/// <summary>
/// Updates the node at the specified index, with the specified item
/// </summary>
/// <param name="index"></param>
/// <param name="item"></param>
private void UpdateNode(int index, object item)
{
BindingTreeNode node = (BindingTreeNode)_nodeCollection[index];
node.DataBoundItem = item;
node.UpdateDisplay(); // force update, even if it is the same item, because its properties may have changed
}
/// <summary>
/// Removes the node at the specified index
/// </summary>
/// <param name="index"></param>
private void RemoveNode(int index)
{
BindingTreeNode node = (BindingTreeNode)_nodeCollection[index];
_nodeCollection.RemoveAt(index);
node.Dispose();
}
/// <summary>
/// Adds a node for the specified item
/// </summary>
/// <param name="item"></param>
private void AddNode(object item)
{
var node = new BindingTreeNode(_tree, item, _bindingTreeView);
_nodeCollection.Add(node);
node.UpdateDisplay();
}
/// <summary>
/// Notify that the <see cref="Selection"/> property has changed
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void _treeCtrl_AfterSelect(object sender, TreeViewEventArgs e)
{
BindingTreeNode selNode = (BindingTreeNode)_treeCtrl.SelectedNode;
_treeCtrl.LabelEdit = selNode != null && selNode.CanSetNodeText();
EventsHelper.Fire(_selectionChanged, this, EventArgs.Empty);
}
private void _treeCtrl_AfterCollapse(object sender, TreeViewEventArgs e)
{
BindingTreeNode node = e.Node as BindingTreeNode;
if (node != null)
{
node.OnExpandCollapse();
}
}
/// <summary>
/// Called when an object is first dragged into this control
/// </summary>
/// <param name="e"></param>
protected override void OnDragEnter(DragEventArgs e)
{
// clear any record of a previous drop target node
_dropTargetNode = null;
_dropEffect = DragDropEffects.None;
_dropPosition = DragDropPosition.Default;
base.OnDragEnter(e);
}
/// <summary>
/// When the user is about to expand a node, need to build the level beneath it
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void _treeCtrl_BeforeExpand(object sender, TreeViewCancelEventArgs e)
{
BindingTreeNode expandingNode = (BindingTreeNode)e.Node;
if (!expandingNode.IsSubTreeBuilt)
{
expandingNode.BuildSubTree();
}
}
private void _treeCtrl_ItemDrag(object sender, ItemDragEventArgs e)
{
// the item being dragged should be selected as well.
BindingTreeNode node = (BindingTreeNode)e.Item;
_treeCtrl.SelectedNode = node;
ItemDragEventArgs args = new ItemDragEventArgs(e.Button, this.GetSelectionHelper());
EventsHelper.Fire(_itemDrag, this, args);
}
private void _contextMenu_Opening(object sender, CancelEventArgs e)
{
// Find the node we're on
Point pt = _treeCtrl.PointToClient(TreeView.MousePosition);
BindingTreeNode node = (BindingTreeNode)_treeCtrl.GetNodeAt(pt.X, pt.Y);
_treeCtrl.SelectedNode = node;
if (node == null)
{
EventsHelper.Fire(_selectionChanged, this, EventArgs.Empty);
}
}
private void _treeCtrl_NodeMouseClick(object sender, TreeNodeMouseClickEventArgs e)
{
if (CheckBoxes && _treeCtrl.HitTest(e.Location).Location == TreeViewHitTestLocations.StateImage)
{
BindingTreeNode node = e.Node as BindingTreeNode;
if (node != null)
{
node.OnChecked();
}
}
EventsHelper.Fire(_nodeMouseClicked, this, e);
}
private void _treeCtrl_AfterLabelEdit(object sender, NodeLabelEditEventArgs e)
{
if (string.IsNullOrEmpty(e.Label))
{
// user cancel the edit, stop editing
e.CancelEdit = true;
}
else
{
BindingTreeNode node = e.Node as BindingTreeNode;
if (node != null)
{
node.AfterLabelEdit(e.Label);
}
}
}
protected override void OnDragLeave(EventArgs e)
{
// is there a current drop-target node?
