Transcript
[ Background Sounds ]
>> Good morning.
Thank you all for coming.
My name is Ian Parks.
[Applause] Thank you.
[ Applause ]
My name is Ian Parks and I work
on the watchOS software team.
I'm really excited to tell you
what's new in watchOS 4 and what
that's going to mean for you as
developers so you can continue
to deliver fantastic apps on
watchOS.
It's only been two years since
we first released Apple Watch
and the platform has come a long
way.
We're continuing to learn from
our users and how Apple Watch is
continuing to make a difference
in their lives.
And this year we're adding a ton
of new features in watchOS 4.
Like a brand new news app that
lets you browse headlines and
mark the ones you'd like to read
later.
And a totally redesigned music
experience that lets you sync
multiple playlists and it has a
new interface that's both fun
and easy to use.
We were also trying to make
workflows more efficient for
users like being able to access
to the now playing UI right from
inside of a workout as well as
surfacing important information
throughout your day in a new
Siri watch face.
And of course, we're introducing
a ton of new features for
developer so you can continue to
create great watchOS apps.
Now last year we introduced
three guiding principles for how
to create great Watch
experiences.
And we're continuing to pursue
these in our system apps as well
as how we're creating frameworks
for you.
Let's take a moment to look back
at these and see how they're
continuing to drive interactions
in watchOS.
The first is making our app
glanceable.
Interactions on Apple Watch are
very short.
And the screen size is much
smaller than on other platforms.
So we need to carefully consider
what information to present on
the UI and make sure that it's
well designed information so the
user can quickly absorb and
respond to the information.
And the second is making the
information actionable.
And what we mean by this is
bringing pieces that the user
can respond to either within the
application like changing a
music track or sometimes in
their current surroundings.
A quick glance at weather
conditions, for example, can
tell me whether or not I need to
pick up an umbrella on my way
out the door but actionable
information can also come in the
form of audio too.
For instance, I can get in ear
coaching during a workout to
tell me when I've fallen behind
my pace.
And finally responsive.
While performance is a really
crucial metric for watchOS apps,
we mean a bit more when we say
responsive here.
This also means making sure that
your content remains up-to-date
always.
And it also takes into
consideration what the user
might want to do next in your
application.
Let's take a look at a few
examples of how these are
manifesting themselves in
watchOS 4.
So last year, we introduced the
Quick Start workout feature
which let you start the workout
that you most commonly do very
quickly.
The idea being that you're most
commonly going to use the same
workout over and over.
So we let use the same goal that
you've set previously to get
started in just a few seconds
but if you do a rotating set of
workouts like do you do a run
one day?
And you do a swim the next day
and the bicycle ride the day
after that?
First of all, congratulations
because you're getting a lot of
exercise.
But also you're going to have an
extra step every time of setting
a goal.
So in watchOS 4, we've made this
a lot easier.
Every workout will track the
previous goal that you've set
for that workout type and if you
haven't set one, with defaults
to an open goal.
And that means that every
workout type is a Quick Start
workout.
This is a great example of
making the most common action
that the user's going to take
the easiest one for them.
It lets them glance at the UI
and get started very quickly.
And while you're inside of a
workout, you can now add a
second workout into your
routine.
For example, if I wanted to
start with a high intensity
interval training and finish
with a quick run.
This used to be a multistep
process where I would have to
finish my workout.
Then save it.
Then return to the list of
workouts.
I would find the next one that
I'm going to do which is
probably not going to be a Quick
Start workout at that point.
So I'm going to have to set a
goal and then continue.
Now it's just a quick tap to add
the second workout and another
to Quick Start it.
This is a great example of
building a responsive user
experience where it's not just
about updating the data in your
UI.
It's also about thinking about
what the user might want to do
next in your app based on what
you already know.
Now the dock is a great place to
showcase glanceable information
from your app.
And as you saw in the keynote,
we've transitioned the dock from
being a horizontally scrolled to
being vertically scrolled.
As you'll see in one of the UI
updates in WatchKit shortly,
apps should consider what kind
of navigation feels most natural
for your app and transition
accordingly.
So that it's really easy to
navigate your app either with
swipes or by scrolling through
information.
In addition to transitioning to
a vertical orientation, the dock
also now has two modes of
operation.
