Bracket-Shell Custom Native (C++) Function not being called

Question

I'm trying to create a custom C++ function which I can call from JavaScript. The function is a simple one to just resize the window.

I have the following bits in the following places:

In appshell_extensions_platform.h:

#if defined(OS_WIN)
void ResizeWindow(CefRefPtr<CefBrowser> browser, int width, int height);
#endif

In appshell_extensions_win.cpp:

void ResizeWindow(CefRefPtr<CefBrowser> browser, int width, int height) {
    OutputDebugString(L"ResizeWindow");
    CefWindowHandle hWnd = browser->GetHost()->GetWindowHandle();
    SetWindowPos(hWnd, 0, 0, 0, width, height, SWP_NOMOVE|SWP_NOZORDER|SWP_NOACTIVATE);
}

In appshell_extensions.js:

/**
  * Resize the window to the given size.
  *
  * @param {number} width
  * @param {number} height
  *
  * @return None. This is an asynchronous call that sends all return information to the callback.
 */
 native function ResizeWindow();
 appshell.app.resizeWindow = function (width, height) {
     ResizeWindow(width, height);
 };

In appshell_extensions.cpp:

} else if (message_name == "ResizeWindow") {
    // Parameters:
    //  0: int32 - width
    //  1: int32 - height
    int width = argList->GetInt(0);
    int height = argList->GetInt(1);
    ResizeWindow(browser, width, height);
}

Using Visual Studio 2012, I then Build and Debug on the Debug Win32 release. When I open the console, appshell.app.resizeWindow is there as expected. I can call it and it works just fine. If I put additional JavaScript code in the function, it also works.

To the function in appshell_extensions.cpp, I've added OutputDebugString(std::wstring(message_name.begin(), message_name.end()).c_str());. For functions other than the one I wrote, it will output the message name properly. For the one I wrote, I get nothing.

I don't get the output from the function itself either.

It appears that the message isn't actually getting to the function which processes it, but I have no clue. I'm just using the sln that came with brackets-shell (converted to 2012) to compile. Is there a build step I'm maybe missing or something?

Thanks.

Answer 1

I figured out the problem.

Apparently, in the JavaScript functions, the first parameter MUST be a callback, even if you don't use it.

Changing the JavaScript portion to this fixed the problem:

/**
  * Resize the window to the given size.
  *
  * @param {number} width
  * @param {number} height
  *
  * @return None. This is an asynchronous call that sends all return information to the callback.
 */
 native function ResizeWindow();
 appshell.app.resizeWindow = function (width, height) {
     ResizeWindow(_dummyCallback, width, height);
 };

I also had a bit of an issue with the actual resize logic. You need to use the window handle of the browser->getHost()->getWindowHandle() parent:

`CefWindowHandle hWnd = getParent(browser->GetHost()->GetWindowHandle());