Direct Manipulation

Support direct manipulation for all objects and for all elements that the user can act on or that represent an application state that the user can change.

Support direct manipulation of the objects or state represented by the element directly under the pointer or, if the pointer is within the area of a selection, the selected elements.

Initiate a direct manipulation operation when the user presses a pointer button on an element.

Do not change the active window while a direct manipulation operation is in progress.

While a direct manipulation operation is in progress, if the action to be performed on termination changes as the pointer is moved or as the state of the keyboard changes, provide appropriate feedback to the user so that the user knows what action will be performed.

If a direct manipulation operation requires that buttons be pressed while the operation is in progress, terminate the direct manipulation operation. Alternatively, change its mode when the user releases all pointer buttons and does not press any more buttons or keys within a time period specified by the operating environment.

If a direct manipulation operation does not require that any button be pressed while the operation is in progress, allow the user to terminate the direct manipulation operation. Alternatively, change its mode by pressing shortcut keys or by clicking on some combination of pointer buttons.

When the user presses Cancel or Esc while a direct manipulation operation is in progress, cancel the direct manipulation operation.

Do not perform any action associated with the operation if the user performs a direct manipulation operation by pressing one or more pointer buttons, moves the pointer but returns it to its starting location, and then releases the buttons, and if there was no change in mode during the motion.

Display a Help window when the user presses Help while a direct manipulation operation is in progress. The Help window should provide help specific to the operation, the application state, and the pointer position. Include information describing what would happen if various inputs were received at that point and how and why the operation could succeed or fail.

If you provide a Help window when the user requests Help during a direct manipulation operation, make it an application modal window and do not accept any input until all pointer buttons or keys that are still pressed are released.

Support the following choices in a Help window displayed during a direct manipulation operation:

Display help information, but not in a secondary window, when the user presses Help and continues to press any other pointer buttons or keys that were pressed. Remove the help information when the user releases the Help key.