407.srt

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[ Silence ]

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>> My name is Troy
and I'm an engineer

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on the debugger UI
team for Xcode.

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And I'm glad to see so
many people here today

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because we all know that
debugging is really important.

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And you know that debugging
is what sets your app apart

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from the app on the App
Store that gets one star

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because it crashes on launch.

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And debugging is what sets
your app apart from the app

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on our iOS devices that use all
the memory and evict other apps

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when our users are trying
to do some multitasking.

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And debugging is what sets
your app apart from the apps

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on our Mac and iOS portables
that use all of battery life

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in just a few hours making it a
worst experience for everyone.

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But you guys know that already.

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You're here because
debugging is hard.

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I like this quote from
Brian Kernighan and it says,

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"Everybody knows that
debugging is twice as hard

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"Everybody knows that
debugging is twice as hard

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as writing a program
in the first place.

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So if you're as clever as you
can be when you're writing it

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in the first place, how are
you ever going to debug it?"

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Well, the answer is better
tools and specifically,

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the new debugging
tools in Xcode 5.

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We have a lot of new
things to cover today.

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But first, let's go
on a tour of the UI

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so we have a common
vocabulary when we know--

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when we're talking
about these things.

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So here is the brand
new, Xcode 5 UI.

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And the first thing you're going

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to notice is we've moved the
breakpoints activation button

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from the toolbar down
into the debug bar

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because it's right there next
to the other tools that you need

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when you're debugging such as
Continue, Step Over, Step Into.

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And it's just a much
more natural place

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to disable all your breakpoints
if you need to do that

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and then hit Continue.

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If you need to enable or
disable breakpoints one by one,

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of course, we go to the
breakpoints navigator.

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of course, we go to the
breakpoints navigator.

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And here you see a list of all
of the breakpoints separated

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by filename and line number.

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And you can edit or disable,
enable breakpoints right here.

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But not all breakpoints have
filenames and file numbers.

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There are some special
breakpoints.

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And we create those down
at the bottom of the window

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where you can create
symbolic breakpoints

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or the exception breakpoints

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that are more special
breakpoints.

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And we got a two new
breakpoint types that are

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like the exception breakpoints.

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And that's the OpenGL
ES error breakpoint

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and the unit test
failure breakpoint.

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Both of these breakpoints
are kind

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of like the exception
breakpoints

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where you can set it once
and just kind of forget

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about it in your project.

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And then when you have an
error, Xcode is going to pause

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in your applications
code instead

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of some error handler later on.

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So that's a really great way to
catch those errors in unit tests

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So that's a really great way to
catch those errors in unit tests

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and in your OpenGL
ES games on iOS.

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Let's move on to the-- there's
another navigator that's really

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important of course and
that's the debug navigator.

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And the first thing
you're going to notice

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in the debug navigator is
this brand new debug gauges.

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And we're going to talk
a lot about that later.

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So let's skip it for now.

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I do want to draw your
attention to this icon here.

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This is the spool of
thread icon and this means

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that your debug navigator
is in threads mode.

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And so, down here, you
get a list of your threads

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and a stack trace where
you're paused in the debugger.

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And this is a really great
place 'cause you can navigate

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through that stack trace and
jump through the files that led

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up to where you are in your
paused application code.

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And you can even check out
the parameters that went

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into the calculations that
got you to this point.

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And so, you can figure out
why you got to this point

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And so, you can figure out
why you got to this point

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and why maybe you need
to go somewhere else.

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But let's return back to
that spool of thread icon

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because you can change that and
a lot of people don't know that.

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If you're using grand central
dispatch, it's more natural

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to organize your threads by cue.

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And so, this is exactly
what this spool--

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this grand central dispatch
stoplight icon indicates

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that we're grouping
your threads by cue.

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Now, let's move on to
the variables view.

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The variables view is where when
you stopped at a breakpoint,

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it will show you the
most important variables

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for that line of code and
that might be local variables,

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it might be instance variables
or parameters to the method

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and Xcode does a
really great job

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of choosing those
variables for you.

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But in some situations,
you need to find

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out a little bit
more information.

