8. Undo History dialog

The Undo History dialog

This dialog shows you a list of the actions you have most recently performed on an image, with a small sketch that attempts to illustrate the changes produced by each. You can revert the image to any point in its Undo History simply by clicking on the right entry in the list. For more information on GIMP's Undo mechanism and how it works, see the section on Undoing.

The Undo History dialog is a dockable dialog; see the section on Dialogs and Docking for help on manipulating it. It can be activated in several ways:

Using the Undo History dialog

The most basic thing you can do is to select a point in the Undo History by clicking on it in the list. You can go back and forth between states in this way as much as you please, without losing any information or consuming any resources. In most cases, the changes are very fast.

At the bottom of the dialog are three buttons:

  • Undo.  This button has the same effect as choosing Edit->Undo from the menu, or pressing Ctrl-Z; it reverts the image to the next state back in the undo history.

  • Redo.  This button has the same effect as choosing Edit->Redo from the menu, or pressing Ctrl-Y; it advances the image to the next state forward in the undo history.

  • Clear Undo History.  This button removes all contents from the undo history except the current state. If you press it, you are asked to confirm that you really want to do this. The only reason for doing it would be if you are very constrained for memory.