write diagram contain current editor output stream png imag overrid save graphic output stream editor ce rectangl draw area io except rectangl canva area save graphic manag adjust draw area draw area creat imag defer render gef diagram demand data pull render imag defer buffer imag canva area buffer imag type argb ce scale defin log lp log granular type statement log debug creat defer buffer imag draw area canva area scale scale endif imag io write png 