Using defaults

The options are used to change how the chart behaves. There are properties to control styling, fonts, the legend, etc.

This concept is allowing for changing options globally across chart types, using chart type defaults and scales defaults appropriately, avoiding the need to specify options for each instance, or the default for a particular chart type.

Charba doesn't merge the options object but delegates Chart.JS to do it which merges the option object passed to the chart with the global configuration.

In this way you can be as specific as you would like in your individual chart configuration, while still changing the defaults for all chart types where applicable.

There are 4 main defaults entities that you can manage to configure your charts, at global level:

1. Global: global options, containing the configuration items which can be applied to all charts, whatever type of chart. Scale configuration is excluded.
2. Chart option: global options related to a specific type of chart, containing both options and scales configuration.
3. Scale: global options related to scale, containing the configuration items which can be applied to all charts (with scales), whatever type of chart.
4. Scale type: global options related to a specific type of scale which can be applied to all charts which are using that type of scale.

Charba is providing a singleton Defaults which allows you to manage all defaults entities above mentioned.

info

It's not possible to apply any callbacks or any events handlers at global level, but only on at chart instance one.

Global

To change the global options, Charba is providing the method getGlobal in the Defaults class. These options will be applied to all charts, whatever type of chart.

With above method you can get all global configurations of Chart.JS and you have got all set and get methods to change or retrieve the global configuration items.

// --------------------------------------
// GLOBAL, for all charts (whatever type)
// --------------------------------------
Defaults.get().getGlobal().setResponsive(false);
Defaults.get().getGlobal().setMaintainAspectRatio(true);

double circumference = Defaults.get().getGlobal().getCircumference();

Charts type

To change the global options for a specific chart type, Charba is providing the method getOptions in the Defaults class.

With this method you can get all global configurations for a specific chart of Chart.JS and you have got all set and get methods to change or retrieve the global configuration items.

The chart type are defined in a enumeration, ChartType but, by controllers, you can create your chart type, therefore the method will accept a Type object.

// --------------------------------------
// GLOBAL options for specific chart type
// --------------------------------------
Defaults.get().getOptions(ChartType.LINE).setResponsive(false);
Defaults.get().getOptions(ChartType.LINE).setMaintainAspectRatio(true);

double circumference = Defaults.get().getOptions(ChartType.LINE).getCircumference();

Defaults.get().getOptions(ChartType.LINE).getElements().getPoint().setPointStyle(PointStyle.RECT);

Scales

To change the global scale, Charba is providing the method getScale in the defaults.

With this method you can get all global configuration of Chart.JS for scale (common one, not related to chart type) and you have got all set and get methods to change or retrieve the global configuration items.

// --------------------------------------
// GLOBAL, for all scales (whatever type)
// --------------------------------------
Defaults.get().getScale().setStacked(true);

Scales type

To change the global scale for a specific scale type, Charba is providing the method getScale in the Defaults class, passing the type of the scale.

With this method you can get all global configurations for a specific type of scale and you have got all set and get methods to change or retrieve the global configuration items.

// --------------------------------------
// GLOBAL options for specific scale type
// --------------------------------------
Defaults.get().getScale(ChartAxisType.LINEAR).setDisaply(false);
Defaults.get().getScale(ChartAxisType.LINEAR).setBeginAtZero(true);

Methods

The default singleton instance provides a set of helpful methods to invoke default behavior of Chart.JS, helpful methods when a callback is implemented and you want to perform a normal behavior.

public class MyLegendClickEventHandler implements LegendClickEventHandler {

    @Override
    public void onClick(LegendClickEvent event){
        // invokes default click callback
        Defaults.get().invokeLegendOnClick(event);
    }

Name	Scope	Description
invokeChartOnClick	Chart	This method invokes the default onClick implementation on a chart, if there is.
invokeChartOnHover	Chart	This method invokes the default onHover implementation on a chart, if there is.
generateLabels	Legend	This method will provide the default legend items of a chart.
invokeLegendOnClick	Legend	This method invokes the default onClick implementation on a legend of a chart, if there is.
invokeLegendOnHover	Legend	This method invokes the default onHover implementation on a legend of a chart, if there is.
invokeLegendOnLeave	Legend	This method invokes the default onLeave implementation on a legend of a chart, if there is.
invokeTooltipsCallbackOnTitle	Tooltip	This method invokes the default implementation on a tooltip of a chart to get the title text of the tooltip.
invokeTooltipsCallbackOnLabel	Tooltip	This method invokes the default implementation on a tooltip of a chart to get an individual item in the tooltip.
invokeTooltipsCallbackOnLabelColor	Tooltip	This method invokes the default implementation on a tooltip of a chart to get the color of an individual item in the tooltip.
invokeTooltipsCallbackOnLabelPointStyle	Tooltip	This method invokes the default implementation on a tooltip of a chart to get the point style of an individual item in the tooltip.