class/System.Windows/System.Windows.Controls.Primitives/Selector.cs

   1 //
   2 // Selector.cs
   3 //
   4 // Contact:
   5 //   Moonlight List (moonlight-list@lists.ximian.com)
   6 //
   7 // Copyright 2008 Novell, Inc.
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 using System.Collections.Specialized;
  30 using System.Windows.Input;
  31
  32 namespace System.Windows.Controls.Primitives {
  33         public abstract class Selector : ItemsControl {
  34                 internal const string TemplateScrollViewerName = "ScrollViewer";
  35
  36                 internal static readonly DependencyProperty IsSelectionActiveProperty =
  37                         DependencyProperty.RegisterReadOnlyCore ("IsSelectionActive", typeof(bool), typeof(Selector), null);
  38
  39                 public static readonly DependencyProperty SelectedIndexProperty =
  40                         DependencyProperty.RegisterCore ("SelectedIndex", typeof(int), typeof(Selector),
  41                                                      new PropertyMetadata(-1, new PropertyChangedCallback(OnSelectedIndexChanged)));
  42
  43                 static void OnSelectedIndexChanged (DependencyObject o, DependencyPropertyChangedEventArgs e)
  44                 {
  45                         ((Selector) o).SelectedIndexChanged (o, e);
  46                 }
  47
  48                 // This is not a core property because it is a non-parenting property
  49                 public static readonly DependencyProperty SelectedItemProperty =
  50                         DependencyProperty.Register ("SelectedItem", typeof(object), typeof(Selector),
  51                                                      new PropertyMetadata(new PropertyChangedCallback(OnSelectedItemChanged_cb)));
  52
  53
  54                 static void OnSelectedItemChanged_cb (DependencyObject o, DependencyPropertyChangedEventArgs e)
  55                 {
  56                         ((Selector) o).SelectedItemChanged (o, e);
  57                 }
  58
  59                 internal static void OnItemContainerStyleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
  60                 {
  61                         Selector s = (Selector) d;
  62                         Style style = (Style) e.NewValue;
  63
  64                         int count = s.Items.Count;
  65                         for (int i = 0; i < count; i++)
  66                         {
  67                                 ListBoxItem item = s.GetContainerItem (i);
  68                                 if (item != null)  // May be null if GetContainerForItemOverride has not been called yet
  69                                         item.Style = style;
  70                         }
  71                 }
  72
  73                 internal Selector ()
  74                 {
  75                         // Set default values for ScrollViewer attached properties
  76                         ScrollViewer.SetHorizontalScrollBarVisibility(this, ScrollBarVisibility.Auto);
  77                         ScrollViewer.SetVerticalScrollBarVisibility(this, ScrollBarVisibility.Auto);
  78                 }
  79
  80                 bool Changing {
  81                         get; set;
  82                 }
  83
  84                 internal bool IsSelectionActive {
  85                         get { return (bool) GetValue (IsSelectionActiveProperty); }
  86                         set { SetValueImpl (IsSelectionActiveProperty, value); }
  87                 }
  88
  89                 [Mono.Xaml.SetPropertyDelayed]
  90                 public int SelectedIndex {
  91                         get { return (int)GetValue(SelectedIndexProperty); }
  92                         set { SetValue (SelectedIndexProperty, value); }
  93                 }
  94
  95                 public object SelectedItem {
  96                         get { return GetValue (SelectedItemProperty); }
  97                         set { SetValue (SelectedItemProperty, value); }
  98                 }
  99
 100                 internal ScrollViewer TemplateScrollViewer {
 101                         get; private set;
 102                 }
 103
 104
 105                 public event SelectionChangedEventHandler SelectionChanged;
 106
 107                 void SelectedIndexChanged (DependencyObject o, DependencyPropertyChangedEventArgs e)
 108                 {
 109                         object oldItem = SelectedItem;
 110                         int newVal = (int) e.NewValue;
 111                         if (newVal == (int) e.OldValue || Changing) {
 112                                 SelectedIndex = newVal;
 113                                 return;
 114                         }
 115
 116                         Changing = true;
 117                         try {
 118                                 if (newVal < 0)
 119                                         ClearValue (SelectedItemProperty);
 120                                 else if (newVal < Items.Count)
 121                                         SelectedItem = Items [newVal];
 122                         } finally {
 123                                 Changing = false;
 124                         }
 125                         RaiseSelectionChanged (o, new SelectionChangedEventArgs (oldItem, SelectedItem));
 126                 }
 127
 128                 void SelectedItemChanged (DependencyObject o, DependencyPropertyChangedEventArgs e)
 129                 {
 130                         if (e.NewValue == e.OldValue || Changing) {
 131                                 SelectedItem = e.NewValue;
 132                                 return;
 133                         }
 134
 135                         Changing = true;
 136                         try {
 137                                 int index = e.NewValue == null ? -1 : Items.IndexOf (e.NewValue);
 138                                 if (index == -1 && e.NewValue != null) {
 139                                         SelectedIndex = e.OldValue == null ? -1 : Items.IndexOf (e.OldValue);
 140                                         if (e.OldValue == null)
 141                                                 ClearValue (SelectedItemProperty);
 142                                         else
 143                                                 SelectedItem = e.OldValue;
 144                                 }
 145                                 else {
 146                                         SelectedItem = e.NewValue;
 147                                         SelectedIndex = index;
 148                                         RaiseSelectionChanged (o, new SelectionChangedEventArgs (e.OldValue, e.NewValue));
 149                                 }
 150                         } finally {
 151                                 Changing = false;
 152                         }
 153                 }
 154
 155                 void OnSelectedItemChanged (object oldValue, object newValue)
 156                 {
 157                         if (oldValue != null) {
 158                                 ListBoxItem oldItem;
