The radial menu is brilliant.
It is reminiscent of how basic team communication works in StarCraft 2. You alt-click to ping the minimap (draw allies' attention to something in that general area). If it's something more specific, you can hold alt, and drag-click to open a directional menu, from which you can choose one of four orders: attack, defend, retreat, and OMW. Some pings are also context-sensitive: click on the minerals/gas to say "I want to gather these resources", useful for establishing expansion patterns, strategy in the early game (macro/rush), tech transitions (ping your hydralisk den to say "I'm gonna make hydras"). All of this is key in a game with hundreds of APM and split-second reaction times.
It's a similar story with GUI actions. Power users appreciate good key shortcuts more than almost anything. If you do something thousands of times a day, it needs to be near-instant. The mouse is often disregarded, and IMHO that's because nobody is really doing any serious research in that area. Radial menus pack a lot of actions (where three mouse buttons fall short), exploit Fitt's law, muscle memory, etc. They are also discoverable and provide immediate visual feedback (contrary how "mouse gestures" work in some applications).
Couple notes on the current implementation (from what I've gathered from the video):
- Settle on how many actions *at most* do you want available in the menu (4? 6? 8?), divide the menu accordingly, and display those divisions regardless of whether there's an actionable item. This will help develop muscle memory. If you need more than say 8 actions, the menu might already be getting more crammed than you'd find useful.
- When figuring out where to place stuff, I would suggest prioritising the four cardinal directions for the most common actions, starting with the horizontal positions. "Surprising" or destructive actions (even if un-doable) should be placed at the harder-to-reach positions.
- Keep the actions as consistent as possible between different contexts, e.g. left on the document closes the document, left on the title bar closes the window, but not: left on an icon deletes the file.
Questions worth considering:
- I'm not sure if a launcher is a good use for this model; once you have a dozen apps (or more than 3-4 windows to switch between), it's gonna get awkward. Maybe a more traditional list-menu, and/or a dock? But I'd be intrigued if you come up with something original.
- What happens when you open a menu too close to the screen edge? It's an interesting case to consider. Warping the pointer might be an option (the physical mouse can keep moving, after all).
- Is this going to work well with a trackpad? Maybe use a two/three finger swipe, but that depends on how precise is your hardware.
- What about a trackpoint, or die-hard keyboard users? Perhaps you can trigger the menu by holding down the space key?
Anyway, this is really inspiring.