javascript - Problems using HTML Canvas & Greasemonkey not able to drawImage() on 2D context -

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in greasemonkey script, when obtain handle on htmlimageelement want use html canvas, following error in firefox's error console (i assume it's because it's enclosed in xpcnativewrapper):

error: component returned failure code: 0x80040111 (ns_error_not_available)         [nsidomcanvasrenderingcontext2d.drawimage]

putting gm_log() statements throughout code, have traced image object i'm trying use it's initial assignment through until try use html canvas.

it's wrapped in xpcnativewrapper:

[object xpcnativewrapper [object htmlimageelement]]

i've unwrapped htmlimageelement obtaining reference image.wrappedjsobject.

my canvas code:

var canvas = document.createelement("canvas"); canvas.width = image.width; canvas.height = image.height;  var ctx = canvas.getcontext("2d"); ctx.drawimage(image, 0, 0);

any ideas why firefox throwing above component failure code?

i should have looked more thoroughly on google.

image.wrappedjsobject;

works.


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