xlsgen > overview > Chart options

Most chart elements share a common set of formatting options. Those common options are exposed in xlsgen using a common interface, IXlsChartOptions. All specific options are exposed in a separate interface, IXlsChartCustomProperties, and is covered in more details here.

The properties managed by this interface are :

• position, width/height
• font options
• border style
• marker style
• area fill options, including gradient, texture, patterns and image
• number format
• alignment

Virtually chart elements implement this interface, which provides a really quick way to customize a chart without having to learn a new interface for each chart element. In the remainder of this page, the underlying semantics of the options are going to be explained.

Options are automatically set by default. That is, unless you set new values, the chart engine will use automatic options.

Position, width/height

To accomodate the arbitrary size of the chart, positions and width and height are expressed in percentage of the chart width and height. If you'd like to put a chart element right in the center, the following statements should be used :

• X = 50
• Y = 50

Font options

Font options are regular options just like those used in cells. Font options are accessed using the Font of the interface, which in turn is described here. There are two additional options specific to fonts used in charts :

• scale font with chart, AutoScale property. Disabled by default, it makes the font size scale automatically based on the size of the chart.
• background is transparent or opaque, BackgroundType property. By default it's automatically set, which means depending on the chart element it will be set transparent or opaque by default.

Border style

Border style is automatically set, which often results in a black border of standard weight. The interface is defined here. When borders are customized, a number of properties can be changed, including :

• the border type itself : automatic, none or custom. See enumerated type enumChartBorder.
• if the border type is chosen to be custom, then the following options can be set :
  • the border style. See enumerated type enumChartBorderStyle.
  • the border color.
  • the border weight. See enumerated type enumChartBorderWeight.
  • the border width.
  • for most borders, it's also possible to define whether or not RoundCorners should be drawn, and if Shadows should be drawn.

Marker style

Marker style options apply to charts like scatter and lines. The interface is defined here. See enumerated types enumChartMarker and enumChartMarkerStyle.

Area style

Area style is automatically set. Area style options are very flexible : regular solid fill can be applied (just like for cells), but also gradient, textures, patterns and even a custom image can be defined. The interface is defined here.

• pattern fill. See interface IXlsChartAreaStylePattern and enumerated type enumChartAreaPattern.
• solid fill. It's a special case of pattern fill.
• gradient fill. See interface IXlsChartAreaStyleGradient and enumerated types enumChartGradientStyle and enumChartGradientPreset.
• texture fill. See interface IXlsChartAreaStyleTexture and enumerated type enumChartTexture.
• image fill. See interface IXlsChartAreaStyleImage.

In addition, the area style interface supports two properties : InverseIfNegative and Bubble 3D effect. The reason why these options are exposed in this interface is because Excel exposes those options in the area style options. The first property inverses the color when values are negative. The second property adds a 3D effect to bubbles and obviously only applies to bubble charts.