//resets the items source
private void ResetItemsSource(IEnumerable newValue)
{
if (newValue != null)
{
compositeChildCollection.Clear();
if (rootNodesInfo == null)
{
rootNodesInfo = new List <TreeListBoxInfo>();
}
else
{
rootNodesInfo.Clear();
}
foreach (object item in newValue)
{
TreeListBoxInfo info = new TreeListBoxInfo(0, item);
//add the new info to the main flattened list
compositeChildCollection.Add(info);
// add the new info to intenal list of data items
rootNodesInfo.Add(info);
}
//set the items sources to be out compositeChildCollection that contains all the VirtualizingTreeViewInfo
ItemsSource = compositeChildCollection;
}
else
{
ItemsSource = null;// if the new source is null set the source to be null
}
}
//event handler for the collection change of the items source
void NotificationEnableCollectionCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
switch (e.Action)
{
case NotifyCollectionChangedAction.Add:
if (e.NewItems != null)
{
int counter = 0;
foreach (object item in e.NewItems)
{
//get the destination index
int originalDestinationIndex =
Math.Min(e.NewStartingIndex + counter, rootNodesInfo.Count);
//walk through the list of ancestors and count their children
int newDestinationIndex = 0;
for (int i = originalDestinationIndex - 1; i >= 0; i--)
{
newDestinationIndex += (rootNodesInfo[i].ChildrenCount + 1);
}
originalDestinationIndex = newDestinationIndex; //if the destination is 0 you still need to add 1
//create the new list item
TreeListBoxInfo newInfo = new TreeListBoxInfo(0, item);
//add the new item in the internal list
rootNodesInfo.Insert(Math.Min(e.NewStartingIndex + counter, rootNodesInfo.Count), newInfo);
//add to the main list(the flattened list)
compositeChildCollection.Insert(originalDestinationIndex, newInfo);
counter++;
}
}
break;
case NotifyCollectionChangedAction.Remove:
if (compositeChildCollection.Count > e.OldStartingIndex)
{
//remove all children
TreeListBoxInfo info = rootNodesInfo[e.OldStartingIndex];
//remove all child items
for (int i = 0; i < info.ChildrenCount; i++)
{
compositeChildCollection.RemoveAt(e.OldStartingIndex);
}
//remove the actual item
compositeChildCollection.RemoveAt(e.OldStartingIndex);
rootNodesInfo.RemoveAt(e.OldStartingIndex);
}
break;
case NotifyCollectionChangedAction.Move:
case NotifyCollectionChangedAction.Replace:
case NotifyCollectionChangedAction.Reset:
//reset the items source
ResetItemsSource(sender as IEnumerable);
break;
}
}
/// <summary>
/// Prepares the new VirtualizingTreeViewItem with the actual business object
/// </summary>
/// <param name="element">The element (VirtualizingTreeViewItem) to apply the template</param>
/// <param name="item">The business object to set</param>
protected override void PrepareContainerForItemOverride(DependencyObject element, object item)
{
TreeListBoxItem listItem = element as TreeListBoxItem;
TreeListBoxInfo actualItem = item as TreeListBoxInfo;
//raise the event to signal that a new item is created
OnNewItemCreated(new TreeListBoxItemCreatedEventArgs(listItem, actualItem));
//prepares the item with the relative VirtualizingTreeViewInfo
listItem.PrepareItem(actualItem);
//pass the actual data item instead of the VirtualizingTreeViewInfo
base.PrepareContainerForItemOverride(element, actualItem.DataItem);
}
//generate a single TreeListBoxItem
private void GenerateSingleItem(object item)
{
//get the current index. TODO done once
int currentIndex = treeListBox.CompositeChildCollection.IndexOf(currentInfo);
if (currentIndex != -1)
{
//create a child list item
TreeListBoxInfo newObject = new TreeListBoxInfo(level + 1, item);
currentInfo.ChildItems.Add(newObject);
treeListBox.CompositeChildCollection.Insert(
currentIndex + lastChildItemCreatedIndex, newObject);
lastChildItemCreatedIndex++;
}
}
/// <summary>
/// Prepares the item by setting the properties
/// Override this method if you want to attach any extra info to the item
/// </summary>
/// <param name="info">The info to apply</param>
internal virtual void PrepareItem(TreeListBoxInfo info)
{
//set the current info for this object
currentInfo = info;
//set the level
level = info.Level;
//check if the item was expanded.
