Class CMScaleBar extends CMItem

CMScaleBar
Class to render a scale bar into the scene. The scale bar will be automatically
repainted with the scale based on its position in the scene.
The algorithm is to find the two points at either end of the rectangle provided
for the scale bar and convert these points to geographic coordinates. Then,
a great arc calculation is performed to find the distance between the points.
The scale displayed is then found by reducing this distance to an even multiple
of 1, 2, or 5. If this distance does not fit in the area provided (including the
the labels), the next smaller distance is computed. This continues until a distance
is found that fits.

Note that the scale bar is placed into a DIV in the map container. Thus is uses a
CSS style (CM_ScaleBar) for the style of the containing box. The contents of the
DIV are drawn in a Canvas element.

Settings
TextStyle - used to write the text above the ticks on the scale bar

Enumerated Types

CMScaleBar.UNITS_ISO=0 - meters, kilometers
CMScaleBar.UNITS_ENGLISH=1 - feet, miles

Settings Group: ScaleBar

Setting	Name	Type	Options	Default	Comments
ClassName	Class Name	CMTYPE_STRING		CM_ScaleBar

Settings Group: UnitText

Setting	Name	Type	Options	Default
Text	Text	CMTYPE_STRING		null
font	Font	CMTYPE_FONT		12px Arial
strokeStyle	Line Style	CMTYPE_CSS_STYLE		rgb(0,0,0)
fillStyle	Fill Style	CMTYPE_CSS_STYLE		rgb(255,255,255)
lineWidth	Width	CMTYPE_INTEGER		1
lineCap	Line Cap	CMTYPE_ENUMERATED	butt, round, square	round
lineJoin	Line Join	CMTYPE_ENUMERATED	bevel, round, miter	round

Settings Group: Factors

Setting	Name	Type	Options	Default	Comments
UnitFontHeightFactor	Corner Width	CMTYPE_FLOAT		0.35	proportion of the height of the scale bar used for units
LabelFontHeightFactor	Corner Height	CMTYPE_FLOAT		0.3
ScaleBarHeightFactor	Corner Height	CMTYPE_FLOAT		0.3
ScaleBarBaseLineFromBottomFactor	Corner Height	CMTYPE_FLOAT		0.2	proportional distance of the bottom of the scale bar from the bottom of the background
Units	Units	CMTYPE_INDEXES	0	CMScaleBar.UnitOptions[0]
Margin	Margin	CMTYPE_FLOAT		4	margin around the scale bar

ScaleBarStyle Scale Bar Style CMTYPE_OBJECT style of the actual bar BoxStyle Box Style CMTYPE_OBJECT style of the actual bar