internal override ObservableCollection<object> QuerySubCollectionViewGroupList( GroupDescription subGroupBy, int nextLevel, bool nextLevelIsBottom )
{
DataGridVirtualizingCollectionView collectionView = this.GetCollectionView() as DataGridVirtualizingCollectionView;
Debug.Assert( collectionView != null );
List<GroupNameCountPair> subGroupInfos = collectionView.OnQueryGroups( this );
int subGroupCount = subGroupInfos.Count;
// Create the collection of sub CollectionViewGroups
ObservableCollection<object> subCollectionViewGroupList = new ObservableCollection<object>();
int runningCount = this.StartGlobalIndex;
for( int i = 0; i < subGroupCount; i++ )
{
object subGroupName = subGroupInfos[ i ].Name;
int subGroupItemCount = subGroupInfos[ i ].ItemCount;
subCollectionViewGroupList.Add(
new DataGridVirtualizingCollectionViewGroup( subGroupName, subGroupItemCount, runningCount, this, nextLevel, nextLevelIsBottom ) );
runningCount += subGroupItemCount;
}
return subCollectionViewGroupList;
}
internal QueryGroupsEventArgs(
DataGridVirtualizingCollectionView collectionView,
DataGridVirtualizingCollectionViewGroup parentGroup,
GroupDescription childGroupDescription )
{
m_dataGridVirtualizingCollectionView = collectionView;
m_readonlyGroupPath = parentGroup.GroupPath.AsReadOnly();
m_childGroupDescription = childGroupDescription;
this.ChildGroupPropertyName = DataGridCollectionViewBase.GetPropertyNameFromGroupDescription( childGroupDescription );
m_sortDirection = SortDirection.None;
SortDescriptionCollection sortDescriptions = m_dataGridVirtualizingCollectionView.SortDescriptions;
int sortDescriptionCount = ( sortDescriptions == null ) ? 0 : sortDescriptions.Count;
for( int i = 0; i < sortDescriptions.Count ; i++ )
{
SortDescription sortDescription = sortDescriptions[ i ];
if( string.Equals( sortDescription.PropertyName, this.ChildGroupPropertyName ) )
{
m_sortDirection = ( sortDescription.Direction == ListSortDirection.Ascending ) ? SortDirection.Ascending : SortDirection.Descending;
break;
}
}
m_childGroupNameCountPairs = new List<GroupNameCountPair>();
}
internal GroupLevelDescription( GroupDescription groupDescription, string fieldName )
{
if( groupDescription == null )
throw new DataGridInternalException( "GroupDescription cannot be null." );
m_groupDescription = groupDescription;
m_fieldName = fieldName;
}
internal DataGridGroupInfo( GroupDescription groupDescription, CollectionViewGroup collectionViewGroup )
{
if( groupDescription == null )
throw new ArgumentNullException( "groupDescription" );
if( collectionViewGroup == null )
throw new ArgumentNullException( "collectionViewGroup" );
this.GroupDescription = groupDescription;
this.PropertyName = DataGridCollectionViewBase.GetPropertyNameFromGroupDescription( groupDescription );
this.Value = collectionViewGroup.Name;
}
internal static string GetPropertyNameFromGroupDescription( GroupDescription groupDescription )
{
PropertyGroupDescription propertyGroupDescription = groupDescription as PropertyGroupDescription;
if( propertyGroupDescription != null )
return propertyGroupDescription.PropertyName;
DataGridGroupDescription dataGridGroupDescription = groupDescription as DataGridGroupDescription;
if( dataGridGroupDescription != null )
return dataGridGroupDescription.PropertyName;
return null;
}
internal LateGroupLevelDescription( GroupDescription groupDescription, IEnumerable<GroupLevelDescription> groupLevelDescriptions )
{
if( groupDescription == null )
throw new ArgumentNullException( "groupDescription" );
var finder = new GroupLevelDescriptionFinder( groupDescription, groupLevelDescriptions );
m_groupDescription = groupDescription;
m_groupLevelDescription = finder.GroupLevelDescription;
if( m_groupLevelDescription == null )
{
m_finder = finder;
m_finder.PropertyChanged += new PropertyChangedEventHandler( this.OnGroupLevelDescriptionFound );
}
else
{
finder.Dispose();
PropertyChangedEventManager.AddListener( m_groupLevelDescription, this, string.Empty );
}
}
internal void SetSubGroupBy( GroupDescription groupBy )
{
bool oldIsBottomLevel = this.IsBottomLevel;
m_subGroupBy = groupBy;
if( m_subGroupBy != null )
{
if( m_groupsDictionary == null )
m_groupsDictionary = new Hashtable();
}
if( oldIsBottomLevel != this.IsBottomLevel )
this.OnPropertyChanged( new PropertyChangedEventArgs( "IsBottomLevel" ) );
}
public virtual GroupConfiguration SelectGroupConfiguration( int groupLevel, CollectionViewGroup collectionViewGroup, GroupDescription groupDescription )
{
return null;
}
/// <summary>
/// Determines whether the <paramref name="groupDescription"/> and <paramref name="groupDescriptor"/> are equivalent.