There's favorites mode and
recents mode.
Favorites mode will be familiar.
It operates just like the dock
does in watchOS 3 where a user
can pick specific apps and the
order in which they'd like them
to appear in the dock as well as
one most recently used slot for
the last app that they've used.
Recents mode will look just like
the app switcher on iOS.
Apps will transition in and out
of the dock as you use them
throughout the day.
And that means that you're more
likely to see your app show up
at some point during the day in
the user's dock.
And that means that it's even
more important to make sure that
you're updating snapshots using
the background snapshot API we
introduced last year in watchOS
3.
We're also making enhancements
to this API.
For example, you can now get a
callback for when you get a
snapshot test to tell whether or
not it's a snapshot that you
have scheduled or one that's
being automatically provided to
you but that's triggered by the
system.
Also remember that apps that
either in complications or in
the dock are launched in the
background and suspended but
kept in memory.
So opening them is really fast.
Now for the rest of our time
here today, we're going to talk
about three topics that we
focused on this year in the
WatchSTK.
The first of them is UI
flexibility.
Giving you more options to
present information and actions
to users.
The second is performance.
So apps always feel as
responsive as possible.
And finally background
processing so the users can
engage in activities beyond the
foreground app experience
whether it's in the dock in a
complication or in an ongoing
task like a workout.
First let's take a look at UI
flexibility.
Now WatchKit provides a focused
set of UI components that have
been optimized for the Watch
screen.
But we want to make sure that
those are flexible enough for
you to create custom user
interfaces that meet the
personality of your app.
Now if you've already created a
Watch app or you're new to
developing on the platform,
you're going to love how easy it
is to take advantage of the new
UI capabilities in watchOS 4.
And if you're a parent, I'm
going to show you how to get
workout credit for the things
you're probably already doing
around the house.
More on that in just a second.
Now I have a 4-year-old and
1-year-old at home.
And often times between work and
wrangling the kids, I don't find
time during the day to do a
formal workout but honestly, a
lot of what I find myself doing
feels an awful lot like a
workout whether it's piggyback
rides or cleaning up toys.
So I created a new app that lets
me track these more
non-traditional workouts.
And we're going to use this as
an example to see some of the
new UI capabilities in watchOS
4.
So here we have a simple
in-workout interface.
It's showing me the calorie
counter in the middle as well as
a time label and a SpriteKit
scene of a child being chased by
their parents around the screen.
This is the kind of interface
that's really hard to do in
watchOS because you can't
overlap interface elements.
So let's take a look at what's
going on here.
So here we have a group in front
containing the labels that I
mentioned.
And that's on top of a SpriteKit
scene.
Now I know you're thinking I
just said you can't overlap
interface elements.
In watchOS 4, we've created a
new group layout that allows you
to do things like this.
Let's take a look at interface
builder to see how you can use
that.
So a new option has been added
to groups.
So in addition to vertical and
horizontal layouts, you can now
select overlap.
And when selected, overlap
groups do not compute offsets
for each individual element.
Instead, you can select their
individual alignments like top,
center, and bottom or left,
center, and right, and the
elements are laid out according
to those in a more absolute
fashion within the group.
And you can also nest groups
within each other like I've done
here with the metrics group,
which contains my labels inside
of a vertical group.
And you can also use [inaudible]
and spacing in order to fine
tune placement within the
groups.
You can also specify z order by
the order in which the elements
appear in the outline view as
seen here.
This is going to make a huge
difference in making it easier
to create custom user
interfaces.
Now in my workout control screen
that you'll see here in a
second, I've now added a water
lock button.
And water lock can be really
helpful for rejecting false
touches from water being on the
screen.
Or in my case because my
daughter's usually trying to eat
my watch [laughter] but
previously in workout apps for
third parties, for a user to
engage water lock you'd have to
start the workout, go back out
to the Watch face, swipe up to
reveal control center, and then
enable water lock.
Then the next time that you
raised your wrist, the workout
app would be on the screen.
We're going to make that a lot
easier in watchOS 4 and now you
can include a button within your
own user interface so that it
fits the personality of your
app.
Now water lock can only be
enabled by developers, never
disabled.
The user has to do that
themselves.
When they try to interact with
the side button or digital
crown, an overlay will appear
just like the one seen here.
