Class DistanceRangeCounterCollection

A collection of entities for which distances need to be counted. The collection provides methods for mapping from a distance position to an entity and vice versa.

For example, in a scrollable grid control you have rows with different heights. Use this collection to determine the total height for all rows in the grid, quickly detemine the row index for a given point and also quickly determine the point at which a row is displayed. This also allows a mapping between the scrollbars value and the rows or columns associated with that value.

Inheritance

System.Object

DistanceRangeCounterCollection

Implements

IDistanceCounterCollection

System.IDisposable

Namespace: Syncfusion.UI.Xaml.Grid.ScrollAxis

Assembly: Syncfusion.SfGridCommon.UWP.dll

Syntax

public class DistanceRangeCounterCollection : Object, IDistanceCounterCollection, IDisposable

Remarks

DistanceCounterCollection internally uses ranges for allocating objects up to the modified entry with the highest index. When you modify the size of an entry the collection ensures that that objects are allocated for all entries up to the given index. Entries that are after the modified entry are assumed to have the DefaultSize and will not be allocated.

Ranges will only be allocated for those lines that have different sizes. If you do for example only change the size of line 100 to be 10 then the collection will internally create two ranges: Range 1 from 0-99 with DefaultSize and Range 2 from 100-100 with size 10. This approach makes this collection work very efficient with grid scenarios where often many rows have the same height.

Constructors

DistanceRangeCounterCollection()

Declaration

public DistanceRangeCounterCollection()

DistanceRangeCounterCollection(Double)

Constructs the class and initializes the internal tree.

Declaration

public DistanceRangeCounterCollection(double paddingDistance)

Parameters

Type	Name	Description
System.Double	paddingDistance

Fields

Empty

Returns an empty collection.

Declaration

public static readonly DistanceRangeCounterCollection Empty

Field Value

Type
DistanceRangeCounterCollection

paddingDistance

Declaration

public double paddingDistance

Field Value

Type
System.Double

Properties

Count

The raw number of entities (lines, rows or columns).

Declaration

public int Count { get; set; }

Property Value

Type
System.Int32

DefaultDistance

The default distance (row height or column width) an entity spans

Declaration

public double DefaultDistance { get; set; }

Property Value

Type
System.Double

Item[Int32]

Gets or sets the distance for an entity.

Declaration

public double this[int index] { get; set; }

Parameters

Type	Name	Description
System.Int32	index	The index for the entity

Property Value

Type
System.Double

TotalDistance

The total distance all entities span (e.g. total height of all rows in grid)

Declaration

public double TotalDistance { get; }

Property Value

Type
System.Double

Methods

Clear()

Clears this instance.

Declaration

public void Clear()

ConnectWithParent(ITreeTableCounterSource)

Connects a nested distance collection with a parent.

Declaration

public void ConnectWithParent(ITreeTableCounterSource treeTableCounterSource)

Parameters

Type	Name	Description
ITreeTableCounterSource	treeTableCounterSource	The nested tree table visible counter source.

Dispose()

Call the Dispose and SuppressFinalize method for dipose the instance of DistanceCounterCollection class.

Declaration

public void Dispose()

Dispose(Boolean)

Dispose the live resources used by the DistanceCounterCollection class.

Declaration

protected virtual void Dispose(bool disposing)

Parameters

Type	Name	Description
System.Boolean	disposing	Dispose the instance, if it is True

GetAlignedScrollValue(Double)

Gets the aligned scroll value which is the starting point of the entity found at the given distance position.

Declaration

public double GetAlignedScrollValue(double point)

Parameters

Type	Name	Description
System.Double	point	The point.

Returns

Type	Description
System.Double	The starting point of the entity.

GetCumulatedDistanceAt(Int32)

Gets the cumulated count of previous distances for the entity at the specifiec index. (e.g. return pixel position for a row index).

Declaration

public double GetCumulatedDistanceAt(int index)

Parameters

Type	Name	Description
System.Int32	index	The entity index.

