// Copyright Epic Games, Inc. All Rights Reserved.

#include "SEditorViewportToolBarButton.h"
#include "Styling/SlateTypes.h"
#include "Widgets/Images/SImage.h"
#include "Widgets/Layout/SBox.h"
#include "Widgets/Input/SButton.h"
#include "Widgets/Input/SCheckBox.h"
#include "EditorStyleSet.h"

void SEditorViewportToolBarButton::Construct(const FArguments& Declaration)
{
    OnClickedDelegate                            = Declaration._OnClicked;
    IsChecked                                    = Declaration._IsChecked;
    const TSharedRef<SWidget>& ContentSlotWidget = Declaration._Content.Widget;

    bool bContentOverride                        = ContentSlotWidget != SNullWidget::NullWidget;

    EUserInterfaceActionType ButtonType          = Declaration._ButtonType;

    // The style of the image to show in the button
    const FName ImageStyleName = Declaration._Image.Get();

    TSharedPtr<SWidget> ButtonWidget;

    if (ButtonType == EUserInterfaceActionType::Button)
    {
        const FSlateBrush* Brush = FEditorStyle::GetBrush(ImageStyleName);

        ButtonWidget =
            SNew(SButton)
                .ButtonStyle(Declaration._ButtonStyle)
                .OnClicked(OnClickedDelegate)
                .HAlign(HAlign_Center)
                .VAlign(VAlign_Center)
                .ForegroundColor(FSlateColor::UseForeground())
                    [
                        // If we have a content override use it instead of the default image
                        bContentOverride ? ContentSlotWidget : TSharedRef<SWidget>(SNew(SImage).Image(Brush))];
    }
    else
    {
        // Cache off checked/unchecked image states
        NormalBrush  = FEditorStyle::GetBrush(ImageStyleName, ".Normal");
        CheckedBrush = FEditorStyle::GetBrush(ImageStyleName, ".Checked");

        if (CheckedBrush->GetResourceName() == FName("Default"))
        {
            // A different checked brush was not specified so use the normal image when checked
            CheckedBrush = NormalBrush;
        }

        ButtonWidget =
            SNew(SCheckBox)
                .Style(Declaration._CheckBoxStyle)
                .OnCheckStateChanged(this, &SEditorViewportToolBarButton::OnCheckStateChanged)
                .IsChecked(this, &SEditorViewportToolBarButton::OnIsChecked)
                    [bContentOverride ? ContentSlotWidget :
                                        TSharedRef<SWidget>(
                                            SNew(SBox)
                                                .Padding(1.0f)
                                                .VAlign(VAlign_Center)
                                                .HAlign(HAlign_Center)
                                                    [SNew(SImage)
                                                         .Image(this, &SEditorViewportToolBarButton::OnGetButtonImage)])];
    }

    ChildSlot
        [ButtonWidget.ToSharedRef()];
}

void SEditorViewportToolBarButton::OnCheckStateChanged(ECheckBoxState NewCheckedState)
{
    // When the check state changes (can only happen during clicking in this case) execute our on clicked delegate
    if (OnClickedDelegate.IsBound() == true)
    {
        OnClickedDelegate.Execute();
    }
}

const FSlateBrush* SEditorViewportToolBarButton::OnGetButtonImage() const
{
    return IsChecked.Get() == true ? CheckedBrush : NormalBrush;
}

ECheckBoxState SEditorViewportToolBarButton::OnIsChecked() const
{
    return IsChecked.Get() == true ? ECheckBoxState::Checked : ECheckBoxState::Unchecked;
}