AttachmentWidget.h

// Copyright 2026 Stream.IO, Inc. All Rights Reserved.
 
#pragma once
 
#include "Channel/Attachment.h"
#include "Components/Border.h"
#include "Components/Image.h"
#include "Components/PanelWidget.h"
#include "Components/SizeBox.h"
#include "Components/TextBlock.h"
#include "CoreMinimal.h"
#include "MessageSide.h"
#include "StreamWidget.h"
 
#include "AttachmentWidget.generated.h"
 
class UTexture2DDynamic;
 
UCLASS()
class STREAMCHATUI_API UAttachmentWidget : public UStreamWidget
{
    GENERATED_BODY()
 
public:
    UFUNCTION(BlueprintCallable, Category = "Stream Chat")
    void Setup(const FAttachment& InAttachment, EMessageSide InSide);
 
protected:
    UPROPERTY(meta = (BindWidgetOptional))
    UPanelWidget* ContentPanel;
 
    UPROPERTY(EditDefaultsOnly, Category = Defaults, meta = (ClampMin = "0.1", ClampMax = "1.0"))
    float ImageWidthFraction = 0.66f;
 
    UPROPERTY(EditDefaultsOnly, Category = Defaults)
    float MaxImageWidth = 320.f;
 
    UPROPERTY(EditDefaultsOnly, Category = Defaults, meta = (ClampMin = "1.0"))
    float MaxImageAspect = 2.f;
 
    UPROPERTY(EditDefaultsOnly, Category = Defaults)
    bool bRequestResizedImages = true;
 
    UPROPERTY(EditDefaultsOnly, Category = Defaults)
    FMargin FileRowPadding = FMargin{12.f, 8.f};
 
    // Only the size is configurable: the typeface is taken from whatever font the text block already
    // carries, which keeps this working without a font asset of our own.
    UPROPERTY(EditDefaultsOnly, Category = Defaults)
    int32 TitleFontSize = 14;
 
    UPROPERTY(EditDefaultsOnly, Category = Defaults)
    int32 SubtitleFontSize = 12;
 
    UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Setup)
    FAttachment Attachment;
 
    UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Setup)
    EMessageSide Side = EMessageSide::You;
 
private:
    virtual void OnSetup() override;
    virtual void NativePreConstruct() override;
 
    bool ShouldRenderInline() const;
    void FetchRemoteImage();
    void OnImageDownloaded(UTexture2DDynamic* Texture);
 
    float GetAvailableWidth() const;
    float GetImageBudgetWidth() const;
    FVector2D GetImageDisplaySize(int32 SourceWidth, int32 SourceHeight) const;
    float GetDpiScale() const;
    void ApplyImageSize(const FVector2D& Size);
 
    FString GetTitle() const;
    FString GetSubtitle() const;
 
    UPanelWidget* GetOrCreateContentPanel();
 
    // Both the image and the file row are built for every attachment: an image that fails to
    // download falls back to the row, and there is no theme to style a late-built one with.
    UPROPERTY(Transient)
    UImage* Image;
    // The image is sized by this rather than by UImage::SetDesiredSizeOverride, which does nothing
    // unless the slate widget already exists and is not reapplied when it is rebuilt
    UPROPERTY(Transient)
    USizeBox* ImageSizer;
    UPROPERTY(Transient)
    UBorder* FileRow;
    UPROPERTY(Transient)
    UTextBlock* TitleTextBlock;
    UPROPERTY(Transient)
    UTextBlock* SubtitleTextBlock;
 
    bool bImageLoaded = false;
};