void initAdd(DataType initialBaseDataType, int allocationOffset, int bitOffset,
			boolean useCurrentAllocation) {
		if (initialBaseDataType == null) {
			initialBaseDataType = baseDataType;
		}
		if (!BitFieldDataType.isValidBaseDataType(initialBaseDataType)) {
			initialBaseDataType = IntegerDataType.dataType.clone(composite.getDataTypeManager());
		}
		long allocationSize = useCurrentAllocation ? (Long) allocSizeModel.getValue()
				: initialBaseDataType.getLength();
		placementComponent.updateAllocation((int) allocationSize, allocationOffset);
		placementComponent.initAdd(1, bitOffset);
		initControls(null, null, initialBaseDataType, 1);
		enableControls(true);
	}
<code>BitFieldEditorPanel</code> provides the ability to add or modify bitfields
within non-packed structures.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/compositeeditor/BitFieldEditorPanel.java