 159                                 if (oldValue is ListBoxItem && IsItemItsOwnContainerOverride (oldValue))
 160                                         oldItem = (ListBoxItem) oldValue;
 161                                 else
 162                                         oldItem = GetContainerItem (Items.IndexOf (oldValue));
 163
 164                                 if (oldItem != null)
 165                                         oldItem.IsSelected = false;
 166                         }
 167
 168                         if (newValue != null) {
 169                                 ListBoxItem newItem;
 170                                 if (newValue is ListBoxItem && IsItemItsOwnContainerOverride (newValue))
 171                                         newItem = (ListBoxItem) newValue;
 172                                 else
 173                                         newItem = GetContainerItem (Items.IndexOf (newValue));
 174
 175                                 if (newItem != null) {
 176                                         newItem.IsSelected = true;
 177                                         newItem.Focus ();
 178                                 }
 179                         }
 180                 }
 181
 182                 void RaiseSelectionChanged (object o, SelectionChangedEventArgs e)
 183                 {
 184                         object oldVal = e.RemovedItems.Count == 1 ? e.RemovedItems [0] : null;
 185                         object newVal = e.AddedItems.Count == 1 ? e.AddedItems [0] : null;
 186                         OnSelectedItemChanged (oldVal, newVal);
 187
 188                         SelectionChangedEventHandler h = SelectionChanged;
 189                         if (h != null)
 190                                 h (o, e);
 191                 }
 192
 193                 public static bool GetIsSelectionActive (DependencyObject element)
 194                 {
 195                         if (element == null)
 196                                 throw new ArgumentNullException ("element");
 197
 198                         return (bool) element.GetValue (ListBox.IsSelectionActiveProperty);
 199                 }
 200
 201                 protected override void ClearContainerForItemOverride (DependencyObject element, object item)
 202                 {
 203                         base.ClearContainerForItemOverride (element, item);
 204                         ListBoxItem lbItem = (ListBoxItem) element;
 205                         lbItem.Content = null;
 206                         lbItem.IsSelected = false;
 207                         lbItem.ParentSelector = null;
 208                         if (SelectedItem == item && GetContainerItem (SelectedIndex) != null)
 209                                 SelectedItem = null;
 210                 }
 211
 212                 protected override void PrepareContainerForItemOverride (DependencyObject element, object item)
 213                 {
 214                         base.PrepareContainerForItemOverride (element, item);
 215                         ListBoxItem listBoxItem = (ListBoxItem) element;
 216                         listBoxItem.ParentSelector = this;
 217                         listBoxItem.Item = item;
 218                         if (listBoxItem.IsSelected && GetContainerItem (SelectedIndex) != null)
 219                                 SelectedItem = item;
 220                 }
 221
 222                 public override void OnApplyTemplate ()
 223                 {
 224                         base.OnApplyTemplate ();
 225                         TemplateScrollViewer = GetTemplateChild("ScrollViewer") as ScrollViewer;
 226
 227                         if (TemplateScrollViewer != null)
 228                         {
 229                                 TemplateScrollViewer.TemplatedParentHandlesScrolling = true;
 230                                 // Update ScrollViewer values
 231                                 TemplateScrollViewer.HorizontalScrollBarVisibility = ScrollViewer.GetHorizontalScrollBarVisibility(this);
 232                                 TemplateScrollViewer.VerticalScrollBarVisibility = ScrollViewer.GetVerticalScrollBarVisibility(this);
 233                         }
 234                 }
 235
 236                 protected override void OnItemsChanged (System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
 237                 {
 238                         switch (e.Action) {
 239                         case NotifyCollectionChangedAction.Add:
 240                                 ListBoxItem item = e.NewItems [0] as ListBoxItem;
 241                                 if (item != null && item.IsSelected) {
 242                                         SelectedItem = item;
 243                                 } else {
 244                                         // Ensure we don't fire a SelectionChanged event when we're just updating the index
 245                                         Changing = true;
 246                                         if (e.NewStartingIndex <= SelectedIndex)
 247                                                 SelectedIndex ++;
 248                                         Changing = false;
 249                                 }
 250                                 break;
 251                         case NotifyCollectionChangedAction.Reset:
 252                                 SelectedIndex = -1;
 253                                 break;
 254
 255                         case NotifyCollectionChangedAction.Remove:
 256                         case NotifyCollectionChangedAction.Replace:
 257                         default:
 258                                 // Yes this is broken, SelectedItem and SelectedIndex do get out of sync with reality.
 259                                 break;
 260                         }
 261                         base.OnItemsChanged (e);
 262                 }
 263
 264                 internal virtual void NotifyListItemClicked(ListBoxItem listBoxItem)
 265                 {
 266                         if (ModifierKeys.Control == (Keyboard.Modifiers & ModifierKeys.Control)) {
 267                                 if (SelectedItem == listBoxItem.Item)
 268                                         SelectedItem = null;
 269                         } else {
 270                                 SelectedItem = listBoxItem.Item;
 271                         }
 272                 }
 273
 274                 internal virtual void NotifyListItemLoaded (ListBoxItem listBoxItem)
 275                 {
 276                         if (listBoxItem.Item == SelectedItem) {
 277                                 listBoxItem.IsSelected = true;
 278                                 listBoxItem.Focus ();
 279                         }
 280                 }
 281
 282                 internal virtual void NotifyListItemGotFocus(ListBoxItem listBoxItemNewFocus)
 283                 {
 284
 285                 }
 286
 287                 internal virtual void NotifyListItemLostFocus(ListBoxItem listBoxItemOldFocus)
 288                 {
 289
 290                 }
 291         }
 292 }