It's the same one that's used by
the system currently.
And it tells them how to disable
water lock.
Water lock can be enabled in
workout as well as in one other
session based activity that
we'll get to in a little bit in
the presentation.
And the reason for this is
because apps that are not in a
workout session, after a period
of time and when the wrist has
been dropped, the app will be
suspended in the background.
So when the user raises their
wrist, they won't see the app
anymore and the screen is locked
so they can't open it back up
but with a workout app, the app
will always appear every time
they raise their wrist.
So I can see up-to-date
information in -- from my
workout as I'm going through it
even though the screen is
locked.
Let's take a look at how to
enable this in code.
As you can see, it's pretty
simple to enable.
It's a single call on the shared
extension object.
Now one last thing to note is
that water lock can only be
enabled while the app is in the
foreground.
So the user is always aware of
what's going on.
Now here you can see my app is
giving me a congratulatory fist
bump for figuring out a way to
fit in a workout into my
parenting responsibilities.
Now this might be something that
I'd like to show someone else
but my options are kind of
limited on watchOS.
I can either do this awkward
gesture where I try and keep the
screen on while I turn it away
from myself or I can turn it
over and tap on the screen but
the content is upside down.
In watchOS 4, we're giving you
the ability to turn on auto
rotate.
When enabled, wrist movement
will not turn off the screen.
And we automatically rotate the
content when your wrist is
turned away from you.
This will not keep the screen on
indefinitely.
The idle timer will still sleep
the display after a period of
inactivity but you should have
plenty of time to show the
content on your watch to someone
else.
Let's take a look at the
property.
You're going to start to see a
bit of a theme here.
You don't have to do a lot of
work to take advantage of a lot
of the UI capabilities that
we're adding in watchOS 4.
There's a lot of applications of
this.
So let's take a look at a few
examples.
Proloquo4Text is a text based
communication app that gives
literate children, teens, and
adults the ability to speak
without voice.
The app allows them to tap on
preprogrammed personal phrases
and turn their wrist towards
another person to communicate
with a text on their wrist.
Here I can place my coffee order
by showing my wrist to the
cashier and having the text
remain on screen and upright
when I turn it away from myself.
I can even pay for my order
using the Starbucks app.
Starbucks lets me open my
barcode from my personal card
and have that shown on screen.
Then I can show that to the
scanner at the cashier and have
it remain on screen so that it
can read it.
There's a ton of different
applications of this.
So you should consider what
content in your application
might be applicable.
In our next step, we have a new
style for paging views, a
vertical paging view.
I could have implemented this as
a scroll view but really these
are two distinct pages.
And it's great how they just
snap into place.
It's also really natural to use
with the digital crown.
And the animation between the
pages is very similar to the one
we introduced last year for
performing segues between table
rows in a master detail
application but now you can do
so without using a navigation
controller.
Let's take a look at how you
implement this interface.
So we replaced the reload root
controller's method with a new
one that takes in two key pieces
of new information.
The first is the ability to set
the orientation.
So you use the same method
whether you're doing it in a
horizontal paging view or a
vertical paging view.
And the second one is something
that we've heard a lot of
feedback about and we're excited
to be able to offer in watchOS
4.
And that's the ability to set
the initial page index.
So this is great for things like
workout apps where you want a
main workout UI.
[Applause] I know we've seen
lots of radars.
And you want the control screen
left to center but you want to
load directly into the main
workout UI.
So this allows you to set the
index to wherever you want and
have it load directly there.
Now here we have a history view.
And when doing an interface like
this where we may have hundreds
of records, there's a couple of
things to keep in mind.
The first is storage.
I probably don't want to store
all of my workouts that I've
ever completed on the watch when
I can easily load them using
watch connectivity from the
phone or from a server.
The second is performance.
Loading too many table rows at
once can lead -- load -- lead to
a decrease in performance and
load time for the table.
So here we're now allowing you
to get callbacks for when the
user scrolls to the bottom of
the screen or the top of the
screen.
So you can do things like I have
here where I'm getting the
callback.
I'm loading -- putting on a
loading indicator and then I'm
loading data from the phone.
Let's take a look at how you can
implement these callbacks.
So the first one is the one I
was just using in the last user
interface.
