perl-win32-gui-users

Re: [perl-win32-gui-users] Drag-n-drop (was: Show In Taskbar)

[<Fo...@ao...>]

This is the 128 message:
#define WS_EX_TOOLWINDOW        0x00000080L

(This is documented in the Win32 Programmer's Reference help file and in 
the winuser.h file from Visual C++)

Yup. Didn't have my VC++ install at work, though...

> 
> 
> And this would be _so_ neat to use:
> 
> WS_EX_ACCEPTFILES -- Specifies that a window created with this style 
> accepts drag-drop files.
> 
> Anyone have any idea of things I have to think about if I want to try to 
> implement a drag-n-drop feature? I have already found the correct set of 
> functions and messages in the Win32 Reference.
> 

Eh, I forget exactly how it works, but in VB you had to subclass some message 
or another... wasn't too bad. If you have the exact procedure down, it's 
pretty simple.

Dave

Re: [perl-win32-gui-users] Drag-n-drop (was: Show In Taskbar)

[<Fo...@ao...>]

In all likelihood, your best bet is to subclass the window you want it to ac=
cept the files, then filter for the appropriate message. I can dig up some M=
SKB articles on it if you'd like.

Dave

In a message dated Sun, 6 May 2001 11:47:29 PM Eastern Daylight Time, Johan=20=
Lindstrom <jp...@bo...> writes:

<< I wrote:
>Anyone have any idea of things I have to think about if I want to try to=20
>implement a drag-n-drop feature? I have already found the correct set of=20
>functions and messages in the Win32 Reference.

Ok, so I managed to tell a window to accept files dragged from the Explorer=20
with the DragAcceptFiles() function (from the shell32.dll).

When I drag the mouse over the window, the mouse pointer changes. When I=20
drop, the window is sent a WM_DROPFILES event.

My problem now is how I should capture this event.

Naive first try: timer which triggers really often. In the event handler I=20
call
   $myWindow->PeekMessage(WM_DROPFILES, WM_DROPFILES)
and if it returns true, I call
   $myWindow->GetMessage(WM_DROPFILES, WM_DROPFILES)

That works like one in ten times or something. Clearly not the way to go.

So, any better way of detecting the WM_DROPFILES event?


/J

--
Johan Lindstr=F6m, Sourcerer, Boss Casinos Ltd, Antigua
jp...@bo...


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Re: [perl-win32-gui-users] Drag-n-drop (was: Show In Taskbar)

[Johan L. <jp...@bo...>]

Dave wrote:
>In all likelihood, your best bet is to subclass the window you want it to 
>accept the files, then filter for the appropriate message. I can dig up 
>some MSKB articles on it if you'd like.

Um... are we talking subclassing using the Win32::GUI::Class here?

After having looked through the XS code, I haven't found any way to change 
which messages are handled, except for the "predefined" classes with their 
own MsgLoops.

Well... there is this %Win32::GUI::callbacks hash, but I still haven't 
figured out if I can get it to work with the WM_DROPFILES event.


/J

--
Johan Lindström, Sourcerer, Boss Casinos Ltd, Antigua
jp...@bo...

Re: [perl-win32-gui-users] Drag-n-drop (was: Show In Taskbar)

[Johan L. <jp...@bo...>]

Wohoo! I got it to work! :)

It took some XS hacking though. Nothing fancy, mostly copy-paste and common 
sense.

I added the WM_DROPFILES message to the WindowMsgLoop so that it throws an 
event DropFiles() with the drop handle in question.

And once in Perl it was piece a cake to call the shell32.dll functions 
DragQueryFile and DragFinish to actually get the files. Cool. This is fun!


Some code:

GUI.xs, line 1839:
----------
     case WM_DROPFILES:
         if(GetObjectName(NOTXSCALL hwnd, Name)) {
             /*
              * (@)EVENT:DropFiles(DROP_HANDLE)
              * Sent when the window receives dropped files.
              * (@)APPLIES_TO:Window, DialogBox
              */
             strcat(Name, "_DropFiles");
             PerlResult = DoEvent_Long(NOTXSCALL Name, UINT(wParam));
         }		
         break;
----------

http://www.bahnhof.se/~johanl/perl/Win32GUI/
- AdHoc.pm
Perl subs for dealing with the shell32.dll calls handling the drop 
operation (among other things).

- dragdrop.pl
Working demo program (if you rebuild the XS code). The actual drag-drop 
code is this simple in a Perl application:

----------
Win32::GUI::AdHoc::windowDragAcceptFiles($winMain, 1);

sub winMain_DropFiles {
	my ($handleDrop) = @_;
	
	print join("\n", Win32::GUI::AdHoc::windowGetDroppedFiles($handleDrop)) . 
"\n\n";
	
	return(1);
	}
----------

I guess a more complete solution would include drag-drop to e.g. a RichEdit 
or Textfield control etc. but I'm not sure what the implications are.

I'm not sure how to continue with this. For my personal use, I'm probably 
gonna create a Win32::GUI::DragDrop module or something (using my XS mod), 
but maybe this belongs in the next release of Win32::GUI after a code 
review (after all, I relly don't _know_ these things). Aldo?


/J
--
Johan Lindström, Sourcerer, Boss Casinos Ltd, Antigua
jp...@bo...

Re: [perl-win32-gui-users] Drag-n-drop (was: Show In Taskbar)

[<Fo...@ao...>]

Eh, no... I was actually thinking pure SetWindowCapture stuff. Haven't done=20=
it in the while, but that's how we used to do it in VB.

Dave

In a message dated Wed, 9 May 2001 12:43:06 AM Eastern Daylight Time, Johan=20=
Lindstrom <jp...@bo...> writes:

<< Dave wrote:
>In all likelihood, your best bet is to subclass the window you want it to=20
>accept the files, then filter for the appropriate message. I can dig up=20
>some MSKB articles on it if you'd like.

Um... are we talking subclassing using the Win32::GUI::Class here?

After having looked through the XS code, I haven't found any way to change=20
which messages are handled, except for the "predefined" classes with their=20
own MsgLoops.

Well... there is this %Win32::GUI::callbacks hash, but I still haven't=20
figured out if I can get it to work with the WM_DROPFILES event.


/J

--
Johan Lindstr=F6m, Sourcerer, Boss Casinos Ltd, Antigua
jp...@bo...


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