Calling Windows API from Native Client/Pepper Plug

问题:

My intention is to create a chrome plugin for the windows users. Is that possible to call windows api from Native Client /PPAPI. If possible how?

回答1:

I am answering my question, as after some study, I found the answer from West a bit not right. I tried calling windows APIs in Pepper(PPAPI) Plugin and it works fine with a command line switch "--register-pepper-plugins" (not the --no-sandbox as specified by West). It seems safer to use this command line attribute as it is only registering a plugin in to the Chrome browser and not removing any sandbox. I thought of adding an answer after finding an actual pepper plugin existing in use, which uses the switch (the NetFlix pepper plugin for chromeos ).

Got more information to add. Chrome API is available which provides the multi-monitor information : chrome.systemInfo.display object provides all the necessary information. The chrome documentation is not updated. Important thing to note is that, the permission "systemInfo.display" is to be added in the manifest to use this object. Two bugs are reported in the functionality of this object.
1. The monitor name is same for all monitors "Generic PnP Monitor", the documentation claims to provide the user friendly name of monitors.
2. There is an event which should get invoked on resolution change of monitors, but the event is never getting invoked.

Currently the implementation is only for Windows OS. Support for other OS are on the way. Documentation says that the API is only available for Chrome App, but I haves tested that and the API is available on Chrome Extensions as well.

回答2:

Unfortunately, the short answer is 'no'. Native Client is designed to be OS-independent and as safe as JavaScript. Think of Native Client as native code that has the same capabilities and restrictions as JavaScript. A Native Client module that made Windows API calls would break both of those design principles: it wouldn't run on, e.g., a Mac, and it would be a major security risk (imagine browsing to a web page that decides to erase files from your harddrive).

Since you mention Chrome, it may be interesting to you to know that web apps - whether they use JavaScript or Native Client - can request additional permissions as packaged apps in Chrome Web Store. However, native OS calls are still not possible for the reasons listed above.

NPAPI plugins do not have these restrictions, but the future of NPAPI, at least in Chrome, is uncertain (see the last paragraph of http://blog.chromium.org/2012/07/npapi-plug-ins-in-windows-8-metro-mode.html).

For development purposes, it is possible to turn Chrome's outer sandbox off with the command-line flag --no-sandbox and then run PPAPI plugins that make direct OS calls. This is meant for developers and is not a suitable option to be used by end-users.

If you could say a bit more about what you're trying to achieve, there may be ways to do this with Native Client/Pepper.