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Maybe, you need to find out
a global variable state,

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or you need to find out
some register states.

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or you need to find out
some register states.

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And so, you can click on this
toggle down here and change auto

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to all and that will give
you a more expansive view

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of your variables.

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Let's move on to
the debug console.

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The debug console is where
you receive the output

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from your application whether
that's NSLogs, printfs,

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or maybe the system frameworks

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that you're using are showing
you some warnings or errors

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that you need to be aware
of and they're going

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to come out right here.

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Of course, when you're paused
in the debugger, this is also

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where you have a direct
conduit to the LLDB debugger

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which is a state of the art
debugger that powers so many

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of the features in Xcode,
and we're going to talk more

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about that and how
it's integrated

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with Xcode more a little later.

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And so, that's basically
the main aspects

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of the debugging in Xcode.

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And of course, we've added new
things which we're going to talk

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about today including
the new debugging gauges

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about today including
the new debugging gauges

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which we saw briefly.

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We're going to see a new way to
debug, a new debugging workflow.

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And then we're going to look at
a specific debugging workflow

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which is really great
now with XPC services.

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So let's talk about performance.

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We all know that performance
is extremely important.

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Nobody likes to see stutters
in their application.

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Nobody wants to see scrolling
stuff for any reason.

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But you've ever hung on
the Apple developer forums,

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you may have heard,
"Don't pre-optimize."

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And you may even get this quote
from Donald Knuth that says,

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"Essentially, pre-optimization
is the root of all evil."

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I think we can agree

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that there's a little
bit of hyperbole here.

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But we can also agree
that if you think

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about performance before you
think about code correctness,

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you end up with code
that's harder to read,

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code that's harder to
maintain, and ultimately,

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code that may not even be
correct in the first place.

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code that may not even be
correct in the first place.

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So if performance is
such an important aspect

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of your application, but we
don't want to pre-optimize

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when are we supposed to
optimize our programs?

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We should optimize when
we measure a problem.

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This is the only time that
we know what's going wrong

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so we can fix that instead

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of what we think
might be going wrong.

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And Instruments is
the best place to go

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and optimize your code.

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There are sessions this week and
there's videos from prior years

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to tell you how to
use Instruments.

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But the good news is now in
Xcode 5, Xcode is measuring

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for you all of the time, and
that's the new debug gauges.

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Debug gauges show up
in the debug navigator,

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right there where you
can always see them.

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And this is really
great a place for them

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because when you just
pause, it switches to that.

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It's right there, you just need

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to peak behind your current
application or if you're

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on a device, it's right
there on your Mac.

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There's a bunch of
debugging gauges

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There's a bunch of
debugging gauges

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to show you the performance
and the characteristics

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of all sorts of technologies.

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There are two debugging gauges

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that are universal no matter
what kind of app you're writing,

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what platform you're
targeting, and that's the CPU

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and the memory debugging gauges.

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And so, since those
are universal,

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we're going to take a look
at them more closely today.

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So first step, the CPU gauge.

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We show you a chart
of the recent history

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of a CPU utilization which
is your first indication

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that something may be going
wrong in your application.

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If you see a spike
that you didn't expect,

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or if you see a pegged on a
processor and you don't know

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that that's happening,
you want to take a look

00:08:42.486 --> 00:08:43.785 A:middle
at that, take a deeper look.

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And to do that, you click on
the CPU gauge and it brings

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up the beautiful CPU
debugging report.

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Some of the characteristics
of these reports

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that are common among all of the
reports, so let's take a look

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through some of the aspects.

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First we have this view here
which is the meter view.

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First we have this view here
which is the meter view.

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The meter view shows you a
snapshot of what's happening

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in your code right now in your
application to give you an idea

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of what's going on right now.

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As you can see here,
we're using 97 percent

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of the CPU utilization.

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And that puts the
needle about halfway

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because this iOS device has
a two core processor and so,

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it's out of a total
of 200 percent.

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We don't know whether that's
50 percent of each core

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and we don't know if that's
100 percent of 1 core,

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and zero percent of the other.

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But we know that approximately,

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half the CPU utilization is
going to our application.

