SButton.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "CoreMinimal.h"
#include "Misc/Attribute.h"
#include "Input/Reply.h"
#include "Widgets/DeclarativeSyntaxSupport.h"
#include "Styling/SlateColor.h"
#include "Layout/Margin.h"
#include "Sound/SlateSound.h"
#include "Styling/SlateTypes.h"
#include "Styling/CoreStyle.h"
#include "Framework/SlateDelegates.h"
#include "Styling/SlateWidgetStyleAsset.h"
#include "Widgets/Layout/SBorder.h"
 
class FPaintArgs;
class FSlateWindowElementList;
enum class ETextFlowDirection : uint8;
enum class ETextShapingMethod : uint8;
 
template <>
struct TWidgetTypeTraits<class SButton>
{
    static constexpr bool SupportsInvalidation() { return true; }
};
 
class SButton : public SBorder
{
    SLATE_DECLARE_WIDGET_API(SButton, SBorder, SLATE_API)
 
#if WITH_ACCESSIBILITY
    // Allow the accessible button to "click" this button
    friend class FSlateAccessibleButton;
#endif
public:
 
    SLATE_BEGIN_ARGS( SButton )
        : _Content()
        , _ButtonStyle( &FCoreStyle::Get().GetWidgetStyle< FButtonStyle >( "Button" ) )
        , _TextStyle( &FCoreStyle::Get().GetWidgetStyle< FTextBlockStyle >("ButtonText") )
        , _HAlign( HAlign_Fill )
        , _VAlign( VAlign_Fill )
        , _ContentPadding(FMargin(4.0, 2.0))
        , _Text()
        , _OnSlateButtonDragDetected()
        , _OnSlateButtonDragEnter()
        , _OnSlateButtonDragLeave()
        , _OnSlateButtonDragOver()
        , _OnSlateButtonDrop()
        , _ClickMethod( EButtonClickMethod::DownAndUp )
        , _TouchMethod( EButtonTouchMethod::DownAndUp )
        , _PressMethod( EButtonPressMethod::DownAndUp )
        , _DesiredSizeScale( FVector2D(1,1) )
        , _ContentScale( FVector2D(1,1) )
        , _ButtonColorAndOpacity(FLinearColor::White)
        , _ForegroundColor(FSlateColor::UseStyle())
        , _IsFocusable( true )
        , _AllowDragDrop( false )
        {
        }
 
        SLATE_DEFAULT_SLOT( FArguments, Content )
 
        
        SLATE_STYLE_ARGUMENT( FButtonStyle, ButtonStyle )
 
        
        SLATE_STYLE_ARGUMENT( FTextBlockStyle, TextStyle )
 
        
        SLATE_ARGUMENT( EHorizontalAlignment, HAlign )
 
        
        SLATE_ARGUMENT( EVerticalAlignment, VAlign )
    
        
        SLATE_ATTRIBUTE( FMargin, ContentPadding )
 
        
        SLATE_ATTRIBUTE( FMargin, NormalPaddingOverride )
 
        
        SLATE_ATTRIBUTE( FMargin, PressedPaddingOverride )
 
        
        SLATE_ATTRIBUTE( FText, Text )
    
        
        SLATE_EVENT( FOnClicked, OnClicked )
 
        
        SLATE_EVENT( FSimpleDelegate, OnPressed )
 
        
        SLATE_EVENT( FSimpleDelegate, OnReleased )
 
        SLATE_EVENT( FSimpleDelegate, OnHovered )
 
        SLATE_EVENT( FSimpleDelegate, OnUnhovered )
 
        SLATE_EVENT( FSimpleDelegate, OnReceivedFocus )
 
        SLATE_EVENT( FSimpleDelegate, OnLostFocus )
 
        // Drag and Drop
        SLATE_EVENT(FOnDragDetected, OnSlateButtonDragDetected)
 
        SLATE_EVENT(FOnDragEnter, OnSlateButtonDragEnter)
 
        SLATE_EVENT(FOnDragLeave, OnSlateButtonDragLeave)
 
        SLATE_EVENT(FOnDragOver, OnSlateButtonDragOver)
 
        SLATE_EVENT(FOnDrop, OnSlateButtonDrop)
        // End Drag and Drop
 
        
        SLATE_ARGUMENT( EButtonClickMethod::Type, ClickMethod )
 
        
        SLATE_ARGUMENT( EButtonTouchMethod::Type, TouchMethod )
 
        
        SLATE_ARGUMENT( EButtonPressMethod::Type, PressMethod )
 
        SLATE_ATTRIBUTE( FVector2D, DesiredSizeScale )
 
