Scrolling with mouse Win 8.1 Metro Hub Navigation - windows-8

Question

I am trying to find a solution to allow a Hub to pan with the mouse when its reaches the left or right boundary. I have implemented the code below which i have gleaned from various sources.
` private void theHubPointerMoved(object sender, PointerRoutedEventArgs e)
{ Windows.UI.Xaml.Input.Pointer ptr = e.Pointer;
if (ptr.PointerDeviceType == Windows.Devices.Input.PointerDeviceType.Mouse)
{
Windows.UI.Input.PointerPoint ptrPt = e.GetCurrentPoint(null);
if (ptrPt.Position.X < this.ActualWidth - 20)
if (ptrPt.Position.X > 20)
{
//Do the SCROLLING HERE
var xcord = Math.Round(ptrPt.Position.X, 2);
var ycord = Math.Round(ptrPt.Position.Y, 2);
}
}
e.Handled = true;
}`
So it is relativley easy to see when the mouse is at the screen edge. I thought it would be easy to simply use the MyHub.ScrollViewer.ScrollToHorizontalOffset(xcord); but the Hub Scrollviewer doesnt expose this ScrollToHorizontalOffset function.
Can anyone assist?
Thanks.

Answer 1

Oh, it's exposed. If you can handle digging for it. Here's how:
http://xaml.codeplex.com/SourceControl/latest#Blog/201401-ScrollHub/MainPage.xaml.cs
In the example below, it is scrolling to a specific hub section. But you should be able to easily adapt it to your specific needs, I hope.
private void ScollHubToSection(Hub hub, HubSection section)
{
var visual = section.TransformToVisual(this.MyHub);
var point = visual.TransformPoint(new Point(0, 0));
var viewer = Helpers.FindChild<ScrollViewer>(hub, "ScrollViewer");
viewer.ChangeView(point.X, null, null);
}
Using this:
public class Helpers
{
public static T FindChild<T>(DependencyObject parent, string childName) where T : DependencyObject
{
if (parent == null) return null;
T foundChild = null;
int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
for (int i = 0; i < childrenCount; i++)
{
var child = VisualTreeHelper.GetChild(parent, i);
T childType = child as T;
if (childType == null)
{
foundChild = FindChild<T>(child, childName);
if (foundChild != null) break;
}
else if (!string.IsNullOrEmpty(childName))
{
var frameworkElement = child as FrameworkElement;
if (frameworkElement != null && frameworkElement.Name == childName)
{
foundChild = (T)child;
break;
}
}
else
{
foundChild = (T)child;
break;
}
}
return foundChild;
}
}
Best of luck!