/// </summary>
/// <param name="groupDescription">The description to compare</param>
/// <param name="groupDescriptor">The descriptor to compare</param>
/// <returns><c>true</c> if the two are equivalent</returns>
private static bool AreEquivalent(GroupDescription groupDescription, GroupDescriptor groupDescriptor)
{
Debug.Assert((groupDescription != null) && (groupDescriptor != null), "Both should be non-null.");
PropertyGroupDescription propertyGroupDescription = groupDescription as PropertyGroupDescription;
if (propertyGroupDescription == null)
{
return false;
}
return (propertyGroupDescription.PropertyName == groupDescriptor.PropertyPath);
}
private void UpdateGrouping( GroupDescription groupDescription )
{
GroupDescriptions.Clear ();
if ( groupDescription != null )
{
GroupDescriptions.Add ( groupDescription );
}
if ( View != null )
{
View.Refresh ();
}
}
private static bool TryFind( IEnumerable<GroupLevelDescription> collection, GroupDescription description, out GroupLevelDescription result )
{
if( ( collection == null ) || ( description == null ) )
{
result = null;
}
else
{
result = collection.Where( item => ( item.GroupDescription == description ) ).FirstOrDefault();
}
return ( result != null );
}
/// <summary>
/// Synchronizes the group descriptors collection to the group descriptions collection.
/// </summary>
/// <param name="description">The description that changed</param>
/// <param name="e">The property change event</param>
private void HandleGroupDescriptionChanged(GroupDescription description, PropertyChangedEventArgs e)
{
this._ignoreChanges = true;
try
{
// We have to reset when the collections were not equal before the change
if (this._sourceCollection.Count != this._descriptionCollection.Count)
{
GroupCollectionManager.ResetToGroupDescriptions(this._descriptionCollection, this._sourceCollection);
}
else
{
int index = this._descriptionCollection.IndexOf(description);
this._sourceCollection[index] = GroupCollectionManager.GetDescriptorFromDescription(description);
}
}
finally
{
this._ignoreChanges = false;
}
}
/// <summary>
/// Initializes the group descriptions
/// </summary>
internal void Initialize()
{
if (topLevelGroupDescription == null)
{
topLevelGroupDescription = new TopLevelGroupDescription();
}
this.InitializeGroup(this, 0, null);
}
internal override ObservableCollection<object> QuerySubCollectionViewGroupList( GroupDescription childGroupBy, int nextLevel, bool nextLevelIsBottom )
{
string childGroupByPropertyName = DataGridCollectionViewBase.GetPropertyNameFromGroupDescription( childGroupBy );
if( String.IsNullOrEmpty( childGroupByPropertyName ) )
throw new NotSupportedException( "Custom groups are not supported when using a DataGridVirtualizingQueryableCollectionView." );
DataGridVirtualizingCollectionViewBase collectionView = this.GetCollectionView();
bool sortGroupBy = false;
ListSortDirection groupByDirection = ListSortDirection.Ascending;
foreach( SortDescription sortDescription in collectionView.SortDescriptions )
{
if( sortDescription.PropertyName == childGroupByPropertyName )
{
sortGroupBy = true;
groupByDirection = sortDescription.Direction;
break;
}
}
IQueryable groupsAndCountsQueryable = this.Queryable.GetSubGroupsAndCountsQueryable( childGroupByPropertyName, sortGroupBy, groupByDirection );
List<QueryableExtensions.IQueryableGroupNameCountPair> distinctValuesAndCounts = new List<QueryableExtensions.IQueryableGroupNameCountPair>();
try
{
System.Collections.IEnumerator enumerator = groupsAndCountsQueryable.GetEnumerator();
while( enumerator.MoveNext() )
{
QueryableExtensions.IQueryableGroupNameCountPair current = enumerator.Current as QueryableExtensions.IQueryableGroupNameCountPair;
if( current != null )
distinctValuesAndCounts.Add( current );
}
}
catch
{
// TimeOut exception on the connection or other.
distinctValuesAndCounts.Clear();
}
// If we are not the bottom level, we should have subgroups.
// However, if the connection timed out and the catch statement set the coundAndDistinctValues to an empty array,
// then we shouldn't add anything. We cannot reset on the spot since we might already be resetting.
