public SlideShow(InstallerVM appState)
{
Installer = appState;
// Wire target slideshow index
var intervalSeconds = 10;
// Compile all the sources that trigger a slideshow update, any of which trigger a counter update
var selectedIndex = Observable.Merge(
// If user requests one manually
SlideShowNextItemCommand.StartingExecution(),
// If the natural timer fires
Observable.Merge(
// Start with an initial timer
Observable.Return(Observable.Interval(TimeSpan.FromSeconds(intervalSeconds))),
// but reset timer if user requests one
SlideShowNextItemCommand.StartingExecution()
.Select(_ => Observable.Interval(TimeSpan.FromSeconds(intervalSeconds))))
// When a new timer comes in, swap to it
.Switch()
.Unit())
// When filter switch enabled, fire an initial signal
.StartWith(Unit.Default)
// Only subscribe to slideshow triggers if enabled and installing
.FlowSwitch(
Observable.CombineLatest(
this.WhenAny(x => x.Enable),
this.WhenAny(x => x.Installer.Installing),
resultSelector: (enabled, installing) => enabled && installing))
// Block spam
.Debounce(TimeSpan.FromMilliseconds(250), RxApp.MainThreadScheduler)
.Scan(
seed: 0,
accumulator: (i, _) => i + 1)
.Publish()
.RefCount();
// Dynamic list changeset of mod VMs to display
var modVMs = this.WhenAny(x => x.Installer.ModList)
// Whenever modlist changes, grab the list of its slides
.Select(modList =>
{
if (modList?.SourceModList?.Archives == null)
{
return(Observable.Empty <NexusDownloader.State>()
.ToObservableChangeSet(x => x.ModID));
}
return(modList.SourceModList.Archives
.Select(m => m.State)
.OfType <NexusDownloader.State>()
// Shuffle it
.Shuffle(_random)
.AsObservableChangeSet(x => x.ModID));
})
// Switch to the new list after every ModList change
.Switch()
.Transform(nexus => new ModVM(nexus))
.DisposeMany()
// Filter out any NSFW slides if we don't want them
.AutoRefreshOnObservable(slide => this.WhenAny(x => x.ShowNSFW))
.Filter(slide => !slide.IsNSFW || ShowNSFW)
.RefCount();
// Find target mod to display by combining dynamic list with currently desired index
_targetMod = Observable.CombineLatest(
modVMs.QueryWhenChanged(),
selectedIndex,
resultSelector: (query, selected) =>
{
var index = selected % (query.Count == 0 ? 1 : query.Count);
return(query.Items.ElementAtOrDefault(index));
})
.StartWith(default(ModVM))
.ToGuiProperty(this, nameof(TargetMod));
// Mark interest and materialize image of target mod
_image = this.WhenAny(x => x.TargetMod)
// We want to Switch here, not SelectMany, as we want to hotswap to newest target without waiting on old ones
.Select(x => x?.ImageObservable ?? Observable.Return(default(BitmapImage)))
.Switch()
.ToGuiProperty(this, nameof(Image));
VisitNexusSiteCommand = ReactiveCommand.Create(
execute: () =>
{
Process.Start(TargetMod.ModURL);
return(Unit.Default);
},
canExecute: this.WhenAny(x => x.TargetMod.ModURL)
.Select(x => x?.StartsWith("https://") ?? false)
.ObserveOnGuiThread());
// Preload upcoming images
var list = Observable.CombineLatest(
modVMs.QueryWhenChanged(),
selectedIndex,
resultSelector: (query, selected) =>
{
// Retrieve the mods that should be preloaded
var index = selected % (query.Count == 0 ? 1 : query.Count);
var amountToTake = Math.Min(query.Count - index, PreloadAmount);
return(query.Items.Skip(index).Take(amountToTake).ToObservable());
})
.Select(i => i.ToObservableChangeSet())
.Switch()
.Transform(mod => mod.ImageObservable.Subscribe())
.DisposeMany()
.AsObservableList();
}
public SlideShow(InstallerVM appState)
{
Installer = appState;
// Wire target slideshow index
var intervalSeconds = 10;
// Compile all the sources that trigger a slideshow update, any of which trigger a counter update
var selectedIndex = Observable.Merge(
// If user requests one manually
SlideShowNextItemCommand.StartingExecution(),
// If the natural timer fires
Observable.Merge(
// Start with an initial timer
Observable.Return(Observable.Interval(TimeSpan.FromSeconds(intervalSeconds))),
// but reset timer if user requests one
SlideShowNextItemCommand.StartingExecution()
.Select(_ => Observable.Interval(TimeSpan.FromSeconds(intervalSeconds))))
// When a new timer comes in, swap to it
.Switch()
.Unit())
// When filter switch enabled, fire an initial signal
.StartWith(Unit.Default)
// Only subscribe to slideshow triggers if enabled and installing
.FilterSwitch(
Observable.CombineLatest(
this.WhenAny(x => x.Enable),
this.WhenAny(x => x.Installer.Installing),
resultSelector: (enabled, installing) => enabled && installing))
// Block spam
.Debounce(TimeSpan.FromMilliseconds(250))
.Scan(
seed: 0,
accumulator: (i, _) => i + 1)
.Publish()
.RefCount();
// Dynamic list changeset of mod VMs to display
var modVMs = this.WhenAny(x => x.Installer.ModList)
// Whenever modlist changes, grab the list of its slides
.Select(modList =>
{
if (modList?.SourceModList?.Archives == null)
{
return(Observable.Empty <ModVM>()
.ToObservableChangeSet(x => x.ModID));
}
return(modList.SourceModList.Archives
.Select(m => m.State)
.OfType <NexusDownloader.State>()
.Select(nexus => new ModVM(nexus))
// Shuffle it
.Shuffle(_random)
.AsObservableChangeSet(x => x.ModID));
})
// Switch to the new list after every modlist change
.Switch()
// Filter out any NSFW slides if we don't want them
.AutoRefreshOnObservable(slide => this.WhenAny(x => x.ShowNSFW))
.Filter(slide => !slide.IsNSFW || ShowNSFW)
.RefCount();
// Find target mod to display by combining dynamic list with currently desired index
_targetMod = Observable.CombineLatest(
modVMs.QueryWhenChanged(),
selectedIndex,
resultSelector: (query, selected) => query.Items.ElementAtOrDefault(selected % (query.Count == 0 ? 1 : query.Count)))
.StartWith(default(ModVM))
.ObserveOn(RxApp.MainThreadScheduler)
.ToProperty(this, nameof(TargetMod));
// Mark interest and materialize image of target mod
_image = this.WhenAny(x => x.TargetMod)
// We want to Switch here, not SelectMany, as we want to hotswap to newest target without waiting on old ones
.Select(x => x?.ImageObservable ?? Observable.Return(default(BitmapImage)))
.Switch()
.ToProperty(this, nameof(Image));
VisitNexusSiteCommand = ReactiveCommand.Create(
execute: () => Process.Start(TargetMod.ModURL),
canExecute: this.WhenAny(x => x.TargetMod.ModURL)
.Select(x => x?.StartsWith("https://") ?? false)
.ObserveOnGuiThread());
// ToDo
// Can maybe add "preload" systems to prep upcoming images
// This would entail subscribing to modVMs, narrowing it down to Top(X) or Page() somehow.
// The result would not be used anywhere, just simply expressing interest in those mods'
// images will implicitly cache them
//
// Page would be really clever to use, but it's not exactly right as its "window" won't follow the current index,
// so at the boundary of a page, the next image won't be cached. Need like a Page() /w an offset parameter, or something.
}