IncludeCollapsedDescendantsOnRangeSelection Property (BeforeSelectEventArgs)

Gets/sets whether the descendants of collapsed nodes are selected when those collapsed nodes lie between the first and last node in a range selection.

Syntax

Visual Basic

'Declaration
 
Public Property IncludeCollapsedDescendantsOnRangeSelection As Boolean

C#

public bool IncludeCollapsedDescendantsOnRangeSelection {get; set;}

Remarks

The IncludeCollapsedDescendantsOnRangeSelection property is applicable only in the case where a range selection is being performed; extending a selection by clicking a node while pressing the Control key does not consitute a range selection.

The UltraTree control also exposes an IncludeCollapsedDescendantsOnRangeSelection property. The value of the control-level property determines the initial value of this property. Changing the value of this property overrides the behavior dictated by the control-level property.

Descendants of the last node in the range selection are not selected, i.e., the last node clicked or dragged to represents the last member of the selection.

Example

The following code sample demonstrates how to use the IncludeCollapsedDescendantsOnRangeSelection property to allow or prevent descendants of collapsed nodes to be selected when their ancesrots fall between the first and last nodes of a range selection:

Visual Basic

Imports System.Collections.Generic
Imports Infragistics.Win
Imports Infragistics.Win.Misc.UltraWinTree

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        '  Set the SelectionBehavior property to 'ExtendedAcrossCollections'
        '  to allow nodes from different collections to be selected concurrently.
        Me.ultraTree1.SelectionBehavior = SelectionBehavior.ExtendedAcrossCollections

        '  Add nodes to the tree
        Me.PopulateTree(Me.ultraTree1)

        '  Determine the deepest level 
        Dim deepestLevel As Integer = Me.GetDeepestLevel(Me.ultraTree1)

        '  Only allow selection of leaf nodes
        Me.AllowSelectionOnLevel(Me.ultraTree1, deepestLevel)
    End Sub

    Private Sub PopulateTree(ByVal treeControl As UltraTree)
        Try

            treeControl.BeginUpdate()
            treeControl.Nodes.Clear()

            Dim i As Integer
            For i = 0 To 2

                Dim text As String = String.Format("Root {0}", i)
                Dim rootNode As UltraTreeNode = treeControl.Nodes.Add(Nothing, text)
                Me.PopulateNodes(rootNode.Nodes, 1)
            Next

        Finally
            treeControl.EndUpdate()
        End Try

        treeControl.ExpandAll()

    End Sub

    Private Sub PopulateNodes(ByVal nodesCollection As TreeNodesCollection, ByVal level As Integer)

        If (level > 3) Then Return

        Dim parentNode As UltraTreeNode = nodesCollection.ParentNode

        Dim i As Integer
        For i = 0 To 2

            Dim text As String = String.Format("{0}\Node {1}", parentNode.Text, i)
            Dim node As UltraTreeNode = nodesCollection.Add(Nothing, text)

            If (level < 3) Then
                Me.PopulateNodes(node.Nodes, level + 1)
            End If
        Next

    End Sub


    Private Sub ultraTree1_BeforeSelect(ByVal sender As System.Object, ByVal e As BeforeSelectEventArgs) Handles ultraTree1.BeforeSelect
        '  Iterate the members of the new selection and check
        '  the level of each node to determine which levels are
        '  included in the selection.
        Dim selectedNodes As SelectedNodesCollection = e.NewSelections
        Dim levels As New List(Of Integer)
        Dim i As Integer
        For i = 0 To selectedNodes.Count - 1

            Dim node As UltraTreeNode = selectedNodes(i)

            Dim level As Integer = node.Level
            If levels.Contains(level) = False Then levels.Add(level)
        Next

        '  If there are no root level nodes selected, allow descendants
        '  of collapsed nodes to be selected.
        If (levels.Contains(0) = False) Then
            e.IncludeCollapsedDescendantsOnRangeSelection = True
        End If

    End Sub

C#

using System.Collections.Generic;
using Infragistics.Win;
using Infragistics.Win.Misc.UltraWinTree;

    private void Form1_Load(object sender, EventArgs e)
    {
        //  Set the SelectionBehavior property to 'ExtendedAcrossCollections'
        //  to allow nodes from different collections to be selected concurrently.
        this.ultraTree1.SelectionBehavior = SelectionBehavior.ExtendedAcrossCollections;

        //  Set the IncludeCollapsedDescendantsOnRangeSelection property to false
        //  so that descendants of collapsed nodes are not selected by default.
        this.ultraTree1.IncludeCollapsedDescendantsOnRangeSelection = DefaultableBoolean.False;

        //  Add nodes to the tree
        this.PopulateTree( this.ultraTree1 );
    }

    private void PopulateTree( UltraTree treeControl, bool expandAll )
    {
        try
        {
            treeControl.BeginUpdate();

            treeControl.Nodes.Clear();

            for ( int i = 0; i < 3; i ++ )
            {
                string text = string.Format( "Root {0}", i );
                UltraTreeNode rootNode = treeControl.Nodes.Add( null, text );
                this.PopulateNodes( rootNode.Nodes, 1 );
            }

            if ( expandAll )
                this.ultraTree1.ExpandAll();
        }
        finally
        {
            treeControl.EndUpdate();
        }
    }

    private void PopulateNodes( TreeNodesCollection nodesCollection, int level )
    {
        if ( level > 3 )
            return;

        UltraTreeNode parentNode = nodesCollection.ParentNode;

        for ( int i = 0; i < 3; i ++ )
        {
            string text = string.Format( @"{0}\Node {1}", parentNode.Text, i );
            UltraTreeNode node = nodesCollection.Add( null, text );
            
            if ( level < 3 )
                this.PopulateNodes( node.Nodes, level + 1 );
        }            
    }

    private void ultraTree1_BeforeSelect(object sender, BeforeSelectEventArgs e)
    {
        //  Iterate the members of the new selection and check
        //  the level of each node to determine which levels are
        //  included in the selection.
        SelectedNodesCollection selectedNodes = e.NewSelections;
        List<int> levels = new List<int>();
        for ( int i = 0; i < selectedNodes.Count; i ++ )
        {
            UltraTreeNode node = selectedNodes[i];

            int level = node.Level;
            if ( levels.Contains(level) == false )
                levels.Add(level);
        }

        //  If there are no root level nodes selected, allow descendants
        //  of collapsed nodes to be selected.
        if ( levels.Contains(0) == false )
            e.IncludeCollapsedDescendantsOnRangeSelection = true;
    }

Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2