16. The non-transitory computer readable medium of claim 14 , wherein the first layout function defines one or more calculations for displaying the first element.
16. The non-transitory computer readable medium of claim 14 , wherein the first layout function defines one or more calculations for displaying the first element. 17. The non-transitory computer readable medium of claim 16 , wherein: the first element comprises a paragraph; and the first layout function defines one or more calculations thr determining a location of one or more lines in the paragraph and whether the paragraph can fit into an available page height.