/// <summary>
/// Create the new slides and load them up.
/// </summary>
/// <param name="n"></param>
/// <param name="pdfFile"></param>
/// <param name="fullVM"></param>
/// <returns></returns>
private async Task <SlideThumbViewModel[]> CreateNewThumbs(int n, PDFFile pdfFile, Lazy <FullTalkAsStripViewModel> fullVM)
{
var newSlides = Enumerable.Range(SlideThumbnails.Count, n - SlideThumbnails.Count).Select(i => new SlideThumbViewModel(pdfFile.GetPageStreamAndCacheInfo(i), fullVM, i)).ToArray();
foreach (var sld in newSlides)
{
await sld.LoadSize();
}
return(newSlides);
}
/// <summary>
/// Get everything setup to show the PDF document
/// </summary>
/// <param name="docSequence"></param>
/// <param name="initialPage">The page that should be shown when we start up. Zero indexed</param>
/// <param name="screen">The screen that hosts everything (routing!)</param>
public FullTalkAsStripViewModel(IScreen screen, PDFFile file)
{
Debug.Assert(file != null);
Debug.Assert(screen != null);
HostScreen = screen;
// We basically re-set each time a new file comes down from the top.
Pages = new ReactiveList <PDFPageViewModel>();
var pageSizeChanged = file.WhenAny(x => x.NumberOfPages, x => x.Value)
.DistinctUntilChanged()
.ObserveOn(RxApp.MainThreadScheduler);
var b = from newPageLength in pageSizeChanged
let np = Pages.Count
from allpages in CreateNPages(newPageLength - np, np, file)
select new {
numPages = newPageLength,
freshPages = allpages
};
b
.ObserveOn(RxApp.MainThreadScheduler)
.Subscribe(info => SetNPages(info.numPages, info.freshPages));
// Page navigation. Make sure things are clean and we don't over-burden the UI before
// we pass the info back to the UI!
_moveToPage = new ReplaySubject <int>(1);
_loaded = new ReplaySubject <Unit>(1);
MoveToPage = _moveToPage
.CombineLatest(_loaded, (p, _) => p)
.Select(scrubPageIndex)
.DistinctUntilChanged();
PageForward = ReactiveCommand.Create();
PageForward
.Cast <int>()
.Select(pn => pn + 1)
.Subscribe(_moveToPage);
PageBack = ReactiveCommand.Create();
PageBack
.Cast <int>()
.Select(pn => pn - 1)
.Subscribe(_moveToPage);
PageMove = ReactiveCommand.Create();
PageMove
.Cast <int>()
.Subscribe(_moveToPage);
}
/// <summary>
/// Create n pages, as requested, and prepare them for the UI.
/// </summary>
/// <param name="n"></param>
/// <param name="file"></param>
/// <returns></returns>
private async Task <PDFPageViewModel[]> CreateNPages(int n, int start_index, PDFFile file)
{
if (n <= 0)
{
return(new PDFPageViewModel[0]);
}
// Create and initialize pages
var newPages = Enumerable.Range(start_index, n).Select(i => new PDFPageViewModel(file.GetPageStreamAndCacheInfo(i))).ToArray();
var sequenceOfPages = newPages.Select(p => p.LoadSize());
foreach (var seq in sequenceOfPages)
{
var r = await seq.ToArray();
}
return(newPages);
}
/// <summary>
/// Setup the VM for the file.
/// </summary>
/// <param name="downloader">The download controller. This assumes this is for a PDF file, and it is Valid.</param>
/// <param name="talkTime">The time that this guy is relevant</param>
public FileSlideListViewModel(PDFFile pdfFile, TimePeriod talkTime)
{
// Get the object consistent.
SlideThumbnails = new ReactiveList <SlideThumbViewModel>();
// We will want to refresh the view of this file depending on how close we are to the actual
// meeting time.
var innerBuffer = new TimePeriod(talkTime);
innerBuffer.StartTime -= TimeSpan.FromMinutes(30);
innerBuffer.EndTime += TimeSpan.FromHours(2);
var updateTalkFile = Observable.Empty <Unit>();
if (innerBuffer.Contains(DateTime.Now))
{
// Fire every 15 minutes, but only while in the proper time.
// We only check when requested, so we will start right off the bat.
updateTalkFile = Observable.Return(default(Unit))
.Concat(Observable.Interval(TimeSpan.FromMinutes(15))
.Where(_ => innerBuffer.Contains(DateTime.Now))
.Select(_ => default(Unit))
)
.Where(_ => Settings.AutoDownloadNewMeeting);
}
// A view model to show the whole thing as a strip view.
var fullVM = new Lazy <FullTalkAsStripViewModel>(() => new FullTalkAsStripViewModel(Locator.Current.GetService <IScreen>(), pdfFile));
// All we do is sit and watch for the # of pages to change, and when it does, we fix up the list of SlideThumbViewModel.
var newSlideInfo = from nPages in pdfFile.WhenAny(x => x.NumberOfPages, x => x.Value).DistinctUntilChanged()
from newSlides in CreateNewThumbs(nPages, pdfFile, fullVM)
select new
{
n = nPages,
slides = newSlides
};
newSlideInfo
.ObserveOn(RxApp.MainThreadScheduler)
.Subscribe(info => SetNumberOfThumbNails(info.n, info.slides));
}
/// <summary>
/// Setup the links to run.
