Pressing the Esc key will terminate the operations described above while in progress. The Tab and Shift-Tab keys will undo and redo the operation, respectively. These operations sound complex when described in print, but become quite natural in practice. The user should spend a few minutes learning these operations.
In the layer menu, button 1 selects the current layer, as indicated by the highlight box drawn around the entry. If the Shift or Ctrl key is pressed while clicking with button 1 in the layer menu, the action is identical to a button 2 press, i.e., the layer visibility status is changed. This is advantageous for users with a two-button pointing device, on which button 2 is usually absent.
Many of the pop-up windows can be moved by pressing button 1 while the pointer in on the background or a label object in the pop-up. While button 1 is held, the outline of the pop-up is ghost-drawn and attached to the pointer. The pop-up is moved to the new location when button 1 is released.