//you need to reset this propety since the Virtualization can delete the instance of this item and after recreate it
if (info.IsExpanded)
{
IsExpanded = true;
}
isInitializing = false;
}
//gets the child count by walking the children tree
private static int GetChildCount(TreeListBoxInfo info)
{
if (info.childItems == null || info.childItems.Count == 0)
{
return(0);
}
int childCount = 0;
foreach (TreeListBoxInfo child in info.childItems)
{
childCount += GetChildCount(child); // add the child count
childCount++; //add the current item
}
return(childCount);
}
//delets a single item from the list
private bool DeleteSingleItem(TreeListBoxInfo info)
{
int index = treeListBox.CompositeChildCollection.IndexOf(info);
if (index != -1)
{
//remove all children
for (int i = 0; i < info.ChildrenCount; i++)
{
treeListBox.CompositeChildCollection[index].IsExpanded = false;
treeListBox.CompositeChildCollection.RemoveAt(index);
}
treeListBox.CompositeChildCollection[index].IsExpanded = false;
treeListBox.CompositeChildCollection.RemoveAt(index);//remove itself
currentInfo.ChildItems.Remove(info);
lastChildItemCreatedIndex--;
return(true);
}
return(false);
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="item">The new item created</param>
/// <param name="info">The info relative to this item</param>
public TreeListBoxItemCreatedEventArgs(TreeListBoxItem item, TreeListBoxInfo info)
{
newItem = item;
newItemInfo = info;
}
//event handler for databinding notification fo children
private void NotificationEnabledCollectionCollectionChanged(object sender,
NotifyCollectionChangedEventArgs e)
{
//if the expanded is false. Unregister to events and exit
//this can happen if the Drop all does not unregister to notification events
if (currentInfo.IsExpanded == false)
{
UnRegisterCollectionNotification();
return;
}
switch (e.Action)
{
//new item(s) where added
case NotifyCollectionChangedAction.Add:
if (e.NewItems != null)
{
int counter = 0;
foreach (object item in e.NewItems)
{
int originalDestinationIndex =
Math.Min(e.NewStartingIndex + counter, currentInfo.ChildItems.Count);
//get the index for the main list (the flattened list)
int newDestinationIndex = 1;
//walk through all ancestor items and get te child count of the items
for (int i = originalDestinationIndex - 1; i >= 0; i--)
{
//get the child count of the item + 1 which is the item itself
newDestinationIndex += (currentInfo.ChildItems[i].ChildrenCount + 1);
}
originalDestinationIndex =
newDestinationIndex + // the new destination
treeListBox.CompositeChildCollection.IndexOf(currentInfo); // the index of the current item
//create the new list item
TreeListBoxInfo newInfo = new TreeListBoxInfo(level + 1, item);
currentInfo.ChildItems.Insert(
Math.Min(e.NewStartingIndex + counter, currentInfo.ChildItems.Count),
newInfo);
treeListBox.CompositeChildCollection.Insert(originalDestinationIndex, newInfo);
counter++;
}
}
break;
//item was removed
case NotifyCollectionChangedAction.Remove:
if (currentInfo.ChildItems.Count > e.OldStartingIndex)
{
DeleteSingleItem(currentInfo.ChildItems[e.OldStartingIndex]);
}
break;
case NotifyCollectionChangedAction.Move:
case NotifyCollectionChangedAction.Replace:
case NotifyCollectionChangedAction.Reset:
DropAllListItems();
GenerateAllListItems();
break;
}
}
//gets the child count by walking the children tree
private static int GetChildCount(TreeListBoxInfo info)
{
if (info.childItems == null || info.childItems.Count == 0)
return 0;
int childCount = 0;
foreach (TreeListBoxInfo child in info.childItems)
{
childCount += GetChildCount(child); // add the child count
childCount++;//add the current item
}
return childCount;
}
//generate a single TreeListBoxItem
private void GenerateSingleItem(object item)
{
//get the current index. TODO done once
int currentIndex = treeListBox.CompositeChildCollection.IndexOf(currentInfo);
if (currentIndex != -1)
{
//create a child list item
TreeListBoxInfo newObject = new TreeListBoxInfo(level + 1, item);
currentInfo.ChildItems.Add(newObject);
treeListBox.CompositeChildCollection.Insert(
currentIndex + lastChildItemCreatedIndex, newObject);
lastChildItemCreatedIndex++;
}
}
//event handler for databinding notification fo children
private void NotificationEnabledCollectionCollectionChanged(object sender,
NotifyCollectionChangedEventArgs e)
{
//if the expanded is false. Unregister to events and exit
//this can happen if the Drop all does not unregister to notification events
if (currentInfo.IsExpanded == false)
{
UnRegisterCollectionNotification();
return;
}
switch (e.Action)
{
//new item(s) where added
case NotifyCollectionChangedAction.Add:
if (e.NewItems != null)
{
int counter = 0;
foreach (object item in e.NewItems)
{
int originalDestinationIndex =
Math.Min(e.NewStartingIndex + counter, currentInfo.ChildItems.Count);
//get the index for the main list (the flattened list)
int newDestinationIndex = 1;
//walk through all ancestor items and get te child count of the items
for (int i = originalDestinationIndex - 1; i >= 0; i--)
//get the child count of the item + 1 which is the item itself
newDestinationIndex += (currentInfo.ChildItems[i].ChildrenCount + 1);
originalDestinationIndex =
newDestinationIndex + // the new destination
treeListBox.CompositeChildCollection.IndexOf(currentInfo);// the index of the current item
//create the new list item
TreeListBoxInfo newInfo = new TreeListBoxInfo(level + 1, item);
currentInfo.ChildItems.Insert(
Math.Min(e.NewStartingIndex + counter, currentInfo.ChildItems.Count),
newInfo);
treeListBox.CompositeChildCollection.Insert(originalDestinationIndex, newInfo);
counter++;
}
}
break;
//item was removed
case NotifyCollectionChangedAction.Remove:
if (currentInfo.ChildItems.Count > e.OldStartingIndex)
DeleteSingleItem(currentInfo.ChildItems[e.OldStartingIndex]);
break;
case NotifyCollectionChangedAction.Move:
case NotifyCollectionChangedAction.Replace:
case NotifyCollectionChangedAction.Reset:
DropAllListItems();
GenerateAllListItems();
break;
}
}
/// <summary>
/// Prepares the item by setting the properties
/// Override this method if you want to attach any extra info to the item
/// </summary>
/// <param name="info">The info to apply</param>
internal virtual void PrepareItem(TreeListBoxInfo info)
{
//set the current info for this object
currentInfo = info;
//set the level
level = info.Level;
//check if the item was expanded.
