Class ScaleBarWidget

A ScaleBarWidget displays the ratio of a distance on the map to the corresponding distance on the ground. It uses always the center of a given Viewport to calc this ratio.

Usage To show a ScaleBarWidget, add a instance of the ScaleBarWidget to Map.Widgets by

map.Widgets.Add(new ScaleBarWidget(map));

Customize ScaleBarMode: Determines, how much scalebars are shown. Could be Single or Both. SecondaryUnitConverter: First UnitConverter for upper scalebar. There are UnitConverters for metric, imperial and nautical units. SecondaryUnitConverter = NauticalUnitConverter.Instance }); MaxWidth: Maximal width of the scalebar. Real width could be smaller. HorizontalAlignment: Where the ScaleBarWidget is shown. Could be Left, Right, Center or Position. VerticalAlignment: Where the ScaleBarWidget is shown. Could be Top, Bottom, Center or Position. PositionX: If HorizontalAlignment is Position, this value determines the distance to the left PositionY: If VerticalAlignment is Position, this value determines the distance to the top TextColor: Color for text and lines Halo: Color used around text and lines, so the scalebar is better visible TextAlignment: Alignment of scalebar text to the lines. Could be Left, Right or Center TextMargin: Space between text and lines of scalebar Font: Font which is used to draw text TickLength: Length of the ticks at scalebar

Inheritance

object

Widget

ScaleBarWidget

Implements

IWidget

IWidgetTouchable

INotifyPropertyChanged

Inherited Members

Widget.HorizontalAlignment

Widget.VerticalAlignment

Widget.MarginX

Widget.MarginY

Widget.Envelope

Widget.Enabled

Widget.CalculatePositionX(float, float, float)

Widget.CalculatePositionY(float, float, float)

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: Mapsui.Widgets.ScaleBar

Assembly: Mapsui.dll

Syntax

public class ScaleBarWidget : Widget, IWidget, IWidgetTouchable, INotifyPropertyChanged

Constructors

ScaleBarWidget(Map, IProjection?)

Declaration

public ScaleBarWidget(Map map, IProjection? projection = null)

Parameters

Type	Name	Description
Map	map
IProjection	projection

Properties

Font

Font to use for drawing text

Declaration

public Font? Font { get; set; }

Property Value

Type	Description
Font

Halo

Halo color of scalebar and text, so that it is better visible

Declaration

public Color Halo { get; set; }

Property Value

Type	Description
Color

Height

Real height of scalebar. Depends on number of unit converters and text size. Is calculated by renderer.

Declaration

public float Height { get; set; }

Property Value

Type	Description
float

MaxWidth

Maximum usable width for scalebar. The real used width could be less, because we want only integers as text.

Declaration

public float MaxWidth { get; set; }

Property Value

Type	Description
float

Scale

Declaration

public float Scale { get; }

Property Value

Type	Description
float

ScaleBarMode

ScaleBarMode of scalebar. Could be Single to show only one or Both for showing two units.

Declaration

public ScaleBarMode ScaleBarMode { get; set; }

Property Value

Type	Description
ScaleBarMode

SecondaryUnitConverter

Secondary unit converter for lower text if ScaleBarMode is Both. Default is ImperialUnitConverter.

Declaration

public IUnitConverter? SecondaryUnitConverter { get; set; }

Property Value

Type	Description
IUnitConverter

ShowEnvelop

Draw a rectangle around the scale bar for testing

Declaration

public bool ShowEnvelop { get; set; }

Property Value

Type	Description
bool

StrokeWidth

Stroke width for lines

Declaration

public float StrokeWidth { get; set; }

Property Value

Type	Description
float

StrokeWidthHalo

Stroke width for halo of lines

Declaration

public float StrokeWidthHalo { get; set; }

Property Value

Type	Description
float

TextAlignment

Alignment of text of scalebar

Declaration

public Alignment TextAlignment { get; set; }

Property Value

Type	Description
Alignment

TextColor

Foreground color of scalebar and text

Declaration

public Color TextColor { get; set; }

Property Value

Type	Description
Color

TextMargin

Margin between end of tick and text

Declaration

public float TextMargin { get; }

Property Value

Type	Description
float

TickLength

Length of the ticks

Declaration

public float TickLength { get; set; }

Property Value

Type	Description
float

Touchable

Declaration

public override bool Touchable { get; }

Property Value

Type	Description
bool

Overrides

Widget.Touchable

UnitConverter

Normal unit converter for upper text. Default is MetricUnitConverter.

Declaration

public IUnitConverter UnitConverter { get; set; }

Property Value

Type	Description
IUnitConverter

Methods

CanProject()

Declaration

public bool CanProject()

Returns

Type	Description
bool

GetScaleBarLengthAndText(Viewport)

Calculates the length and text for both scalebars

Declaration

public (float scaleBarLength1, string? scaleBarText1, float scaleBarLength2, string? scaleBarText2) GetScaleBarLengthAndText(Viewport viewport)

Parameters

Type	Name	Description
Viewport	viewport

Returns

Type	Description
(float scaleBarLength1, string scaleBarText1, float scaleBarLength2, string scaleBarText2)	Length of upper scalebar Text of upper scalebar Length of lower scalebar Text of lower scalebar

GetScaleBarLinePositions(Viewport, float, float, float)

Get pairs of points, which determine start and stop of the lines used to draw the scalebar

Declaration

public IReadOnlyList<MPoint> GetScaleBarLinePositions(Viewport viewport, float scaleBarLength1, float scaleBarLength2, float stroke)

Parameters

Type	Name	Description
Viewport	viewport	The viewport of the map
float	scaleBarLength1	Length of upper scalebar
float	scaleBarLength2	Length of lower scalebar
float	stroke	Width of line

Returns

Type	Description
IReadOnlyList<MPoint>	Array with pairs of Points. First is always the start point, the second is the end point.

GetScaleBarTextPositions(Viewport, MRect, MRect, MRect, float)

Calculates the top-left-position of upper and lower text

Declaration

public (float posX1, float posY1, float posX2, float posY2) GetScaleBarTextPositions(Viewport viewport, MRect textSize, MRect textSize1, MRect textSize2, float stroke)

Parameters

Type	Name	Description
Viewport	viewport	The viewport
MRect	textSize	Default text size for the string "9999 m"
MRect	textSize1	Size of upper text of scalebar
MRect	textSize2	Size of lower text of scalebar
float	stroke	Width of line

Returns

Type	Description
(float posX1, float posY1, float posX2, float posY2)	posX1 as left position of upper scalebar text posY1 as top position of upper scalebar text posX2 as left position of lower scalebar text posY2 as top position of lower scalebar text

HandleWidgetTouched(Navigator, MPoint)

Function, which is called, when a Widget is hidden

Declaration

public override bool HandleWidgetTouched(Navigator navigator, MPoint position)

Parameters

Type	Name	Description
Navigator	navigator	Navigator of MapControl
MPoint	position	Screen position

Returns

Type	Description
bool	True, if the Widget had handled the touch event

Overrides

Widget.HandleWidgetTouched(Navigator, MPoint)

Events

PropertyChanged

Declaration

public event PropertyChangedEventHandler? PropertyChanged

Event Type

Type	Description
PropertyChangedEventHandler

Implements

IWidget

IWidgetTouchable

INotifyPropertyChanged