        SLATE_ATTRIBUTE( FVector2D, ContentScale )
 
        SLATE_ATTRIBUTE( FSlateColor, ButtonColorAndOpacity )
 
        SLATE_ATTRIBUTE( FSlateColor, ForegroundColor )
 
        
        SLATE_ARGUMENT( bool, IsFocusable )
 
        
        SLATE_ARGUMENT(bool, AllowDragDrop)
 
        
        SLATE_ARGUMENT( TOptional<FSlateSound>, PressedSoundOverride )
 
        
        SLATE_ARGUMENT( TOptional<FSlateSound>, ClickedSoundOverride )
 
        
        SLATE_ARGUMENT( TOptional<FSlateSound>, HoveredSoundOverride )
 
        
        SLATE_ARGUMENT( TOptional<ETextShapingMethod>, TextShapingMethod )
        
        
        SLATE_ARGUMENT( TOptional<ETextFlowDirection>, TextFlowDirection )
 
    SLATE_END_ARGS()
 
        SLATE_API virtual ~SButton();
 
protected:
        SLATE_API SButton();
 
public:
    virtual FSlateColor GetForegroundColor() const final
    {
        return Super::GetForegroundColor();
    }
 
    SLATE_API virtual FSlateColor GetDisabledForegroundColor() const final;
 
    bool IsPressed() const
    {
        return bIsPressed || AppearPressedAttribute.Get();
    }
 
    SLATE_API void Construct( const FArguments& InArgs );
 
    SLATE_API void SetContentPadding(TAttribute<FMargin> InContentPadding);
 
    SLATE_API void SetHoveredSound(TOptional<FSlateSound> InHoveredSound);
 
    SLATE_API void SetPressedSound(TOptional<FSlateSound> InPressedSound);
 
    SLATE_API void SetClickedSound(TOptional<FSlateSound> InClickedSound);
 
    SLATE_API void SetOnClicked(FOnClicked InOnClicked);
 
    SLATE_API void SetOnHovered(FSimpleDelegate InOnHovered);
 
    SLATE_API void SetOnUnhovered(FSimpleDelegate InOnUnhovered);
 
    SLATE_API void SetOnFocusReceived(FSimpleDelegate InOnFocusReceived);
 
    SLATE_API void SetOnFocusLost(FSimpleDelegate InOnFocusLost);
 
    SLATE_API void SetButtonStyle(const FButtonStyle* ButtonStyle);
 
    SLATE_API void SetClickMethod(EButtonClickMethod::Type InClickMethod);
    SLATE_API void SetTouchMethod(EButtonTouchMethod::Type InTouchMethod);
    SLATE_API void SetPressMethod(EButtonPressMethod::Type InPressMethod);
 
    SLATE_API void SetAllowDragDrop(bool bAllowDragDrop);
 
#if !UE_BUILD_SHIPPING
    SLATE_API void SimulateClick();
#endif // !UE_BUILD_SHIPPING
 
public:
 
    //~ SWidget overrides
    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;
    SLATE_API virtual bool SupportsKeyboardFocus() const override;
    SLATE_API virtual void OnFocusLost( const FFocusEvent& InFocusEvent ) override;
    SLATE_API virtual FReply OnFocusReceived(const FGeometry& MyGeometry, const FFocusEvent& InFocusEvent) override;
    SLATE_API virtual FReply OnKeyDown( const FGeometry& MyGeometry, const FKeyEvent& InKeyEvent ) override;
    SLATE_API virtual FReply OnKeyUp( const FGeometry& MyGeometry, const FKeyEvent& InKeyEvent ) override;
    SLATE_API virtual FReply OnMouseButtonDown( const FGeometry& MyGeometry, const FPointerEvent& MouseEvent ) override;
    SLATE_API virtual FReply OnMouseButtonDoubleClick(const FGeometry& InMyGeometry, const FPointerEvent& InMouseEvent) override;
    SLATE_API virtual FReply OnMouseButtonUp( const FGeometry& MyGeometry, const FPointerEvent& MouseEvent ) override;
    SLATE_API virtual FReply OnMouseMove( const FGeometry& MyGeometry, const FPointerEvent& MouseEvent ) override;
    SLATE_API virtual void OnMouseEnter( const FGeometry& MyGeometry, const FPointerEvent& MouseEvent ) override;
    SLATE_API virtual FReply OnDragDetected(const FGeometry& MyGeometry, const FPointerEvent& MouseEvent) override;
    SLATE_API virtual void OnDragEnter(FGeometry const& MyGeometry, FDragDropEvent const& DragDropEvent) override;
    SLATE_API virtual void OnDragLeave(FDragDropEvent const& DragDropEvent) override;
    SLATE_API virtual FReply OnDragOver(const FGeometry& MyGeometry, const FDragDropEvent& DragDropEvent) override;
    SLATE_API virtual FReply OnDrop(const FGeometry& MyGeometry, const FDragDropEvent& DragDropEvent) override;
    SLATE_API virtual void OnMouseLeave( const FPointerEvent& MouseEvent ) override;
    SLATE_API virtual void OnMouseCaptureLost(const FCaptureLostEvent& CaptureLostEvent) override;
    SLATE_API virtual bool IsInteractable() const override;
 
