public static string GeneratePathString(DependencyObject element, string keyPrefix, string keySuffix)
{
// get a listing of the types from SketchFlow Player's model
List <string> screenTypeNames = (
from screen in PlayerContext.Instance.RuntimeData.Screens
select screen.ClassName)
.ToList();
// find the topmost SketchFlow screen
DependencyObject topmostScreen = (
from ancestor in DependencyObjectHelper.GetSelfAndVisualAncestors(element)
let typeName = ancestor.GetType().FullName
where screenTypeNames.Contains(typeName)
select ancestor)
.LastOrDefault();
if (topmostScreen == null)
{
return(null);
}
// get the visual ancestors up to but not including the topmost screen
List <DependencyObject> visualHierarchy = DependencyObjectHelper.GetSelfAndVisualAncestors(element)
.TakeWhile(visual => visual != topmostScreen)
.ToList();
// walk up to it, recording child indices at each level in the visual tree
IEnumerable <int> indices = (
from child in visualHierarchy
let parent = VisualTreeHelper.GetParent(child)
let siblings = DependencyObjectHelper.GetVisualChildren(parent).ToList()
let index = siblings.IndexOf(child)
select index)
.Reverse();
// create the path to the screen
string key = string.Format(PathFormatString, keyPrefix, topmostScreen.GetType().FullName);
foreach (int index in indices)
{
key = string.Format(PathFormatString, key, index);
}
// add the group name
key = string.Format(PathFormatString, key, keySuffix);
return(key);
}
private void SaveState(FrameworkElement element, DependencyProperty property, string propertyName)
{
if (HasBindingExpression(element, property))
{
return;
}
string key = DependencyObjectHelper.GeneratePathString(element, this.GetType().FullName, element.GetType().FullName + "/" + propertyName);
if (string.IsNullOrEmpty(key))
{
return;
}
dataStore[key] = element.GetValue(property);
}
private void PreserveState(Action <UserControl, VisualStateGroup, string> preserveStateAction)
{
UserControl screen = this.AssociatedObject;
FrameworkElement content = screen.Content as FrameworkElement;
IEnumerable <VisualStateGroup> groups = VisualStateManager.GetVisualStateGroups(content).OfType <VisualStateGroup>();
foreach (VisualStateGroup group in groups)
{
string key = DependencyObjectHelper.GeneratePathString(screen, this.GetType().FullName, group.Name);
if (string.IsNullOrEmpty(key))
{
continue;
}
preserveStateAction(screen, group, key);
}
}
private void PreserveStateVisitor(Action <FrameworkElement, DependencyProperty, string> preserveStateAction, DependencyObject parent)
{
FrameworkElement parentElement = parent as FrameworkElement;
if (parentElement != null)
{
foreach (PreservePropertyInfo target in propertiesToPreserve
.Where(target => target.Type.IsAssignableFrom(parent.GetType())))
{
preserveStateAction(parentElement, target.Property, target.PropertyName);
}
}
foreach (DependencyObject child in DependencyObjectHelper.GetVisualChildren(parent))
{
PreserveStateVisitor(preserveStateAction, child);
}
}
