|
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
//
// Description: Defines CollectionViewSource object, the markup-accessible entry
// point to CollectionView.
//
// See spec at CollectionViewSource.mht
//
using System.Collections; // IEnumerable
using System.Collections.ObjectModel; // ObservableCollection<T>
using System.Collections.Specialized; // NotifyCollectionChanged*
using System.Globalization; // CultureInfo
using System.ComponentModel; // ICollectionView
using System.Windows.Markup; // XmlLanguage
using MS.Internal; // Invariant.Assert
using MS.Internal.Data; // DataBindEngine
namespace System.Windows.Data
{
/// <summary>
/// Describes a collection view.
/// </summary>
public class CollectionViewSource : DependencyObject, ISupportInitialize, IWeakEventListener
{
#region Constructors
//
// Constructors
//
/// <summary>
/// Initializes a new instance of the CollectionViewSource class.
/// </summary>
public CollectionViewSource()
{
_sort = new SortDescriptionCollection();
((INotifyCollectionChanged)_sort).CollectionChanged += new NotifyCollectionChangedEventHandler(OnForwardedCollectionChanged);
_groupBy = new ObservableCollection<GroupDescription>();
((INotifyCollectionChanged)_groupBy).CollectionChanged += new NotifyCollectionChangedEventHandler(OnForwardedCollectionChanged);
}
#endregion Constructors
#region Public Properties
//
// Public Properties
//
/// <summary>
/// The key needed to define a read-only property.
/// </summary>
private static readonly DependencyPropertyKey ViewPropertyKey
= DependencyProperty.RegisterReadOnly(
"View",
typeof(ICollectionView),
typeof(CollectionViewSource),
new FrameworkPropertyMetadata((ICollectionView)null));
/// <summary>
/// The DependencyProperty for the View property.
/// Flags: None
/// Other: Read-Only
/// Default Value: null
/// </summary>
public static readonly DependencyProperty ViewProperty
= ViewPropertyKey.DependencyProperty;
/// <summary>
/// Returns the ICollectionView currently affiliated with this CollectionViewSource.
/// </summary>
[ReadOnly(true)]
public ICollectionView View
{
get
{
return GetOriginalView(CollectionView);
}
}
/// <summary>
/// The DependencyProperty for the Source property.
/// Flags: none
/// Default Value: null
/// </summary>
public static readonly DependencyProperty SourceProperty
= DependencyProperty.Register(
"Source",
typeof(object),
typeof(CollectionViewSource),
new FrameworkPropertyMetadata(
(object)null,
new PropertyChangedCallback(OnSourceChanged)),
new ValidateValueCallback(IsSourceValid));
/// <summary>
/// Source is the underlying collection.
/// </summary>
public object Source
{
get { return (object) GetValue(SourceProperty); }
set { SetValue(SourceProperty, value); }
}
/// <summary>
/// Called when SourceProperty is invalidated on "d."
/// </summary>
/// <param name="d">The object on which the property was invalidated.</param>
/// <param name="e">Argument.</param>
private static void OnSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
CollectionViewSource ctrl = (CollectionViewSource) d;
ctrl.OnSourceChanged(e.OldValue, e.NewValue);
ctrl.EnsureView();
}
/// <summary>
/// This method is invoked when the Source property changes.
/// </summary>
/// <param name="oldSource">The old value of the Source property.</param>
/// <param name="newSource">The new value of the Source property.</param>
protected virtual void OnSourceChanged(object oldSource, object newSource)
{
}
private static bool IsSourceValid(object o)
{
return (o == null ||
o is IEnumerable ||
o is IListSource ||
o is DataSourceProvider) &&
!(o is ICollectionView);
}
private static bool IsValidSourceForView(object o)
{
return ( o is IEnumerable ||
o is IListSource);
}
/// <summary>
/// The DependencyProperty for the CollectionViewType property.
/// Flags: none
/// Default Value: null
/// </summary>
public static readonly DependencyProperty CollectionViewTypeProperty
= DependencyProperty.Register(
"CollectionViewType",
typeof(Type),
typeof(CollectionViewSource),
new FrameworkPropertyMetadata(
(Type)null,
new PropertyChangedCallback(OnCollectionViewTypeChanged)),
new ValidateValueCallback(IsCollectionViewTypeValid));
/// <summary>
/// CollectionViewType is the desired type of the View.
