private static bool GoToStateInternal(Control control, FrameworkElement stateGroupsRoot, VisualStateGroup group, VisualState state, bool useTransitions)
{
if (stateGroupsRoot == null)
{
throw new ArgumentNullException("stateGroupsRoot");
}
if (state == null)
{
throw new ArgumentNullException("state");
}
if (group == null)
{
throw new InvalidOperationException();
}
try
{
VisualState lastState = group.CurrentState;
if (lastState == state)
{
return(true);
}
// todo: see if this should be possible or if there should be a default State.
if (lastState != null)
{
lastState.StopStoryBoard(control);
}
// Note: when a property is set for the first time through a Storyboard, we need
// to replace the value with a copy so that the other elements with the same Style
// are not affected (example: PointerOver on one button must not change the
// Background of another with the same Style)
// we apply the new state
Dictionary <Tuple <string, string>, Timeline> newPropertiesChanged = state.ApplyStoryboard(control, useTransitions);
// we remove the former state if any
if (lastState != null)
{
// if the former VisualState changed properties that are not set in the new
// VisualState, we remove the value it put on it.
var formerPropertiesChanged = lastState.GetPropertiesChangedByStoryboard();
if (formerPropertiesChanged != null)
{
foreach (Tuple <string, string> formerProp in formerPropertiesChanged.Keys)
{
if (newPropertiesChanged == null || !newPropertiesChanged.ContainsKey(formerProp))
{
formerPropertiesChanged[formerProp].UnApply(control);
}
}
lastState.Storyboard.IsUnApplied = true;
}
}
// remember the current state
group.CurrentState = state;
// Fire both CurrentStateChanging and CurrentStateChanged events
group.RaiseCurrentStateChanging(stateGroupsRoot, lastState, state, control);
group.RaiseCurrentStateChanged(stateGroupsRoot, lastState, state, control);
return(true);
}
catch
{
return(false);
}
}
/// <summary>
/// Transitions the control between two states.
/// </summary>
/// <param name="control">The control to transition between states.</param>
/// <param name="stateName">The state to transition to.</param>
/// <param name="useTransitions">
/// True to use a VisualTransition to transition between states; otherwise,
/// false.
/// </param>
/// <returns>
/// True if the control successfully transitioned to the new state; otherwise,
/// false.
/// </returns>
public static bool GoToState(Control control, string stateName, bool useTransitions)
{
try
{
VisualState state = control.INTERNAL_GetVisualStateGroups().GetVisualState(stateName);
if (state != null)
{
VisualState formerState = state.INTERNAL_Group.CurrentState;
if (formerState != null) //todo: see if this should be possible or if there should be a default State.
{
formerState.StopStoryBoard(control);
}
if (state != formerState)
{
//Note: when a property is set for the first time through a Storyboard, we need to replace the value with a copy so that the other elements with the same Style are not affected (example: PointerOver on one button must not change the Background of another with the same Style)
//we apply the new state:
Dictionary <Tuple <string, string>, Timeline> newPropertiesChanged = state.ApplyStoryboard(control, useTransitions);//, _propertiesSetAtLeastOnce);
////we add the properties that have been changed to the list of the properties already set:
//foreach (Tuple<string, string> propertyChanged in newPropertiesChanged.Keys)
//{
// if (!_propertiesSetAtLeastOnce.Contains(propertyChanged))
// {
// _propertiesSetAtLeastOnce.Add(propertyChanged);
// }
//}
//we remove the former state if any:
if (formerState != null)
{
//if the former VisualState changed properties that are not set in the new VisualState, we remove the value it put on it.
var formerPropertiesChanged = formerState.GetPropertiesChangedByStoryboard();
if (formerPropertiesChanged != null)
{
foreach (Tuple <string, string> formerProp in formerPropertiesChanged.Keys)
{
if (newPropertiesChanged == null || !newPropertiesChanged.ContainsKey(formerProp))
{
formerPropertiesChanged[formerProp].UnApply(control);
}
}
formerState.Storyboard.isUnApplied = true;
}
}
//remember the current state:
state.INTERNAL_Group.CurrentState = state;
}
return(true);
}
else
{
return(false);
}
}
catch
{
return(false);
}
}