Class LineScrollAxis

The LineScrollAxis implements scrolling only for whole lines. You can hide lines and LineScrollAxis provides a mapping mechanism between the index of the line and the scroll index and vice versa. Hidden lines are not be counted when the scroll index is determined for a line.

The LineScrollAxis does not support scrolling in between lines (pixel scrolling). This can be of advantage if you have a large number of lines with varying line sizes. In such case the LineScrollAxis does not need to maintain a collection that tracks line sizes whereas the PixelScrollAxis does need to.

Inheritance
System.Object
ScrollAxisBase
LineScrollAxis
Implements
System.IDisposable
Inherited Members
Namespace: Syncfusion.Maui.GridCommon.ScrollAxis
Assembly: Syncfusion.Maui.GridCommon.dll
Syntax
public class LineScrollAxis : ScrollAxisBase, IDisposable

Constructors

LineScrollAxis(IScrollBar, ILineSizeHost)

Initializes a new instance of the LineScrollAxis class.

Declaration
public LineScrollAxis(IScrollBar sb, ILineSizeHost scrollLinesHost)
Parameters
Type Name Description
IScrollBar sb

The state of the scrollbar.
ILineSizeHost scrollLinesHost

The scroll lines host.

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

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

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, Boolean)

Gets the index of the scroll line.

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

Index of the scroll linde.
System.Double scrollLineDelta

The scroll line delta.
System.Boolean isRightToLeft

The boolean value used to calculate visible columns in right to left mode.
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

OnLinesInserted(Int32, Int32)

Called when lines were inserted in ScrollLinesHost.

Declaration
protected override void OnLinesInserted(int insertAt, int count)
Parameters
Type Name Description
System.Int32 insertAt

Index of the first inserted line.
System.Int32 count

The count.
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

ScrollInView(Int32, Double)

Scrolls the line into viewable area.

Declaration
public override void ScrollInView(int lineIndex, double lineSize)
Parameters
Type Name Description
System.Int32 lineIndex

Index of the line.
System.Double lineSize
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. Will do nothing for a LineScrollAxis

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 line count in header, footer and body.

Declaration
public override void UpdateScrollBar()
Overrides

Implements

System.IDisposable