribute.h"
#include "Widgets/DeclarativeSyntaxSupport.h"
#include "Input/PopupMethodReply.h"
#include "Widgets/SWidget.h"
#include "Layout/Margin.h"
#include "Layout/Children.h"
#include "Widgets/SPanel.h"
#include "Widgets/Text/STextBlock.h"
#include "Framework/Application/IMenu.h"
 
class FArrangedChildren;
class FPaintArgs;
class FSlateWindowElementList;
class SWindow;
 
DECLARE_DELEGATE_OneParam(FOnIsOpenChanged, bool)
 
 
 
 
 
class SMenuAnchor : public SPanel, public IMenuHost
{
public:
    SLATE_BEGIN_ARGS( SMenuAnchor )
        : _Content()
        , _Padding(FMargin(0.f))
        , _MenuContent( SNew(STextBlock) .Text( NSLOCTEXT("SMenuAnchor", "NoMenuContent", "No Menu Content Assigned; use .MenuContent") ) )
        , _OnGetMenuContent()
        , _Placement( MenuPlacement_BelowAnchor )
        , _FitInWindow( true )
        , _Method()
        , _ShouldDeferPaintingAfterWindowContent(true)
        , _UseApplicationMenuStack(true)
        , _ShowMenuBackground(true)
        , _IsCollapsedByParent(false)
        , _ApplyWidgetStyleToMenu(true)
        {}
        
        SLATE_DEFAULT_SLOT( FArguments, Content )
 
        SLATE_ARGUMENT( FMargin, Padding )
        
        SLATE_ARGUMENT( TSharedPtr<SWidget>, MenuContent )
 
        SLATE_EVENT( FOnGetContent, OnGetMenuContent )
        
        SLATE_EVENT( FOnIsOpenChanged, OnMenuOpenChanged )
 
        SLATE_ATTRIBUTE( EMenuPlacement, Placement )
 
        SLATE_ARGUMENT(bool, FitInWindow)
 
        SLATE_ARGUMENT(TOptional<EPopupMethod>, Method)
 
        SLATE_ARGUMENT(bool, ShouldDeferPaintingAfterWindowContent)
 
        SLATE_ARGUMENT(bool, UseApplicationMenuStack)
 
        SLATE_ARGUMENT(bool, ShowMenuBackground)
        
        
        SLATE_ARGUMENT(bool, IsCollapsedByParent)
 
        
        SLATE_ARGUMENT(bool, ApplyWidgetStyleToMenu)
 
    SLATE_END_ARGS()
 
    SLATE_API virtual ~SMenuAnchor();
    
    SLATE_API void Construct( const FArguments& InArgs );
    
    SLATE_API SMenuAnchor();
 
    SLATE_API void SetContent(TSharedRef<SWidget> InContent);
 
    SLATE_API virtual void SetMenuContent(TSharedRef<SWidget> InMenuContent);
    
    SLATE_API virtual void SetIsOpen( bool InIsOpen, const bool bFocusMenu = true, const int32 FocusUserIndex = 0 );
    
    SLATE_API bool IsOpen() const;
 
    SLATE_API bool ShouldOpenDueToClick() const;
 
    SLATE_API FVector2D GetMenuPosition() const;
 
    SLATE_API void SetMenuPlacement(TAttribute<EMenuPlacement> InMenuPlacement);
 
    SLATE_API void SetFitInWindow(bool bFit);
 
    SLATE_API bool HasOpenSubMenus() const;
 
    // IMenuHost interface
    SLATE_API virtual TSharedPtr<SWindow> GetMenuWindow() const override;
    SLATE_API virtual void OnMenuDismissed() override;
    SLATE_API virtual bool UsingApplicationMenuStack() const override;
    // End of IMenuHost interface
 
    static SLATE_API void DismissAllApplicationMenus();
 
protected:
    // SWidget interface
    SLATE_API virtual void Tick( const FGeometry& AllottedGeometry, const double InCurrentTime, const float InDeltaTime ) override;
    SLATE_API virtual bool ComputeVolatility() const override;
    SLATE_API virtual void OnArrangeChildren( const FGeometry& AllottedGeometry, FArrangedChildren& ArrangedChildren ) const override;
    SLATE_API virtual FVector2D ComputeDesiredSize(float) const override;
    SLATE_API virtual FChildren* GetChildren() override;
    SLATE_API virtual int32 OnPaint( const FPaintArgs& Args, const FGeometry& AllottedGeometry, const FSlateRect& MyCullingRect, FSlateWindowElementList& OutDrawElements, int32 LayerId, const FWidgetStyle& InWidgetStyle, bool bParentEnabled ) const override;
    // End of SWidget interface
 
    SLATE_API bool IsOpenAndReusingWindow() const;
 
    SLATE_API bool IsOpenViaCreatedWindow() const;
 
    SLATE_API void OnMenuClosed(TSharedRef<IMenu> InMenu);
 
    SLATE_API void ResetPopupMenuContent();
 
    SLATE_API FGeometry ComputeNewWindowMenuPlacement(const FGeometry& AllottedGeometry, const FVector2D& PopupDesiredSize, EMenuPlacement PlacementMode) const;
 
    static SLATE_API TArray<TWeakPtr<IMenu>> OpenApplicationMenus;
 
protected:
    struct FPopupPlacement
    {
        SLATE_API FPopupPlacement(const FGeometry& PlacementGeometry, const FVector2D& PopupDesiredSize, EMenuPlacement PlacementMode);
        
        FVector2D LocalPopupSize;
        FVector2D LocalPopupOffset;
        FSlateRect AnchorLocalSpace;
        EOrientation Orientation;
    };
 
    TWeakPtr<SWindow> PopupWindowPtr;
 
    TWeakPtr<IMenu> PopupMenuPtr;
 
    TSharedPtr<IMenu> OwnedMenuPtr;
 
    TSharedPtr<SWidget> MenuContent;
 
    TSharedPtr<SWidget> WrappedContent;
    
    FOnGetContent OnGetMenuContent;
 
    FOnIsOpenChanged OnMenuOpenChanged;
 
    TAttribute<EMenuPlacement> Placement;
 
    bool bFitInWindow;
 
    bool bDismissedThisTick;
 
    bool bIsCollapsedByParent;
 
    TOptional<EPopupMethod> Method;
 
    FPopupMethodReply MethodInUse;
 
    bool bShouldDeferPaintingAfterWindowContent;
 
    bool bUseApplicationMenuStack;
 
    bool bApplyWidgetStyleToMenu;
 
    FVector2D LocalPopupPosition;
 
    FVector2D ScreenPopupPosition;
 
    TPanelChildren<FBasicLayoutWidgetSlot> Children;
};