if (_dropTargetNode != null)
{
// remove highlighting from drop target node
HighlightNode(_dropTargetNode, false);
SetInsertMark(_dropTargetNode, DragDropPosition.Default);
}
// clear the drop target node
_dropTargetNode = null;
_dropEffect = DragDropEffects.None;
_dropPosition = DragDropPosition.Default;
base.OnDragLeave(e);
}
/// <summary>
/// Builds or rebuilds the entire level
/// </summary>
private void BuildLevel()
{
// dispose of all existing tree nodes before clearing the collection
foreach (TreeNode node in _nodeCollection)
{
if (node is IDisposable)
{
(node as IDisposable).Dispose();
}
}
_nodeCollection.Clear();
// create new node for each item
foreach (object item in _tree.Items)
{
BindingTreeNode node = new BindingTreeNode(_tree, item, _bindingTreeView);
_nodeCollection.Add(node);
node.UpdateDisplay();
}
}
/// <summary>
/// Called when an object is dropped onto this control
/// </summary>
/// <param name="e"></param>
protected override void OnDragDrop(DragEventArgs e)
{
// is there a current drop-target node?
if (_dropTargetNode != null)
{
try
{
object dragDropData = GetDragDropData(e);
// ask the node to accept the drop
DragDropKind result = _dropTargetNode.AcceptDrop(dragDropData, GetDragDropKind(e.Effect), _dropPosition);
// be sure to set the resulting effect in the event args, so that it gets communicated
// back to the initiator of the drag drop operation
e.Effect = GetDragDropEffect(result);
// Fire the item dropped event
if (e.Effect != DragDropEffects.None)
{
ItemDroppedEventArgs args = new ItemDroppedEventArgs(dragDropData, result);
EventsHelper.Fire(_itemDropped, this, args);
}
}
catch (Exception ex)
{
Platform.Log(LogLevel.Error, ex);
}
// remove highlighting from drop target node
HighlightNode(_dropTargetNode, false);
SetInsertMark(_dropTargetNode, DragDropPosition.Default);
}
// clear the drop target node
_dropTargetNode = null;
_dropEffect = DragDropEffects.None;
_dropPosition = DragDropPosition.Default;
base.OnDragDrop(e);
}
/// <summary>
/// Searches the tree depth-first for a node matching the specified criteria
/// </summary>
/// <param name="nodeCollection"></param>
/// <param name="criteria"></param>
/// <returns></returns>
private BindingTreeNode FindNodeRecursive(TreeNodeCollection nodeCollection, Predicate <BindingTreeNode> criteria)
{
foreach (TreeNode node in nodeCollection)
{
// Bug #871
// See BindingTreeNode.UpdateDisplay():
// the Nodes property may contain a "dummy" TreeNode, so ensure each iterated TreeNode is actually a BindingTreeNode
BindingTreeNode bindingTreeNode = node as BindingTreeNode;
if (bindingTreeNode != null && criteria(bindingTreeNode))
{
return(bindingTreeNode);
}
else
{
BindingTreeNode nodeFound = FindNodeRecursive(node.Nodes, criteria);
if (nodeFound != null)
{
return(nodeFound);
}
}
}
return(null);
}
private void InsertNode(int index, object item)
{
BindingTreeNode node = new BindingTreeNode(_tree, item, _bindingTreeView);
_nodeCollection.Insert(index, node);
}
/// <summary>
/// Adds a node for the specified item
/// </summary>
/// <param name="item"></param>
private void AddNode(object item)
{
var node = new BindingTreeNode(_tree, item, _bindingTreeView);
_nodeCollection.Add(node);
node.UpdateDisplay();
}
private void InsertNode(int index, object item)
{
BindingTreeNode node = new BindingTreeNode(_tree, item, _bindingTreeView);
_nodeCollection.Insert(index, node);
}
/// <summary>
/// Obtains the current selection
/// </summary>
/// <returns></returns>
private ISelection GetSelectionHelper()
{
BindingTreeNode selNode = (BindingTreeNode)_treeCtrl.SelectedNode;
return(selNode == null ? new Selection() : new Selection(selNode.DataBoundItem));
}
protected override void OnDragLeave(EventArgs e)
{
// is there a current drop-target node?