/// </summary>
/// <remarks>
/// This property may only be set during initialization.
/// </remarks>
public Type CollectionViewType
{
get { return (Type) GetValue(CollectionViewTypeProperty); }
set { SetValue(CollectionViewTypeProperty, value); }
}
private static void OnCollectionViewTypeChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
CollectionViewSource ctrl = (CollectionViewSource) d;
Type oldCollectionViewType = (Type) e.OldValue;
Type newCollectionViewType = (Type) e.NewValue;
if (!ctrl._isInitializing)
throw new InvalidOperationException(SR.CollectionViewTypeIsInitOnly);
ctrl.OnCollectionViewTypeChanged(oldCollectionViewType, newCollectionViewType);
ctrl.EnsureView();
}
/// <summary>
/// This method is invoked when the CollectionViewType property changes.
/// </summary>
/// <param name="oldCollectionViewType">The old value of the CollectionViewType property.</param>
/// <param name="newCollectionViewType">The new value of the CollectionViewType property.</param>
protected virtual void OnCollectionViewTypeChanged(Type oldCollectionViewType, Type newCollectionViewType)
{
}
private static bool IsCollectionViewTypeValid(object o)
{
Type type = (Type)o;
return type == null ||
typeof(ICollectionView).IsAssignableFrom(type);
}
/// <summary>
/// CultureInfo used for sorting, comparisons, etc.
/// This property is forwarded to any collection view created from this source.
/// </summary>
[TypeConverter(typeof(System.Windows.CultureInfoIetfLanguageTagConverter))]
public CultureInfo Culture
{
get { return _culture; }
set { _culture = value; OnForwardedPropertyChanged(); }
}
/// <summary>
/// Collection of SortDescriptions, describing sorting.
/// This property is forwarded to any collection view created from this source.
/// </summary>
public SortDescriptionCollection SortDescriptions
{
get { return _sort; }
}
/// <summary>
/// Collection of GroupDescriptions, describing grouping.
/// This property is forwarded to any collection view created from this source.
/// </summary>
public ObservableCollection<GroupDescription> GroupDescriptions
{
get { return _groupBy; }
}
/// <summary>
/// The key needed to define a read-only property.
/// </summary>
private static readonly DependencyPropertyKey CanChangeLiveSortingPropertyKey
= DependencyProperty.RegisterReadOnly(
"CanChangeLiveSorting",
typeof(bool),
typeof(CollectionViewSource),
new FrameworkPropertyMetadata((bool)false));
/// <summary>
/// The DependencyProperty for the CanChangeLiveSorting property.
/// Flags: None
/// Other: Read-Only
/// Default Value: false
/// </summary>
public static readonly DependencyProperty CanChangeLiveSortingProperty
= CanChangeLiveSortingPropertyKey.DependencyProperty;
///<summary>
/// Gets a value that indicates whether the underlying view allows
/// turning live sorting on or off.
///</summary>
[ReadOnly(true)]
public bool CanChangeLiveSorting
{
get { return (bool)GetValue(CanChangeLiveSortingProperty); }
private set { SetValue(CanChangeLiveSortingPropertyKey, value); }
}
/// <summary>
/// The DependencyProperty for the IsLiveSortingRequested property.
/// Flags: None
/// Default Value: false
/// </summary>
public static readonly DependencyProperty IsLiveSortingRequestedProperty
= DependencyProperty.Register(
"IsLiveSortingRequested",
typeof(bool),
typeof(CollectionViewSource),
new FrameworkPropertyMetadata((bool)false,
new PropertyChangedCallback(OnIsLiveSortingRequestedChanged)));
///<summary>
/// Gets or sets a value that the CollectionViewSource will use to
/// set the IsLiveSorting property of its views, when possible.
///</summary>
///<notes>
/// When the underlying view implements ICollectionViewLiveShaping and
/// its CanChangeLiveSortingProperty is true, this property is used to
/// set the view's IsLiveSorting property.
///</notes>
public bool IsLiveSortingRequested
{
get { return (bool)GetValue(IsLiveSortingRequestedProperty); }
set { SetValue(IsLiveSortingRequestedProperty, value); }
}
private static void OnIsLiveSortingRequestedChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
CollectionViewSource cvs = (CollectionViewSource)d;
cvs.OnForwardedPropertyChanged();
}
/// <summary>
/// The key needed to define a read-only property.