Returns

Type	Description
System.Double	The cumulated count of previous distances for the entity at the specifiec index.

GetNestedDistances(Int32)

Gets the nested entities at a given index. If the index does not hold a mested distances collection the method returns null.

Declaration

public IDistanceCounterCollection GetNestedDistances(int index)

Parameters

Type	Name	Description
System.Int32	index	The index.

Returns

Type	Description
IDistanceCounterCollection	The nested collection or null.

GetNextScrollValue(Double)

Gets the distance position of the next entity after a given point.

Declaration

public double GetNextScrollValue(double point)

Parameters

Type	Name	Description
System.Double	point	The point.

Returns

Type	Description
System.Double	The distance position.

GetNextVisibleIndex(Int32)

Skip subsequent entities for which the distance is 0.0 and return the next entity.

Declaration

public int GetNextVisibleIndex(int index)

Parameters

Type	Name	Description
System.Int32	index

Returns

Type
System.Int32

GetPreviousScrollValue(Double)

Gets the distance position of the entity preceeding a given point. If the point is in between entities the starting point of the matching entity is returned.

Declaration

public double GetPreviousScrollValue(double point)

Parameters

Type	Name	Description
System.Double	point	The point.

Returns

Type	Description
System.Double	The distance position.

GetPreviousVisibleIndex(Int32)

Skip previous entities for which the distance is 0.0 and return the next entity.

Declaration

public int GetPreviousVisibleIndex(int index)

Parameters

Type	Name	Description
System.Int32	index

Returns

Type
System.Int32

IndexOfCumulatedDistance(Double)

Gets the index of an entity in this collection for which the cumulated count of previous distances is greater or equal the specified cumulatedDistance. (e.g. return row index for pixel position).

Declaration

public int IndexOfCumulatedDistance(double cumulatedDistance)

Parameters

Type	Name	Description
System.Double	cumulatedDistance	The cumulated count of previous distances.

Returns

Type	Description
System.Int32	The entity index.

Insert(Int32, Int32)

Insert entities in the collection.

Declaration

public void Insert(int insertAt, int count)

Parameters

Type	Name	Description
System.Int32	insertAt	Insert position.
System.Int32	count	The number of entities to be inserted.

Insert(Int32, Int32, Double)

Insert entities in the collection.

Declaration

public void Insert(int insertAt, int count, double distance)

Parameters

Type	Name	Description
System.Int32	insertAt	Insert position.
System.Int32	count	The number of entities to be inserted.
System.Double	distance	The distance to be set.

InvalidateNestedEntry(Int32)

Declaration

public void InvalidateNestedEntry(int index)

Parameters

Type	Name	Description
System.Int32	index

Remove(Int32, Int32)

Removes enities from the collection.

Declaration

public void Remove(int removeAt, int count)

Parameters

Type	Name	Description
System.Int32	removeAt	Index of the first entity to be removed.
System.Int32	count	The number of entities to be removed.

ResetRange(Int32, Int32)

Resets the range by restoring the default distance for all entries in the specified range.

Declaration

public void ResetRange(int from, int to)

Parameters

Type	Name	Description
System.Int32	from	From.
System.Int32	to	To.

SetNestedDistances(Int32, IDistanceCounterCollection)

Assigns a collection with nested entities to an item.

Declaration

public void SetNestedDistances(int index, IDistanceCounterCollection nestedCollection)

Parameters

Type	Name	Description
System.Int32	index	The index.
IDistanceCounterCollection	nestedCollection	The nested collection.

SetRange(Int32, Int32, Double)

Hides a specified range of entities (lines, rows or colums)

Declaration

public void SetRange(int from, int to, double distance)

Parameters

Type	Name	Description
System.Int32	from	The index for the first entity>
System.Int32	to	The raw index for the last entity
System.Double	distance	The distance.

Implements

IDistanceCounterCollection

System.IDisposable

Extension Methods

DateTimeExtension.ToDateTime(Object)