The document model comes with a number of predefined themes called Document themes. They enable you to specify colors, fonts and a variety of graphic effects in a document and affect the look and feel of the whole workbook. Each theme contains a color scheme and a font scheme and is represented by the DocumentTheme class.
A color scheme has a unique name and contains a number of predefined colors. Its representation in the document model is the ThemeColorScheme class. A scheme defines twelve colors and each of these is assigned a sole ThemeColorType. The following list contains all ThemeColorType values:
The twelve color types above are used for creating ThemableColor objects. They determine the color of the scheme that appears as the actual color of the ThemableColor instance. As you change the theme or the color scheme, the actual color of the ThemeableColor object changes as well. For example, if you set the fill of a cell to be a ThemableColor, applying a new theme or another scheme also affects the solid fill.
Example 1 demonstrates how to create a ThemeColorScheme object. Note that the example passes a name and twelve colors to the constructor. Every color has a comment next to it, so you can see its corresponding ThemeColorType.
Example 1: Create ThemeColorScheme
ThemeColorScheme colorScheme = new ThemeColorScheme( "Mine", Colors.Black, // background 1 Colors.Blue, // text 1 Colors.Brown, // background 2 Colors.Cyan, // text 2 Colors.DarkGray, // accent 1 Colors.Gray, // accent 2 Colors.Green, // accent 3 Colors.LightGray, // accent 4 Colors.Magenta, // accent 5 Colors.Orange, // accent 6 Colors.Purple, // hyperlink Colors.Red); // followedHyperlink
There are several ways to create a ThemableColor object:
Passing two parameters to the constructor – ThemeColorType and double.
ThemeColorType is an enum which has twelve possible values (the aforementioned color types).
The second parameter is of type double and should be between -1 and 1. It represents the tint and shade to be applied to the selected color.
Passing ThemeColorType and ColorShadeType.
ThemeColorType is the same as in the previously mentioned constructor.
In order to create colors that depend on the current document theme, you need to use ThemableColor objects.
Example 2 shows how you can create a ThemableColor.
Example 2: Create ThemableColor
ThemableColor themableColor = new ThemableColor(ThemeColorType.Accent1);
A font scheme is represented by the ThemeFontScheme class. Every font scheme consists of a name and a number of predefined font families. Each font family corresponds to one of two font types:
To create a ThemeFontScheme you need to pass a name and two font family names to the font scheme constructor. The former font family name corresponds to the Major ThemeFontType and the latter - to the Minor.
Example 3 illustrates how to create a ThemeFontScheme object.
Example 3: Create ThemeFontScheme
ThemeFontScheme fontScheme = new ThemeFontScheme( "Mine", "Times New Roman", // latinMajor "Arial"); // latinMinor
In order to use the document theme's fonts, you need to use ThemableFontFamily objects. Again, there are several ways you can create one:
Passing a ThemeFontType object as a constructor parameter – this way you will bind the object being created to the currently selected document theme.
Passing a FontFamily object or a string representing a FontFamily name – the result would be a static FontFamily, meaning it will not be changed when the document theme is changed.
When you need to create а font that depends on the current document theme, you can use the ThemableFontFamily objects.
Example 4 shows how to create a ThemableFontFamily.
Example 4: Create ThemableFontFamily
ThemableFontFamily themableFont = new ThemableFontFamily(ThemeFontType.Major);
Now that when you have a color and a font schemes, you can create a new DocumentTheme. You need to specify a name and pass the already created color and font schemes.
Example 5 demonstrates how to create a DocumentTheme using the color scheme from Example 1 and the font scheme from Example 3.
Example 5: Create DocumentTheme
DocumentTheme theme = new DocumentTheme("Mine", colorScheme, fontScheme);
In the predefined static class PredefinedThemeSchemes, you can find a number of predefined color and font schemes. The class exposes the properties ColorSchemes and FontSchemes that hold all predefined schemes.
Example 6 shows how you can create a document theme using the predefined color and font schemes.
Example 6: Create DocumentTheme from predefined schemes
DocumentTheme theme = new DocumentTheme("From predefined schemes", PredefinedThemeSchemes.ColorSchemes, PredefinedThemeSchemes.FontSchemes);
Changing the current document theme is as easy as setting a single property:
Example 7 changes the theme of a newly created workbook.
Example 7: Change DocumentTheme
Workbook workbook = new Workbook(); workbook.Worksheets.Add(); workbook.Theme = theme;
In order to get the actual value from ThemableColor or ThemableFontFamily you need to call the GetActualValue() method on the corresponding object.
Example 8: Get actual color
Color actualColor = themableColor.GetActualValue(theme); // the actual color is the same as Accent1 color of the colorScheme
Example 9: Get actual font
var actualFont = themableFont.GetActualValue(theme); // the actualFont is the same as the Major font of the fontScheme