if (_dropTargetNode != null)
{
// remove highlighting from drop target node
HighlightNode(_dropTargetNode, false);
SetInsertMark(_dropTargetNode, DragDropPosition.Default);
}
// clear the drop target node
_dropTargetNode = null;
_dropEffect = DragDropEffects.None;
_dropPosition = DragDropPosition.Default;
base.OnDragLeave(e);
}
/// <summary>
/// Called when an object is dropped onto this control
/// </summary>
/// <param name="e"></param>
protected override void OnDragDrop(DragEventArgs e)
{
// is there a current drop-target node?
if (_dropTargetNode != null)
{
try
{
object dragDropData = GetDragDropData(e);
// ask the node to accept the drop
DragDropKind result = _dropTargetNode.AcceptDrop(dragDropData, GetDragDropKind(e.Effect), _dropPosition);
// be sure to set the resulting effect in the event args, so that it gets communicated
// back to the initiator of the drag drop operation
e.Effect = GetDragDropEffect(result);
// Fire the item dropped event
if (e.Effect != DragDropEffects.None)
{
ItemDroppedEventArgs args = new ItemDroppedEventArgs(dragDropData, result);
EventsHelper.Fire(_itemDropped, this, args);
}
}
catch (Exception ex)
{
Platform.Log(LogLevel.Error, ex);
}
// remove highlighting from drop target node
HighlightNode(_dropTargetNode, false);
SetInsertMark(_dropTargetNode, DragDropPosition.Default);
}
// clear the drop target node
_dropTargetNode = null;
_dropEffect = DragDropEffects.None;
_dropPosition = DragDropPosition.Default;
base.OnDragDrop(e);
}
/// <summary>
/// Called repeatedly as the object is dragged within this control
/// </summary>
/// <param name="e"></param>
protected override void OnDragOver(DragEventArgs e)
{
// determine the node under the cursor
Point cursor = _treeCtrl.PointToClient(new Point(e.X, e.Y));
BindingTreeNode node = (BindingTreeNode)_treeCtrl.GetNodeAt(cursor);
// determine what effect the user is trying to accomplish
DragDropEffects desiredEffect = GetDragDropDesiredEffect(e);
// determine if the user is trying to drag to the top, middle or bottom areas of the node
DragDropPosition position = DragDropPosition.Default;
if (this.AllowDropToIndex && node != null)
{
float result = 1f*(cursor.Y - node.Bounds.Y)/node.Bounds.Height;
if (result <= 0.2f)
position = DragDropPosition.Before;
else if (result >= 0.8f)
position = DragDropPosition.After;
}
// optimization: only care if different than the last known drop-target node, or different desired effect, or different drop position
if (node != _dropTargetNode || desiredEffect != _dropEffect || position != _dropPosition)
{
_treeCtrl.BeginUpdate(); // suspend drawing
// un-highlight the last known drop-target node
HighlightNode(_dropTargetNode, false);
SetInsertMark(_dropTargetNode, DragDropPosition.Default);
// set the drop target node to this node
_dropTargetNode = node;
_dropEffect = desiredEffect;
_dropPosition = position;
// check if drop target node exists and what kind of operation it will accept
DragDropKind acceptableKind = (_dropTargetNode == null) ?
