Figure 4-6 Setting the Vertical Axis

Description of "Figure 4-6 Setting the Vertical Axis"

Adding Negative Values

Because the vertical axis in the Temperature Monitoring application is created by using the NumberAxis class, you can specify negative values for the area chart data.

Create one more series of data as shown in Example 4-7.

Figure 4-7 demonstrates the Temperature Monitoring application modified to display the weather data for three months: March, April, and May.

Figure 4-7 Adding Negative Data

Description of "Figure 4-7 Adding Negative Data"

StylingAreaCharts

The color for each month in Example 4-7 is defined by the order of the corresponding data series as declared in the addAll method. That is why the March area in Figure 4-7 is painted yellow. You can set the color for AreaChart objects through CSS.

Create the Chart.css file and save it in the same directory as the main class of the AreaChartSample application. Add the lines shown in Example 4-8 to the Chart.css file.

The chart-area-symbol CSS class defines parameters of the symbol in the chart legend for a particular data series. Example 4-8 sets the inner and outer colors for the circles in the chart legend.

The chart-series-area-line CSS class sets parameters for the area chart lines. In this example, the color of the line stroke. The chart-series-area-fill CSS class defines the color and the opacity level of the areas.

These styles are applied to the AreaChartSample application by using the getStylesheets() method of the Scene class, as shown Example 4-9.

Compiling and running this application produces the modified appearance of the area chart shown in Figure 4-8.