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I also want to draw
your attention

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to the small inner blue
arc because that's a range

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of the last few minutes
of CPU utilization.

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So you know whether things
have been wildly swinging back

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and forth or if it's just
been pegged at a narrow range

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such as it is here between
about 60 and 100 percent.

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The next area is the utilization
across the whole system

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The next area is the utilization
across the whole system

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because all know that our
applications do not run

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in isolation.

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Other applications affect
how our application runs.

00:10:08.326 --> 00:10:10.676 A:middle
And so here, you can see
in purple that we are using

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about half of the total
CPU utilization potential.

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The orange area is all
the other applications

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which on iOS is very
well-behaved.

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So it's a tiny little
15 percent slither.

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And then of course, the
free area is the gray area.

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And as we've been stressing all
week, if you have work to do,

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you really do want to
use all the CPU can

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and then let it go to sleep.

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Let the computer-- the machinery
underneath your application go

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to rest for better
performance and power.

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Now, we have the main
section of the report.

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This is where we have some
graph showing you with history,

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basically, the history
of that needle up above.

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And the first one
is a large graph

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because that's showing
an aggregate

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across all your threads at
the CPU utilization over time.

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Below that, we split
it out by the threads.

WEBVTT
X-TIMESTAMP-MAP=MPEGTS:181083,LOCAL:00:00:00.000

00:11:00.726 --> 00:11:01.996 A:middle
And here, we only
have two threads.

00:11:02.466 --> 00:11:05.136 A:middle
But these-- as your threads
come and go, we will add

00:11:05.136 --> 00:11:06.366 A:middle
or remove graphs down here.

00:11:07.316 --> 00:11:09.856 A:middle
In this case, we can
see that thread 1,

00:11:09.856 --> 00:11:12.866 A:middle
the main thread is getting a
lot of activity and whatever

00:11:12.866 --> 00:11:15.146 A:middle
that second thread is
basically doing nothing.

00:11:15.206 --> 00:11:16.636 A:middle
So this might be
a good opportunity

00:11:16.946 --> 00:11:19.266 A:middle
to profile our application
and see if we can move any

00:11:19.266 --> 00:11:20.326 A:middle
of that off the main thread.

00:11:21.156 --> 00:11:23.646 A:middle
And of course, as I said,
the best place to do

00:11:23.646 --> 00:11:25.286 A:middle
that is in Instruments.

00:11:25.286 --> 00:11:29.766 A:middle
So the most important part
of this report is the Profile

00:11:29.766 --> 00:11:30.576 A:middle
and Instruments button.

00:11:30.576 --> 00:11:31.926 A:middle
And this will launch
Instruments,

00:11:32.246 --> 00:11:35.656 A:middle
open up the time profiler
template, and gets you started

00:11:36.286 --> 00:11:37.896 A:middle
down the path to
fixing this problem.

00:11:39.096 --> 00:11:40.856 A:middle
Let's move on to
the memory report.

00:11:42.076 --> 00:11:45.106 A:middle
The memory gauge sets in
the debugging navigator just

00:11:45.106 --> 00:11:48.306 A:middle
like the CPU gauge and it shows
you a chart of what's going

00:11:48.306 --> 00:11:51.276 A:middle
on giving you a first indication
that something maybe going wrong

00:11:51.666 --> 00:11:54.486 A:middle
or maybe, an indication that
everything is just fine.

00:11:55.316 --> 00:11:58.096 A:middle
If we click on this gauge,
we get the memory report.

00:11:58.716 --> 00:12:06.586 A:middle
And like the CPU report,
it has similar sections

WEBVTT
X-TIMESTAMP-MAP=MPEGTS:181083,LOCAL:00:00:00.000

00:11:58.716 --> 00:12:06.586 A:middle
And like the CPU report,
it has similar sections

00:12:06.636 --> 00:12:08.366 A:middle
and the first section
is the meter view.

00:12:09.696 --> 00:12:13.706 A:middle
The meter view in this case is
showing 153 megabytes being used

00:12:14.226 --> 00:12:18.116 A:middle
which is about a third of this
iOS' devices total memory.

