<img src="@src" title="@title" disabled=@Disabled @onclick="SetValue" />

@code {
    [Parameter]
    public bool? Value { get; set; }

    [Parameter]
    public bool Disabled { get; set; }

    [Parameter]
    public Action<bool?> OnChange { get; set; }

    bool? value = null;
    string title;
    string src = "";

    protected override void OnInitialized()
    {
        value = Value;
        SetImage();
    }

    private void SetValue()
    {
        switch (value)
        {
            case true:
                value = false;
                break;
            case false:
                value = null;
                break;
            case null:
                value = true;
                break;
        }
        SetImage();
        OnChange(value);
    }

    private void SetImage()
    {
        switch (value)
        {
            case true:
                src = "images/checked.png";
                title = "Permission Granted";
                break;
            case false:
                src = "images/unchecked.png";
                title = "Permission Denied";
                break;
            case null:
                src = "images/null.png";
                title = "";
                break;
        }
        StateHasChanged();
    }
}