/// </summary>
private static readonly DependencyPropertyKey IsLiveSortingPropertyKey
= DependencyProperty.RegisterReadOnly(
"IsLiveSorting",
typeof(bool?),
typeof(CollectionViewSource),
new FrameworkPropertyMetadata((bool?)null));
/// <summary>
/// The DependencyProperty for the IsLiveSorting property.
/// Flags: None
/// Other: Read-Only
/// Default Value: null
/// </summary>
public static readonly DependencyProperty IsLiveSortingProperty
= IsLiveSortingPropertyKey.DependencyProperty;
///<summary>
/// Gets a value that indicates whether live sorting is enabled for the
/// underlying view.
///</summary>
///<notes>
/// The value is null if the view does not implement ICollectionViewLiveShaping,
/// or if it cannot tell whether it is live-sorting.
///</notes>
[ReadOnly(true)]
public bool? IsLiveSorting
{
get { return (bool?)GetValue(IsLiveSortingProperty); }
private set { SetValue(IsLiveSortingPropertyKey, value); }
}
///<summary>
/// Gets a collection of strings describing the properties that
/// trigger a live-sorting recalculation.
/// The strings use the same format as SortDescription.PropertyName.
///</summary>
///<notes>
/// When the underlying view implements ICollectionViewLiveShaping,
/// this collection is used to set the underlying view's LiveSortingProperties.
/// When this collection is empty, the view will use the PropertyName strings
/// from its SortDescriptions.
///</notes>
public ObservableCollection<string> LiveSortingProperties
{
get
{
if (_liveSortingProperties == null)
{
_liveSortingProperties = new ObservableCollection<string>();
((INotifyCollectionChanged)_liveSortingProperties).CollectionChanged += new NotifyCollectionChangedEventHandler(OnForwardedCollectionChanged);
}
return _liveSortingProperties;
}
}
/// <summary>
/// The key needed to define a read-only property.
/// </summary>
private static readonly DependencyPropertyKey CanChangeLiveFilteringPropertyKey
= DependencyProperty.RegisterReadOnly(
"CanChangeLiveFiltering",
typeof(bool),
typeof(CollectionViewSource),
new FrameworkPropertyMetadata((bool)false));
/// <summary>
/// The DependencyProperty for the CanChangeLiveFiltering property.
/// Flags: None
/// Other: Read-Only
/// Default Value: false
/// </summary>
public static readonly DependencyProperty CanChangeLiveFilteringProperty
= CanChangeLiveFilteringPropertyKey.DependencyProperty;
///<summary>
/// Gets a value that indicates whether the underlying view allows
/// turning live Filtering on or off.
///</summary>
[ReadOnly(true)]
public bool CanChangeLiveFiltering
{
get { return (bool)GetValue(CanChangeLiveFilteringProperty); }
private set { SetValue(CanChangeLiveFilteringPropertyKey, value); }
}
/// <summary>
/// The DependencyProperty for the IsLiveFilteringRequested property.
/// Flags: None
/// Default Value: false
/// </summary>
public static readonly DependencyProperty IsLiveFilteringRequestedProperty
= DependencyProperty.Register(
"IsLiveFilteringRequested",
typeof(bool),
typeof(CollectionViewSource),
new FrameworkPropertyMetadata((bool)false,
new PropertyChangedCallback(OnIsLiveFilteringRequestedChanged)));
///<summary>
/// Gets or sets a value that the CollectionViewSource will use to
/// set the IsLiveFiltering property of its views, when possible.
///</summary>
///<notes>
/// When the underlying view implements ICollectionViewLiveShaping and
/// its CanChangeLiveFilteringProperty is true, this property is used to
/// set the view's IsLiveFiltering property.
///</notes>
public bool IsLiveFilteringRequested
{
get { return (bool)GetValue(IsLiveFilteringRequestedProperty); }
set { SetValue(IsLiveFilteringRequestedProperty, value); }
}
private static void OnIsLiveFilteringRequestedChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
CollectionViewSource cvs = (CollectionViewSource)d;
cvs.OnForwardedPropertyChanged();
}
/// <summary>
/// The key needed to define a read-only property.
/// </summary>
private static readonly DependencyPropertyKey IsLiveFilteringPropertyKey
= DependencyProperty.RegisterReadOnly(
"IsLiveFiltering",
typeof(bool?),
typeof(CollectionViewSource),
new FrameworkPropertyMetadata((bool?)null));
/// <summary>
/// The DependencyProperty for the IsLiveFiltering property.
