It's been a classic design principle that any scrollable view should auto-scroll when an object is dragged outside or close to boundary of the view.
Here's what Alan Cooper wrote in his "About Face" book: "Auto-scroll is a very important adjunct to drag-and-drop. Wherever the drop target can possibly be scrolled offscreen, the program needs to auto-scroll. Any scrollable drag-and-drop target must auto-scroll." However I've suddenly realized that I've never seen any implementation of auto-scrolling (including my own :) that would not SUCK. Auto-scrolling is perhaps the most awkward feature associated with drag-and-drop that I would name. IMHO, auto-scrolling sucks because: 1. It lacks control over precision. Variable auto-scroll rate sucks because when I want to scroll faster (and I always do :), I often over-scroll. Then I need to drag the object to the opposite side of the screen and auto-scroll back. 2. It is not informative nor it is flexible. At the beginning, you don't see how far you may need to scroll, so I usually pick the fastest rate and over-scroll, as in 1. or have to wait too long if I take a low scroll rate. The transition from lower to faster scroll rates appears abruptly and often cause over-scrolling. 3. It is slow. First, you have to wait until it starts in vicinity of the view border, then wait until it scrolls with a particular speed. This all ends up in that with auto-scrolling I never feel comfortable and confident, but often strained and lacking control. This made me think about good alternatives to auto-scrolling. What do you think? ________________________________________________________________ Welcome to the Interaction Design Association (IxDA)! To post to this list ....... [EMAIL PROTECTED] Unsubscribe ................ http://www.ixda.org/unsubscribe List Guidelines ............ http://www.ixda.org/guidelines List Help .................. http://www.ixda.org/help
