* Left-button: add to current selection. * Right-button: remove from current selection. * Left-button: add to current selection. * Right-button: remove from current selection. * Left-button: add to current selection. * Right-button: remove from current selection. * Left-button: add to current selection. * Right-button: remove from current selection. * Left-button: add to current selection. * Right-button: remove from current selection. * Left-button: Erase with the background color in `Background' layer or transparent color in any other layer. * Right-button: Replace foreground with background color.