Regarding Apple Watch, listen to what the engineer who developed the Watch App for two months said

In January this year, I was invited by Apple to secretly participate in the on-site debugging of the Apple Watch App. In April, Apple Watch will be officially launched. Before that, I also personally experienced the Apple Watch and developed some Watch App applications. I would like to share some of my experience with students who are interested in Apple Watch.

The students from Alipay Wallet went with us. The WeChat team also went there at the same time as us. Apple officially does not allow third-party developer teams to communicate with each other, but we still found an opportunity to chat together.

Apple Watch has two sizes and three versions, and there are more personalized and diverse straps to choose from. After seeing the real machine and wearing it, the overall feeling is that it is a bit small. 38mm and 42mm, in fact, you can estimate the size by pinching your fingers. The 42mm version is about the same size for my body type. Male compatriots with slightly larger bodies will definitely feel that it is more pocket-sized.

The differences between the three versions are all in the material of the watch and the wristband. There is no difference in the watch itself and the software. I didn't see the pure gold version during the test, which is a pity. The wristband is completely customized. It is estimated that after the official launch, this accessory will be very popular. The material of the sports version of the wristband feels very cheap, and the lock is not completely adsorbed by magnets. If you are used to MagSafe or Smartcover, which are completely magnetically adsorbed, it will feel low.

The thickness is closely related to the size. The 38mm version looks much thicker than the 42mm version, but it doesn't feel too cumbersome when worn. The screen resolutions are 272×340 and 312×390, respectively, and the aspect ratio is 4:5. Both are Retina-level, and the fineness is high enough that designers only need to use @2x.png to draw. Sapphire glass surface, ceramic back.

gesture

The gestures of clicking, scrolling vertically, and switching horizontally are similar to those on mobile phones. In order to better browse the watch interface, Digital Crown and Force Touch are added.

The Digital Crown is the scroll wheel, which can be used for scrolling, zooming, and other operations. In addition, the center of the scroll wheel is actually a Home button, which can be clicked to return to the Home page. The Digital Crown gives hope to students with thick fingers, allowing some browsing operations to be performed off-screen. Imagine that if a student has thick fingers, the small dial will be submerged as soon as they cover it with their fingers, which must be embarrassing.

Force Touch is what we call a poke. The poke gesture will bring up the Menu page. Developers can use this method to add some additional interactive options to the current page.

Digital Crown and Force Touch gestures are not currently open, which means that the effects of gestures are fixed and developers cannot obtain specific execution information of gestures. WatchKit does not have custom gestures.

sensor

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Heart rate sensor: It can provide a lot of health data through heart rate detection and corresponding analysis, and it can also distinguish various sports situations when detecting heart rate. For applications focusing on medical health, this is the main focus.

Accelerometer: used to detect body movement and step count, detect exercise type, and calculate calories. If it were just this, the accuracy might not be much different from that of a normal wristband. Fortunately, with the help of the phone's GPS and WiFi, it can achieve accurate measurements that are not possible with normal wristbands.

Taptic Engine: To be precise, this is not a sensor, but a linear actuator that Apple uses to implement Haptic feedback. Haptic feedback is known as the next generation of interaction, and it often appears in game controllers, including Oculus, to provide tactile feedback to the wearer. Apple Watch interacts with the wearer in a more intimate way through the Taptic Engine, and can even send heartbeat information to friends.

App Presentation

WatchKit App

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WatchKit App is the main body of the entire Watch App, carrying Glance and Notification. It can display information in a relatively rich style, and most ideas and UI interactions about watches should be implemented here. The interaction method of WatchKit App can be imagined as a streamlined small-screen customized iOS App, but many UI frameworks of iOS App cannot be used here. Accordingly, Apple has set up another set of UI frameworks specifically for Watch App. However, the cost of switching is not high. On the one hand, it is because the current Watch UI library is still very simple; on the other hand, you can find many correspondences with the UI library on iOS App, such as: WKInterfaceController corresponds to UIViewController, WKInterfaceImage corresponds to UIImageView, etc.

Glance

Glance is a centralized way to browse information specifically for watches. You should display your most important data that users will care about in real time here. For example, the current flight information of the flight app and the completion status information of the Todo List app. The Glance interaction method takes into account that users may not want to browse information on the watch. Users are used to raising their hands to take a glance and then put it down. This is because they have always relied on watches to check time. Glance does not support interaction. Clicking it can only jump to the WatchKit App, so don't consider adding buttons and other elements when designing. There is only one Glance interface, which does not support scrolling view. The only customizable area is a roughly square Group.

