UI Patterns and Techniques

Smart Selection

From Photoshop
Use when:	The user is working with selectable objects of any kind -- text, pixels, geometric objects, even tree items or table cells. The selectable things are organized into coherent visual groups, like words or sentences in a text editor, or contiguous color areas in an image. Normally, selection of one of these groups would require the user to click and drag the pointer with some precision.
Why:	Precision isn't everyone's strong suit. Once it becomes clear to the program that you are trying to select a particular group, it ought to help you out and do it for you. Some users will find it much faster and more convenient if a certain gesture did a groupwise selection. (Other users will find it possible!)
How:	Define a certain UI gesture to make a "smart selection" where the pointer currently is. The gesture might be: a double-click or double-tap, a single click while in a particular tool or mode, such as Photoshop's magic wand, a single click while a key is held down, merely the act of enlarging the selection out towards the boundaries of a group, as some text editors do (but see the warning below). If there are larger groups containing the small groups, consider ways to enlarge the smart selection to the enclosing groups too -- like expanding the selection of a word to the selection of a sentence, then a whole paragraph. But be careful. When done thoughtlessly, smart selections can be incredibly irritating. Imagine the user's aggravation when he tries to precisely select a chunk of text or pixels, but every time he comes close to a word or color boundary, the selection "snaps" out to where he didn't want it! This happens in some text editors, including Word.
Examples:
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