Re: Attempt for an UNO Undo API

Hi Malte, Michael,

Am Mon, 18 Oct 2010 15:46:00 +0200
schrieb Michael Stahl <[email protected]>:

> On 18/10/2010 14:55, Malte Timmermann wrote:
> > The Undo actions could have pointers to some data which doesn't
> > exist anymore, and the extension can't remove the actions from the
> > UndoManager.

That is broken by design.

> > Avoiding pointers could mean making the Undo actions
> > more "expensive" (memory, time). For example, Writer and EditEngine
> > simply keep Paragraph* when paragraphs are being deleted completely.
> 
> this is probably one of the reasons why using Undo/Redo in writer is
> the fastest way to crash OOo...
> using bare pointers to objects that are not owned by the Undo action
> is a horrible idea.

+1

> making copies of data is an acceptable overhead of an Undo
> implementation that actually _works_.

+1
 
> [oh, and what you said is not actually true for paragraphs, but lots
> of other stuff]

- Create page style
- Delete newly created page style
- undo twice => crash (issue i92304, fixed in cws swbookmarkfixes01)

BR,

Bjoern