Package com.jbstrap.ui.components.charts

Class BarChart

java.lang.Object
com.jbstrap.ui.components.charts.BaseChart<T>
com.jbstrap.ui.components.charts.SeriesBasedChart<T>
com.jbstrap.ui.components.charts.AxesBasedChart<BarChart>
com.jbstrap.ui.components.charts.BarChart
All Implemented Interfaces:
DataDescriptorCallback, ClickableChartData<BarChart>, MultiSeriesChart<BarChart,BarSeries>, SupportBrush<BarChart>, SupportLasso<BarChart>, SupportZoom<BarChart>
public class BarChart extends AxesBasedChart<BarChart> implements MultiSeriesChart<BarChart,BarSeries>, ClickableChartData<BarChart>, SupportLasso<BarChart>, SupportZoom<BarChart>, SupportBrush<BarChart>

A bar chart displays data series as columns. A chart may contain one or more data series. If you display multiple data series on a bar chart, the series are display next to each other. A bar chart is an axis-based chart that has an X and Y axis. Bars are visualized on the chart according to this rotation. All displayed data series constitute a separate column of different color. Each bar is separately displayed in the legend. The legend shows the user the type of data for each series. Users are allowed to enable or disable each bar by clicking on legend items. Bar colors on a horizontal bar chart are automatically calculated but can also be specified. By default, columns contain all associated values and the bars’ corners are not rounded. You can change these settings, rounding off bar corners. You can also control where each data point is displayed or if they should be displayed at all.

Marker setting also work with horizontal stacked bar charts, but they only modify the legend’s appearance; markers are not displayed on individual columns. Markers are not displayed on columns, therefore users can select data points and display a tooltip by clicking on the entire area of a bar.

You can modify the tooltip type or create a custom tooltip using any JBStrap component. The bar chart can use three different tooltip types, each one displaying data points differently. You can use the following tooltip types on a bar chart: DOT, LINE and SIMPLE. By default, the simple tooltip is displayed on the chart. If you want to display a different tooltip type, you need to create it on your own using ChartTooltipRenderer. You only need to implement one method which returns the tooltip as a component. In order to do this, you can reuse any JBStrap component. It is possible to display a button, a list or even another chart on the tooltip.

The chart also supports click events. This means that you can implement server-side business logic for the event that is triggered when a user clicks on a data point. This is when a ChartClick event is triggered. This event provides you information on where and which chart the user clicked on. This can be reused in various ways, e.g. to update a list.

The chart also supports the lasso feature. This function is disabled by default. If enabled, the user is allowed to select one or more data points. You can select a data point by circling the data points on the chart. You can make a selection on multiple charts or series at the same time. If a user selects multiple data points on the chart, a Lasso event is triggered on the server side. This event is associated with every selection. If a user selects a data point on a chart, the event is triggered on every chart. The lasso event contains information on the selected chart and series. This piece of information can be then used in any business logic, e.g. to group data points or conduct further analysis.

The chart also supports the zoom feature. This function is disabled by default. If you enable it, the user is allowed to zoom in on a chart area by using the mouse scroll wheel, thereby allowing a closer look at the details. If a user zooms in on the chart while the lasso feature is disabled, it is possible to horizontally move the chart by keeping the mouse button pressed. If the lasso feature is enabled, users are not allowed to move the chart as the lasso feature is active when keeping the mouse button pressed.

This chart supports the brush feature which works with the zoom feature. This function is disabled by default. If you enable it, a miniature version of the chart appears below the chart. Users can zoom in on the chart, but in this case the miniature version of the chart is not zoomed. Instead, a small dark area indicates the area of the chart currently displayed on the normal size chart. Users can move this darker area, at the same time moving the zoomed area on the normal size chart. If you use this feature alongside the lasso feature, users are able to use all functionalities of these features on the chart.

Since:
4.0
Author:
JBStrap
See Also:

  • Constructor Details

    • BarChart

      public BarChart(String name)
      Creates the bar chart.
      Parameters:
      name - Chart name It is mandatory to specify the chart name and it must be unique within the ChartCanvas. Later on, you can reference the chart with the name specified here.
      Throws:
      NullPointerException - Thrown if the specified name is null or it is an empty string

    • BarChart

      public BarChart(String name, DataDescriptor dataDescriptor, String categoryColumnName)
      Creates a bar chart component and sets the associated DataDescriptor and the name of the column containing X axis values.
      Parameters:
      name - Chart name It is mandatory to specify the chart name and it must be unique within the ChartCanvas. Later on, you can reference the chart with the name specified here.
      dataDescriptor - The DataDescriptor that contains the chart data
      categoryColumnName - The name of the DataDescriptor containing X axis data If not specified, or null is specified, the framework starts looking for the “CATEGORY” column.
      Throws:
      NullPointerException - Thrown if the specified name is null or it is an empty string
      IllegalArgumentException - Thrown if the column specified in the categoryColumnName parameter is not found in the DataDescriptor or if the categoryColumnName parameter is not specified and no “CATEGORY” column is found in the DataDescriptor.

  • Method Details