get real width & height for ctx.clear method
get real width & height for ctx.clear method

Huji/vexflow,Mdonmounts/vexflow,mwicat/vexflow,Kosar79/vexflow,shuanzi/vexflow,Tails/vexflow,voidest1/vexflow,ringw/vexflow,pinxue/vexflow,toni07/vexflow,spencerhitch/vexflow_extended,JanvanCasteren/vexflow,Chipairon/vexflow,bsouthward/vexflow,burnnat/vexflow,petehamilton/vexflow,springzh/vexflow,johndpope/vexflow,petehamilton/vexflow,wander2001/vexflow,johndpope/vexflow,winning1120xx/vexflow,cute/vexflow-musicxml,aaronmars/scottish-writer,ecompositor/vexflow,Kosar79/vexflow,rukor/vexflow,ohoushyar/vexflow,lasconic/vexflow-musicxml,vikeen/vexflow,mcanthony/vexflow,zolaemil/vexflow,spencerhitch/vexflow_extended,pinxue/vexflow,mariushe/vexflow,FatPanther/vexflow,zex713/vexflow,bwbohl/vexflow,LarryKu/vexflow,niklasgrahl/vexflow,Silverwolf90/vexflow,JanvanCasteren/vexflow,FatPanther/vexflow,aaronmars/scottish-writer,fgeorgy/vexflow,springzh/vexflow,avorio/vexflow,jbernie2/vexflow,DigitalCoder/vexflow,Tails/vexflow,bwbohl/vexflow,JanvanCasteren/vexflow,incompleteopus/vexflow,redreamality/vexflow,Silverwolf90/vexflow,cdosborn/vexflow,clecap/vexflow-musicxml,Kosar79/vexflow,ohoushyar/vexflow,jmahmud/vexflow,alexmao86/vexflow,Tails/vexflow,clecap/vexflow-musicxml,Mdonmounts/vexflow,avorio/vexflow,spencerhitch/vexflow_extended,toni07/vexflow,aerhard/vexflow,gaborveszpremi/vexflow,incompleteopus/vexflow,vikeen/vexflow,wander2001/vexflow,IcculusC/vexflow,cute/vexflow-musicxml,cgamache/vexflow,redreamality/vexflow,incompleteopus/vexflow,pinxue/vexflow,JasonLil/vexflow,burnnat/vexflow,IcculusC/vexflow,dfcreative/vexflow,cute/vexflow-musicxml,Charlie-Wellesley/vexflow,LarryKu/vexflow,dhruvrajan/vexflow,cgamache/vexflow,jdowner/vexflow,cgamache/vexflow,mcanthony/vexflow,cdosborn/vexflow,winning1120xx/vexflow,jmahmud/vexflow,dfcreative/vexflow,cpill0789/vexflow,bwbohl/vexflow,amitgur/vexflow,zolaemil/vexflow,Charlie-Wellesley/vexflow,zex713/vexflow,shuanzi/vexflow,Huji/vexflow,vmoll/vexflow,Chipairon/vexflow,JasonLil/vexflow,nybbs2003/vexflow,Fabrico/vexflow,RSid/vexflow,jcrogel/vexflow,zolaemil/vexflow,avorio/vexflow,ssoRL/vexflow,fgeorgy/vexflow,zachledoux/vexflow,guert/vexflow,Fabrico/vexflow,nybbs2003/vexflow,vmoll/vexflow,ecompositor/vexflow,petehamilton/vexflow,cdosborn/vexflow,ssoRL/vexflow,RSid/vexflow,bsouthward/vexflow,Chipairon/vexflow,Petezah/vexflow,fgeorgy/vexflow,lasconic/vexflow-musicxml,FatPanther/vexflow,aaronmars/scottish-writer,DigitalCoder/vexflow,cpill0789/vexflow,jbernie2/vexflow,Mdonmounts/vexflow,trinketapp/vexflow,burnnat/vexflow,amitgur/vexflow,toni07/vexflow,natedsaint/vexflow,liuyang1204/vexflow,Petezah/vexflow,Daremyth/vexflow,natedsaint/vexflow,LarryKu/vexflow,amitgur/vexflow,Daremyth/vexflow,ecompositor/vexflow,toni07/vexflow,niklasgrahl/vexflow,mwicat/vexflow,guert/vexflow,jmahmud/vexflow,mwicat/vexflow,liuyang1204/vexflow,wander2001/vexflow,alexmao86/vexflow,jcrogel/vexflow,ohoushyar/vexflow,nybbs2003/vexflow,Fabrico/vexflow,voidest1/vexflow,alexmao86/vexflow,natedsaint/vexflow,clecap/vexflow-musicxml,mariushe/vexflow,aaronmars/vexflow,guert/vexflow,ssoRL/vexflow,aerhard/vexflow,niklasgrahl/vexflow,zhhz/vexflow,dhruvrajan/vexflow,rukor/vexflow,cute/vexflow-musicxml,Daremyth/vexflow,Charlie-Wellesley/vexflow,jdowner/vexflow,clecap/vexflow-musicxml,Petezah/vexflow,vmoll/vexflow,gaborveszpremi/vexflow,rukor/vexflow,zhhz/vexflow,mcanthony/vexflow,IcculusC/vexflow,winning1120xx/vexflow,dfcreative/vexflow,gaborveszpremi/vexflow,cpill0789/vexflow,zachledoux/vexflow,Huji/vexflow,jdowner/vexflow,voidest1/vexflow,Silverwolf90/vexflow,redreamality/vexflow,JasonLil/vexflow,dhruvrajan/vexflow,trinketapp/vexflow,aerhard/vexflow,trinketapp/vexflow,springzh/vexflow,liuyang1204/vexflow,jcrogel/vexflow,DigitalCoder/vexflow,aaronmars/vexflow,lasconic/vexflow-musicxml,aaronmars/vexflow,bsouthward/vexflow,zex713/vexflow