InterfaceOffsetDidScrollToTop.
This gets called when the
animation completes, when the
user scrolls all the way to the
bottom of the screen.
The second is the exact
opposite,
interfaceOffsetDidScrollToTop
which gets called when you
scroll to the top of the screen.
And the last one,
interfaceDidScrollToTop gets
called when the user taps on the
status bar, which scrolls the
interface all the way to the
top.
Now we've also included in a
scroll function, which lets you
pass in an interface element and
have it scrolls to appear at
either the top, center, or
bottom of the screen.
I use that in my history view to
show loading indicator.
When I loaded the group that
contained my animation, it
loaded off screen.
So I passed it into the scroll
method and set it to show at the
bottom of the screen.
All right.
And here we have a reimagined
post workout screen that's been
redesigned as a full screen
animation.
In watchOS 4 for SpriteKit and
SyncIt [phonetic] apps, you can
now make use of the entire
display.
It is still a watch though, so
we are always going to display
the time in the top corner with
a gradient behind it so the user
can always read the display
regardless of the color of
content behind it.
As you can see, there's a lot of
new changes in creating your
user interfaces in watchOS 4.
I encourage you to check out a
session later this week on
planning a great Watch
experience, which will be going
through planning both the
interactions that you should do
on a Watch as well as the design
of the application.
Next, let's take a look at
performance.
Now interactions on watches
we've talked about previously,
are short but numerous.
So we always want to make sure
that we're both preparing ahead
but we're also as responsive as
possible.
And to that end, in watchOS 2,
we moved the extension from
running on the phone to running
on the Watch.
And that did a couple of things.
It meant that you could run the
app when the phone was no longer
present but it also meant lower
latency and communication.
The behind the scenes, the app
and extension are still running
in separate processes where your
code is trying to make updates
and you're responding to events.
So there's latency in the
communication for the inner
process communication between
the two.
With a little bit of magic in
watchOS 4, at run time, we're
loading both the extension and
the app into the same process.
This is going to make a huge
difference in performance of
your apps.
You should see things like lower
touch latency, faster loading of
views as well as higher frame
rates while you're interacting
with the device.
And the best part is you don't
have to do anything for your
users to gain from this.
This is a completely binary
compatible change for all apps
watchOS 2 and later.
That means no updates.
[Applause] No recompiling.
All existing apps either on a
user's device or in the App
Store are just going to start
benefiting in watchOS 4.
This is going to make a huge
difference.
So we can't wait for you to
check it out.
I moved too far away.
And finally let's take a look at
background processing.
Like I said before, it's really
important to prepare ahead of
time and making sure that the
app is always up-to-date
whenever the user wants to look
at their wrist.
And this can be done with a
combination of background
running modes, use of the
complication, and snapshot APIs
as well as some changes that
we're making this year for what
will be called the Frontmost App
State.
We'll get to that in just a few
minutes.
Now last year we introduced the
workout processing background
mode allowing third party apps
to run in the background and
making the app available every
time the user raised their
wrist.
We're continuing to make these
APIs better this year by adding
a few new additions.
The first is a hardware pause
and resume API.
When a user presses the side
button and digital crown at the
same time, an event is generated
that you can respond to in your
application.
That way you can pause and
resume the workout depending on
which state the session is in.
The second is workout segments.
And this allows you -- it's a
new type on the HK [phonetic]
workout event class and this
allows you to mark important
durations of time within your
workout.
This could be used for things
like marking the different
sections of an interval
training, for example.
And last year we started to
track workout routes for
specific types of workouts using
the Apple Workout app.
Now with a user's permission,
you can both read these workout
routes as well as create your
own.
Now if you already have a
workout app or you're
considering making one, you
should check out the what's new
in health session later this
week which will be going through
how to use these APIs as well as
other changes in HealthKit that
you should take advantage of.
Remember also adding a few new
background modes in WatchKit
this year.
The first of which is a location
background mode.
This is great for things like
location based games as well as
turn-by-turn navigation apps.
And similar to workout apps,
it'll always be available every
time the user raises their
wrist.
And if there's something that
you need to alert the user to
like when I've made a wrong
turn, you can use audio and
haptics from the background in
order to get their attention.
