Subclassing is quite a useful way of monitoring the messages sent to the keyboard (such as key presses), mouse (such as right mouse clicks) and windows (such as minimizing).

Plus! can already do some subclassing; take for example matty's hotkey code and SpunkyLoveMuff's StatusKey script. These both involve an invisible Plus! window which monitors the keyboard for a specific hotkey.

However, sometimes Plus! windows are not enough. For example, (as far as I know) it is impossible to detect the changing of tabbed chats using only the Plus! scripting engine and the Win32 API. It is even more impossible to detect messages sent to external applications (like Winamp for example).

This is where the ActiveXObjects come in. By using these, we are able to do all these things, right in Plus! itself!

After doing some browsing, I came across two free subclassing ActiveX files.

code:

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<OleFiles>
    <FileName>ARSubclass.dll</FileName>
</OleFiles>

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code:

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var ARSubclass = new ActiveXObject("ARSubclassLib.ARSubclass");

function OnEvent_Initialize(MessengerStart) {
    ARSubclass.hWnd = Messenger.ContactListWndHandle;
    ARSubclass.Message(/* WM_ACTIVATE */ 6) = true;
}

function OnEvent_ContactListWndCreated() { OnEvent_Initialize(); }

var Event = function() {
    function ARSubclass::WindowProc(hWnd, iMessage, wParam, lParam, Res) {
        if(wParam === /* WA_INACTIVE */ 0) Debug.Trace("WA_INACTIVE");
        if(wParam === /* WA_ACTIVE */ 1) Debug.Trace("WA_ACTIVE");
        if(wParam === /* WA_CLICKACTIVE */ 2) Debug.Trace("WA_CLICKACTIVE");
    }
}

Event();

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code:

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<OleFiles>
    <FileName>SubClassX6.dll</FileName>
</OleFiles>

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code:

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var SubClassX6 = new ActiveXObject("SubClassX6.Window");

function OnEvent_ChatWndCreated(ChatWnd) {
    SubClassX6.SubClass_Start(ChatWnd.Handle);
}

function OnEvent_ChatWndDestroyed(ChatWnd) {
    SubClassX6.SubClass_Stop(ChatWnd.Handle);
}

var Event = function() {
    function SubClassX6::Message(hWnd, Msg, wParam, lParam, Return_Value, Return_SetValue) {
        if(Msg == /* WM_ACTIVATE */ 6 && wParam != /* WA_INACTIVE */ 0) Debug.Trace(hWnd);
    }
}

Event();

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very very nice piece of work

quote:

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Originally posted by phalanxii
However, sometimes Plus! windows are not enough. For example, (as far as I know) it is impossible to detect the changing of tabbed chats using only the Plus! scripting engine and the Win32 API.

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quote:

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Originally posted by phalanxii
It is even more impossible to detect messages sent to external applications (like Winamp for example).

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quote:

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Originally posted by phalanxii
Firstly, the DLL is required to be registered when the script is imported, so this line must be added to ScriptInfo.xml:

code:

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<OleFiles>
    <FileName>ARSubclass.dll</FileName>
</OleFiles>

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Here is an example code of how to use it:

code:

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var ARSubclass = new ActiveXObject("ARSubclassLib.ARSubclass");

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quote:

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Originally posted by effection
very very nice piece of work

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quote:

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Originally posted by CookieRevised
No need for an ActiveX for all of this. Just some API stuff... In fact, the ActiveXs do exactly what you already can do in Plus! by using the Windows API.

Though using this ActiveX might be the easy solution for some. So, very good and nice find though ...

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quote:

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Originally posted by CookieRevised
I actually do not recommend all of this (even including the use of <OleFiles>). (I think Patchou will shoot me now ) The reason is again that you will get into trouble when more than one script is going to use that DLL and you later install or remove even more scripts which use it.

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quote:

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Originally posted by CookieRevised
As for the tabbed chat window example, I think that can be done much easier and with subclassing just 1 window. The hidden Plus! window which controls the tabs.

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Hi :]

phalanxii:  i'm not totally sure if it's correct, but it works fine here

code:

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var GWL_WNDPROC = -4
var lpPrevWndProc = 0

function OnEvent_Initialize() {
    if(Messenger.MyStatus > 0) OnEvent_SigninReady();
}

function OnEvent_SigninReady() {
    for (var e = new Enumerator(Messenger.CurrentChats); !e.atEnd(); e.moveNext()) OnEvent_ChatWndCreated(e.item());
}

function OnEvent_Uninitialize(MessengerExit){
    for (var e = new Enumerator(Messenger.CurrentChats); !e.atEnd(); e.moveNext()){
        if (lpPrevWndProc != 0)    Interop.Call('user32', 'SetWindowLongW', e.item().Handle, GWL_WNDPROC, lpPrevWndProc)
    }
}

function OnEvent_ChatWndCreated(ChatWnd){
    lpPrevWndProc = Interop.Call('user32', 'SetWindowLongW', ChatWnd.Handle, GWL_WNDPROC,  Interop.GetCallbackPtr('WindowProc') )
}

function OnEvent_ChatWndDestroyed(ChatWnd){
    if (lpPrevWndProc != 0)    Interop.Call('user32', 'SetWindowLongW', ChatWnd.Handle, GWL_WNDPROC, lpPrevWndProc)
}

function WindowProc(hwnd, uMsg, wParam, lParam){
    if (uMsg == 0x6 && wParam != 0){
        // stuff
    }
    return Interop.Call('user32', 'CallWindowProcW', lpPrevWndProc, hwnd, uMsg, wParam, lParam)
}

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* felipEx waits for Cookie's reply

Thanks felipEx! It works fine over here too. I must say that it is also a lot more reliable than the ActiveX libraries and the script file size is obviously much smaller.

