[Lazarus] Clipboard.HasFormat issue

[Hans-Peter Diettrich]

Michael Van Canneyt schrieb:

> Is there a reason why ClipBoard.HasFormat() is so slow ?
> 
> Putting a call to ClipBoard.HasFormat() in an OnUpdate handler of an action
> coupled to a toolbutton, seriously slows down an application, to the point
> of being unusable. If I comment out the call, the application responds normally.

The request may go to the clipboard owner, which is responsible for 
providing the clipboard contents in the various formats. The system also 
may search for conversion tools, capable to render the desired format 
from one of the supplied formats.

> This is on Linux (GTK1). I looked at the clipboard calls, but on the first 
> look of things I see no reason why it should be so slow, except maybe the
> ClipboardGetFormats() call.

I only know about the Windows clipboard, not on other systems. The 
graphics system should not be involved on any platform.

> The strange thing is that if something suitable is on the clipboard, 
> the application responds normally.

Isn't there a method EnumClipboardFormats, which should return only the 
currently available formats?

DoDi