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UnrealEngine/Engine/Source/Runtime/Slate/Public/Widgets/Views/SExpanderArrow.h
2025-05-18 13:04:45 +08:00

78 lines
2.6 KiB
C++

// Copyright Epic Games, Inc. All Rights Reserved.
#pragma once
#include "CoreMinimal.h"
#include "Misc/Attribute.h"
#include "Input/Reply.h"
#include "Layout/Visibility.h"
#include "Widgets/DeclarativeSyntaxSupport.h"
#include "Layout/Margin.h"
#include "Widgets/SCompoundWidget.h"
#include "Styling/CoreStyle.h"
class ITableRow;
class SButton;
/**
* Expander arrow and indentation component that can be placed in a TableRow
* of a TreeView. Intended for use by TMultiColumnRow in TreeViews.
*/
class SExpanderArrow : public SCompoundWidget
{
SLATE_DECLARE_WIDGET_API(SExpanderArrow, SCompoundWidget, SLATE_API)
public:
SLATE_BEGIN_ARGS( SExpanderArrow )
: _StyleSet(&FCoreStyle::Get())
, _IndentAmount(10)
, _BaseIndentLevel(0)
, _ShouldDrawWires(false)
{ }
SLATE_ARGUMENT(const ISlateStyle*, StyleSet)
/** How many Slate Units to indent for every level of the tree. */
SLATE_ATTRIBUTE(float, IndentAmount)
/** The level that the root of the tree should start (e.g. 2 will shift the whole tree over by `IndentAmount*2`) */
SLATE_ATTRIBUTE(int32, BaseIndentLevel)
/** Whether to draw the wires that visually reinforce the tree hierarchy. */
SLATE_ATTRIBUTE(bool, ShouldDrawWires)
SLATE_END_ARGS()
SLATE_API SExpanderArrow();
SLATE_API ~SExpanderArrow();
SLATE_API void Construct( const FArguments& InArgs, const TSharedPtr<class ITableRow>& TableRow );
protected:
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;
/** Invoked when the expanded button is clicked (toggle item expansion) */
SLATE_API FReply OnArrowClicked();
/** @return Visible when has children; invisible otherwise */
SLATE_API EVisibility GetExpanderVisibility() const;
/** @return the margin corresponding to how far this item is indented */
SLATE_API FMargin GetExpanderPadding() const;
/** @return the name of an image that should be shown as the expander arrow */
SLATE_API const FSlateBrush* GetExpanderImage() const;
TWeakPtr<class ITableRow> OwnerRowPtr;
/** A reference to the expander button */
TSharedPtr<SButton> ExpanderArrow;
/** The slate style to use */
const ISlateStyle* StyleSet;
/** The amount of space to indent at each level */
TAttribute<float> IndentAmount;
/** The level in the tree that begins the indention amount */
TAttribute<int32> BaseIndentLevel;
/** Whether to draw the wires that visually reinforce the tree hierarchy. */
TSlateAttribute<bool> ShouldDrawWires;
};