private static IEnumerable <Change> GetAppChanges(ValueChange <AppToken> diff)
{
var ids = new ChangeSet <AppId, AppToken, BookId, BookToken>(diff, diff.Select(app => app.Books));
var result = Enumerable.Empty <Change>();
if (diff.IsChanged(app => app.IsVisible))
{
var newValue = diff.NewValue.IsVisible;
result = result.Concat(Change.SetVisibility(diff.NewValue.Id, newValue));
if (!newValue)
{
return(result); //Don't look for other changes if the app just went invisible.
}
}
if (diff.IsChanged(app => app.IsActive))
{
result = result.Concat(Change.SetActive(diff.NewValue.Id, diff.NewValue.IsActive));
}
result = result.Concat(ids.RemovedChanges)
.Concat(ids.AddedChanges)
.Concat(ids.NestedChanges(GetBookChanges));
return(result);
}
private static IEnumerable <Change> GetSheetCollectionChanges(ValueChange <BookToken> diff)
{
var ids = new ChangeSet <BookId, BookToken, SheetId, SheetToken>(diff, diff.Select(book => book.Sheets));
return(ids.RemovedChanges
.Concat(ids.AddedChanges)
.Concat(ids.NestedChanges(GetSheetChanges)));
}
private static IEnumerable <Change> GetSessionChanges(ValueChange <SessionToken> diff)
{
var ids = new ChangeSet <SessionId, SessionToken, AppId, AppToken>(diff, diff.Select(session => session.Apps));
return(ids.RemovedChanges
.Concat(ids.AddedChanges)
.Concat(ids.NestedChanges(GetAppChanges)));
}