/// Flags: None
/// Other: Read-Only
/// Default Value: null
/// </summary>
public static readonly DependencyProperty IsLiveFilteringProperty
= IsLiveFilteringPropertyKey.DependencyProperty;
///<summary>
/// Gets a value that indicates whether live Filtering is enabled for the
/// underlying view.
///</summary>
///<notes>
/// The value is null if the view does not implement ICollectionViewLiveShaping,
/// or if it cannot tell whether it is live-Filtering.
///</notes>
[ReadOnly(true)]
public bool? IsLiveFiltering
{
get { return (bool?)GetValue(IsLiveFilteringProperty); }
private set { SetValue(IsLiveFilteringPropertyKey, value); }
}
///<summary>
/// Gets a collection of strings describing the properties that
/// trigger a live-filtering recalculation.
/// The strings use the same format as SortDescription.PropertyName.
///</summary>
///<notes>
/// When the underlying view implements ICollectionViewLiveShaping,
/// this collection is used to set the underlying view's LiveFilteringProperties.
///</notes>
public ObservableCollection<string> LiveFilteringProperties
{
get
{
if (_liveFilteringProperties == null)
{
_liveFilteringProperties = new ObservableCollection<string>();
((INotifyCollectionChanged)_liveFilteringProperties).CollectionChanged += new NotifyCollectionChangedEventHandler(OnForwardedCollectionChanged);
}
return _liveFilteringProperties;
}
}
/// <summary>
/// The key needed to define a read-only property.
/// </summary>
private static readonly DependencyPropertyKey CanChangeLiveGroupingPropertyKey
= DependencyProperty.RegisterReadOnly(
"CanChangeLiveGrouping",
typeof(bool),
typeof(CollectionViewSource),
new FrameworkPropertyMetadata((bool)false));
/// <summary>
/// The DependencyProperty for the CanChangeLiveGrouping property.
/// Flags: None
/// Other: Read-Only
/// Default Value: false
/// </summary>
public static readonly DependencyProperty CanChangeLiveGroupingProperty
= CanChangeLiveGroupingPropertyKey.DependencyProperty;
///<summary>
/// Gets a value that indicates whether the underlying view allows
/// turning live Grouping on or off.
///</summary>
[ReadOnly(true)]
public bool CanChangeLiveGrouping
{
get { return (bool)GetValue(CanChangeLiveGroupingProperty); }
private set { SetValue(CanChangeLiveGroupingPropertyKey, value); }
}
/// <summary>
/// The DependencyProperty for the IsLiveGroupingRequested property.
/// Flags: None
/// Default Value: false
/// </summary>
public static readonly DependencyProperty IsLiveGroupingRequestedProperty
= DependencyProperty.Register(
"IsLiveGroupingRequested",
typeof(bool),
typeof(CollectionViewSource),
new FrameworkPropertyMetadata((bool)false,
new PropertyChangedCallback(OnIsLiveGroupingRequestedChanged)));
///<summary>
/// Gets or sets a value that the CollectionViewSource will use to
/// set the IsLiveGrouping property of its views, when possible.
///</summary>
///<notes>
/// When the underlying view implements ICollectionViewLiveShaping and
/// its CanChangeLiveGroupingProperty is true, this property is used to
/// set the view's IsLiveGrouping property.
///</notes>
public bool IsLiveGroupingRequested
{
get { return (bool)GetValue(IsLiveGroupingRequestedProperty); }
set { SetValue(IsLiveGroupingRequestedProperty, value); }
}
private static void OnIsLiveGroupingRequestedChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
CollectionViewSource cvs = (CollectionViewSource)d;
cvs.OnForwardedPropertyChanged();
}
/// <summary>
/// The key needed to define a read-only property.
/// </summary>
private static readonly DependencyPropertyKey IsLiveGroupingPropertyKey
= DependencyProperty.RegisterReadOnly(
"IsLiveGrouping",
typeof(bool?),
typeof(CollectionViewSource),
new FrameworkPropertyMetadata((bool?)null));
/// <summary>
/// The DependencyProperty for the IsLiveGrouping property.
/// Flags: None
/// Other: Read-Only
/// Default Value: null
/// </summary>
public static readonly DependencyProperty IsLiveGroupingProperty
= IsLiveGroupingPropertyKey.DependencyProperty;
///<summary>
/// Gets a value that indicates whether live Grouping is enabled for the
/// underlying view.