00:12:19.106 --> 00:12:22.596 A:middle
It also has that inner blue
arc which shows you the range

00:12:23.026 --> 00:12:27.326 A:middle
and since I've been measuring
quickly after the start

00:12:27.326 --> 00:12:30.346 A:middle
of this application, the range
goes from zero to where we are,

00:12:30.346 --> 00:12:34.516 A:middle
153, because hardly,
any time is elapsed.

00:12:35.166 --> 00:12:38.036 A:middle
If we go over to the total
system utilization area,

00:12:38.086 --> 00:12:40.606 A:middle
we can again see in this
pie charts that we're using

00:12:40.606 --> 00:12:42.616 A:middle
about a third of the
total system's memory.

00:12:43.546 --> 00:12:45.186 A:middle
And that the other applications

00:12:45.186 --> 00:12:48.036 A:middle
on the system are not using
very much but you can imagine

00:12:48.036 --> 00:12:51.086 A:middle
that other applications might
be affecting our application.

00:12:51.086 --> 00:12:52.216 A:middle
We might be getting
memory warnings

00:12:52.246 --> 00:12:55.406 A:middle
because of our app
or other apps.

00:12:55.556 --> 00:12:57.476 A:middle
And finally, we have
the main gauge area.

00:12:57.476 --> 00:13:00.176 A:middle
And this is where you
can see at a glance

WEBVTT
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00:12:57.476 --> 00:13:00.176 A:middle
And this is where you
can see at a glance

00:13:00.216 --> 00:13:02.706 A:middle
that something might be going
wrong with this application

00:13:02.706 --> 00:13:05.766 A:middle
because we seemed to be doing
a repeatable set of steps

00:13:06.196 --> 00:13:09.186 A:middle
and memory usage is just
monotonously climbing up,

00:13:09.186 --> 00:13:10.006 A:middle
and up, and up.

00:13:10.236 --> 00:13:14.646 A:middle
And so, this would be a
great opportunity to profile

00:13:14.646 --> 00:13:17.836 A:middle
in Instruments or
as my colleague,

00:13:17.916 --> 00:13:20.836 A:middle
Han Ming [phonetic] is going
to show in a real life example,

00:13:21.186 --> 00:13:24.626 A:middle
how we can solve these problems
by looking at these reports.

00:13:27.516 --> 00:13:33.776 A:middle
[ Applause ]

00:13:34.276 --> 00:13:35.166 A:middle
>> Thank you Troy.

00:13:35.166 --> 00:13:38.496 A:middle
So I'd like to show you
how to make use of the CPU

00:13:38.616 --> 00:13:42.996 A:middle
and memory gauges to detect
performance issues even while

00:13:42.996 --> 00:13:44.726 A:middle
you're actively developing
your application.

00:13:45.226 --> 00:13:45.826 A:middle
So let's get to it.

00:13:46.516 --> 00:13:52.336 A:middle
[ Pause ]

00:13:52.836 --> 00:13:55.706 A:middle
So the app I'm using
is a Mac application.

00:13:56.036 --> 00:13:59.006 A:middle
But everything I say here
today applies completely

00:13:59.006 --> 00:13:59.976 A:middle
to your iOS apps.

WEBVTT
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00:14:01.396 --> 00:14:05.866 A:middle
So to set the stage, imagine
I have an award-winning

00:14:05.866 --> 00:14:07.486 A:middle
application on the
Mac App Store.

00:14:08.576 --> 00:14:12.796 A:middle
People love it because it does
one and one thing really well.

00:14:13.746 --> 00:14:15.426 A:middle
It shows you exactly
one picture.

00:14:15.986 --> 00:14:20.676 A:middle
Now because of this
unsurpassed simplicity,

00:14:20.676 --> 00:14:23.046 A:middle
it has been downloaded
many times

00:14:23.236 --> 00:14:24.466 A:middle
over the last couple of years.

00:14:25.066 --> 00:14:27.296 A:middle
But my users are
clamoring for more features.

00:14:28.116 --> 00:14:31.486 A:middle
So in the next release, I'm
adding two new features.

00:14:32.176 --> 00:14:35.096 A:middle
The ability to add
filters to the image

00:14:35.096 --> 00:14:37.786 A:middle
and the ability to do rotation.

