Abstract
Readonly
engineInterface for end user API of the LCJS engine. It provides some useful capabilities over the area enclosed by a single LCJS context (which can be just a single chart, or a Dashboard with several charts).
Scale for panel area in pixels.
Scale for panel area in percentages (0-100).
Add a legendbox.
Legendbox is a type of UI element, that floats inside the chart/component it is created inside. It can be freely moved around with user interactions, as well as positioned in application code.
The purpose of legendbox is to describe the series and other visual components of the chart, by displaying their names and colors. Hovering over a series' legendbox entry will highlight that series, and clicking on the entry will toggle that series' visibility.
Legendbox alignment:
Alignment of legendbox can be selected by supplying one of the available LegendBoxBuilders to addLegendBox
:
// Default (vertical) LegendBox.
const legendBox = ChartXY.addLegendBox()
// Horizontal LegendBox.
const horizontalLegendBox = ChartXY.addLegendBox(LegendBoxBuilders.HorizontalLegendBox)
Custom Legendbox positioning:
By default LegendBoxes are placed on the right side, or bottom of the chart (depending on alignment).
A custom location can be configured with UIElement API:
Position coordinate system is specified when creating legendbox.
addLegendBox( LegendBoxBuilders.VerticalLegendBox )
// Position = [0, 100] as percentages.
.setPosition({ x: 50, y: 50 })
addLegendBox( LegendBoxBuilders.VerticalLegendBox, chart.pixelScale )
// Position = pixels.
.setPosition({ x: 300, y: 100 })
addLegendBox( LegendBoxBuilders.VerticalLegendBox, { x: chartXY.getDefaultAxisX(), y: chartXY.getDefaultAxisY() } )
// Position = Axis values.
.setPosition({ x: 5, y: 5 })
LegendBox
LegendBoxBuilder. If omitted, VerticalLegendBox will be selected. Use LegendBoxBuilders for selection.
Optional parameter for altering the coordinate system used for positioning the LegendBox. Defaults to whole Chart in percentages [0, 100].
Add a stand-alone UIElement using a builder.
Example usage:
addUIElement( UIElementBuilders.TextBox )
// Position = [0, 100] as percentages.
.setPosition({ x: 50, y: 50 })
addUIElement( UIElementBuilders.TextBox, chart.pixelScale )
// Position = pixels.
.setPosition({ x: 300, y: 100 })
addUIElement( UIElementBuilders.TextBox, { x: chartXY.getDefaultAxisX(), y: chartXY.getDefaultAxisY() } )
// Position = Axis values.
.setPosition({ x: 5, y: 5 })
Object that fulfills interfaces: UIElementType (typeparam) and UIElement
Type of UIElement that is specified by 'builder'-parameter.
UIElementBuilder. If omitted, TextBoxBuilder will be selected. Use UIElementBuilders for selection.
Optional parameter for altering the coordinate system used for positioning the UIElement. Defaults to whole Chart in percentages [0, 100].
Permanently dispose the component.
To fully allow Garbage-Collection to free the resources used by the component, make sure to remove any references to the component and its children in application code.
let chart = ...ChartXY()
let axisX = chart.getDefaultAxisX()
// Dispose Chart, and remove all references so that they can be garbage-collected.
chart.dispose()
chart = undefined
axisX = undefined
Object itself for fluent interface
Get theme effect enabled on component or disabled.
A theme can specify an Effect to add extra visual oomph to chart applications, like Glow effects around data or other components.
Whether this effect is drawn above a particular component can be configured using the setEffect
method.
// Example, disable theme effect from a particular component.
Component.setEffect(false)
For the most part, theme effects are enabled by default on most components.
Theme effect is configured with effect property.
Boolean that describes whether drawing the theme effect is enabled around the component or not.
Get font of Chart title.
FontSettings object
Subscribe to mouse-click event on Chart background
Subscribe to mouse-doubleClick event on Chart background
Subscribe to mouse-down event on Chart background
Subscribe to mouse-drag event on Chart background
Subscribe to mouse-drag start event on Chart background
Subscribe to mouse-drag stop event on Chart background
Subscribe to mouse-enter event on Chart background
Subscribe to mouse-leave event on Chart background
Subscribe to mouse-move event on Chart background
Subscribe to mouse-up event on Chart background
Subscribe to mouse-wheel event on Chart background
Subscribe to touch-end event on Chart background
Subscribe to touch-move event on Chart background
Subscribe to touch-start event on Chart background
Subscribe onDispose
event.
This event is triggered whenever the Control (Dashboards and all chart types) is disposed.
// Example usage
Chart.onDispose(() => {
console.log('chert was disposed')
})
Chart.dispose()
Token of subscription
Subscribe to resize
event.
