Class TreeNodesScrollAxis

TreeNodesScrollAxis provides support for vertical pixel scrolling through nodes in a TreeModel of a VirtualTreeView with its ScrollRows property.

The axis provides the mapping between a row index or pixel position in the VirtualTreeView and the TreeNodes and vice versa.

The TreeNodes maintain their IsExpanded state and also keep track of the height of themselves and their child nodes in a TreeTable that counts the number of nested child nodes and their height.

The axis listens to scrollbar events, resizing and hiding of nodes and updates scrollbar properties with setting calculated from header and footer size and total size of lines in body.

Inheritance
System.Object
ScrollAxisBase
TreeNodesScrollAxis
Implements
System.IDisposable
Inherited Members
System.Object.Equals(System.Object)
System.Object.Equals(System.Object, System.Object)
System.Object.GetHashCode()
System.Object.GetType()
System.Object.MemberwiseClone()
System.Object.ReferenceEquals(System.Object, System.Object)
System.Object.ToString()
Namespace: Syncfusion.Windows.Controls.VirtualTreeView
Assembly: Syncfusion.GridCommon.Wpf.dll
Syntax
public class TreeNodesScrollAxis : ScrollAxisBase, IDisposable

Constructors

TreeNodesScrollAxis(IScrollBar, TreeModel)

Initializes a new instance of the TreeNodesScrollAxis class.

Declaration
public TreeNodesScrollAxis(IScrollBar sb, TreeModel treeModel)
Parameters
Type Name Description
IScrollBar sb

The sb.
TreeModel treeModel

The tree model.

Properties

DefaultLineSize

Gets or sets the default size of lines.

Declaration
public override double DefaultLineSize { get; set; }
Property Value
Type Description
System.Double

The default size of lines.
Overrides

FooterExtent

Gets the footer extent. This is total height (or width) of the footer lines.

Declaration
public override double FooterExtent { get; }
Property Value
Type Description
System.Double

The footer extent.
Overrides

HeaderExtent

Gets the header extent. This is total height (or width) of the header lines.

Declaration
public override double HeaderExtent { get; }
Property Value
Type Description
System.Double

The header extent.
Overrides

IsPixelScroll

Gets a value indicating whether this axis supports pixel scrolling.

Declaration
public override bool IsPixelScroll { get; }
Property Value
Type Description
System.Boolean

true if this instance supports pixel scrolling; otherwise, false.
Overrides

LineCount

Gets or sets the line count.

Declaration
public override int LineCount { get; set; }
Property Value
Type Description
System.Int32

The line count.
Overrides

ScrollLineIndex

Gets or sets the index of the first visible Line in the Body region.

Declaration
public override int ScrollLineIndex { get; set; }
Property Value
Type Description
System.Int32

The index of the scroll line.
Overrides

TotalExtent

Gets the total extent.

Declaration
public double TotalExtent { get; }
Property Value
Type Description
System.Double

The total extent.

ViewSize

Gets the view size of the (either height or width) of the parent control. Normally the ViewSize is the same as RenderSize. Only if the parent control has more space then needed to display all lines, the ViewSize will be less. In such case the ViewSize is the total height for all lines.

Declaration
public override double ViewSize { get; }
Property Value
Type Description
System.Double

The size of the view.
Overrides

VisibleNodes

Gets the visible nodes.

Declaration
public TreeNodesFlattenedList VisibleNodes { get; }
Property Value
Type Description
TreeNodesFlattenedList

The visible nodes.

Methods

AlignScrollLine()

Aligns the scroll line.

Declaration
public override void AlignScrollLine()
Overrides

GetNextScrollLineIndex(Int32)

Gets the index of the next scroll line.

Declaration
public override int GetNextScrollLineIndex(int index)
Parameters
Type Name Description
System.Int32 index

The index.
Returns
Type
System.Int32
Overrides

GetPreviousScrollLineIndex(Int32)

Gets the index of the previous scroll line.