#if WITH_ACCESSIBILITY
    SLATE_API virtual TSharedRef<FSlateAccessibleWidget> CreateAccessibleWidget() override;
#endif
protected:
    SLATE_API virtual FVector2D ComputeDesiredSize(float) const override;
    //~ SWidget
 
protected:
    SLATE_API virtual void Press();
 
    SLATE_API virtual void Release();
 
    SLATE_API FReply ExecuteOnClick();
 
    SLATE_API FMargin GetCombinedPadding() const;
 
    SLATE_API bool GetShowDisabledEffect() const;
 
    SLATE_API TEnumAsByte<EButtonClickMethod::Type> GetClickMethodFromInputType(const FPointerEvent& MouseEvent) const;
 
    SLATE_API bool IsPreciseTapOrClick(const FPointerEvent& MouseEvent) const;
 
    SLATE_API void PlayPressedSound() const;
 
    SLATE_API void PlayClickedSound() const;
 
    SLATE_API void PlayHoverSound() const;
 
    void SetIsFocusable(bool bInIsFocusable)
    {
        bIsFocusable = bInIsFocusable;
    }
 
    SLATE_API void ExecuteHoverStateChanged(bool bPlaySound);
 
protected:
    TSlateAttributeRef<FSlateColor> GetBorderForegroundColorAttribute() const { return TSlateAttributeRef<FSlateColor>(SharedThis(this), BorderForegroundColorAttribute); }
 
    TSlateAttributeRef<FMargin> GetContentPaddingAttribute() const { return TSlateAttributeRef<FMargin>(SharedThis(this), ContentPaddingAttribute); }
 
    void SetAppearPressed(TAttribute<bool> InValue)
    {
        AppearPressedAttribute.Assign(*this, MoveTemp(InValue));
    }
 
    TSlateAttributeRef<bool> GetAppearPressedAttribute() const { return TSlateAttributeRef<bool>(SharedThis(this), AppearPressedAttribute); }
 
private:
    SLATE_API void UpdatePressStateChanged();
 
    SLATE_API void UpdatePadding();
    SLATE_API void UpdateShowDisabledEffect();
    SLATE_API void UpdateBorderImage();
    SLATE_API void UpdateForegroundColor();
    SLATE_API void UpdateDisabledForegroundColor();
 
private:
    FVector2D PressedScreenSpacePosition;
 
    const FButtonStyle* Style;
    FOnClicked OnClicked;
 
    FSimpleDelegate OnPressed;
 
    FSimpleDelegate OnReleased;
 
    FSimpleDelegate OnHovered;
 
    FSimpleDelegate OnUnhovered;
 
    FSimpleDelegate OnReceivedFocus;
 
    FSimpleDelegate OnLostFocus;
 
    FOnDragDetected OnSlateButtonDragDetected;
 
    FOnDragEnter OnSlateButtonDragEnter;
 
    FOnDragLeave OnSlateButtonDragLeave;
 
    FOnDragOver OnSlateButtonDragOver;
 
    FOnDrop OnSlateButtonDrop;
 
    FSlateSound HoveredSound;
 
    FSlateSound PressedSound;
 
    FSlateSound ClickedSound;
 
    TEnumAsByte<EButtonClickMethod::Type> ClickMethod;
 
    TEnumAsByte<EButtonTouchMethod::Type> TouchMethod;
 
    TEnumAsByte<EButtonPressMethod::Type> PressMethod;
 
    bool bAllowDragDrop = false;
 
    uint8 bIsFocusable:1;
 
    uint8 bIsPressed:1;
 
    uint8 bIsStyleNormalPaddingOverridden:1;
 
    uint8 bIsStylePressedPaddingOverridden:1;
 
private:
    TSlateAttribute<FSlateColor> BorderForegroundColorAttribute;
    TSlateAttribute<FMargin> ContentPaddingAttribute;
    TSlateAttribute<FMargin> NormalPaddingAttribute;
    TSlateAttribute<FMargin> PressedPaddingAttribute;
    TSlateAttribute<bool> AppearPressedAttribute;
};