Calling a 2 Parameter Delegate from slate

Development Programming & Scripting UI
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1

Hello everyone…

My custom slate widget has 2 int variables.

say

TAttribute<int32> RowNum;
TAttribute<int32> ColNum;

I have a 2d array in HUD containing some values which are changed dynamically.

I want to get the values from the array using the 2 variables.

Say there is a FText present inside the array and I want to get its value at run time using the 2 variables and update it on my slate. Whats the best way to do it?

2

Hi,

Slate handles retrieving dynamic content for widgets intrinsically, so you should be able to (for instance, set up a text block that shows you the element) do something like this:

class SMyWidget : public SCompoundWidget
{
public:

	SLATE_BEGIN_ARGS(SMyWidget)
		: _RowIndex(0), _ColumnIndex(0)
	{ }
		SLATE_ATTRIBUTE(int32, RowIndex)
		SLATE_ATTRIBUTE(int32, ColumnIndex)
	SLATE_END_ARGS()

	void Construct(const FArguments& InArgs)
	{
		RowIndex = InArgs._RowIndex;
		ColumnIndex = InArgs._ColumnIndex;

		ChildWidget
		[
			SNew(STextBlock)
			.Text(this, &SMyWidget::OnGetText)
		];
	}

	FText OnGetText() const
	{
		return MyHUD->FindText(RowIndex.Get(), ColumnIndex.Get());
	}

private:

	TAttribute<int32> RowIndex, ColumnIndex;
};

You could optionally pass in a pointer to the array as well, so the widget isn’t tied to the HUD explicitly, if you can guarantee the HUD will outlive the slate widget.

3

I tried something like this

BEGIN_SLATE_FUNCTION_BUILD_OPTIMIZATION
void SItemWidget::Construct(const FArguments& InArgs)
{
	GameHUD = InArgs._GameHUD;
	SlotLoc = InArgs._SlotLoc;
	
	ChildSlot
	[
		SNew(SBox)
		.Padding(5)
		.HeightOverride(100)
		.WidthOverride(100)
		[
			SNew(SBorder)
			.HAlign(HAlign_Center)
			.VAlign(VAlign_Center)
			.BorderImage(&GameHUD->EmptySlotImg)
			.Padding(FMargin(5,0,0,0))
			[
				SNew(STextBlock)
				.Text(this, &SItemWidget::GetNumOfStacks)
			]
		]
	];
}
END_SLATE_FUNCTION_BUILD_OPTIMIZATION

FText SItemWidget::GetNumOfStacks()
{
	return FText::FromString(FString::FromInt(GameHUD->StoragePtr->Storage.Rows[SlotLoc.Get().RowNum].Columns[SlotLoc.Get().ColNum].ItemIndex));
}

And I am getting this compiling error

1>C:\Users\Srikant\Documents\Unreal Projects\SurvivalGame\Source\SurvivalGame\Inventory\Slate\Widgets\SItemWidget.cpp(31): error C2664: 'STextBlock::FArguments::WidgetArgsType &STextBlock::FArguments::Text(const TAttribute<FText> &)' : cannot convert argument 2 from 'FText (__cdecl SItemWidget::* )(void)' to 'FString (__cdecl SItemWidget::* )(void) const'
1>          Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast
4

Corrected just added a const