And like I had mentioned before,
there was another session based
activity that you can also water
lock mode with and this is --
that's location mode.
So you can use it in conjunction
with water-based activities.
In order to conserve battery
power, though, CPU in the
background is limited.
So you need to monitor what
things need to be done in the
background and what can be saved
for later.
And lastly, you must start the
location session from the
foreground just like a workout
so that the user's always aware
of what's going on.
And while you're accessing
location, there will be a status
indicator and control center so
that they can always monitor
their privacy.
And we've also added in-line
audio recording as well as a
background mode.
And recording has been available
since watchOS 2 but it was only
offered in a modal form where we
would hand a file back to you
after the user had finished
their recording.
You could also continue
recording when the user had
dropped their wrist but it would
keep the screen on for the
entire time.
Now in watchOS 4, we're offering
in-line audio recording to solve
some of these problems.
First, you no longer are limited
to the modal form so you can
create your own custom U
recording controls that fit the
UI of your app.
You can also do in-line audio
recording.
So if you wanted to look for a
certain signature in the audio
or if you wanted to do things
like real time language
translation on the watch.
And you can continue recording
when the user has dropped their
wrist but now it's a full
background mode.
So you don't need to waste the
additional battery power of
keeping the screen on.
Imagine being able to walk into
classroom and record an entire
lecture right from your wrist.
And similar to other background
modes in watchOS, the app will
always appear every time the
user raises their wrist.
It'll be CPU limited and the app
must be started -- the session
must be started from the
foreground.
And while you're doing a
recording, there will be an
indicator on the watch face that
the user can tap on to return to
the recording app.
These background modes are going
to make a huge difference in
doing ongoing tasks in watchOS
4.
All right.
We're also supporting core
Bluetooth on Watch -- in watchOS
4.
This --
[ Applause ]
This means you can connect
directly to the Watch from your
devices.
And get updated data with lower
latency as well as continue use
when the phone is no longer
present.
And previously for Bluetooth
devices, you'd have to connect
with the phone and then shuttle
data over using Watch
connectivity.
Now you should get much faster
updates.
And with core Bluetooth on the
Watch, you can connect up to two
peripherals.
And we're only supporting
central mode which means that
you need to -- you can connect
to other devices but the Watch
cannot be used as a peripheral
itself.
And while you're in the
foreground, there's a minimum
time between samples of 30
milliseconds and when used in
conjunction with the background
mode, that time is limited to
120 milliseconds.
Now when used in conjunction
with a background mode,
background running apps can only
connect not scan.
So you need to do your pairing
and discovery process while the
app is in the foreground.
Now when the app is suspended,
the peripheral will
automatically be disconnected
and we will not wake up the app
for newly advertised values.
So if you need ongoing updates,
you need to use it in
conjunction with the background
mode.
If you want to learn more, you
should check out the core
Bluetooth session later this
week but first let's take a look
at an example of how an app can
make a use of this.
So ReSound Smart 3D is an app
that lets you connect to
Bluetooth enabled hearing aids
so you can change the listening
environment depending on where
you are.
So I can change from an outdoor
listening environment to a
restaurant, which has a pretty
different audio profile just
with a tap on my wrist.
And with watchOS 4, they can
connect directly to the hearing
aids so that they can make
faster updates and they can
continue using the device when
the phone is no longer present.
And that's core Bluetooth.
[ Applause ]
Now I mentioned before though
there's something called the
Frontmost App State.
This is something that we're
really excited about and I think
it's going to change the way
that we think about creating our
Watch apps.
The experience of using a Watch
app is very different from apps
on other platforms.
When I use an iPhone app, for
example, I open the app.
I use it for some period of time
and eventually I close it by
pressing the home button.
On a Watch app, though, I may
use it for a much shorter period
of time.
Perhaps just a few seconds but I
may use the app dozens or more
time within a single session.
For example, I may use the
reminders app to go shopping at
the grocery store to check off
items as I'm putting them in my
cart.
Every time I put something in my
cart, I raise my wrist and the
app is right there where I left
it.
It makes it really easy for me
to find the item that I'd like
to check off and tap it and then
get on with my shopping.
This period where we resumed to
your app rather than the clock
face is what we call the
Frontmost App State.
In watchOS 3, that period of
time was eight minutes between
each wrist raise.
