@Override
	public int getRowCount() {
		int componentCount = getNumComponents();
		int rowCount = componentCount + 1; // add blank edit row
		return rowCount;
	}
Returns the number of component rows in the viewer. There may be a
blank row at the end for selecting. Therefore this number can be
different than the actual number of components currently in the
structure being viewed.

@return the number of rows in the model
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/compositeeditor/StructureEditorModel.java