BaseContentLoadedView for Xamarin iOS

BaseContentLoadedView.cs

namespace <Namespace>
{
    using CoreAnimation;

    using Foundation;

    using MvvmCross.Binding.BindingContext;
    using MvvmCross.Platform;

    using UIKit;

    public abstract class BaseContentLoadedView<TViewModel> : BaseView<TViewModel>
        where TViewModel : class, IBaseViewModel, IContentLoadedViewModel
    {
        private ContentLoadedProperties contentLoadedProperties;
        private UIActivityIndicatorView indicatorView;
        private UILabel titleLabel;
        private UILabel descriptionLabel;
        private UIView emptyContainerView;
        private ContentLoadedProperties.ContentLoadedType contentLoadedType;
        private string emptyTitle;
        private string emptyButtonTitle;
        private string emptyDescription;
        private UIButton emptyButton;

        protected BaseContentLoadedView(string nibName, NSBundle bundle)
            : base(nibName, bundle)
        {

        }

        protected BaseContentLoadedView()
        {

        }

        protected abstract UIView ContentProcessingView { get; }

        protected abstract UIView ContentView { get; }

        public ContentLoadedProperties ContentLoadedProperties
        {
            get => this.contentLoadedProperties;
            set => this.SetContentLoadedProperties(value);
        }

        public ContentLoadedProperties.ContentLoadedType ContentLoadedType
        {
            get => this.contentLoadedType;
            set => this.SetContentLoadedType(value);
        }

        public string EmptyTitle
        {
            get => this.emptyTitle;
            set => this.SetEmptyTitle(value);
        }

        public string EmptyButtonTitle
        {
            get => this.emptyButtonTitle;
            set => this.SetEmptyButtonTitle(value);
        }

        public string EmptyDescription
        {
            get => this.emptyDescription;
            set => this.SetEmptyDescription(value);
        }

        protected override void Binding()
        {
            base.Binding();
            if (this.ContentProcessingView == null || this.ContentView == null)
            {
                return;
            }

            this.ConfigureContentProcessingView(this.ContentProcessingView);
            var set = this.CreateBindingSet<BaseContentLoadedView<TViewModel>, TViewModel>();
            set.Bind(this).For(v => v.ContentLoadedProperties).To(vm => vm.ContentLoadedProperties);
            set.Bind(this).For(v => v.ContentLoadedType).To(vm => vm.ContentLoadedProperties.Type);
            set.Bind(this).For(v => v.EmptyTitle).To(vm => vm.ContentLoadedProperties.Title);
            set.Bind(this).For(v => v.EmptyDescription).To(vm => vm.ContentLoadedProperties.Description);
            set.Bind(this.emptyButton).To(vm => vm.ContentLoadedProperties.RetryButtonCommand);
            set.Bind(this).For(v => v.EmptyButtonTitle).To(vm => vm.ContentLoadedProperties.RetryButtonTitle);
            set.Apply();
        }

        protected void SetContentLoadedProperties(ContentLoadedProperties value)
        {
            this.contentLoadedProperties = value;
            if (value == null)
            {
                return;
            }
        }

        protected void SetContentLoadedType(ContentLoadedProperties.ContentLoadedType value)
        {
            this.contentLoadedType = value;
            var fromView = this.ContentView;
            var toView = this.ContentProcessingView;
            switch (value)
            {
                case ContentLoadedProperties.ContentLoadedType.Loading:
                    this.indicatorView.StartAnimating();
                    this.emptyContainerView.Hidden = true;
                    break;
                case ContentLoadedProperties.ContentLoadedType.Loaded:
                    this.indicatorView.StopAnimating();
                    fromView = this.ContentProcessingView;
                    toView = this.ContentView;
                    break;
                case ContentLoadedProperties.ContentLoadedType.Empty:
                    this.indicatorView.StopAnimating();
                    this.emptyContainerView.Hidden = false;
                    break;
                default:
                    break;
            }

            if (value == ContentLoadedProperties.ContentLoadedType.Loaded)
            {
                fromView.Alpha = 1;
                toView.Alpha = 0;
                UIView.AnimateNotify(CATransaction.AnimationDuration, () =>
                {
                    fromView.Alpha = 0;
                    toView.Alpha = 1;
                }, finished =>
                {
                    fromView.Hidden = true;
                    toView.Hidden = false;
                });
            }
            else
            {
                fromView.Hidden = true;
                toView.Hidden = false;
            }
        }

