The Scale Bar Item
To add a scale bar, click the 
Add new scalebar icon, place
the element with the left mouse button on the Print Composer canvas and position
and customize the appearance in the scale bar Item Properties tab.
The Item properties of a scale bar item tab provides the following
functionalities (see figure_composer_scalebar_1):
Figure Composer Scalebar 1:
The Main properties dialog of the scale bar Item Properties tab
provides the following functionalities (see figure_composer_scalebar_2):
Figure Composer Scalebar 2:
- First, choose the map the scale bar will be attached to.
- Then, choose the style of the scale bar. Six styles are available:
- Single box and Double box styles, which contain one or two lines of boxes alternating colors.
- Middle, Up or Down line ticks.
- Numeric, where the scale ratio is printed (i.e., 1:50000).
The Units and Segments dialogs of the scale bar
Item Properties tab provide the following functionalities
(see figure_composer_scalebar_3):
Figure Composer scalebar 3:
In these two dialogs, you can set how the scale bar will be represented.
- Select the units you want to use with Scalebar units.
There are four possible choices: Map Units, the default one and Meters,
Feet or Nautical Miles which may force unit conversions.
- The Label unit multiplier specifies how many scalebar units per labeled unit.
Eg, if your scalebar units are set to “meters”, a multiplier of 1000 will result
in the scale bar labels in “kilometers”.
- The Label for units field defines the text used to describe the units
of the scale bar, eg “m” or “km”. This should be matched to reflect the multiplier above.
- You can define how many Segments will be drawn on the left and on the right side of the scale bar.
- You can set how long each segment will be (fixed width), or limit the scale bar size in mm
with Fit segment width option. In the latter case, each time the map scale changes,
the scale bar is resized (and its label updated) to fit the range set.
- Height is used to define the height of the bar.
The Display dialog of the scale bar Item Properties tab provide
the following functionalities (see figure_composer_scalebar_4):
Figure Composer Scalebar 4:
You can define how the scale bar will be displayed in its frame.
- Box margin : space between text and frame borders
- Labels margin : space between text and scale bar drawing
- Line width : line width of the scale bar drawing
- Join style : Corners at the end of scalebar in style Bevel, Rounded or Square
(only available for Scale bar style Single Box & Double Box)
- Cap style : End of all lines in style Square, Round or Flat
(only available for Scale bar style Line Ticks Up, Down and Middle)
- Alignment : Puts text on the left, middle or right side of the frame
(works only for Scale bar style Numeric)
The Fonts and colors dialog of the scale bar Item Properties tab
provide the following functionalities (see figure_composer_scalebar_5):
Figure Composer Scalebar 5:
You can define the fonts and colors used for the scale bar.
- Use the [Font] button to set the font of scale bar label
- Font color: set the font color
- Fill color: set the first fill color
- Secondary fill color: set the second fill color
- Stroke color: set the color of the lines of the Scale Bar
Fill colors are only used for scale box styles Single Box and Double Box.
To select a color you can use the list option using the dropdown arrow to open
a simple color selection option or the more advanced color selection option, that is
started when you click in the colored box in the dialog.