///</summary>
///<notes>
/// The value is null if the view does not implement ICollectionViewLiveShaping,
/// or if it cannot tell whether it is live-Grouping.
///</notes>
[ReadOnly(true)]
public bool? IsLiveGrouping
{
get { return (bool?)GetValue(IsLiveGroupingProperty); }
private set { SetValue(IsLiveGroupingPropertyKey, value); }
}
///<summary>
/// Gets a collection of strings describing the properties that
/// trigger a live-grouping recalculation.
/// The strings use the same format as PropertyGroupDescription.PropertyName.
///</summary>
///<notes>
/// When the underlying view implements ICollectionViewLiveShaping,
/// this collection is used to set the underlying view's LiveGroupingProperties.
///</notes>
public ObservableCollection<string> LiveGroupingProperties
{
get
{
if (_liveGroupingProperties == null)
{
_liveGroupingProperties = new ObservableCollection<string>();
((INotifyCollectionChanged)_liveGroupingProperties).CollectionChanged += new NotifyCollectionChangedEventHandler(OnForwardedCollectionChanged);
}
return _liveGroupingProperties;
}
}
#endregion Public Properties
#region Public Events
/// <summary>
/// An event requesting a filter query.
/// </summary>
public event FilterEventHandler Filter
{
add
{
// Get existing event hanlders
FilterEventHandler handlers = FilterHandlersField.GetValue(this);
if (handlers != null)
{
// combine to a multicast delegate
handlers = (FilterEventHandler)Delegate.Combine(handlers, value);
}
else
{
handlers = value;
}
// Set the delegate as an uncommon field
FilterHandlersField.SetValue(this, handlers);
OnForwardedPropertyChanged();
}
remove
{
// Get existing event hanlders
FilterEventHandler handlers = FilterHandlersField.GetValue(this);
if (handlers != null)
{
// Remove the given handler
handlers = (FilterEventHandler)Delegate.Remove(handlers, value);
if (handlers == null)
{
// Clear the value for the uncommon field
// cause there are no more handlers
FilterHandlersField.ClearValue(this);
}
else
{
// Set the remaining handlers as an uncommon field
FilterHandlersField.SetValue(this, handlers);
}
}
OnForwardedPropertyChanged();
}
}
#endregion Public Events
#region Public Methods
//
// Public Methods
//
/// <summary>
/// Return the default view for the given source. This view is never
/// affiliated with any CollectionViewSource.
/// </summary>
public static ICollectionView GetDefaultView(object source)
{
return GetOriginalView(GetDefaultCollectionView(source, true));
}
// a version of the previous method that doesn't create the view (bug 108595)
private static ICollectionView LazyGetDefaultView(object source)
{
return GetOriginalView(GetDefaultCollectionView(source, false));
}
/// <summary>
/// Return true if the given view is the default view for its source.
/// </summary>
public static bool IsDefaultView(ICollectionView view)
{
if (view != null)
{
object source = view.SourceCollection;
return (GetOriginalView(view) == LazyGetDefaultView(source));
}
else
{
return true;
}
}
/// <summary>
/// Enter a Defer Cycle.
/// Defer cycles are used to coalesce changes to the ICollectionView.
/// </summary>
public IDisposable DeferRefresh()
{
return new DeferHelper(this);
}
#endregion Public Methods
//
// Interfaces
//
#region ISupportInitialize
/// <summary>Signals the object that initialization is starting.</summary>
void ISupportInitialize.BeginInit()
{
_isInitializing = true;
}
/// <summary>Signals the object that initialization is complete.</summary>
void ISupportInitialize.EndInit()
{
_isInitializing = false;
EnsureView();
}
#endregion ISupportInitialize
#region IWeakEventListener
/// <summary>
/// Handle events from the centralized event table
/// </summary>
bool IWeakEventListener.ReceiveWeakEvent(Type managerType, object sender, EventArgs e)
{
return ReceiveWeakEvent(managerType, sender, e);
}
/// <summary>
/// Handle events from the centralized event table
/// </summary>
protected virtual bool ReceiveWeakEvent(Type managerType, object sender, EventArgs e)
{
return false; // this method is no longer used (but must remain, for compat)
}
#endregion IWeakEventListener
#region Internal Properties
//
// Internal Properties
//
// Returns the CollectionView currently affiliate with this CollectionViewSource.
