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// -------------------------------------------------------------------
// Copyright (c) Microsoft Corporation. All Rights Reserved.
// -------------------------------------------------------------------
using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Markup;
using System.Windows.Media.Animation;
namespace System.Windows
{
/// <summary>
/// A group of mutually exclusive visual states.
/// </summary>
[ContentProperty("States")]
[RuntimeNameProperty("Name")]
public class VisualStateGroup : DependencyObject
{
/// <summary>
/// The Name of the VisualStateGroup.
/// </summary>
public string Name
{
get;
set;
}
/// <summary>
/// VisualStates in the group.
/// </summary>
public IList States
{
get
{
if (_states == null)
{
_states = new FreezableCollection<VisualState>();
}
return _states;
}
}
/// <summary>
/// Transitions between VisualStates in the group.
/// </summary>
public IList Transitions
{
get
{
if (_transitions == null)
{
_transitions = new FreezableCollection<VisualTransition>();
}
return _transitions;
}
}
/// <summary>
/// VisualState that is currently applied.
/// </summary>
public VisualState CurrentState
{
get;
internal set;
}
internal VisualState GetState(string stateName)
{
for (int stateIndex = 0; stateIndex < States.Count; ++stateIndex)
{
VisualState state = (VisualState)States[stateIndex];
if (state.Name == stateName)
{
return state;
}
}
return null;
}
internal Collection<Storyboard> CurrentStoryboards
{
get
{
if (_currentStoryboards == null)
{
_currentStoryboards = new Collection<Storyboard>();
}
return _currentStoryboards;
}
}
internal void StartNewThenStopOld(FrameworkElement element, params Storyboard[] newStoryboards)
{
// Remove the old Storyboards. Remove is delayed until the next TimeManager tick, so the
// handoff to the new storyboard is unaffected.
for (int index = 0; index < CurrentStoryboards.Count; ++index)
{
if (CurrentStoryboards[index] == null)
{
continue;
}
CurrentStoryboards[index].Remove(element);
}
CurrentStoryboards.Clear();
// Start the new Storyboards
for (int index = 0; index < newStoryboards.Length; ++index)
{
if (newStoryboards[index] == null)
{
continue;
}
newStoryboards[index].Begin(element, HandoffBehavior.SnapshotAndReplace, true);
// Hold on to the running Storyboards
CurrentStoryboards.Add(newStoryboards[index]);
// Silverlight had an issue where initially, a checked CheckBox would not show the check mark
// until the second frame. They chose to do a Seek(0) at this point, which this line
// is supposed to mimic. It does not seem to be equivalent, though, and WPF ends up
// with some odd animation behavior. I haven't seen the CheckBox issue on WPF, so
// commenting this out for now.
// newStoryboards[index].SeekAlignedToLastTick(element, TimeSpan.Zero, TimeSeekOrigin.BeginTime);
}
}
internal void RaiseCurrentStateChanging(FrameworkElement stateGroupsRoot, VisualState oldState, VisualState newState, FrameworkElement control)
{
if (CurrentStateChanging != null)
{
CurrentStateChanging(stateGroupsRoot, new VisualStateChangedEventArgs(oldState, newState, control, stateGroupsRoot));
}
}
internal void RaiseCurrentStateChanged(FrameworkElement stateGroupsRoot, VisualState oldState, VisualState newState, FrameworkElement control)
{
if (CurrentStateChanged != null)
{
CurrentStateChanged(stateGroupsRoot, new VisualStateChangedEventArgs(oldState, newState, control, stateGroupsRoot));
}
}
/// <summary>
/// Raised when transition begins
/// </summary>
public event EventHandler<VisualStateChangedEventArgs> CurrentStateChanged;
/// <summary>
/// Raised when transition ends and new state storyboard begins.
/// </summary>
public event EventHandler<VisualStateChangedEventArgs> CurrentStateChanging;
private Collection<Storyboard> _currentStoryboards;
private FreezableCollection<VisualState> _states;
private FreezableCollection<VisualTransition> _transitions;
}
}
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