00:14:38.926 --> 00:14:39.676 A:middle
Let's try them out.

00:14:40.516 --> 00:14:44.176 A:middle
[ Pause ]

00:14:44.676 --> 00:14:47.796 A:middle
So you can see, I
have four filters.

00:14:47.796 --> 00:14:49.756 A:middle
Let's try the rotation--

00:14:51.046 --> 00:14:53.896 A:middle
distortion, I'm sorry,
sepia tone.

00:14:54.456 --> 00:14:58.316 A:middle
I notice a little bit of a
lag, maybe a tenth of a second,

00:14:58.316 --> 00:15:00.606 A:middle
or a quarter of a second every
time I change the filter.

WEBVTT
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00:14:58.316 --> 00:15:00.606 A:middle
or a quarter of a second every
time I change the filter.

00:15:00.606 --> 00:15:04.896 A:middle
I'm going to assume that Apple
has done an incredible job

00:15:04.896 --> 00:15:07.326 A:middle
of optimizing those
core image filters.

00:15:08.496 --> 00:15:11.576 A:middle
So my next idea is to
add a cache so that

00:15:11.576 --> 00:15:13.966 A:middle
if my user reselects
the same filter,

00:15:13.966 --> 00:15:15.256 A:middle
it would be lightning fast.

00:15:15.776 --> 00:15:19.386 A:middle
So I'm going to do that.

00:15:22.876 --> 00:15:30.096 A:middle
So this is where I create
a cache, scrolling down,

00:15:32.296 --> 00:15:33.756 A:middle
this is where after the cache,

00:15:33.756 --> 00:15:36.406 A:middle
I'm going to put a breakpoint
here so that when it breaks,

00:15:36.406 --> 00:15:39.486 A:middle
I can validate that I have
successfully added to the cache.

00:15:40.866 --> 00:15:47.256 A:middle
And this is where I make use
of it, I'm going to recompile

00:15:47.256 --> 00:15:51.266 A:middle
and run so I hit the
breakpoint, that C.

00:15:51.266 --> 00:15:57.886 A:middle
I'm going to make use of our
variable view, zooming in here.

00:15:59.126 --> 00:16:02.076 A:middle
And oops, so one key value pair.

WEBVTT
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00:15:59.126 --> 00:16:02.076 A:middle
And oops, so one key value pair.

00:16:02.076 --> 00:16:02.816 A:middle
So that's good.

00:16:04.766 --> 00:16:06.366 A:middle
So remove breakpoint
and continue.

00:16:10.226 --> 00:16:13.206 A:middle
Now, the debugger team would
like you to build up a habit

00:16:13.206 --> 00:16:16.686 A:middle
of whenever you add a new
feature, a new enhancement

00:16:17.006 --> 00:16:22.896 A:middle
to cleanse over to the debug
gauges, just to make sure

00:16:22.896 --> 00:16:24.366 A:middle
that now everything
is behaving OK.

00:16:24.366 --> 00:16:27.516 A:middle
So please keep your eyes
peeled in this particular case

00:16:27.516 --> 00:16:32.546 A:middle
to the CPU and the memory gauge
while I try out my new cache.

00:16:33.076 --> 00:16:38.266 A:middle
With distortion, CPU is
behaving pretty well.

00:16:38.616 --> 00:16:39.736 A:middle
Memory went up a little bit

00:16:39.736 --> 00:16:42.576 A:middle
because I just added
a new filtered image.

00:16:43.706 --> 00:16:45.866 A:middle
Sepia tone, same logic.

00:16:46.206 --> 00:16:52.916 A:middle
Now, let's try out our new cache
by reselecting back distortion.

00:16:53.476 --> 00:16:56.866 A:middle
Oops, memory went
up a little bit.

00:16:56.866 --> 00:17:01.476 A:middle
Now, just to reconfirm
what I saw, yup!

WEBVTT
X-TIMESTAMP-MAP=MPEGTS:181083,LOCAL:00:00:00.000

00:16:56.866 --> 00:17:01.476 A:middle
Now, just to reconfirm
what I saw, yup!

