MessageListWidget.h

// Copyright 2022 Stream.IO, Inc. All Rights Reserved.
 
#pragma once
 
#include "Channel/Message.h"
#include "Common/SPaginateListWidget.h"
#include "Components/NativeWidgetHost.h"
#include "CoreMinimal.h"
#include "MessagePosition.h"
#include "MessageSide.h"
#include "MessageWidget.h"
#include "StreamWidget.h"
 
#include "MessageListWidget.generated.h"
 
class UChannelContextWidget;
 
UCLASS()
class STREAMCHATUI_API UMessageListWidget final : public UStreamWidget
{
    GENERATED_BODY()
 
public:
    UMessageListWidget();
 
    DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(FPaginatingMessagesDelegate, EPaginationDirection, Direction, EHttpRequestState, RequestState);
    UPROPERTY(BlueprintAssignable)
    FPaginatingMessagesDelegate OnPaginatingMessages;
 
protected:
    UPROPERTY(meta = (BindWidget))
    UNativeWidgetHost* ListView;
 
    UPROPERTY(EditAnywhere, Category = Pagination)
    int32 Limit = 20;
 
    UPROPERTY(EditDefaultsOnly, Category = Defaults)
    TSubclassOf<UMessageWidget> MessageWidgetClass;
 
    DECLARE_DYNAMIC_DELEGATE_RetVal_ThreeParams(UMessageWidget*, FGetMessageWidget, const FMessage&, Message, EMessageSide, Side, EMessagePosition, Position);
    UPROPERTY(EditAnywhere, Category = Events)
    FGetMessageWidget OnGetMessageWidgetEvent;
 
private:
    virtual void NativePreConstruct() override;
    virtual void NativeConstruct() override;
    virtual void NativeDestruct() override;
    virtual void ReleaseSlateResources(bool bReleaseChildren) override;
 
    UWidget* CreateMessageWidget(const FMessageRef&);
    void Paginate(const EPaginationDirection PaginationDirection, const TFunction<void()> Callback);
 
    UFUNCTION()
    void OnMessagesUpdated();
    UFUNCTION()
    void ScrollToBottom(const FMessage& Message);
 
    EMessagePosition GetPosition(const FMessage& Message) const;
 
    TSharedPtr<SPaginateListWidget<FMessageRef>> PaginateListWidget;
};