// Create the collection of sub CollectionViewGroups
ObservableCollection<object> subCollectionViewGroupList = new ObservableCollection<object>();
int runningCount = this.StartGlobalIndex;
int distinctValuesCount = distinctValuesAndCounts.Count;
for( int i = 0; i < distinctValuesCount; i++ )
{
QueryableExtensions.IQueryableGroupNameCountPair queryableGroupNameCountPair = distinctValuesAndCounts[ i ];
subCollectionViewGroupList.Add(
new DataGridVirtualizingQueryableCollectionViewGroup( queryableGroupNameCountPair.GroupName, queryableGroupNameCountPair.Count, runningCount, this, nextLevel, nextLevelIsBottom ) );
runningCount += queryableGroupNameCountPair.Count;
}
return subCollectionViewGroupList;
}
internal abstract ObservableCollection<object> QuerySubCollectionViewGroupList( GroupDescription subGroupBy, int nextLevel, bool nextLevelIsBottom );
// return the description of how to divide the given group into subgroups
GroupDescription GetGroupDescription(CollectionViewGroup group, GroupDescription parentDescription, int level)
{
GroupDescription result = null;
if (group == this)
{
group = null; // users don't see the synthetic group
}
if (parentDescription != null)
{
#if GROUPDESCRIPTION_HAS_SUBGROUP
// a. Use the parent description's subgroup description
result = parentDescription.Subgroup;
#endif // GROUPDESCRIPTION_HAS_SUBGROUP
#if GROUPDESCRIPTION_HAS_SELECTOR
// b. Call the parent description's selector
if (result == null && parentDescription.SubgroupSelector != null)
{
result = parentDescription.SubgroupSelector(group, level);
}
#endif // GROUPDESCRIPTION_HAS_SELECTOR
}
// c. Call the global chooser
if (result == null && GroupBySelector != null)
{
result = GroupBySelector(group, level);
}
// d. Use the global array
if (result == null && level < GroupDescriptions.Count)
{
result = GroupDescriptions[level];
}
return result;
}
// Initialize the given group
void InitializeGroup(CollectionViewGroupInternal group, GroupDescription parentDescription, int level)
{
// set the group description for dividing the group into subgroups
GroupDescription groupDescription = GetGroupDescription(group, parentDescription, level);
group.GroupBy = groupDescription;
// create subgroups for each of the explicit names
ObservableCollection<object> explicitNames =
(groupDescription != null) ? groupDescription.GroupNames : null;
if (explicitNames != null)
{
for (int k=0, n=explicitNames.Count; k<n; ++k)
{
CollectionViewGroupInternal subgroup = new CollectionViewGroupInternal(explicitNames[k], group);
InitializeGroup(subgroup, groupDescription, level+1);
group.Add(subgroup);
}
}
group.LastIndex = 0;
}
internal void ClearGroup()
{
m_groupDescription = null;
m_collectionViewGroup = null;
m_propertyChanged = null;
this.DataGridContext = null;
this.GeneratorNode = null;
this.GroupLevelDescription = null;
}
internal GroupLevelDescriptionFinder( GroupDescription groupDescription, IEnumerable<GroupLevelDescription> groupLevelDescriptions )
{
if( groupDescription == null )
throw new ArgumentNullException( "groupDescription" );
if( groupLevelDescriptions == null )
throw new ArgumentNullException( "groupLevelDescriptions" );
if( !GroupLevelDescriptionFinder.TryFind( groupLevelDescriptions, groupDescription, out m_groupLevelDescription ) )
{
m_groupDescription = groupDescription;
m_groupLevelDescriptions = groupLevelDescriptions;
this.RegisterCollectionChanged( ( INotifyCollectionChanged )groupLevelDescriptions );
}
}
/// <summary>
/// Get the group name(s) for the given item
/// </summary>
/// <param name="item">Item to get group name for</param>
/// <param name="groupDescription">GroupDescription for the group</param>
/// <param name="level">The level of grouping</param>
/// <returns>Group names for the specified item</returns>
private object GetGroupName(object item, GroupDescription groupDescription, int level)
{
if (groupDescription != null)
{
return groupDescription.GroupNameFromItem(item, level, this.Culture);
}
else
{
return UseAsItemDirectly;
}
}
/// <summary>
/// Returns a <see cref="GroupDescriptor"/> equivalent to the specified description
/// </summary>
/// <param name="groupDescription">The description to get a descriptor from</param>
/// <returns>A <see cref="GroupDescriptor"/> equivalent to the specified description</returns>
/// <exception cref="InvalidOperationException"> is thrown if the description is not a
/// <see cref="PropertyGroupDescription"/>.
/// </exception>
private static GroupDescriptor GetDescriptorFromDescription(GroupDescription groupDescription)
{
PropertyGroupDescription propertyGroupDescription = groupDescription as PropertyGroupDescription;
if (propertyGroupDescription == null)
{
throw new InvalidOperationException(DomainDataSourceResources.RequiresPropertyGroupDescription);
}
return new GroupDescriptor(propertyGroupDescription.PropertyName);
}
