SWidgetCarouselWithNavigation.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "CoreMinimal.h"
#include "Layout/Visibility.h"
#include "Widgets/DeclarativeSyntaxSupport.h"
#include "Input/Reply.h"
#include "Widgets/SWidget.h"
#include "Widgets/SCompoundWidget.h"
#include "Framework/SlateDelegates.h"
#include "Widgets/Layout/SBorder.h"
#include "Widgets/SBoxPanel.h"
#include "Widgets/Layout/SBox.h"
#include "WidgetCarouselStyle.h"
#include "Widgets/SOverlay.h"
#include "SWidgetCarousel.h"
#include "SCarouselNavigationButton.h"
#include "SCarouselNavigationBar.h"
 
#include "Widgets/Layout/SScaleBox.h"
 
template <typename ItemType>
class SWidgetCarouselWithNavigation
    : public SCompoundWidget
{
public:
    typedef typename TSlateDelegates< ItemType >::FOnGenerateWidget FOnGenerateWidget;
 
    SLATE_BEGIN_ARGS(SWidgetCarouselWithNavigation<ItemType>)
        : _NavigationBarStyle()
        , _NavigationButtonStyle()
        , _WidgetItemsSource(static_cast<const TArray<ItemType>*>(NULL))
    { }
 
        SLATE_STYLE_ARGUMENT(FWidgetCarouselNavigationBarStyle, NavigationBarStyle)
 
        SLATE_STYLE_ARGUMENT(FWidgetCarouselNavigationButtonStyle, NavigationButtonStyle)
 
        
        SLATE_EVENT(FOnGenerateWidget, OnGenerateWidget)
 
        
        SLATE_ARGUMENT(const TArray<ItemType>*, WidgetItemsSource)
 
    SLATE_END_ARGS();
 
    void Construct(const FArguments& InArgs)
    {
        OnGenerateWidget = InArgs._OnGenerateWidget;
        WidgetItemsSource = InArgs._WidgetItemsSource;
 
        ChildSlot
        [
            SNew(SVerticalBox)
            + SVerticalBox::Slot()
            .AutoHeight()
            .HAlign(HAlign_Center)
            .VAlign(VAlign_Center)
            [
                SNew(SBox)
                .MaxDesiredHeight(442)
                [
                    SNew(SOverlay)
                    + SOverlay::Slot()
                    .HAlign(HAlign_Center)
                    .VAlign(VAlign_Center)
                    [
                        SNew(SBorder)
                        .BorderImage(FWidgetCarouselModuleStyle::Get().GetBrush("WidgetBackground"))
                        .Padding(0)
                        [
                            SNew(SScaleBox)
                            .Stretch(EStretch::ScaleToFit)
                            .StretchDirection(EStretchDirection::DownOnly)
                            [
                                SAssignNew(Carousel, SWidgetCarousel<ItemType>)
                                .WidgetItemsSource(WidgetItemsSource)
                                .FadeRate(0)
                                .SlideValueLeftLimit(-1)
                                .SlideValueRightLimit(1)
                                .MoveSpeed(5.f)
                                .OnGenerateWidget(this, &SWidgetCarouselWithNavigation::GenerateWidget)
                            ]
                        ]
                    ]
 
                    + SOverlay::Slot()
                    .Padding(0)
                    [
                        SNew(SHorizontalBox)
                        + SHorizontalBox::Slot()
                        .HAlign(HAlign_Left)
                        [
                            SNew(SCarouselNavigationButton)
                            .Style(InArgs._NavigationButtonStyle)
                            .OnClicked(this, &SWidgetCarouselWithNavigation::HandleNextButtonClicked)
                            .Visibility(this, &SWidgetCarouselWithNavigation::GetScreenshotNavigationVisibility)
                            .OnBeginPeek(this, &SWidgetCarouselWithNavigation::HandlePeak, EWidgetCarouselScrollDirection::Carousel_Right)
                            .OnEndPeek(this, &SWidgetCarouselWithNavigation::HandlePeak, EWidgetCarouselScrollDirection::Carousel_Center)
                            .Direction(SCarouselNavigationButton::ENavigationButtonDirection::Left)
                        ]
                        + SHorizontalBox::Slot()
                        .HAlign(HAlign_Right)
                        [
                            SNew(SCarouselNavigationButton)
                            .Style(InArgs._NavigationButtonStyle)
                            .OnClicked(this, &SWidgetCarouselWithNavigation::HandlePreviousButtonClicked)
                            .Visibility(this, &SWidgetCarouselWithNavigation::GetScreenshotNavigationVisibility)
                            .OnBeginPeek(this, &SWidgetCarouselWithNavigation::HandlePeak, EWidgetCarouselScrollDirection::Carousel_Left)
                            .OnEndPeek(this, &SWidgetCarouselWithNavigation::HandlePeak, EWidgetCarouselScrollDirection::Carousel_Center)
                            .Direction(SCarouselNavigationButton::ENavigationButtonDirection::Right)
                        ]
                    ]
                ]
            ]
            + SVerticalBox::Slot()
            .AutoHeight()
            .HAlign(HAlign_Center)
            .Padding(10.0f, 10.f)
            [
                SNew(SCarouselNavigationBar)
                .Style(InArgs._NavigationBarStyle)
                .Visibility(this, &SWidgetCarouselWithNavigation::GetScreenshotNavigationVisibility)
                .ItemCount(WidgetItemsSource->Num())
                .CurrentItemIndex(this, &SWidgetCarouselWithNavigation::GetCurrentItemIndex)
                .CurrentSlideAmount(this, &SWidgetCarouselWithNavigation::GetCurrentSlideAmount)
                .OnSelectedIndexChanged(this, &SWidgetCarouselWithNavigation::CarouselScrollBarIndexChanged)
            ]
        ];
    }
 
    ~SWidgetCarouselWithNavigation()
    {
    }
 
private:
    TSharedRef<SWidget> GenerateWidget(ItemType Item)
    {
        return OnGenerateWidget.Execute(Item);
    }
 
    FReply HandleNextButtonClicked()
    {
        Carousel->SetNextWidget();
        return FReply::Handled();
    }
 
    FReply HandlePreviousButtonClicked()
    {
        Carousel->SetPreviousWidget();
        return FReply::Handled();
    }
 
    void HandlePeak(EWidgetCarouselScrollDirection::Type Direction)
    {
        Carousel->Peak(Direction);
    }
 
    EVisibility GetScreenshotVisibility() const
    {
        return WidgetItemsSource->Num() ? EVisibility::Visible : EVisibility::Collapsed;
    }
 
    EVisibility GetScreenshotNavigationVisibility() const
    {
        return WidgetItemsSource->Num() > 1 ? EVisibility::Visible : EVisibility::Collapsed;
    }
 
    int32 GetCurrentItemIndex() const
    {
        return Carousel->GetWidgetIndex();
    }
 
    float GetCurrentSlideAmount() const
    {
        return Carousel->GetPrimarySlide();
    }
 
    void CarouselScrollBarIndexChanged(int32 NewIndex)
    {
        Carousel->SetActiveWidgetIndex(NewIndex);
    }
 
private:
    TSharedPtr<SWidgetCarousel<ItemType>> Carousel;
    FOnGenerateWidget OnGenerateWidget;
    const TArray<ItemType>* WidgetItemsSource;
};