// This may be a CollectionViewProxy over the original view.
internal CollectionView CollectionView
{
get
{
ICollectionView view = (ICollectionView)GetValue(ViewProperty);
if (view != null && !_isViewInitialized)
{
// leak prevention: re-fetch ViewRecord instead of keeping a reference to it,
// to be sure that we don't inadvertently keep it alive.
object source = Source;
DataSourceProvider dataProvider = source as DataSourceProvider;
// if the source is DataSourceProvider, use its Data instead
if (dataProvider != null)
{
source = dataProvider.Data;
}
if (source != null)
{
DataBindEngine engine = DataBindEngine.CurrentDataBindEngine;
ViewRecord viewRecord = engine.GetViewRecord(source, this, CollectionViewType, true, null);
if (viewRecord != null)
{
viewRecord.InitializeView();
_isViewInitialized = true;
}
}
}
return (CollectionView)view;
}
}
// Returns the property through which inheritance context was established
internal DependencyProperty PropertyForInheritanceContext
{
get { return _propertyForInheritanceContext; }
}
#endregion Internal Properties
#region Internal Methods
//
// Internal Methods
//
// Return the default view for the given source. This view is never
// affiliated with any CollectionViewSource. It may be a
// CollectionViewProxy over the original view
static internal CollectionView GetDefaultCollectionView(object source, bool createView, Func<object, object> GetSourceItem=null)
{
if (!IsValidSourceForView(source))
return null;
DataBindEngine engine = DataBindEngine.CurrentDataBindEngine;
ViewRecord viewRecord = engine.GetViewRecord(source, DefaultSource, null, createView, GetSourceItem);
return (viewRecord != null) ? (CollectionView)viewRecord.View : null;
}
/// <summary>
/// Return the default view for the given source. This view is never
/// affiliated with any CollectionViewSource. The internal version sets
/// the culture on the view from the xml:Lang of the host object.
/// </summary>
internal static CollectionView GetDefaultCollectionView(object source, DependencyObject d, Func<object, object> GetSourceItem=null)
{
CollectionView view = GetDefaultCollectionView(source, true, GetSourceItem);
// at first use of a view, set its culture from the xml:lang of the
// element that's using the view
if (view != null && view.Culture == null)
{
XmlLanguage language = (d != null) ? (XmlLanguage)d.GetValue(FrameworkElement.LanguageProperty) : null;
if (language != null)
{
try
{
view.Culture = language.GetSpecificCulture();
}
catch (InvalidOperationException)
{
}
}
}
return view;
}
// Define the DO's inheritance context
internal override DependencyObject InheritanceContext
{
get { return _inheritanceContext; }
}
// Receive a new inheritance context (this will be a FE/FCE)
internal override void AddInheritanceContext(DependencyObject context, DependencyProperty property)
{
// remember which property caused the context - BindingExpression wants to know
// (this must happen before calling AddInheritanceContext, so that the answer
// is ready during the InheritanceContextChanged event)
if (!_hasMultipleInheritanceContexts && _inheritanceContext == null)
{
_propertyForInheritanceContext = property;
}
else
{
_propertyForInheritanceContext = null;
}
InheritanceContextHelper.AddInheritanceContext(context,
this,
ref _hasMultipleInheritanceContexts,
ref _inheritanceContext );
}
// Remove an inheritance context (this will be a FE/FCE)
internal override void RemoveInheritanceContext(DependencyObject context, DependencyProperty property)
{
InheritanceContextHelper.RemoveInheritanceContext(context,
this,
ref _hasMultipleInheritanceContexts,
ref _inheritanceContext);
// after removing a context, we don't know which property caused it
_propertyForInheritanceContext = null;
}
// Says if the current instance has multiple InheritanceContexts
internal override bool HasMultipleInheritanceContexts
{
get { return _hasMultipleInheritanceContexts; }
}
// Replace this by the extensible version (see remark in
// OptimizedTemplateContent.ReadSharedRecord.
internal bool IsShareableInTemplate()
{
return false;
}
#endregion Internal Methods
#region Private Methods
//
// Private Methods
//
// Obtain the view affiliated with the current source. This may create
// a new view, or re-use an existing one.