This event is triggered whenever the area of chart changes (due to document or dashboard resizing).
// Example usage,
ChartXY.onResize((chart, width, height, engineWidth, engineHeight) => {
console.log('Chart resized', 'width', width, 'height', height, 'engineWidth', engineWidth, 'engineHeight', engineHeight)
})
Token of subscription
Handler function for event
Capture rendered state in an image file. Prompts the browser to download the created file.
NOTE: The download might be blocked by browser/plugins as harmful. To prevent this, only call the method in events tied to user-interactions. From mouse-event handlers, for example.
Has two optional parameters which directly reference JavaScript API HTMLCanvasElement.toDataURL. For supported image formats, compression quality, Etc. refer to:
https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement/toDataURL
Example usage:
// Download 'screenshot.png'
Panel.saveToFile('screenshot')
// Attempt download 'maybeNotSupported.bmp'
Panel.saveToFile('maybeNotSupported', 'image/bmp')
// Attempt download jpeg.file with specified compression quality
Panel.saveToFile('fileName', 'image/jpeg', 0.50)
If 'type' is not supported by browser, an Error will be thrown.
Name of prompted download file as string. File extension shouldn't be included as it is automatically detected from 'type'-argument.
Optional
type: stringA DOMString indicating the image format. The default format type is image/png.
Optional
encoderOptions: numberA Number between 0 and 1 indicating the image quality to use for image formats that use lossy compression such as image/jpeg and image/webp. If this argument is anything else, the default value for image quality is used. The default value is 0.92.
Set FillStyle of chart background.
// Example usage,
ChartXY.setBackgroundFillStyle(new SolidFill({ color: ColorRGBA( 80, 0, 0 ) }))
Related API:
Transparent chart backgrounds:
LightningChart JS charts can be configured to be fully or partially transparent.
// Example, partially transparent chart
// Engine background exists under all LCJS components. In case of Dashboard, there is only 1 shared engine background.
chart.engine.setBackgroundFillStyle(emptyFill)
// Chart background covers every 1 chart. In case of Dashboard, every chart has its own chart background.
chart.setBackgroundFillStyle(new SolidFill({ color: ColorRGBA(0, 0, 0, 100) }))
// Some charts also have a separate series background.
chart.setSeriesBackgroundFillStyle(new SolidFill({ color: ColorRGBA(0, 0, 0, 100) }))
Object itself
FillStyle
or function which mutates the active FillStyle
.
Set LineStyle of chart background border stroke.
// Example usage,
ChartXY.setBackgroundStrokeStyle(new SolidLine({
thickness: 2,
fillStyle: new SolidFill({ color: ColorRGBA( 0, 255, 0 ) })
}))
Related API:
Object itself
LineStyle
or function which mutates the active LineStyle
.
Set padding around Chart in pixels.
// Example 1, specify complete padding (four sides).
ChartXY.setPadding({ left: 16, right: 16, top: 32, bottom: 8 })
// Example 2, specify only single padding.
ChartXY.setPadding({ right: 64 })
Object itself
Number with pixel margins for all sides or datastructure with individual pixel paddings for each side. Any side can be omitted, only passed values will be overridden.
Set theme effect enabled on component or disabled.
A theme can specify an Effect to add extra visual oomph to chart applications, like Glow effects around data or other components.
Whether this effect is drawn above a particular component can be configured using the setEffect
method.
// Example, disable theme effect from a particular component.
Component.setEffect(false)
For the most part, theme effects are enabled by default on most components.
Theme effect is configured with effect property.
Object itself.
Theme effect enabled
Set fill style of Chart Title.
Example usage:
// Create a new style
Chart.setTitleFillStyle(new SolidFill({ color: ColorHEX('#F00') }))
// Change transparency
Chart.setTitleFillStyle((solidFill) => solidFill.setA(80))
// Set hidden
Chart.setTitleFillStyle(emptyFill)
Chart itself
Either a FillStyle object or a function, which will be used to create a new FillStyle based on current value.
Set font of Chart Title.
Example usage:
// Create a new FontSettings
Chart.setTitleFont(new FontSettings({ size: 24, style: 'italic' }))
// Change existing settings
Chart.setTitleFont((fontSettings) => fontSettings.setWeight('bold'))
Chart itself
Either a FontSettings object or a function, which will be used to create a new FontSettings based on current value.
Specifies padding after chart title.
This does not have an effect if title is hidden (empty FillStyle).
// Example 2, specify margins for all sides with same value for Title.
ChartXY.setTitleMargin(40)
Chart itself for fluent interface
Gap after the chart title in pixels.
Chart abstraction layer that implements Chart title and padding.