In this situation - undoes over a period of time - would not a time/date stamp within the array provide such a temporal key order? Best, Keith..
On 8 Dec 2011, at 16:40, Bob Sneidar wrote: > If there were a property that contained all of the standard properties of an > object, you could simply store the array for that object in another array > with 4 keys: The first being the version of the undo (for multiple undo's), > the long id of the object, the defaultProperties (??) of the object, and the > customProperties of the object. Here is where storing keys in an array in the > order they were added would be REALLY handy, but alas, Livecode don' play > dat! > > It's not very efficient storing both property sets in full, but much simpler > to work with. This way you would not have to trap for every change a user > could make to an object. > > Bob > > > On Dec 8, 2011, at 8:02 AM, Ken Ray wrote: > >> >> On Dec 7, 2011, at 1:28 PM, Alejandro Tejada wrote: >> >>> Hi All, >>> >>> I am trying to create an Undo function >>> for one of my stacks. >>> >>> Not sucessful at all. Everything seems so simple, >>> but it failed everytime. >>> >>> The model that I am using for this task is the >>> "History palette" used in Photoshop: >>> http://livedocs.adobe.com/en_US/Photoshop/10.0/help.html?content=WSfd1234e1c4b69f30ea53e41001031ab64-7497.html >>> >>> Now, I am asking for advice from all of you >>> that have created similar function for your >>> applications or stacks. >> >> Al, I've done that for my Stykz animation program, but only focused on >> objects (it doesn't do any text undoing). You basically need to store the >> state of an object before it is manipulated by the user so that you can >> reinstate the same state after it's 'undone'. With the exception of actions >> that physically destroy an object (like a "cut" or "delete" command), the >> methods to choose from would fall into these three categories: >> >> 1) Using 'save' and 'revert' >> 2) Store a physical copy of the original object, and then copy it back again >> on an "undo" >> 3) Storing/restoring all the properties of an object >> >> #1 is very touchy and doesn't give you the ability for multiple undos/redos >> (which would seem to be your intention with the History palette), so you can >> ignore that one. >> >> #2 could be used, but you're deleting and copying objects which will use up >> object IDs rather quickly, and it is also a pain if the objects in question >> are inside of a group at a specific layer in the group. >> >> #3 seemed to be the best choice for me, with #2 being used only when the >> user wanted to cut or delete an object (I have an offscreen stack I use to >> hold the objects in that instance. >> >> Basically you want to store the properties of an object *before* they are >> manipulated by the user; if someone's doing that through an interface (like >> changing the fill color of a graphic), you can store the old fill color >> before you change it to the color they selected. It's a little trickier with >> resizing/moving objects themselves, but it can be done. It's more of a pain >> if you're giving the user the pointer tool, but it can be done there as >> well. The bottom line is you need a message you can trap that will take >> place *before* the user's action, then store the relevant property(ies) in >> your undo history list, and then let the user's actions take place. >> >> Hope this helps, >> >> Ken Ray >> Sons of Thunder Software, Inc. >> Email: k...@sonsothunder.com >> Web Site: http://www.sonsothunder.com/ >> >> _______________________________________________ >> use-livecode mailing list >> use-livecode@lists.runrev.com >> Please visit this url to subscribe, unsubscribe and manage your subscription >> preferences: >> http://lists.runrev.com/mailman/listinfo/use-livecode > > > _______________________________________________ > use-livecode mailing list > use-livecode@lists.runrev.com > Please visit this url to subscribe, unsubscribe and manage your subscription > preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode _______________________________________________ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