void EnsureView()
{
EnsureView(Source, CollectionViewType);
}
void EnsureView(object source, Type collectionViewType)
{
if (_isInitializing || _deferLevel > 0)
return;
DataSourceProvider dataProvider = source as DataSourceProvider;
// listen for DataChanged events from an DataSourceProvider
if (dataProvider != _dataProvider)
{
if (_dataProvider != null)
{
DataChangedEventManager.RemoveHandler(_dataProvider, OnDataChanged);
}
_dataProvider = dataProvider;
if (_dataProvider != null)
{
DataChangedEventManager.AddHandler(_dataProvider, OnDataChanged);
_dataProvider.InitialLoad();
}
}
// if the source is DataSourceProvider, use its Data instead
if (dataProvider != null)
{
source = dataProvider.Data;
}
// get the view
ICollectionView view = null;
if (source != null)
{
DataBindEngine engine = DataBindEngine.CurrentDataBindEngine;
ViewRecord viewRecord = engine.GetViewRecord(source, this, collectionViewType, true,
(object x) =>
{
BindingExpressionBase beb = BindingOperations.GetBindingExpressionBase(this, SourceProperty);
return (beb != null) ? beb.GetSourceItem(x) : null;
});
if (viewRecord != null)
{
view = viewRecord.View;
_isViewInitialized = viewRecord.IsInitialized;
// bring view up to date with the CollectionViewSource
if (_version != viewRecord.Version)
{
ApplyPropertiesToView(view);
viewRecord.Version = _version;
}
}
}
// update the View property
SetValue(ViewPropertyKey, view);
}
// Forward properties from the CollectionViewSource to the CollectionView
void ApplyPropertiesToView(ICollectionView view)
{
if (view == null || _deferLevel > 0)
return;
ICollectionViewLiveShaping liveView = view as ICollectionViewLiveShaping;
using (view.DeferRefresh())
{
int i, n;
// Culture
if (Culture != null)
{
view.Culture = Culture;
}
// Sort
if (view.CanSort)
{
view.SortDescriptions.Clear();
for (i=0, n=SortDescriptions.Count; i < n; ++i)
{
view.SortDescriptions.Add(SortDescriptions[i]);
}
}
else if (SortDescriptions.Count > 0)
throw new InvalidOperationException(SR.Format(SR.CannotSortView, view));
// Filter
Predicate<object> filter;
if (FilterHandlersField.GetValue(this) != null)
{
filter = FilterWrapper;
}
else
{
filter = null;
}
if (view.CanFilter)
{
view.Filter = filter;
}
else if (filter != null)
throw new InvalidOperationException(SR.Format(SR.CannotFilterView, view));
// GroupBy
if (view.CanGroup)
{
view.GroupDescriptions.Clear();
for (i=0, n=GroupDescriptions.Count; i < n; ++i)
{
view.GroupDescriptions.Add(GroupDescriptions[i]);
}
}
else if (GroupDescriptions.Count > 0)
throw new InvalidOperationException(SR.Format(SR.CannotGroupView, view));
// Live shaping
if (liveView != null)
{
ObservableCollection<string> properties;
// sorting
if (liveView.CanChangeLiveSorting)
{
liveView.IsLiveSorting = IsLiveSortingRequested;
properties = liveView.LiveSortingProperties;
properties.Clear();
if (IsLiveSortingRequested)
{
foreach (string s in LiveSortingProperties)
{
properties.Add(s);
}
}
}
CanChangeLiveSorting = liveView.CanChangeLiveSorting;
IsLiveSorting = liveView.IsLiveSorting;
// filtering
if (liveView.CanChangeLiveFiltering)
{
liveView.IsLiveFiltering = IsLiveFilteringRequested;
properties = liveView.LiveFilteringProperties;
properties.Clear();
if (IsLiveFilteringRequested)
{
foreach (string s in LiveFilteringProperties)
{
properties.Add(s);
}
}
}
CanChangeLiveFiltering = liveView.CanChangeLiveFiltering;
IsLiveFiltering = liveView.IsLiveFiltering;
// grouping
if (liveView.CanChangeLiveGrouping)
{
liveView.IsLiveGrouping = IsLiveGroupingRequested;
properties = liveView.LiveGroupingProperties;
properties.Clear();
if (IsLiveGroupingRequested)
{
foreach (string s in LiveGroupingProperties)
{
properties.Add(s);
}
}
}
CanChangeLiveGrouping = liveView.CanChangeLiveGrouping;
IsLiveGrouping = liveView.IsLiveGrouping;
}
else
{
CanChangeLiveSorting = false;
IsLiveSorting = null;
CanChangeLiveFiltering = false;
IsLiveFiltering = null;
CanChangeLiveGrouping = false;
IsLiveGrouping = null;
}
}
}
// return the original (un-proxied) view for the given view