We found that this was often too
long for users and they would
end up in the same app long
after they were finished using
it.
So in watchOS 3.2, we changed
this limit to two minutes.
And that happens between each
wrist raise.
So for the most part, most
activities will remain frontmost
for the entire duration of using
it but we recognize that there's
some use cases in which you will
need more than two minutes
between each wrist raise.
And for that, we're allowing you
to specify when you need to
extend your frontmost time.
And that will change the time
out back from two minutes out to
eight minutes.
So let's take a look at how you
enable this in code.
Like most of the other things
that we've talked about today,
it's a simple call on the shared
extension.
It's a simple property.
You can set to true whenever you
need to extend your frontmost
time.
You must be judicious about this
though because we don't want
users to remain in apps long
after they're finished using
them.
So let's take a look back at my
reminder shopping list example.
When I turn on -- when I open up
the shopping list, I probably
want to turn on and extended
frontmost time so that if I had
like an item between two aisles
that took longer than two
minutes, I wouldn't have to go
back to open up the app.
But as soon as I've finished the
items in my shopping list, it's
probably a good opportunity to
turn off extended frontmost
time.
So that the app will just
automatically close in the
background without the user
having to do anything.
Now in addition to giving you
more flexibility for when you
remain in frontmost, we're also
changing some of the behaviors
of the API so that you can have
more up-to-date information and
meet the expectations of users.
Now you can already extend your
run time by up to 30 seconds
using the expiring activity on
NS [phonetic] process info.
And this is a great opportunity
to do things like networking
tasks.
And we've increased the priority
of this request in watchOS 4 so
that you can do more things in
the time that you've requested.
And if Watch connectivity or url
session data comes into your app
while you're in the frontmost
state, we will immediately
resume your app and in most
cases, the payload will begin
downloading immediately as well.
And if there's important
information that you recognize
in that data, while you're in
the frontmost state if you have
run time, you can play haptics
to alert the user.
And if a notification for your
app comes in while you're in
that state, you could also
handle it using the user
notification API just like you
can when the app is in the
foreground.
Let's take a look at an example
that ties all of these
capabilities together.
So here we have a simple
ride-sharing app.
It's showing me that I have an
expected five-minute wait time.
This is a great opportunity to
turn extended frontmost time on
because I already know it's
pretty likely that the user's
going to need longer than the
two-minute timeout.
It's going to be a bit of a wait
and I probably don't want to
keep my wrist up the entire
time.
So I tap on the request ride
button and drop my wrist.
Now the screen may be off but
I'm definitely not done using
the app because I'm still
waiting for the ride.
And at some point, the server's
going to send a push
notification that'll get
forwarded to my Watch and at
that point, the app can handle
the notification and recognize
that it's important information
and play a haptic to alert me.
When I raise my wrist, the app
has already been updated showing
me important information like
the arrival time as well as the
driver's name and star rating.
Even the ability to call the
driver.
At this point, I should turn off
extended frontmost time because
it's likely that the user's done
using the app for now, at least.
Getting this frontmost state
right will make your app feel
like magic.
Always knowing when the user's
done using your app as well as
when they need more time in it.
And making sure that the data in
your app is up-to-date and
showing just what the user wants
to see for the next time that
they may use their app.
I'd highly encourage you to
check out the session later
today on the life of a watchOS
app.
This will be going into detail
about app life cycle events,
making use of the frontmost
state as well as background
modes and more to make a great
Watch experience.
To summarize, we've added a
bunch of new capabilities to our
user interface components to
make them flexible, to create
custom user interfaces like
overlapping interface
controllers as well as auto
rotate mode.
We're changing the architecture
of Watch apps to make them
perform even better by loading
the extension and an app into
the same process at run time.
And we're adding new background
modes as well as core Bluetooth
support and the changes that we
just went through for the
frontmost app state, which
should make it easier for you to
keep your app up-to-date for
users.
And I mentioned a number of
sessions that you should check
out this week to learn more
about developing on the Watch
platform.
If you want to get more
information like the session
links for videos as well as
other resources, please visit
the developer.apple.com link.
Thank you so much for coming to
hear what's new in watchOS 4.
I can't wait to see what you
guys build next.
[ Applause ]