/// <summary>
/// Initializes a new instance of the <see cref="ImageEditorViewModel" /> class.
/// </summary>
/// <param name="imageService">Service for image loading and manipulation.</param>
public ImageEditorViewModel(IImageService imageService = null)
{
_imageService = imageService ?? Locator.Current.GetService <IImageService>();
IObservable <ImageHandle> selectionChanges = this.WhenAnyValue(x => x.SelectedImage).Publish().RefCount();
ImageExplorer = new ImageExplorerViewModel(_source.AsObservableCache());
ImagePreview = new ImagePreviewViewModel(selectionChanges);
Settings = new ImageSettingsViewModel(selectionChanges);
SelectFolder = new Interaction <string, string>();
LoadImage = ReactiveCommand.CreateFromObservable <string, ImageHandle>(x => _imageService.LoadImage(x));
ExportSelected = ReactiveCommand.CreateFromObservable(ExportSelectedImpl);
ExportAll = ReactiveCommand.CreateFromObservable(ExportAllImpl);
_calculatePreview = ReactiveCommand.CreateFromObservable <ImageHandle, ImageHandle>(x => _imageService.CalculatePreview(x));
var connection = _source.Connect();
this.WhenActivated(d =>
{
// Dispose handles removed from the source collection
connection
.DisposeMany()
.ObserveOn(RxApp.MainThreadScheduler)
.Bind(out _images)
.Subscribe()
.DisposeWith(d);
// Recaluclate image when quality changes
connection.WhenPropertyChanged(x => x.ManipulationState.Quality, false)
.Throttle(TimeSpan.FromMilliseconds(50))
.Select(x => x.Sender)
.InvokeCommand(_calculatePreview)
.DisposeWith(d);
// Notify about successful export.
ExportSelected
.Do(name => this.Notify().PublishInfo($"Image export to {name}", "Export completed!", TimeSpan.FromSeconds(3)))
.Subscribe()
.DisposeWith(d);
// Notify about successful export.
ExportAll
.Do(path => this.Notify().PublishInfo($"All images exported to {path}", "Export completed!", TimeSpan.FromSeconds(3)))
.Subscribe()
.DisposeWith(d);
// Add loaded images to source
LoadImage
.ObserveOn(RxApp.TaskpoolScheduler)
.Where(x => x != null)
.SelectMany(x => _calculatePreview.Execute(x))
.ObserveOn(RxApp.MainThreadScheduler)
.Subscribe(handle => _source.AddOrUpdate(handle))
.DisposeWith(d);
// Show image loading error
LoadImage.ThrownExceptions
.OfType <ImageLoadingException>()
.Subscribe(ex => this.Notify()
.PublishError($"Sorry. \"{ex.FilePath}\" does not have a supported file format.", "Error", TimeSpan.FromSeconds(5)))
.DisposeWith(d);
// Pipe loadings to property
Observable.CombineLatest(
LoadImage.IsExecuting,
ExportSelected.IsExecuting,
ExportAll.IsExecuting,
_calculatePreview.IsExecuting,
(a, b, c, d) => a || b || c || d)
.ObserveOn(RxApp.MainThreadScheduler)
.ToPropertyEx(this, x => x.IsLoading)
.DisposeWith(d);
// React on close requests from explorer view
this.WhenAnyObservable(x => x.ImageExplorer.DeletionRequests)
.ObserveOn(RxApp.MainThreadScheduler)
.Subscribe(x => _source.Remove(x))
.DisposeWith(d);
// Select explorer item
this.WhenAnyObservable(x => x.ImageExplorer.Selections)
.ObserveOn(RxApp.MainThreadScheduler)
.Subscribe(x => SelectedImage = x)
.DisposeWith(d);
});
}