I'm wondering about the documentation though:

quote:

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Originally posted by Messenger Plus! Live Scripting Documentation

Interop::GetCallbackPtr

Remember that the use of callback functions is restricted to synchronous calls. This means that all the calls made to the callback function must be done before the callee returns. Asynchronous calls are not permitted and must not be attempted in any circumstances.

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quote:

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Originally posted by felipEx
* felipEx waits for Cookie's reply

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quote:

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Originally posted by CookieRevised
And, but I never made this experiment yet, I think you could also device something with a Plus! Window of which you 'borrowed' the WinProc address to be used to overwrite the WinProc of another window. And with OnWindowidEvent_MessageNotification you can catch the window messages of that 'external' window. If this works, it also means you could subclass already long before GetCallbackPtr() existed.

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Isn't the reason you want to subclass something because you need to catch just a certain message? I don't see why you would want to catch all possible messages there are, that would be useless (unless you make a Windows Message Spying program).

quote:

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Originally posted by CookieRevised
Isn't the reason you want to subclass something because you need to catch just a certain message? I don't see why you would want to catch all possible messages there are, that would be useless (unless you make a Windows Message Spying program).

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the only thing I'll say on this subject is: careful. Subclassing windows properly is something that takes time and anybody doing this kind of thing needs to make sure his code is tested extensively.

As for using GetCallbackPtr with SetWindowLong: don't. The documentation specifically mentions that this function can only be used for synchronous calls. If you make a script that defys this rule, it may work at first but the combination of several scripts will certainely cause unexpected results / crashes.

quote:

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Originally posted by deAd

quote:

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Originally posted by CookieRevised
Isn't the reason you want to subclass something because you need to catch just a certain message? I don't see why you would want to catch all possible messages there are, that would be useless (unless you make a Windows Message Spying program).

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Yes, but you have to send the messages you don't want back to the original windowproc. You can't do this with a Plus! window because you only have control over the messages you ask for.

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quote:

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Originally posted by Patchou
As for using GetCallbackPtr with SetWindowLong: don't. The documentation specifically mentions that this function can only be used for synchronous calls. If you make a script that defys this rule, it may work at first but the combination of several scripts will certainely cause unexpected results / crashes.

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quote:

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Originally posted by Patchou
the problem is a technical limitation: for callbacks I dont have much other choice than using static functions in my code so I cant have two scripts using a callback at the same time, which is why they have to be synchronous.
...
Thus right now, calling GetCallbackPtr() many times, from different scripts, will always return the same pointer for a function with a given number of arguments.
...
Meaning two scripts can't subclass any two window at the same time. Even one single script wouldn't be able to subclass two windows with that method.
...

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quote:

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Originally posted by CookieRevised
EDIT: Plus! doesn't know the original WinProc, that would of course be the reason, no?

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quote:

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Originally posted by CookieRevised
Now, he also gave a hint as in how it would be possible, but that involves asm (which _is_ possible in scripting, but extremely advanced).

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quote:

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Originally posted by deAd

quote:

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Originally posted by CookieRevised
Now, he also gave a hint as in how it would be possible, but that involves asm (which _is_ possible in scripting, but extremely advanced).

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It's very messy, but you can inject the ASM bytes of a new wndproc into memory and use a pointer to those. It's really better to just use a dll if you need to subclass.

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quote:

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Originally posted by phalanxii
<snip>

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Well, I certainly have no idea about ASM, but for those who are interested, deAd has explained how to do it in this separate thread.

Anyway, I was browsing around MSDN and found this page explaining how to subclass windows.

It uses the SetWindowSubclass, RemoveWindowSubclass and DefSubclassProc functions from comctl32.dll which comes with Windows XP (?).

Is it possible to use these functions with GetCallbackPtr in order to subclass, or is there still the same problem as using SetWindowLong and GetCallbackPtr?

quote:

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Originally posted by riahc4
Also big thanks for "TabbedStatusIcon" but if its suppose to work like Veggie's Status Icon, it doesnt. At least not here:
Vista
Plus! 3.60
Messenger 9.0

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quote:

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Originally posted by riahc4
Also big thanks for "TabbedStatusIcon" but if its suppose to work like Veggie's Status Icon, it doesnt. At least not here:
Vista
Plus! 3.60
Messenger 9.0

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