        protected void SetEmptyTitle(string value)
        {
            this.emptyTitle = value;
            if (Mvx.TryResolve(out IEmptyDataSetSourceDelegate dataSetSourceDelegate))
            {
                if (!string.IsNullOrEmpty(value))
                {
                    this.titleLabel.AttributedText = dataSetSourceDelegate.GetTitle(value);
                    return;
                }
            }

            this.titleLabel.Text = value;
        }

        protected void SetEmptyButtonTitle(string value)
        {
            this.emptyButtonTitle = value;
            var isEmpty = string.IsNullOrEmpty(value);
            this.emptyButton.Hidden = isEmpty;
            this.emptyButton.SetTitle(value, UIControlState.Normal);
            if (!isEmpty && Mvx.TryResolve(out IEmptyDataSetSourceDelegate dataSetSourceDelegate))
            {
                this.emptyButton.SetAttributedTitle(dataSetSourceDelegate.GetButtonAttributedString(value), UIControlState.Normal);
                return;
            }

            this.emptyButton.SetTitle(value, UIControlState.Normal);
        }

        protected void SetEmptyDescription(string value)
        {
            this.emptyDescription = value;
            var isEmpty = string.IsNullOrEmpty(value);
            this.descriptionLabel.Hidden = isEmpty;
            if (!isEmpty && Mvx.TryResolve(out IEmptyDataSetSourceDelegate dataSetSourceDelegate))
            {
                this.descriptionLabel.AttributedText = dataSetSourceDelegate.GetDescription(value);
                return;
            }

            this.descriptionLabel.Text = value;
        }

        private void ConfigureContentProcessingView(UIView contentView)
        {
            this.indicatorView = new UIActivityIndicatorView(Mvx.TryResolve(out IEmptyDataSetSourceDelegate dataSetSourceDelegate)
                                                             ? dataSetSourceDelegate.RefreshableActivityIndicatorViewStyle
                                                             : UIActivityIndicatorViewStyle.Gray)
            {
                TranslatesAutoresizingMaskIntoConstraints = false,
                HidesWhenStopped = true
            };

            this.titleLabel = new UILabel
            {
                TranslatesAutoresizingMaskIntoConstraints = false,
                Lines = 0
            };

            this.descriptionLabel = new UILabel
            {
                TranslatesAutoresizingMaskIntoConstraints = false,
                Lines = 0
            };

            var textContainerView = new UIView
            {
                TranslatesAutoresizingMaskIntoConstraints = false
            };

            this.emptyButton = new UIButton(UIButtonType.System)
            {
                TranslatesAutoresizingMaskIntoConstraints = false,
                TintColor = this.ThemeManager().Colors.TintColor
            };

            this.emptyContainerView = new UIView
            {
                TranslatesAutoresizingMaskIntoConstraints = false
            };

            // textContainerView
            textContainerView.AddSubviews(this.titleLabel, this.descriptionLabel);
            this.titleLabel.SetFillXContraintTo(textContainerView);
            this.descriptionLabel.SetFillXContraintTo(textContainerView);
            textContainerView.AddConstraints(NSLayoutConstraint.FromVisualFormat("V:|[titleLabel]-2-[descriptionLabel]|", 0, "titleLabel", this.titleLabel, "descriptionLabel", this.descriptionLabel));

            // emptyContainerView
            this.emptyContainerView.AddSubviews(textContainerView, this.emptyButton);
            this.emptyContainerView.AddConstraints(NSLayoutConstraint.FromVisualFormat("V:|[textContainerView]-2-[emptyButton]|", 0, "textContainerView", textContainerView, "emptyButton", this.emptyButton));
            this.emptyButton.SetCenterXContraintTo(this.emptyContainerView);
            textContainerView.SetFillXContraintTo(this.emptyContainerView);

            // contentView
            contentView.AddSubviews(this.indicatorView, this.emptyContainerView);
            this.indicatorView.SetCenterContraintTo(contentView);
            this.emptyContainerView.SetFillXContraintTo(contentView, 8);
            this.emptyContainerView.SetCenterYContraintTo(contentView);
        }
    }
}