Re: New clipboard handling notes (XFree86-xserv-4.3.0-31)

[Alexander Gottwald <alexander.gottwald@s1999.tu-chemnitz.de>]

On Mon, 5 Jan 2004, Harold L Hunt II wrote:

> Here are my notes that I put together to convince myself that the new 
> clipboard handling was complete and would not cause infinite loops. 
> Please examine the notes if you are interested in the new code or if you 
> would like to double-check my logic for errors.
> 
> Please review the steps and post to the list if you think you have found 
> an error.  Also, if you find a bug or a crash, look at these steps and 
> try to identify the approximate location of your problem so that we can 
> do a better job of debugging.
> 
> Harold
> 
> 
> Copy in X11
> ===========
> 1) winProcSetSelectionOwner gets called and takes ownership of the Win32 
> clipboard (OpenClipboard, EmptyClipboard, SetClipboardData (foo, NULL)).
> 
> 2) Selection is owned by another X11 client (the one that called 
> XSetSelectionOwner).
> 
> 3) EmptyClipboard() in step #1 files WM_DRAWCLIPBOARD message, which is 
> ignored since hwnd == GetClipboardOwner ().
> 
> 4) Paste in X11
>      a) Owning X11 client handles SelectionRequest events.
> 
>      b) Item is pasted within X11 without round-trip to Win32.
> 
> 5) Paste in Win32
>      a) WM_RENDERFORMAT fires.
> 
>      b) SelectionRequest is sent, conversion from X11 to Win32 is done.
> 
>      c) SetClipboardData is called, passing converted text.
> 
> 6) Copy in X11 (different app)
>      a) Goto Step #1.
> 
> 7) Copy in Win32
>      a) Clipboard is emptied and owned by the other application.
> 
>      b) WM_DRAWCLIPBOARD fires, XSetSelectionOwner is called, owning the
>      selection for the clipboard integration manager.
> 
> 
> Copy in Win32
> =============
> 1) WM_DRAWCLIPBOARD fires, calls XSetSelectionOwner for itself.
> 
> 2) winProcSetSelectionOwner gets called, does nothing since clipboard 
> X11 window is the window that is taking ownership.
> 
> 3) Paste in Win32
>      a) Clipboard owning Win32 app handles GetClipboardData call.
> 
>      b) Item is pasted without round-trip to X11.
> 
> 4) Paste in X11
>      a) Clipboard integration manager receives SelectionRequest.
> 
>      b) GetClipboardData is called, returning Win32 clipboard contents.
> 
>      c) Conversion from Win32 to X11 is done and text is pasted.
> 
> 5) Copy in X11
>      a) winProcSetSelectionOwner is called.
> 
>      b) Clipboard integration manager takes ownership of Win32 clipboard.
> 
>      c) WM_DRAWCLIPBOARD fires and is ignored since hwnd ==
>      GetClipboardOwner ().
> 
> 6) Copy in Win32 (different app)
>      a) Goto Step #1.
> 

Looks good to me.

bye
	ago

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