Marked Polyline Displayer

Class	IlvMarkedPolylineChartDisplayer
Category	Composite
Number of real data sets displayed	1
Can be used with all types of projections	Yes
Number of child displayers	2 (1 scatter displayer + 1 polyline displayer)
Items drawn	Markers and/or Polyline

The marked polyline displayer is composed of a scatter displayer (an instance of the IlvScatterChartDisplayer class) and a polyline displayer (an instance of the IlvPolylineChartDisplayer class). Each child displayer can be customized individually. You can specify the palette, the marker type, and the marker size directly for the scatter displayer. You can specify the palette directly for the polyline displayer. Use the following methods to access the child displayers:

The Charts Library also provides some methods at the level of the IlvMarkedPolylineChartDisplayer class that allow you to set properties defined for child displayers more quickly. The following table lists all the properties that can be set at the level of the IlvMarkedPolylineChartDisplayer class. (For details on all the properties that can be set on a scatter displayer, see Scatter Displayer. For details on all the properties that can be set on a polyline displayer, see Polyline Displayer.)

Property	Methods	Default Value
General Properties
Markers Displayed	isMarkerVisible setMarkerVisible	IlvTrue
Polyline Displayed	isLineVisible setLineVisible	IlvTrue
Scatter Displayer Properties
Palette	getMarkerPalette setMarkerPalette	0
Palette Foreground	getMarkerForeground setMarkerForeground	0
Palette Background	getMarkerBackground setMarkerBackground	0
Polyline Displayer Properties
Palette	getLinePalette setLinePalette	0
Palette Foreground	getLineForeground setLineForeground	0
Palette Background	getLineBackground setLineBackground	0

By default, a marked polyline displayer displays a data set with both markers and a polyline. However, you can specify that only markers are to be displayed by setting the property Polyline Displayed to IlvFalse. You can specify that only a polyline is to be displayed by setting the property Markers Displayed to IlvFalse.

Figure 8.13 illustrates the fact that a marked polyline displayer can be used with all types of projections. Data sets are represented by marked polyline displayers in a Cartesian chart (using a Cartesian projection) and in a polar chart (using a polar projection).

We can use the marked polyline displayer displaying the red lines and gold markers as an example. To create this displayer, we can use the following code:

IlvMarkedPolylineChartDisplayer* displayer =

new IlvMarkedPolylineChartDisplayer();

displayer->setMarkerForeground(dpy->getColor("gold"));

displayer->setLineForeground(dpy->getColor("red"));