In Comparison: Multiple Selection, part 2
Yesterday, I began to describe the detailed behavior of multiple selection in Windows and Mac OS. We took a detailed look at shift-clicking. Let’s add in control-clicking now. On the Mac, that would be a command-click, but there are some differences in behavior, so we’ll start off with Windows.
Control-clicking selects non-contiguous items. Control-click an unselected item to add it to the selection; control-click a selected item to deselect it. That’s simple, but what happens when we combine control and shift clicking. Try the following sequence:
- Click item 1.
- Shift-click item 5.
- Control-click item3.
At this point, items 1, 2, 4, and 5 are selected. What do you think would happen if you now shift-clicked item 6? Windows considers a control-click to be an anchoring click, regardless of whether it is adding to or removing from the selection. Deselecting item 3 with a control-click replaces the original anchor on item 1. So, shift-clicking item 6 results in the deselection of items 1 and 2, and the selection of items 3 through 6.
Apple’s selection logic is a bit more sophisticated. The exact same sequence of clicks (replacing control with the command key) results in a more logical selection: 1, 2, 4, 5, and 6. 3 remains deselected. As it turns out, instead of treating a deselecting command-click as an anchor, Mac OS makes the next selected item in the list the anchor. This is a smart distinction, and I’ll show you why.
Going back to Windows, do the following:
- Click item 1.
- Shift-click item 3.
- Control-click item 5.
- Shift-click item 7.
Upon the last step, items 1 through 3 are deselected, leaving you with items 5 through 7 selected. The same steps in Mac OS result in two selected ranges. In a long list of items, you can repeat this pattern as many times as you like. With every command-click, Mac OS creates a new anchor point without affecting the already selected items. The only thing that screws it up is when you double-back, shift-selecting a range back over already selected items, and then reversing again with another shift-click. Since shift-clicks aren’t anchors, they don’t hold, and any contiguous items above the anchor point will become deselected.
The net result is that Mac OS X will allow you to easily move through a list, selecting multiple groups of contiguous items. Windows, on the other hand, will only allow selection of one group of contiguous items—all additional items must be selected individually.
