How to wait for the final renderer OnPaint call

[Robar]

Hi,

I'm currently developing an application which opens a SVG via CEF and takes a screenshot. I'm using C# and the CefGlue binding (v3.2704.1409).

I'm waiting for the OnLoadingStateChange call and as soon as the page is loaded I'm waiting for the first OnPaint call in the RenderHandler. After the first call I save the screenshot as a bitmap.

Unfortunately the first OnPaint call is not always the last one, which leaves me with an incomplete bitmap/screenshot.

How can I tell if the browser is done with the rendering? Is there a way to check if a OnPaint call is the last one?

[magreenblatt]

You can wait some delay that works for you. There is no way to know when a page has stopped painting because the content may be constantly changing (via JS, user interaction, etc).

[amaitland]

Their are a couple of approaches I've used in the past, the first being In OnLoadingStateChange when IsLoading == false trigger a timer, reset that time every time paint is called (before the trigger), when OnPaint stops being called, the timer stops being reset and the trigger takes a screenshot. Crude, but mostly effective.

Secondly purely for screen shot purposes in combination with a delay I like to drop the WindowlessFrameRate way down. If I'm not particularly worried about performance I'll even drop it to 1fps (You can even count the number of OnPaint calls and capture on the nth call)

[Robar]

Thanks for your responses. I've already dropped the frame rate to 1fps. And I will now try the approach where I take the screenshot after the nth call.