class/WPF.Toolkit/VSM/System/Windows/VisualStateGroup.cs

   1 // -------------------------------------------------------------------
   2 // Copyright (c) Microsoft Corporation. All Rights Reserved.
   3 // -------------------------------------------------------------------
   4
   5 using System;
   6 using System.Collections;
   7 using System.Collections.Generic;
   8 using System.Collections.ObjectModel;
   9 using System.Windows;
  10 using System.Windows.Controls;
  11 using System.Windows.Markup;
  12 using System.Windows.Media.Animation;
  13
  14 using Mono;
  15
  16 namespace System.Windows
  17 {
  18     /// <summary>
  19     ///     A group of mutually exclusive visual states.
  20     /// </summary>
  21     [ContentProperty("States")]
  22     public class VisualStateGroup : DependencyObject
  23     {
  24         /// <summary>
  25         ///     The Name of the VisualStateGroup.
  26         /// </summary>
  27         public string Name
  28         {
  29             get { return _name; }
  30             internal set { _name = value; }
  31         }
  32
  33         /// <summary>
  34         ///     VisualStates in the group.
  35         /// </summary>
  36         public IList States
  37         {
  38             get
  39             {
  40                 if (_states == null)
  41                 {
  42                     _states = new Collection<VisualState>();
  43                 }
  44
  45                 return _states;
  46             }
  47         }
  48
  49         /// <summary>
  50         ///     Transitions between VisualStates in the group.
  51         /// </summary>
  52         public IList Transitions
  53         {
  54             get
  55             {
  56                 if (_transitions == null)
  57                 {
  58                     _transitions = new Collection<VisualTransition>();
  59                 }
  60
  61                 return _transitions;
  62             }
  63         }
  64
  65         /// <summary>
  66         ///     VisualState that is currently applied.
  67         /// </summary>
  68         internal VisualState CurrentState
  69         {
  70             get; set;
  71         }
  72
  73         internal VisualState GetState(string stateName)
  74         {
  75             for (int stateIndex = 0; stateIndex < States.Count; ++stateIndex)
  76             {
  77                 VisualState state = (VisualState)States[stateIndex];
  78                 if (state.Name == stateName)
  79                 {
  80                     return state;
  81                 }
  82             }
  83
  84             return null;
  85         }
  86
  87         internal Collection<Storyboard> CurrentStoryboards
  88         {
  89             get
  90             {
  91                 if (_currentStoryboards == null)
  92                 {
  93                     _currentStoryboards = new Collection<Storyboard>();
  94                 }
  95
  96                 return _currentStoryboards;
  97             }
  98         }
  99
 100         internal void StartNewThenStopOld(FrameworkElement element, params Storyboard[] newStoryboards)
 101         {
 102             // Start the new Storyboards
 103             for (int index = 0; index < newStoryboards.Length; ++index)
 104             {
 105                 if (newStoryboards[index] == null)
 106                 {
 107                     continue;
 108                 }
 109
 110                 element.Resources.Add (newStoryboards [index].native.ToString (), newStoryboards[index]);
 111                 try {
 112                     newStoryboards[index].Begin();
 113                 } catch {
 114                     // If an exception is thrown calling begin, clear all the SBs out of the tree before propagating
 115                     for (int i = 0; i <= index; i++)
 116                         if (newStoryboards [i] != null)
 117                         element.Resources.Remove (newStoryboards [i].native.ToString ());
 118
 119                     throw;
 120                 }
 121                 // Silverlight had an issue where initially, a checked CheckBox would not show the check mark
 122                 // until the second frame. They chose to do a Seek(0) at this point, which this line
 123                 // is supposed to mimic. It does not seem to be equivalent, though, and WPF ends up
 124                 // with some odd animation behavior. I haven't seen the CheckBox issue on WPF, so
 125                 // commenting this out for now.
 126                 // newStoryboards[index].SeekAlignedToLastTick(element, TimeSpan.Zero, TimeSeekOrigin.BeginTime);
 127             }
 128
 129             // Stop the old Storyboards
 130             for (int index = 0; index < CurrentStoryboards.Count; ++index)
 131             {
 132                 if (CurrentStoryboards[index] == null)
 133                 {
 134                     continue;
 135                 }
 136
 137                 element.Resources.Remove (CurrentStoryboards [index].native.ToString ());
 138                 CurrentStoryboards[index].Stop();
 139             }
 140
 141             // Hold on to the running Storyboards
 142             CurrentStoryboards.Clear();
 143             for (int index = 0; index < newStoryboards.Length; ++index)
 144             {
 145                 CurrentStoryboards.Add(newStoryboards[index]);
 146             }
 147         }
 148
 149                 internal void RaiseCurrentStateChanging(FrameworkElement element, VisualState oldState, VisualState newState, Control control)
 150                 {
 151                         RaiseCurrentStateChanging (new VisualStateChangedEventArgs(oldState, newState, control));
 152                 }
 153
 154                 internal void RaiseCurrentStateChanged(FrameworkElement element, VisualState oldState, VisualState newState, Control control)
 155                 {
 156                         RaiseCurrentStateChanged(new VisualStateChangedEventArgs(oldState, newState, control));
 157                 }
 158
 159                 internal void RaiseCurrentStateChanging (VisualStateChangedEventArgs e)
 160                 {
 161                         EventHandler<VisualStateChangedEventArgs> h = (EventHandler<VisualStateChangedEventArgs>) EventList [CurrentStateChangingEvent];
 162                         if (h != null)
 163                                 h (this, e);
 164                 }
 165
 166                 internal void RaiseCurrentStateChanged (VisualStateChangedEventArgs e)
 167                 {
 168                         EventHandler<VisualStateChangedEventArgs> h = (EventHandler<VisualStateChangedEventArgs>) EventList [CurrentStateChangedEvent];
 169                         if (h != null)
 170                                 h (this, e);
 171                 }
 172
 173                 static object CurrentStateChangingEvent = new object ();
 174                 static object CurrentStateChangedEvent = new object ();
 175
 176         /// <summary>
 177         ///     Raised when transition begins
 178         /// </summary>
 179                 public event EventHandler<VisualStateChangedEventArgs> CurrentStateChanging {
 180                         add {
 181                                 RegisterEvent (CurrentStateChangingEvent, "CurrentStateChanging", Events.current_state_changing, value);
 182                         }
 183                         remove {
 184                                 UnregisterEvent (CurrentStateChangingEvent, "CurrentStateChanging", Events.current_state_changing, value);
 185                         }
 186                 }
 187
 188         /// <summary>
 189         ///     Raised when transition ends and new state storyboard begins.
 190         /// </summary>
 191                 public event EventHandler<VisualStateChangedEventArgs> CurrentStateChanged {
 192                         add {
 193                                 RegisterEvent (CurrentStateChangedEvent, "CurrentStateChanged", Events.current_state_changed, value);
 194                         }
 195                         remove {
 196                                 UnregisterEvent (CurrentStateChangedEvent, "CurrentStateChanged", Events.current_state_changed, value);
 197                         }
 198                 }
 199
 200
 201         private Collection<Storyboard> _currentStoryboards;
 202         private Collection<VisualState> _states;
 203         private Collection<VisualTransition> _transitions;
 204         private string _name = String.Empty;
 205     }
 206 }