internal static bool TryGetState(IList <VisualStateGroup> groups, string stateName, out VisualStateGroup group, out VisualState state)
{
for (int groupIndex = 0; groupIndex < groups.Count; ++groupIndex)
{
VisualStateGroup g = groups[groupIndex];
VisualState s = g.GetState(stateName);
if (s != null)
{
group = g;
state = s;
return(true);
}
}
group = null;
state = null;
return(false);
}
/// <summary>
/// Get the most appropriate transition between two states.
/// </summary>
/// <param name="element">Element being transitioned.</param>
/// <param name="group">Group being transitioned.</param>
/// <param name="from">VisualState being transitioned from.</param>
/// <param name="to">VisualState being transitioned to.</param>
/// <returns>
/// The most appropriate transition between the desired states.
/// </returns>
internal static VisualTransition GetTransition(FrameworkElement element, VisualStateGroup group, VisualState from, VisualState to)
{
if (element == null)
{
throw new ArgumentNullException("element");
}
if (group == null)
{
throw new ArgumentNullException("group");
}
if (to == null)
{
throw new ArgumentNullException("to");
}
VisualTransition best = null;
VisualTransition defaultTransition = null;
int bestScore = -1;
IList <VisualTransition> transitions = (IList <VisualTransition>)group.Transitions;
if (transitions != null)
{
foreach (VisualTransition transition in transitions)
{
if (defaultTransition == null && transition.IsDefault)
{
defaultTransition = transition;
continue;
}
int score = -1;
VisualState transitionFromState = group.GetState(transition.From);
VisualState transitionToState = group.GetState(transition.To);
if (from == transitionFromState)
{
score += 1;
}
else if (transitionFromState != null)
{
continue;
}
if (to == transitionToState)
{
score += 2;
}
else if (transitionToState != null)
{
continue;
}
if (score > bestScore)
{
bestScore = score;
best = transition;
}
}
}
return(best ?? defaultTransition);
}