00:17:01.986 --> 00:17:04.685 A:middle
So now, we don't want
you to get paranoid

00:17:04.685 --> 00:17:06.836 A:middle
over every single
bump on the chart.

00:17:07.386 --> 00:17:09.695 A:middle
But if you see a monotonous
growth pattern like this,

00:17:09.695 --> 00:17:11.715 A:middle
it should pick your interest.

00:17:11.976 --> 00:17:12.866 A:middle
And it does for me.

00:17:12.915 --> 00:17:17.746 A:middle
So I want to get
more detail about it.

00:17:18.006 --> 00:17:21.836 A:middle
So I can do that like Troy
said, I can select the gauge

00:17:21.836 --> 00:17:24.675 A:middle
on the navigator and it
will show me a report of it.

00:17:25.276 --> 00:17:28.726 A:middle
The top section is a
snapshot but what really jumps

00:17:28.726 --> 00:17:30.526 A:middle
out at me is the graph.

00:17:31.326 --> 00:17:32.446 A:middle
This pattern here.

00:17:32.676 --> 00:17:34.356 A:middle
So something is definitely
cuckoo here.

00:17:35.076 --> 00:17:39.386 A:middle
Now, I can select, I
can click on the profile

00:17:39.386 --> 00:17:42.106 A:middle
and instruments button to get
more detail but sometimes,

00:17:42.106 --> 00:17:43.846 A:middle
because this is your own
source code, you have reached

00:17:43.846 --> 00:17:45.246 A:middle
in for last couple of years.

00:17:45.246 --> 00:17:48.266 A:middle
And I just added some more new
lines so we can reflect on it

00:17:48.266 --> 00:17:49.546 A:middle
and see what you just did.

00:17:50.276 --> 00:17:52.526 A:middle
So let's look at that.

00:17:57.266 --> 00:18:01.276 A:middle
So here is where the cache is
created, nothing is wrong here.

WEBVTT
X-TIMESTAMP-MAP=MPEGTS:181083,LOCAL:00:00:00.000

00:17:57.266 --> 00:18:01.276 A:middle
So here is where the cache is
created, nothing is wrong here.

00:18:01.276 --> 00:18:07.366 A:middle
Here is what I make use
of it, seems-- looks OK.

00:18:10.776 --> 00:18:13.486 A:middle
So this line right
here, now, those of you

00:18:13.486 --> 00:18:16.106 A:middle
with eagle eyes would
have noticed

00:18:16.106 --> 00:18:17.886 A:middle
that I've made the
classic rookie mistake

00:18:17.886 --> 00:18:19.836 A:middle
of confusing the
key and the value.

00:18:20.576 --> 00:18:23.306 A:middle
So, you know, obviously,
that's not going to work.

00:18:23.506 --> 00:18:25.766 A:middle
Even though when I've checked
it early on, it was in the,

00:18:25.896 --> 00:18:27.076 A:middle
you know, I added one key value.

00:18:28.036 --> 00:18:30.626 A:middle
So let's switch them,
switch the order.

00:18:31.516 --> 00:18:36.956 A:middle
[ Pause ]

00:18:37.456 --> 00:18:38.686 A:middle
I'm going to recompile and run.

00:18:38.776 --> 00:18:44.476 A:middle
And I'm going to
try them out again.

00:18:46.476 --> 00:18:51.786 A:middle
Distortion, sepia tone,
this is the important part.

00:18:52.286 --> 00:18:53.626 A:middle
Let's go back to distortion.

00:18:54.006 --> 00:18:56.216 A:middle
And you can see that
we are staying

00:18:56.216 --> 00:18:57.616 A:middle
at for about 39 megabytes.

00:18:58.276 --> 00:18:58.996 A:middle
Let's try it again.

00:18:58.996 --> 00:19:02.386 A:middle
So that the debug gauge,

WEBVTT
X-TIMESTAMP-MAP=MPEGTS:181083,LOCAL:00:00:00.000

00:18:58.996 --> 00:19:02.386 A:middle
So that the debug gauge,

00:19:02.386 --> 00:19:05.046 A:middle
the memory gauge validates
what I think is happening,

00:19:05.226 --> 00:19:06.016 A:middle
the correctness of it.