Notification

Notification is a link that needs to be considered more when designing a Watch App. It has a different status from notifications in mobile apps. The notification styles on the watch are very diverse. Although they have the same format as mobile phone notifications, they are positioned in a completely different way of presentation. We need to enrich the existing notification data for use, especially after iOS8 added the interaction with Notification, the interaction of notifications has gradually become richer.

Watch notifications have two forms: Short Look and Long Look. Short Look provides simple text information; Long Look is divided into Static and Dynamic. The style of Static is determined by the design, while Dynamic provides the ability to customize the UI according to the content of the notification. Whether the notification is displayed on the watch or the phone is determined by the system. When I tested it on site, if I closed the mobile phone application from the background and locked the screen, the notification came from the watch.

Glance and Notification have restrictions on fonts. By default, only system fonts can be displayed. If customization is required, they need to be rendered into images for display.

UI Layout

If you are struggling with whether to write UI in code, xib or StoryBoard on iOS, you can now give up completely. When developing a Watch App, all UI elements must be added through StoryBoard during design. We can no longer add or remove elements from the interface (but can hide them) during runtime. Certain attributes related to layout, such as row height and number of rows, cannot be changed or set at runtime. Basically, at runtime we can only change the content of the view and achieve limited changes to the layout by hiding certain view elements.

WatchKit provides relatively limited layout possibilities and flexibility. You can only use Group to layout columns within rows using rows as the basic unit. Since Group is a type of filling layout for a single plane, it is impossible to overlay views, which brings challenges to interface design and interaction.

Currently, the only animation method open to third parties is frame animation, similar to GIF effects. Some people use 360 ​​pictures to accurately achieve 360-degree circular animation effects. The cool animation effects of the built-in apps cannot be realized yet.

Designers need to pay more attention to the above three points. If you are not careful, you will start to play freely. Don’t make things difficult for developers.

San Francisco Font

Apple Watch has a new font "San Francisco" built in specifically for small-screen typesetting and interaction. The new font compresses complex letters (such as "g" or "y") in large font sizes to save vertical space; in small font sizes, it leaves more space between strokes to ensure that users can see the bottom of the recognition cost, and the size of punctuation marks will also be relatively larger. When the font size or text area changes, Apple Watch will dynamically adjust the font weight and font size to ensure the best reading effect.

There are still many restrictions

Although as a new product, it is much more open than the first generation of iPhone, but Apple still carefully keeps many permissions in its hands. Currently, many pre-installed applications on Apple Watch are very elegant and have many more functions. Some of the main information that third-party developers cannot access for the time being are:

Third-party applications cannot obtain sensor information yet;

The animation API is not open;

Tasks that require permissions, background tasks, and time-consuming tasks are not allowed.

Apple is also constantly experimenting with what permissions and capabilities should be given to the Watch, including frequent changes to the API in the Beta version and some permissions being opened and then revoked.

Comparison with Android Wear

At the software level, Apple Watch and Android Wear are similar in many ways:

Reliance on mobile phone processing;

The center of gravity of notifications rises;

The app is designed to be lightweight.

Although there are many similarities, the current positioning of apps for Apple Watch and Android Wear is fundamentally different. For Android Wear, apps on the watch and apps on the phone are equal, even the watch relies on the phone for computing. For Apple Watch, its engineering structure is an extension of iOS apps, and perhaps this difference will lead to the two taking completely different paths in the future. In the real Apple device, there will be a dedicated Watch management app on the phone to manage and set apps and information on the watch. It is said that there will be a watch app store here in the future.

Apple Watch positioning

There are many different opinions on smart watches. Some people think that a wristband can do everything, and there is no need for a screen. Some people think that function is secondary, and appearance is the first priority. Some people are happy to get a Moto 360, but then they are frustrated to find that it can't do anything. From the current strategic focus of Apple:

Decoration: A watch is first and foremost a decoration. Not many people really use a watch to tell time. Apple is aware of this and has launched various customizations and different versions, but it is not good enough. So there are many products that want to compete with Apple Watch in this regard.

Health management: Based on some of the applications we saw on site, the health tracking function is what interests me the most. Starting from iOS 8, Apple opened the HealthKit framework and began to build a health management platform. As a wearable device with so many sensors, the watch can provide a lot of health data that mobile phones cannot.

Controller: The portability of watches as controllers is a natural advantage. After the launch of HomeKit, we can guess that Apple is considering smart home. There have been some cool attempts, such as operating Philips Hue Light smart bulbs and even controlling Tesla.

Note: The author of this article is Jia Fu, a mobile Taobao development engineer. Jia Fu and his colleagues were invited by Apple in December last year to travel to the United States in January 2015 to conduct a week-long secret debugging at Apple Campus in Cupertino, Apple's headquarters in Silicon Valley, California.