If you are using RTE then you can use Justify or Styles plugin for the same.
If you are not using RTE then you can have a tab and a widget of xtype - componentstyles.
With component styles you can provide options to wrap the content of component with custom styles.
Take a look at foundation textimage component (/libs/foundation/components/textimage/dialog/items/tab4)
- Drag textimage component in parsys container of any geometrixx page made with template Geometrixx Content Page (http://localhost:4502/cf#/content/geometrixx/en/services.html)
- Open the dialog and observe Styles Tab
- Values of styles tab comes from its design level configuration which is present at - /etc/designs/geometrixx/jcr:content/contentpage/par/textimage/cq:styles
the styles that you select while configuring content that style class gets placed in your autogenerated CQ Div tag.
Hope it helps.
- Runal