static ICollectionView GetOriginalView(ICollectionView view)
{
for ( CollectionViewProxy proxy = view as CollectionViewProxy;
proxy != null;
proxy = view as CollectionViewProxy)
{
view = proxy.ProxiedView;
}
return view;
}
Predicate<object> FilterWrapper
{
get
{
if (_filterStub == null)
{
_filterStub = new FilterStub(this);
}
return _filterStub.FilterWrapper;
}
}
bool WrapFilter(object item)
{
FilterEventArgs args = new FilterEventArgs(item);
FilterEventHandler handlers = FilterHandlersField.GetValue(this);
if (handlers != null)
{
handlers(this, args);
}
return args.Accepted;
}
void OnDataChanged(object sender, EventArgs e)
{
EnsureView();
}
// a change occurred in one of the collections that we forward to the view
void OnForwardedCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
OnForwardedPropertyChanged();
}
// a change occurred in one of the properties that we forward to the view
void OnForwardedPropertyChanged()
{
// increment the version number. This causes the change to get applied
// to dormant views when they become active.
unchecked {++ _version;}
// apply the change to the current view
ApplyPropertiesToView(View);
}
// defer changes
void BeginDefer()
{
++ _deferLevel;
}
void EndDefer()
{
if (--_deferLevel == 0)
{
EnsureView();
}
}
//
// This property
// 1. Finds the correct initial size for the _effectiveValues store on the current DependencyObject
// 2. This is a performance optimization
//
internal override int EffectiveValuesInitialSize
{
get { return 3; }
}
#endregion Private Methods
#region Private Types
//
// Private Types
//
private class DeferHelper : IDisposable
{
public DeferHelper(CollectionViewSource target)
{
_target = target;
_target.BeginDefer();
}
public void Dispose()
{
if (_target != null)
{
CollectionViewSource target = _target;
_target = null;
target.EndDefer();
}
GC.SuppressFinalize(this);
}
private CollectionViewSource _target;
}
// This class is used to break the reference chain from a collection
// view to a UI element (typically Window or Page), created when the
// app adds a handler (belonging to the Window or Page) to the Filter
// event. This class uses a weak reference to the CollectionViewSource
// to break the chain and avoid a leak (bug 123012)
private class FilterStub
{
public FilterStub(CollectionViewSource parent)
{
_parent = new WeakReference(parent);
_filterWrapper = new Predicate<object>(WrapFilter);
}
public Predicate<object> FilterWrapper
{
get { return _filterWrapper; }
}
bool WrapFilter(object item)
{
CollectionViewSource parent = (CollectionViewSource)_parent.Target;
if (parent != null)
{
return parent.WrapFilter(item);
}
else
{
return true;
}
}
WeakReference _parent;
Predicate<object> _filterWrapper;
}
#endregion Private Types
#region Private Data
//
// Private Data
//
// properties that get forwarded to the view
CultureInfo _culture;
SortDescriptionCollection _sort;
ObservableCollection<GroupDescription> _groupBy;
ObservableCollection<string> _liveSortingProperties;
ObservableCollection<string> _liveFilteringProperties;
ObservableCollection<string> _liveGroupingProperties;
// other state
bool _isInitializing;
bool _isViewInitialized; // view is initialized when it is first retrieved externally
int _version; // timestamp of last change to a forwarded property
int _deferLevel; // counts nested calls to BeginDefer
DataSourceProvider _dataProvider; // DataSourceProvider whose DataChanged event we want
FilterStub _filterStub; // used to support the Filter event
// Fields to implement DO's inheritance context
DependencyObject _inheritanceContext;
bool _hasMultipleInheritanceContexts;
DependencyProperty _propertyForInheritanceContext;
// the placeholder source for all default views
internal static readonly CollectionViewSource DefaultSource = new CollectionViewSource();
// This uncommon field is used to store the handlers for the Filter event
private static readonly UncommonField<FilterEventHandler> FilterHandlersField = new UncommonField<FilterEventHandler>();
#endregion Private Data
}
}
|