undo

[babaden]

Is there a way to add an "undo" function to an application just like in windows the regular undo or "contrl z" which will undo or reverse the last operation?

[DavidN]

Yes, but how it's done depends on what kind of application you're making. One way to do it would be to store information about each action performed by the user in a list (what an 'action' means is up to you), and when 'Undo' is pressed, to look at the latest one and reverse it.

[Jax]

If your program is based around Ini++, then you can use the "undo/redo" feature of Ini++ v1.5.

However, usually this will require you to write your program around this feature. Still, if you do there are quite a few benefits!

[babaden]

Can u give me an example of this or an idea of how to go about this method?

[babaden]

Referring to the storing "action" information method.

[MuddyMole]

Like DavidN said, it depends on what you're doing.

For example, if you have an action which adds x to a counter, you just need to remember the value of x, and you could then undo the action by simply subtracting x from the counter.

However, a lot of actions aren't going to be reversible - the only way to undo the action is to save a backup copy of the entire file. For example, a pixelation filter in a graphics app.

[babaden]

ok think i understand the gist of it. Thank you.

[babaden]

In my case it is mostly the position(s) and content of an active object(s). Content meaning there was a picture loaded from file into it(the active object) and they all moved say 96 points or pixels left and by doing the undo action they would return to the coordinates they were at before they all moved. I was thinking save frame position but that would mean constantly writing a file with every move that is made which can then be reloaded by the undo action.