_ff-addon-snippet-ChangeWindowIcon - Uses js-ctypes to change the icon of a window. (Windows Only)

_ff-addon-snippet-ChangeWindowIcon.js

Cu.import('resource://gre/modules/ctypes.jsm');

var user32 = ctypes.open('user32.dll');

/* http://msdn.microsoft.com/en-us/library/windows/desktop/ms644950%28v=vs.85%29.aspx
 * LRESULT WINAPI SendMessage(
 * __in HWND hWnd,
 * __in UINT Msg,
 * __in WPARAM wParam,
 * __in LPARAM lParam
 * );
 */
var SendMessage = user32.declare('SendMessageW', ctypes.winapi_abi, ctypes.uintptr_t,
	ctypes.voidptr_t,
	ctypes.unsigned_int,
	ctypes.int32_t,
	ctypes.voidptr_t
);

/* http://msdn.microsoft.com/en-us/library/windows/desktop/ms648045%28v=vs.85%29.aspx
 * HANDLE WINAPI LoadImage(
 * __in_opt_  HINSTANCE hinst,
 * __in_      LPCTSTR lpszName,
 * __in_      UINT uType,
 * __in_      int cxDesired,
 * __in_      int cyDesired,
 * __in_      UINT fuLoad
 * );
 */
var LoadImage = user32.declare('LoadImageA', ctypes.winapi_abi, ctypes.voidptr_t,
	ctypes.voidptr_t,
	ctypes.char.ptr,
	ctypes.unsigned_int,
	ctypes.int,
	ctypes.int,
	ctypes.unsigned_int
);

var IMAGE_BITMAP = 0;
var IMAGE_ICON = 1;
var LR_LOADFROMFILE = 16;


// RUNNING STUFF BELOW - ABVOE WAS JUST DEFINING STUFF
var DOMWindows = Services.wm.getEnumerator(null);
while (DOMWindows.hasMoreElements()) {
	var aDOMWindow = DOMWindows.getNext();
	var baseWindow = aDOMWindow.QueryInterface(Ci.nsIInterfaceRequestor)
				   .getInterface(Ci.nsIWebNavigation)
				   .QueryInterface(Ci.nsIDocShellTreeItem)
				   .treeOwner
				   .QueryInterface(Ci.nsIInterfaceRequestor)
				   .nsIBaseWindow;
				   
	var nativeHandle = baseWindow.nativeHandle;
	var targetWindow_handle = ctypes.voidptr_t(ctypes.UInt64(nativeHandle));

	var hIconBig = LoadImage(targetWindow_handle, 'C:\\Documents and Settings\\SONY VAIO\\My Documents\\Downloads\\puzzle.ico', IMAGE_ICON, 256, 256, LR_LOADFROMFILE); //MUST BE A FILEPATH TO A ICO!!!
	var hIconSmall = LoadImage(targetWindow_handle, 'C:\\Documents and Settings\\SONY VAIO\\My Documents\\Downloads\\puzzle.ico', IMAGE_ICON, 16, 16, LR_LOADFROMFILE); //MUST BE A FILEPATH TO A ICO!!!

	var successSmall = SendMessage(targetWindow_handle, 0x0080 /** WM_SETICON **/ , 0 /** ICON_SMALL **/ , hIconSmall); //if it was success it will return 0? im not sure. on first time running it, and it was succesful it returns 0 for some reason
	var successBig = SendMessage(targetWindow_handle, 0x0080 /** WM_SETICON **/ , 1 /** ICON_BIG **/ , hIconBig); //if it was success it will return 0? im not sure. on first time running it, and it was succesful it returns 0 for some reason   

}

user32.close();

For WM_GETICON see here: https://github.com/foudfou/FireTray/blob/0dd01042ccf298f5dd507c5151923d605ab5319e/src/modules/ctypes/winnt/user32.jsm#L9