Identify the monitor with the browser window in FireBreath

Question

I am using FireBreath to create a cross browser plugin which makes use of some native libraries for the respective platform (some .NET based DLLs for Windows and Objective-C based dylibs/frameworks for Mac). Native libraries display UI screens. In order to improve usability, if the user has a multi/extended monitor setup, i would like the native UIs to appear on the same screen as the browser window is currently on.

If an identifier to the monitor with the browser window can be retrieved, that can be passed down to the native components which can be configured to display their UIs on that monitor. I have used FireBreath's getWindowPosition() method to get the rect coordinates of the plugin and used that info to identify the correct monitor in the Windows platform.

However, the coordinates returned in Mac seems to be always 0 (or 1) irrespective of monitor on which the browser window currently resides. I understand that we have to configure an event model and a drawing model in order for this to work in Mac. I have tried following event/drawing model combinations without much success.

1) Cocoa/CoreGraphics 2) Carbon/CoreGraphics

Any help in this regard is much appreciated. Also please do share if there are other approaches to achieve the same. What i want to achieve is to identify the monitor on which the current active browser window resides in Mac. I am unsure at this point, but it maybe possible to achieve this at Objective-C level (without any changes at FireBreath level). Also please note that i want to support Safari, Firefox and Chrome browsers.

Answer 1

I did manage to come up with a workaround and i am just replying here for the completeness of the thread. As @taxilian explained, it is not possible to retrieve plugin coordinates using the window reference. As an alternative approach, Javascript 'Window' object has 2 properties called 'screenX' and 'screenY' that return X and Y coordinates of the browser window relative to the screen. If the user has an extended monitor setup, these are the absolute coordinates with respect to the full extended screen. We can use these values to determine the monitor with the browser window (if the X coordinate is outside the bounds of the primary monitor's width, then the browser should essentially be on the extended monitor). We can retrieve DOM properties from Firebreath as explained in the following link:

http://www.firebreath.org/display/documentation/Invoking+methods+on+the+DOM

Answer 2

You won't like this answer, but simply put you can't do that on Mac. The problem is that with CoreGraphics you are only given a CGContextRef to work with, and it doesn't know where it will be drawn. It was technically possible in older browsers to get an NSWindow by exploiting some internal implementation details, but many browsers that's no longer possible and it was never supported.

Other drawing models are the same; CoreAnimation you have a CALayer but it doesn't know which screen or monitor it is drawn to. I personally think it's a bit annoying as well, but I do not know of any way to find out which monitor your plugin is rendered to, particularly since most of them actually copy the buffer to something else and render in a different process.