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:
“When a Man is in a serious Mood, and ponders upon his own Make, with a Retrospect to the Actions of his Life, and the many fatal Miscarriages in it, which he owes to ungoverned Passions, he is then apt to say to himself, That Experience has guarded him against such Errors for the future: But Nature often recurs in Spite of his best Resolutions, and it is to the very End of our Days a Struggle between our Reason and our Temper, which shall have the Empire over us.”
—Richard Steele (1672–1729)
“Our actions seem to have their lucky and unlucky stars, to which a great part of that blame and that commendation is due which is given to the actions themselves.”
—François, Duc De La Rochefoucauld (1613–1680)
“Long ago I added to the true old adage of “What is everybody’s business is nobody’s business,” another clause which, I think, more than any other principle has served to influence my actions in life. That is, What is nobody’s business is my business.”
—Clara Barton (1821–1912)