Building Slate Widgets

Creation

Do not subclass SWidget

As mentioned in the class comment, do not subclass directly SWidget. Epic recommends using LeafWidget or SPanel (or any other subclass) as the minimum slate widget class.

Example of custom Slate class with args

// .h
class SPSPrefabSystemBlueprintWindow : public SVerticalBox
{
	SLATE_BEGIN_ARGS(SPSPrefabSystemBlueprintWindow)
		: _BlueprintEditorPtr(),
		_PrefabEditorSubsystem()
    {}
	
    SLATE_ARGUMENT(TSharedPtr<FBlueprintEditor>, BlueprintEditorPtr)
    SLATE_ARGUMENT(UPSPrefabEditorSubsystem*, PrefabEditorSubsystem)
	
    SLATE_END_ARGS()
	
public:
    SPSPrefabSystemBlueprintWindow(): PrefabEditorSubsystem(nullptr) {}
	
    void Construct(const FArguments& InArgs);
	
    virtual void Tick(const FGeometry& AllottedGeometry, const double InCurrentTime, const float InDeltaTime) override;
	
    virtual int32 OnPaint(const FPaintArgs& Args, const FGeometry& AllottedGeometry, const FSlateRect& MyCullingRect, FSlateWindowElementList& OutDrawElements, int32 LayerId, const FWidgetStyle& InWidgetStyle, bool bParentEnabled) const override;
	
private:
    TSharedPtr<FBlueprintEditor> BlueprintEditorPtr;
    UPSPrefabEditorSubsystem* PrefabEditorSubsystem;
};
 
// .cpp
void SPSPrefabSystemBlueprintWindow::Construct(const FArguments& InArgs)
{
	BlueprintEditorPtr = InArgs._BlueprintEditorPtr;
    PrefabEditorSubsystem = InArgs._PrefabEditorSubsystem;
    
    const bool bHasBlueprintPRC = PrefabEditorSubsystem->DoesBlueprintHavePRC(BlueprintEditorPtr.Get());
    if (bHasBlueprintPRC)
    {
	    AddSlot()
		    .AutoHeight()
		    [
			    SNew(STextBlock).Text(INVTEXT("Hello"))
			];
    }
    else
    {
	    AddSlot()
		    .AutoHeight()
		    [
			    SNew(STextBlock).Text(INVTEXT("No Prefab Reference Component were found in this Blueprint Actor.")).ColorAndOpacity(FSlateColor(FColor::Red))
			];
    }
}
    
void SPSPrefabSystemBlueprintWindow::Tick(const FGeometry& AllottedGeometry, const double InCurrentTime, const float InDeltaTime)  
{
	SWidget::Tick(AllottedGeometry, InCurrentTime, InDeltaTime);  
}
	
int32 SPSPrefabSystemBlueprintWindow::OnPaint(const FPaintArgs& Args, const FGeometry& AllottedGeometry, const FSlateRect& MyCullingRect, FSlateWindowElementList& OutDrawElements, int32 LayerId, const FWidgetStyle& InWidgetStyle, bool bParentEnabled) const
{
	return SVerticalBox::OnPaint(Args, AllottedGeometry, MyCullingRect, OutDrawElements, LayerId, InWidgetStyle, bParentEnabled);
}
	

Assign new widget to variable for later edit

TSharedPtr<SHorizontalBox> HorizontalBox;
// ...
SAssignNew(HorizontalBox, SHorizontalBox)
// ...

Combo box

See example of use of SComboBox

Horizontal & Vertical Box

Examples

// Method 1
SNew(SHorizontalBox)
+SHorizontalBox::Slot()
.AutoWidth()
[
    SNew(STextBlock).Text(INVTEXT("Hello"))
]
+SHorizontalBox::Slot()
.AutoWidth()
[
    SNew(STextBlock).Text(INVTEXT("Hello"))
]
 
// method 2
TSharedPtr<SVerticalBox> VerticalBox;  
SAssignNew(VerticalBox, SVerticalBox);  
if (bSomeCondition)  
{  
    VerticalBox->AddSlot()  
       .AutoHeight()
       [
	       SNew(STextBlock).Text(INVTEXT("Hello"))
	   ];  
}
else
{
	VerticalBox->AddSlot()
		.AutoHeight()
		[
			SNew(STextBlock).Text(INVTEXT("No Prefab Reference Component were found in this Blueprint Actor.")).ColorAndOpacity(FSlateColor(FColor::Red))
		];
}

Fill dropdown from enum

See SEnumComboBox

Example:

auto PreviewSelectionDrawModeWidget = SNew(SEnumComboBox, StaticEnum<EPSEditorPRCPreviewSettings_SelectionDrawMode>())
.OnEnumSelectionChanged(SEnumComboBox::FOnEnumSelectionChanged::CreateLambda([this, BlueprintEditorContext] (int32 InValue, ESelectInfo::Type InSelectInfo)
{...}))
.CurrentValue_Lambda([this, BlueprintEditorContext]()  
{ return ...});
 

Common Slate Arguments

Common Slate Arguments (Docs)

Scroll Box

Use SScrollBox.

Color Block

Use SColorBlock. Good for lines to