This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
Window.onpaint is an event handler for the
paint event on the window.
Not working in Gecko-based applications currently, see Notes section!
window.onpaint = funcRef;
funcRefis a handler function.
onpaint doesn't work currently, and it is questionable whether this event is going to work at all, see bug 239074.
paint event is raised when the window is rendered. This event occurs after the
load event for a window, and reoccurs each time the window needs to be re-rendered, such as when another window obscures it and is then cleared away.
This is not part of any specification.