Declaration
public override int GetPreviousScrollLineIndex(int index)
Parameters
Type Name Description
System.Int32 index

The index.
Returns
Type
System.Int32
Overrides

GetScrollLineIndex(out Int32, out Double)

Gets the index of the scroll line.

Declaration
public override void GetScrollLineIndex(out int scrollLindeIndex, out double scrollLineDelta)
Parameters
Type Name Description
System.Int32 scrollLindeIndex

Index of the scroll linde.
System.Double scrollLineDelta

The scroll line delta.
Overrides

MouseWheel(Int32)

This method is called in response to a MouseWheel event.

Declaration
public override void MouseWheel(int delta)
Parameters
Type Name Description
System.Int32 delta

The delta.
Overrides

RangeToPoints(ScrollAxisRegion, Int32, Int32, Boolean)

Returns the first and last point for the given lines in a region.

Declaration
public override DoubleSpan RangeToPoints(ScrollAxisRegion region, int first, int last, bool allowEstimatesForOutOfViewLines)
Parameters
Type Name Description
ScrollAxisRegion region

The region.
System.Int32 first

The index of the first line.
System.Int32 last

The index of the last line.
System.Boolean allowEstimatesForOutOfViewLines

if set to true allow estimates for out of view lines.
Returns
Type
DoubleSpan
Overrides

RangeToRegionPoints(Int32, Int32, Boolean)

Returns an array with 3 ranges indicating the first and last point for the given lines in each region.

Declaration
public override DoubleSpan[] RangeToRegionPoints(int first, int last, bool allowEstimatesForOutOfViewLines)
Parameters
Type Name Description
System.Int32 first

The index of the first line.
System.Int32 last

The index of the last line.
System.Boolean allowEstimatesForOutOfViewLines

if set to true allow estimates for out of view lines.
Returns
Type
DoubleSpan[]
Overrides

ScrollToNextLine()

Scrolls to next line.

Declaration
public override void ScrollToNextLine()
Overrides

ScrollToNextPage()

Scrolls to next page.

Declaration
public override void ScrollToNextPage()
Overrides

ScrollToPreviousLine()

Scrolls to previous line.

Declaration
public override void ScrollToPreviousLine()
Overrides

ScrollToPreviousPage()

Scrolls to previous page.

Declaration
public override void ScrollToPreviousPage()
Overrides

SetFooterLineCount(Int32)

Sets the footer line count.

Declaration
protected override void SetFooterLineCount(int value)
Parameters
Type Name Description
System.Int32 value

The value.
Overrides

SetHeaderLineCount(Int32)

Sets the header line count.

Declaration
protected override void SetHeaderLineCount(int value)
Parameters
Type Name Description
System.Int32 value

The value.
Overrides

SetLineHiddenState(Int32, Int32, Boolean)

Sets the hidden state of the lines.

Declaration
public override void SetLineHiddenState(int from, int to, bool hide)
Parameters
Type Name Description
System.Int32 from

From.
System.Int32 to

To.
System.Boolean hide

if set to true [hide].
Overrides

SetLineSize(Int32, Int32, Double)

Sets the size of the lines.

Declaration
public override void SetLineSize(int from, int to, double size)
Parameters
Type Name Description
System.Int32 from

From.
System.Int32 to

To.
System.Double size

The size.
Overrides

SetScrollLineIndex(Int32, Double)

Sets the index of the scroll line.

Declaration
public override void SetScrollLineIndex(int scrollLindeIndex, double scrollLineDelta)
Parameters
Type Name Description
System.Int32 scrollLindeIndex

Index of the scroll linde.
System.Double scrollLineDelta

The scroll line delta.
Overrides

UpdateScrollBar()

Initialize scrollbar properties from header and footer size and total size of lines in body.

Declaration
public override void UpdateScrollBar()
Overrides

Implements

System.IDisposable