Constructor
new ChartLine()
Used by Lightstreamer to provide a ChartLine object to each call of the ChartListener#onNewLine event. This constructor is not supposed to be used by custom code.
Methods
getYField() → {Number}
Inquiry method that retrieves the field in the Chart internal model representing the Y axis to which this ChartLine pertains.
- See:
Returns:
the field representing the Y axis.
- Type
- Number
positionYAxis(min, max)
Operation method that sets or changes the limits for the visible part of the Y axis of the chart (that is, the minimum and maximum Y-coordinates shown in the chart for this line). When these limits are changed a full repaint of the line is performed.
Lifecycle: The Y axis limits can be set at any time.
Parameters:
| Name | Type | Description |
|---|---|---|
min |
Number |
lower limit for the visible part of the Y axis. |
max |
Number |
higher limit for the visible part of the Y axis. |
Throws:
-
if the min parameter is greater than the max one.
setStyle(pointColoropt, lineColoropt, pointSizeopt, lineSizeopt)
Setter method that sets the style to be applied to the points drawn on the chart area. Colors of the points, and lines can be customized using valid CSS colors while size is specified in pixels.
Parameters:
| Name | Type | Attributes | Default | Description |
|---|---|---|---|---|
pointColor |
String |
<optional> |
black |
color use to draw the points on the chart. A point is drawn per each new value in the model. Any valid CSS color can be used. By default "black" is used. |
lineColor |
String |
<optional> |
black |
the color use to draw the lines on the chart. A line is to connect two consecutive points for the same line. Any valid CSS color can be used. By default "black" is used. |
pointSize |
Number |
<optional> |
1 |
the size in pixel of the drawn points. By default 1 is used. |
lineSize |
Number |
<optional> |
1 |
the size in pixel of the drawn lines. By default 1 is used. |
Throws:
-
if pointSize or lineSize are not valid positive integer numbers.
setYLabels(labelsNum, labelsClassopt, labelsFormatteropt)
Setter method that configures the legend for the Y axis. The legend
consists of a specified number of labels for the values in the Y axis.
The labels values are determined based on the axis limits; the labels
appearance is controlled by supplying a stylesheet and a formatter
function.
Note that the room for the Y axis labels on the page is not provided
by the library; it should be provided by specifying a chart width
smaller then the container element width and displaced on the right,
through the Chart#configureArea setting.
Moreover, as the upmost and lowest labels are centered on the chart
area borders, a little space should be provided also over and under
the chart area, through the same method.
Lifecycle: Labels can be configured at any time. If not set, no labels are displayed relative to the Y axis. If set for different ChartLine instances on the same Chart then more sets of labels will be printed.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
labelsNum |
Number |
the number of labels to be spread on the Y axis; it should be 1 or greater. |
|
labelsClass |
String |
<optional> |
the name of an existing stylesheet, to be applied to the Y axis label HTML elements. The parameter is optional; if missing or null, then no specific stylesheet is applied. |
labelsFormatter |
LabelsFormatter |
<optional> |
a Function instance
used to format the Y axis values designated for the labels.
|
Throws:
-
if labelsNum is not a valid positive integer number.