private bool TrySet(GalleryContentView element, GalleryContent content)
{
if (object.Equals(element.Item, content))
{
return(false);
}
element.UpdateItem(this, content);
return(true);
}
private void PrepareNext(int direction, bool initialize = false)
{
var viewModel = ViewModel;
if (viewModel == null)
{
return;
}
GalleryContentView previous = null;
GalleryContentView target = null;
GalleryContentView next = null;
if (Grid.GetColumn(Element1) == direction + 1)
{
previous = Element0;
target = Element1;
next = Element2;
}
else if (Grid.GetColumn(Element0) == direction + 1)
{
previous = Element2;
target = Element0;
next = Element1;
}
else if (Grid.GetColumn(Element2) == direction + 1)
{
previous = Element1;
target = Element2;
next = Element0;
}
Grid.SetColumn(target, 1);
Grid.SetColumn(previous, 0);
Grid.SetColumn(next, 2);
var index = viewModel.SelectedIndex;
if (index < 0 || viewModel.Items.IsEmpty())
{
return;
}
var set = TrySet(target, viewModel.Items[index]);
TrySet(previous, index > 0 ? viewModel.Items[index - 1] : null);
TrySet(next, index < viewModel.Items.Count - 1 ? viewModel.Items[index + 1] : null);
if (initialize)
{
TrySet(Preview, viewModel.Items[index]);
}
if (UIViewSettings.GetForCurrentView().UserInteractionMode == UserInteractionMode.Mouse)
{
Transport.PreviousVisibility = index > 0 ? Visibility.Visible : Visibility.Collapsed;
Transport.NextVisibility = index < viewModel.Items.Count - 1 ? Visibility.Visible : Visibility.Collapsed;
}
else
{
Transport.PreviousVisibility = Visibility.Collapsed;
Transport.NextVisibility = Visibility.Collapsed;
}
#if GALLERY_EXPERIMENTAL
LayoutRoot.ColumnDefinitions[0].Width = new GridLength(0, index > 0 ? GridUnitType.Auto : GridUnitType.Pixel);
LayoutRoot.ColumnDefinitions[2].Width = new GridLength(0, index < viewModel.Items.Count - 1 ? GridUnitType.Auto : GridUnitType.Pixel);
#endif
if (set)
{
Dispose();
viewModel.OpenMessage(viewModel.Items[index]);
}
}
