_ff-addon-snippet-winapi_setMouseHook - Uses js-ctypes to set a mouse hook. [jsctypes] [winapi]

_ff-addon-snippet-winapi_setMouseHook.js

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

var is64bit = ctypes.voidptr_t.size == 4 ? false : true;
var ifdef_UNICODE = true;

var TYPES = {
    ABI: is64bit ? ctypes.default_abi : ctypes.winapi_abi,
    CALLBACK_ABI: is64bit ? ctypes.default_abi : ctypes.stdcall_abi,

    BOOL: ctypes.bool,
    CHAR: ctypes.char,
    DWORD: ctypes.uint32_t,
    INT: ctypes.int,
    LONG: ctypes.long,
    LONG_PTR: is64bit ? ctypes.int64_t : ctypes.long,
    PVOID: ctypes.voidptr_t,
    UINT_PTR: is64bit ? ctypes.uint64_t : ctypes.unsigned_int,
    ULONG_PTR: is64bit ? ctypes.uint64_t : ctypes.unsigned_long,
};

// advanced types - based on simple types
TYPES.HANDLE = TYPES.PVOID;
TYPES.LPARAM = TYPES.LONG_PTR;
TYPES.LRESULT = TYPES.LONG_PTR;
TYPES.WPARAM = TYPES.UINT_PTR;

// advanced advanced types - based on advanced types
TYPES.HHOOK = TYPES.HANDLE;
TYPES.HINSTANCE = TYPES.HANDLE;
TYPES.HWND = TYPES.HANDLE;

// simple structs
TYPES.POINT = ctypes.StructType('_tagPOINT', [
	{ x: TYPES.LONG },
	{ y: TYPES.LONG }
]);
TYPES.MSLLHOOKSTRUCT = ctypes.StructType('tagMSLLHOOKSTRUCT', [
	{ pt: TYPES.POINT },
	{ mouseData: TYPES.DWORD },
	{ flags: TYPES.DWORD },
	{ time: TYPES.DWORD },
	{ dwExtraInfo: TYPES.ULONG_PTR }
]);

// simple callbacks
TYPES.LowLevelMouseProc = ctypes.FunctionType(TYPES.CALLBACK_ABI, TYPES.LRESULT, [TYPES.INT, TYPES.WPARAM, TYPES.LPARAM]);


// guess types
TYPES.HOOKPROC = TYPES.LowLevelMouseProc.ptr; // not a guess really, as this is the hook type i use, so yeah it has to be a pointer to it

var CONST = {
    WH_MOUSE_LL: 14
};

var justMouseConsts = {
	WM_MOUSEMOVE: 0x200,
	WM_LBUTTONDOWN: 0x201,
	WM_LBUTTONUP: 0x202,
	WM_LBUTTONDBLCLK: 0x203,
	WM_RBUTTONDOWN: 0x204,
	WM_RBUTTONUP: 0x205,
	WM_RBUTTONDBLCLK: 0x206,
	WM_MBUTTONDOWN: 0x207,
	WM_MBUTTONUP: 0x208,
	WM_MBUTTONDBLCLK: 0x209,
	WM_MOUSEWHEEL: 0x20A,
	WM_XBUTTONDOWN: 0x20B,
	WM_XBUTTONUP: 0x20C,
	WM_XBUTTONDBLCLK: 0x20D,
	WM_MOUSEHWHEEL: 0x20E
}

var user32 = ctypes.open('user32');
var SetWindowsHookEx = user32.declare(ifdef_UNICODE ? 'SetWindowsHookExW' : 'SetWindowsHookExA', TYPES.ABI, TYPES.HHOOK, TYPES.INT, TYPES.HOOKPROC, TYPES.HINSTANCE, TYPES.DWORD);
var UnhookWindowsHookEx = user32.declare('UnhookWindowsHookEx', TYPES.ABI, TYPES.BOOL, TYPES.HHOOK);
var CallNextHookEx = user32.declare('CallNextHookEx', TYPES.ABI, TYPES.LRESULT, TYPES.HHOOK, TYPES.INT, TYPES.WPARAM, TYPES.LPARAM);

try {
    var cancelFinally = false;

    var myLLMouseHook_js = function(nCode, wParam, lParam) {

        var eventType;
        for (var p in justMouseConsts) {
            if (justMouseConsts[p] == wParam) {
                eventType = p;
                break;
            }
        }

        var mhs = TYPES.MSLLHOOKSTRUCT.ptr(ctypes.UInt64(lParam));

        console.info('myLLMouseHook | ', eventType, 'nCode:', nCode, nCode.toString(), 'wParam:', wParam, wParam.toString(), 'lParam:', lParam, lParam.toString(), 'mhs.contents:', mhs.contents, mhs.contents.toString());

        var rez_CallNext = CallNextHookEx(null, nCode, wParam, lParam);
        // console.info('rez_CallNext:', rez_CallNext, rez_CallNext.toString());
        return rez_CallNext;
    };
    var myLLMouseHook_c = TYPES.LowLevelMouseProc.ptr(myLLMouseHook_js);

    var aHhk = SetWindowsHookEx(CONST.WH_MOUSE_LL, myLLMouseHook_c, null, 0);
    console.info('aHhk:', aHhk, aHhk.toString());
    if (aHhk.isNull()) {
        console.error('failed to set hook, winLastError:', ctypes.winLastError);
        throw new Error('failed to set hook');
    }

    cancelFinally = true; // cancel as i will handle it in the setTimeout
    setTimeout(function() {
        var rez_Unhook = UnhookWindowsHookEx(aHhk);
        console.info('rez_Unhook:', rez_Unhook);

        user32.close();
        console.log('user32 closed');
    }, 5000);
} finally {
    if (!cancelFinally) {
        user32.close();
        console.log('user32 closed');
    }
}

README

Rev1

• Works baby! Took less than half hour to write up after last year of js-ctypes learning goodness! Was stuck on it previously since before November 2012! That's over 3 years ago! No one helped in over 3 years for such a simple piece of code my goodness! I help people on stackoverflow with way more complicated js-ctypes haha feeling soooo cool now.

Rev2

• Corrected so eventType is logged
• And added the middle mouse button constants and others that were not there previously, the docs on MSDN were incomplete, a guy in the comments of https://msdn.microsoft.com/en-us/library/ms644986%28v=vs.85%29.aspx detailed all the constants
• Through trial I found that returning -1 blocks the input, but I need to research on if I should call CallNextHookEx and still return -1 or just return without calling to CallNextHookEx. And I haven't found documented anywhere yet that returning -1 is the proper way to block. Once I find proper way to block then I can write about that here.