/// </summary>
public ExpandingSlideThumbViewModel(PDFFile downloader, TimePeriod talkTime)
{
// Showing the slides should generate it here, and nullify it everywhere else.
ShowSlides = ReactiveCommand.Create();
// FIre the reset command, with the current downloader as an argument
ShowSlides
.Select(_ => downloader)
.InvokeCommand(_resetSlideShow);
// When the reset shows up, only pay attention if a different file is being shown
// and we have something to show!
var noThumbs = _resetSlideShow
.Where(dl => downloader != dl && downloader.NumberOfPages != 0)
.Select(_ => (FileSlideListViewModel)null);
// When we want to show the slides just create the new view model.
var newThumbs = ShowSlides
.Select(_ => new FileSlideListViewModel(downloader, talkTime));
// Now, allow the property we manage to flip back and forth here.
Observable.Merge(newThumbs, noThumbs)
.WriteLine(x => string.Format("--> writing out a {0} to the actual display property.", x == null ? "null" : "non-null"))
.ToProperty(this, x => x.TalkAsThumbs, out _talkAsThumbs, null, RxApp.MainThreadScheduler);
// The logic for canShowThumbs is tricky:
// 1. True if the downloader has downloaded and opened the file and parsed it successfully (# pages != 0).
// 2. False if we have fired off a new thumbs guy, but that can be only active if can show thumbs is true (right??).
// 3. True if we've shown thumbs and we stop showing them.
var downloaded = downloader.WhenAny(x => x.NumberOfPages, x => x.Value != 0);
var areShowing = Observable.Merge(newThumbs, noThumbs)
.Select(x => x == null ? true : false);
Observable.Merge(downloaded, areShowing)
.WriteLine(x => string.Format(" -> and writing out {0} for can show thumbs", x))
.ToProperty(this, x => x.CanShowThumbs, out _canShowThumbs, false, RxApp.MainThreadScheduler);
// Track the # of pages. Used to display some info below the button in most implementations.
downloader.WhenAny(x => x.NumberOfPages, x => x.Value)
.ToProperty(this, x => x.NumberOfSlides, out _numberOfSlides, 0, RxApp.MainThreadScheduler);
}
/// <summary>
/// Configure for showing multiple files.
/// </summary>
/// <param name="files"></param>
public TalkFileCollectionUserControlViewModel(IFile[] files, ITalk t)
{
// The title we use is what we grab from the first file.
Title = files.Length > 0 ? files[0].DisplayName : "";
// Show the list of files that can downloaded/opened. These guys can opened by other
// apps in the system by clicking or pressing on them.
var allFilesVM = (from f in files
select new
{
FilePointer = f,
UserControl = new FileUserControlViewModel(f)
})
.ToArray();
TalkFiles = new ReactiveList <FileUserControlViewModel>();
TalkFiles.AddRange(allFilesVM.Select(f => f.UserControl));
#if WINDOWS_APP
// If there is a PDF file, then we use that to show a "hero" slide.
// TODO: WARNING - this will create a PDFFile, but one may not want that here
// if one is also going to create other PDF file guys!!
var pdf = allFilesVM.Where(f => f.FilePointer.FileType == "pdf" && f.FilePointer.IsValid).FirstOrDefault();
if (pdf != null)
{
var pdfFile = new PDFFile(pdf.UserControl.FileDownloader);
var fullVM = new Lazy <FullTalkAsStripViewModel>(() => new FullTalkAsStripViewModel(Locator.Current.GetService <IScreen>(), pdfFile));
HeroSlide = new FirstSlideHeroViewModel(pdfFile, fullVM);
var timeSpan = new TimePeriod(t.StartTime, t.EndTime);
Thumbs = new ExpandingSlideThumbViewModel(pdfFile, timeSpan);
}
else
{
HeroSlide = new FirstSlideHeroViewModel((PDFFile)null, null);
}
#endif
}
/// <summary>
/// Create the VM. We generate a first page hero slide.
/// </summary>
/// <param name="file">The PDF File to generate. If null, we will make this VM as invalid</param>
public FirstSlideHeroViewModel(PDFFile file, Lazy <FullTalkAsStripViewModel> fullVM)
{
// If we are actually connected to a file, then
// - setup the hero slide
// - a button to show all slides
_heroPageUC = null;
HaveHeroSlide = false;
if (file != null)
{
// Hero slide. Tricky because we can't display until
// a fetch has been done on the PDF data.
var pdf = new PDFPageViewModel(file.GetPageStreamAndCacheInfo(0));
_heroPageUC = pdf.LoadSize()
.Select(_ => pdf)
.ToProperty(this, m => m.HeroPageUC, scheduler: RxApp.MainThreadScheduler);
HaveHeroSlide = true;
// Allow a full view
OpenFullView = ReactiveCommand.Create();
OpenFullView
.Subscribe(_ => fullVM.Value.LoadPage(0));
}
}
