Actions
The basic sequence involved in drag and drop is:
- Move the pointer to the object
- Press, and hold down, the button on the mouse or other pointing device, to "grab" the object,
- "Drag" the object to the desired location,
- "Drop" the object by releasing the button.
Dragging requires more physical effort than moving the same pointing device without holding down any buttons. Because of this, a user cannot move as quickly and precisely while dragging (see Fitts' law). However, drag-and-drop operations have the advantage of thoughtfully chunking together two operands (the object to drag, and the drop location) into a single action. Extended dragging and dropping (as in graphic design) can stress the mousing hand.
A design problem appears when the same button selects and drags items. Imprecise movement can cause a dragging when the user just wants to select.
Another problem is that the target of the dropping can be hidden under other objects. The user would have to stop the dragging, make both the source and the target visible and start again. In classic Mac OS the top-of-screen menu bar served as a universal "drag cancel" target. This issue has been dealt with in Mac OS X with the introduction of Exposé.
Read more about this topic: Drag And Drop
Famous quotes containing the word actions:
“The principal office of history I take to be this: to prevent virtuous actions from being forgotten, and that evil words and deeds should fear an infamous reputation with posterity.”
—Tacitus (c. 55–c. 120)
“The course of my long life hath reached at last
In fragile bark o’er a tempestuous sea
The common harbor, where must rendered be
Account for all the actions of the past.”
—Henry Wadsworth Longfellow (1807–1882)
“Now they express
All that’s content to wear a worn-out coat,
All actions done in patient hopelessness,
All that ignores the silences of death,
Thinking no further than the hand can hold,
All that grows old,
Yet works on uselessly with shortened breath.”
—Philip Larkin (1922–1986)