DragDropKind.None : _dropTargetNode.CanAcceptDrop(GetDragDropData(e), GetDragDropKind(desiredEffect), _dropPosition);
// display the appropriate effect cue based on the result
e.Effect = GetDragDropEffect(acceptableKind);
// if the drop target is valid and willing to accept data, highlight it
if (acceptableKind != DragDropKind.None)
{
HighlightNode(_dropTargetNode, _dropPosition == DragDropPosition.Default);
SetInsertMark(_dropTargetNode, _dropPosition);
}
_treeCtrl.EndUpdate(); // resume drawing
}
// perform drag scrolling
if (_treeCtrl.ClientRectangle.Contains(cursor))
{
if (cursor.Y > _treeCtrl.Height - _treeCtrl.ItemHeight/2)
SendMessage(_treeCtrl.Handle, (int) WindowsMessages.WM_VSCROLL, new IntPtr(1), IntPtr.Zero);
else if (cursor.Y < _treeCtrl.ItemHeight/2)
SendMessage(_treeCtrl.Handle, (int) WindowsMessages.WM_VSCROLL, IntPtr.Zero, IntPtr.Zero);
}
base.OnDragOver(e);
}
/// <summary>
/// Called when an object is first dragged into this control
/// </summary>
/// <param name="e"></param>
protected override void OnDragEnter(DragEventArgs e)
{
// clear any record of a previous drop target node
_dropTargetNode = null;
_dropEffect = DragDropEffects.None;
_dropPosition = DragDropPosition.Default;
base.OnDragEnter(e);
}
/// <summary>
/// Called repeatedly as the object is dragged within this control
/// </summary>
/// <param name="e"></param>
protected override void OnDragOver(DragEventArgs e)
{
// determine the node under the cursor
Point cursor = _treeCtrl.PointToClient(new Point(e.X, e.Y));
BindingTreeNode node = (BindingTreeNode)_treeCtrl.GetNodeAt(cursor);
// determine what effect the user is trying to accomplish
DragDropEffects desiredEffect = GetDragDropDesiredEffect(e);
// determine if the user is trying to drag to the top, middle or bottom areas of the node
DragDropPosition position = DragDropPosition.Default;
if (this.AllowDropToIndex && node != null)
{
float result = 1f * (cursor.Y - node.Bounds.Y) / node.Bounds.Height;
if (result <= 0.2f)
{
position = DragDropPosition.Before;
}
else if (result >= 0.8f)
{
position = DragDropPosition.After;
}
}
// optimization: only care if different than the last known drop-target node, or different desired effect, or different drop position
if (node != _dropTargetNode || desiredEffect != _dropEffect || position != _dropPosition)
{
_treeCtrl.BeginUpdate(); // suspend drawing
// un-highlight the last known drop-target node
HighlightNode(_dropTargetNode, false);
SetInsertMark(_dropTargetNode, DragDropPosition.Default);
// set the drop target node to this node
_dropTargetNode = node;
_dropEffect = desiredEffect;
_dropPosition = position;
// check if drop target node exists and what kind of operation it will accept
DragDropKind acceptableKind = (_dropTargetNode == null) ?
DragDropKind.None : _dropTargetNode.CanAcceptDrop(GetDragDropData(e), GetDragDropKind(desiredEffect), _dropPosition);
// display the appropriate effect cue based on the result
e.Effect = GetDragDropEffect(acceptableKind);
// if the drop target is valid and willing to accept data, highlight it
if (acceptableKind != DragDropKind.None)
{
HighlightNode(_dropTargetNode, _dropPosition == DragDropPosition.Default);
SetInsertMark(_dropTargetNode, _dropPosition);
}
_treeCtrl.EndUpdate(); // resume drawing
}
// perform drag scrolling
if (_treeCtrl.ClientRectangle.Contains(cursor))
{
if (cursor.Y > _treeCtrl.Height - _treeCtrl.ItemHeight / 2)
{
SendMessage(_treeCtrl.Handle, (int)WindowsMessages.WM_VSCROLL, new IntPtr(1), IntPtr.Zero);
}
else if (cursor.Y < _treeCtrl.ItemHeight / 2)
{
SendMessage(_treeCtrl.Handle, (int)WindowsMessages.WM_VSCROLL, IntPtr.Zero, IntPtr.Zero);
}
}
base.OnDragOver(e);
}
/// <summary>
/// Builds or rebuilds the entire level
/// </summary>
private void BuildLevel()
{
// dispose of all existing tree nodes before clearing the collection
foreach (TreeNode node in _nodeCollection)
{
if(node is IDisposable)
(node as IDisposable).Dispose();
}
_nodeCollection.Clear();
// create new node for each item
foreach (object item in _tree.Items)
{
BindingTreeNode node = new BindingTreeNode(_tree, item, _bindingTreeView);
_nodeCollection.Add(node);
node.UpdateDisplay();
}
}