//you need to reset this propety since the Virtualization can delete the instance of this item and after recreate it
if (info.IsExpanded)
IsExpanded = true;
isInitializing = false;
}
public void ExposePrepareItem(TreeListBoxInfo info)
{
PrepareItem(info);
}
//resets the items source
private void ResetItemsSource(IEnumerable newValue)
{
if (newValue != null)
{
compositeChildCollection.Clear();
if (rootNodesInfo == null)
rootNodesInfo = new List<TreeListBoxInfo>();
else
rootNodesInfo.Clear();
foreach (object item in newValue)
{
TreeListBoxInfo info = new TreeListBoxInfo(0, item);
//add the new info to the main flattened list
compositeChildCollection.Add(info);
// add the new info to intenal list of data items
rootNodesInfo.Add(info);
}
//set the items sources to be out compositeChildCollection that contains all the VirtualizingTreeViewInfo
ItemsSource = compositeChildCollection;
}
else
ItemsSource = null;// if the new source is null set the source to be null
}
//event handler for the collection change of the items source
void NotificationEnableCollectionCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
switch (e.Action)
{
case NotifyCollectionChangedAction.Add:
if (e.NewItems != null)
{
int counter = 0;
foreach (object item in e.NewItems)
{
//get the destination index
int originalDestinationIndex =
Math.Min(e.NewStartingIndex + counter, rootNodesInfo.Count);
//walk through the list of ancestors and count their children
int newDestinationIndex = 0;
for (int i = originalDestinationIndex - 1; i >= 0; i--)
newDestinationIndex += (rootNodesInfo[i].ChildrenCount + 1);
originalDestinationIndex = newDestinationIndex;//if the destination is 0 you still need to add 1
//create the new list item
TreeListBoxInfo newInfo = new TreeListBoxInfo(0, item);
//add the new item in the internal list
rootNodesInfo.Insert(Math.Min(e.NewStartingIndex + counter, rootNodesInfo.Count), newInfo);
//add to the main list(the flattened list)
compositeChildCollection.Insert(originalDestinationIndex, newInfo);
counter++;
}
}
break;
case NotifyCollectionChangedAction.Remove:
if (compositeChildCollection.Count > e.OldStartingIndex)
{
//remove all children
TreeListBoxInfo info = rootNodesInfo[e.OldStartingIndex];
//remove all child items
for (int i = 0; i < info.ChildrenCount; i++)
compositeChildCollection.RemoveAt(e.OldStartingIndex);
//remove the actual item
compositeChildCollection.RemoveAt(e.OldStartingIndex);
rootNodesInfo.RemoveAt(e.OldStartingIndex);
}
break;
case NotifyCollectionChangedAction.Move:
case NotifyCollectionChangedAction.Replace:
case NotifyCollectionChangedAction.Reset:
//reset the items source
ResetItemsSource(sender as IEnumerable);
break;
}
}
//delets a single item from the list
private bool DeleteSingleItem(TreeListBoxInfo info)
{
int index = treeListBox.CompositeChildCollection.IndexOf(info);
if (index != -1)
{
//remove all children
for (int i = 0; i < info.ChildrenCount; i++)
{
treeListBox.CompositeChildCollection[index].IsExpanded = false;
treeListBox.CompositeChildCollection.RemoveAt(index);
}
treeListBox.CompositeChildCollection[index].IsExpanded = false;
treeListBox.CompositeChildCollection.RemoveAt(index);//remove itself
currentInfo.ChildItems.Remove(info);
lastChildItemCreatedIndex--;
return true;
}
return false;
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="item">The new item created</param>
/// <param name="info">The info relative to this item</param>
public TreeListBoxItemCreatedEventArgs(TreeListBoxItem item, TreeListBoxInfo info)
{
newItem = item;
newItemInfo = info;
}
public void ExposePrepareItem(TreeListBoxInfo info)
{
PrepareItem(info);
}