ZK Spreadsheet Essentials/Working with Spreadsheet/Handling Data Model/Chart

Available in ZK Spreadsheet EE only

Overview

Range API can allow you to add, move, and delete a charts of a Spreadsheet:

public Chart addChart(SheetAnchor anchor, Type type, Grouping grouping, LegendPosition pos);

public void deleteChart(Chart chart);

public void moveChart(SheetAnchor anchor,Chart chart);

A chart (Chart) is a simple object that you can only get its ID and position. All chart types constant are listed in Chart.Type. Most chart types are supported except OF_PIE, RADAR, STOCK, SURFACE_3D, and SURFACE. Supported grouping(Chart.Grouping) are STANDARD, STACKED, PERCENT_STACKED and, CLUSTERED. Supported legend positions(Chart.LegendPosition) are BOTTOM, LEFT, RIGHT, TOP, and TOP_RIGHT.

The SheetAnchor represents a chart's position on a sheet. When adding or moving a chart, you must provide one SheetAnchor to assign a chart's position. You can create a SheetAnchor by passing 4 index numbers, left-top corner's and right-bottom's row and column of a chart. When invoking addChart(), you will get the newly-created chart object in returned value. You had better store it somewhere you can retrieve it back later if you plan to delete or move it. Otherwise, you can only get them from a Sheet method:

	public List<Chart> getCharts();

Then, use its ID or position to identify a chart.

Example

The screenshot below is a application that can add, move and delete a chart. For simplicity, this application only adds pie charts.

When we click "Add", it will add a pie chart with the data from A1:B6 and add a items in the Listbox on the top right corner. Select a chart item in the listbox, enter destination row and column index in 2 Intboxes, then click "Move". The selected chart will be moved to specified position. The "Delete" button will delete the selected chart.

Notice that there are 5 columns in the Listbox on the top right corner which display information about charts we add. The ID is a chart's ID generated automatically by Spreadsheet. The row and column represents a chart's position of the left top corner in 0-based index and the last row and last column represents symmetric position of a chart (right bottom corner). For example, in the screenshot, the topmost chart whose ID is "rid1", its left top corner is at "F1" represented in column index "5" and row index "0". Its right bottom corner is at "K9" represented in column index "10" and row index "8". in column index "1" and row index "6". Its right bottom corner is at "C12" represented in column index "11" and row index "2". These position information is stored in SheetAnchor. When adding or moving a picture, you must provide one SheetAnchor to assign a picture's position. The SheetOperationUtil provides methods to simplify this.

Let's see this application's controller codes:

public class ChartComposer extends SelectorComposer<Component> {

	@Wire
	private Intbox toRowBox;
	@Wire
	private Intbox toColumnBox;
	@Wire
	private Spreadsheet ss;
	@Wire
	private Listbox chartListbox;

	private ListModelList<Chart> chartList = new ListModelList<Chart>();

	@Listen("onClick = #addButton")
	public void addByUtil(){
		SheetOperationUtil.addChart(Ranges.range(ss.getSelectedSheet(),new AreaRef("A1:B6")),
		Type.PIE, Grouping.STANDARD, LegendPosition.RIGHT);
		refreshChartList();
	}
	
	@Listen("onClick = #moveButton")
	public void moveByUtil(){
		if (chartListbox.getSelectedItem() != null){
			SheetOperationUtil.moveChart(Ranges.range(ss.getSelectedSheet()),
					(Chart)chartListbox.getSelectedItem().getValue(),
					toRowBox.getValue(), toColumnBox.getValue());
			refreshChartList();
		}
	}
	
	@Listen("onClick = #deleteButton")
	public void deleteByUtil(){
		if (chartListbox.getSelectedItem() != null){
			SheetOperationUtil.deleteChart(Ranges.range(ss.getSelectedSheet()), 
					(Chart)chartListbox.getSelectedItem().getValue());
			refreshChartList();
		}
	}

	private void refreshChartList(){
		chartList.clear();
		chartList.addAll(ss.getSelectedSheet().getCharts());
		chartListbox.setModel(chartList);
	}
}

• Line 16: SheetOperationUtil.addChart() converts a range of cells automatically to chart data based on a predefined assumption. For example, it will assume that the first column contains category labels.

All source code listed in this book is at Github.