protected int getNumSubComponents(int rowIndex) {
		DataTypeComponent dtc = getComponent(rowIndex);
		if (dtc instanceof Composite) {
			Composite comp = (Composite) dtc;
			return comp.getNumComponents();
		}
		return 0;
	}
If the component at the indicated index is a composite data type,
this gets the number of components that it contains.

@param rowIndex the index of the component in the editor.
@return the number of sub-components or 0.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/compositeeditor/CompositeEditorModel.java