On the other hand, you don't need any instruction for pinch-to-zoom. Intuitive interactions like that — or even double-tap-to-zoom — are much harder to come up with, but they're also accessible to everybody. This is a cool piece of trivia, but it's far from solving the one-handed zooming problem. I hope Google (or anybody else) is working on something to make this better for everyone.
Once users "get it", it's powerful. They'll attempt to pinch to zoom all over the place. I guess I don't see how this is any different. It's a gesture, and I find it to be intuitive (it's been available on the Android version for a really long time).
It is, however, a bad idea to rely on that. I see gestures as I see keyboard shortcuts: not intuitive at all, but potentially great time savers once you learned them.
For those making touch UIs this means, quite simply, that you always have to be able to do something without gestures or that if a gesture is essential, it has to be taught to you.
There's no "metamode" here and it's tripped over quite easily during normal interactions.
Are you sure your two year old didn't watch you first?
"... gestures are to iOS what keyboard shortcuts are to Mac OS — an alternative way to do something as a convenience for advanced users." 
I understand that this gesture doesn't solve the problem of one-handed zooming for everyone, and that the solution will need to be more obvious to include everyone. It's just that a more obvious solution may add unnecessary clutter.
The HN crowd compiles versions of iOS? If so, I'd definitely like to find out how that's done.
This is super useful, thanks! (I've nearly dropped my phone several times trying to do a two point zoom with one hand).
If it's a nice day in NYC, I'll often opt for a very long walk between meetings. If I stop for a coffee, as I tend to do, I usually try to memorize the directions to where I'm going. Failing that, I have to either put my coffee down for a moment or attempt the dreaded thumb and index finger zoom maneuver.
Now that I've written that, I'm hesitant to post it. This is probably the most "first world problem"-ish thing I have ever said. I don't even really rely that heavily on Google maps since I know the major streets in the city pretty well. However, this mini-dilema has really struck me several times. I guess that means life is good!
Anyway: Thanks to the guy who discovered this. And extra thanks to the dev who implemented this. I don't know if it's an accessibility feature (limited use of second hand) or a debugging feature (second hand on the keyboard). Either way: awesome!
After a single tap happens, you can't react instantly because it's not yet known if the user will tap a second time until some threshold time (around 200 ms) passes. Alternatively, something else can gets in the way (e.g. quickly tap anywhere else to "break the combo" and skip the 200 ms tap delay).
It's not a big drawback in this particular case (tapping on things on the map makes the pin appear slightly delayed), but it's important to realize the negative effects of recognizing more elaborate gestures.
On the other hand, it's not obvious it's not the double tap zoom, so there's a delay for that anyways.
Dear Apple, I’d love to see you implement this in iOS, so that developers don't have to.
Yes, just you try doing this on a rocking bus - it's a pretty effective way to turn your phone into a projectile. Or a train. Or a car. Or...
> "On a Stanford or MIT keyboard in raw mode, use of four shift keys while typing a fifth character, where the four shift keys are the control and meta keys on both sides of the keyboard. This was very difficult to do! One accepted technique was to press the left-control and left-meta keys with your left hand, the right-control and right-meta keys with your right hand, and the fifth key with your nose."
The map not rotating is great!
What's the problem here? Should Apple remove keyboard shortcuts, because they aren't as discoverable?
I use the exact same gesture in Apple iBooks, when I want to highlight paragraphs, and it saves me so much time and interaction, it's not even funny.
Funnily enough, I don't have this problem with Apple maps as I suppose their sensitivity is less.
Incidentally, xScope was also the first multi-touch browser for Android. I'm not sure what that dev is up to now, but I like to give him props when this UI technique comes up.
It's my opinion that these are few of those gestures which are OK to be left as something to be 'discovered'. Just yesterday, my daughter struggled with my Macbook trying to zoom-in on the photos she saw, pinching them, dragging them on the screen. Such gestures and its variations are ones that we have to consider 'should/might work'.
There's another app that has a very similar gesture, Readmill. They allow brightness adjustment with a vertical slide. The downside is the lack of initial gesture to toggle its activation. So, while reading, trying to vertically scroll the page has caused the gesture to activate brightness adjustment. It becomes frustrating.
Since you're using this with one hand, tapping anywhere other than the area where your thumb naturally rests would be uncomfortable.
Also, and more importantly I think, what if you wanted to zoom in to a position near the top of the screen? You would have to tap near the top of the screen and move your finger up, causing your thumb to go off the screen. So you wouldn't be able to zoom in to an area near the top of the screen or zoom out from an area near the bottom. If such a large segment of the screen is unusable for this feature, you might as well just have it zoom to the middle, and make the user center the place they want to zoom to on their own.
Not any more uncomfortable than single tapping any other part of the screen one-handed. Of course this depends on screen size...
what if you wanted to zoom in to a position near the top of the screen?
Point well taken.
Assuming that the content of interest is a good centimeter or so in from the edge, you could map that point-to-edge distance to cover the remaining zoom scale. If it's inside that centimeter, zooming into the middle is useless anyway.
You're right, this would probably be perfectly fine on the iPhone, though it could be annoying on something like a Galaxy S3, especially for someone with small hands.
If it's inside that centimeter, zooming into the middle is useless anyway.
True, but if it always zooms to the middle, the user knows that they need to center the point that they want to zoom into before they actually zoom.
Samsung Browser on Galaxy S3 has one hand zoom already. In a browser, drag your finger up and down to zoom in or out. I miss it on Chrome on Android.
So.. that being said, I am not sure, who is first in implementing one hand zoom, Google or Samsung or somebody else.
Some other tricks I know but no idea if others know also:
- double tap with one finger to zoom in
- tap with two fingers simultaneously to zoom out
- tap and hold finger over selectable content, then move finger to move selection
- shake iPhone to undo typing
That was months ago.
What it is NOT is intuitive. Which Apple's pinch-to-zoom IP is.
...why am I comparing iphones to emacs?