Working with a laptop and large external display reminded me of an interface irritation particular to multi-monitor setups in which the displays are of different sizes. For instance, a stacked arrangement with the menu bar on the large display on top and the Dock on the small one below. You can easily move the cursor to the large display anywhere along the top of the smaller screen. The inverse is not true; there are portions of the large display that will not allow the cursor to move to the smaller display.
- I believe an indicator showing just the passthrough zone is the best design, but there are alternatives:
- Show indicators for the portions of the display that do not allow the cursor through
- Show indicators for both
- Keep the existing “mouse around until you find it” implementation
- The color of the indicator could be calculated based on the desktop background to ensure sufficient contrast.
- Some smarts about determining cursor movement direction (like that used to keep sub-menus open when the cursor is moved diagonally) would prevent the indicator from appearing when the cursor is moved toward a hot corner to activate Mission Control or an Exposé mode.
- The indicator is obviously not needed when moving between displays of the same size.