00:19:06.016 --> 00:19:09.776 A:middle
I just want to expand a little
on what goes hand in hand

00:19:10.116 --> 00:19:11.566 A:middle
with the memory gauge.

00:19:12.206 --> 00:19:13.756 A:middle
Some of you may have had used

00:19:13.756 --> 00:19:16.816 A:middle
that usually involves
a repeatable pattern,

00:19:17.276 --> 00:19:19.036 A:middle
a repeatable user gesture.

00:19:19.036 --> 00:19:22.576 A:middle
You know, you do X and then
you do Y to make X go away.

00:19:22.696 --> 00:19:23.986 A:middle
Sometimes, you have
to do X again.

00:19:24.076 --> 00:19:29.846 A:middle
A concrete example would be on
the iOS, you put up a picture,

00:19:30.066 --> 00:19:32.086 A:middle
you flick it away,
then you flick it back.

00:19:32.086 --> 00:19:36.986 A:middle
On your Mac, you may open a, you
know, NSDocument-based document

00:19:37.336 --> 00:19:40.876 A:middle
and then close it
so you get the idea.

00:19:41.086 --> 00:19:42.316 A:middle
So I'm pretty happy
with the cache,

00:19:42.486 --> 00:19:43.636 A:middle
let's move on to the slider.

00:19:44.516 --> 00:19:47.956 A:middle
[ Pause ]

00:19:48.456 --> 00:19:50.786 A:middle
All right, let's try it out.

00:19:50.786 --> 00:19:53.306 A:middle
OK, it looks like it does
what it says and now rotating.

00:19:54.516 --> 00:19:57.576 A:middle
Again, I'm going to
glance over to my CPU

00:19:57.576 --> 00:20:00.026 A:middle
and memory gauge and try it out.

WEBVTT
X-TIMESTAMP-MAP=MPEGTS:181083,LOCAL:00:00:00.000

00:19:57.576 --> 00:20:00.026 A:middle
and memory gauge and try it out.

00:20:02.376 --> 00:20:03.796 A:middle
So memory seems pretty stable,

00:20:04.276 --> 00:20:06.746 A:middle
but there's something
interesting about the CPU.

00:20:07.306 --> 00:20:11.666 A:middle
You cannot see here but even
after I've released the button,

00:20:11.926 --> 00:20:13.336 A:middle
there seems to be
some activities,

00:20:13.336 --> 00:20:14.846 A:middle
CPU activity going on.

00:20:16.036 --> 00:20:17.786 A:middle
Again, I'm interested in it.

00:20:20.296 --> 00:20:21.636 A:middle
So let's select it.

00:20:23.046 --> 00:20:24.866 A:middle
The top section is the snapshot,

00:20:24.866 --> 00:20:27.316 A:middle
the middle section is
the utilization overtime

00:20:27.606 --> 00:20:31.386 A:middle
which is the accumulation
over the usage on the threats,

00:20:31.856 --> 00:20:34.526 A:middle
and the last section
at the bottom,

00:20:34.856 --> 00:20:36.766 A:middle
the threat activities
on each threat.

00:20:37.256 --> 00:20:42.566 A:middle
You can see that, well, I know
that when I did the rotation,

00:20:42.566 --> 00:20:44.866 A:middle
I'm using set bounce
rotation on NSView.

00:20:45.186 --> 00:20:46.696 A:middle
And what's surprising for me is

00:20:46.696 --> 00:20:51.026 A:middle
that I'm seeing activities
on many threats.

00:20:51.846 --> 00:20:54.526 A:middle
So I'm going to leave the
report right there and try

00:20:54.526 --> 00:20:58.156 A:middle
out my slider again to see if
I see anything interesting.

00:20:59.146 --> 00:21:02.876 A:middle
So I can see that a whole
slew of threats just came on.

WEBVTT
X-TIMESTAMP-MAP=MPEGTS:181083,LOCAL:00:00:00.000

00:20:59.146 --> 00:21:02.876 A:middle
So I can see that a whole
slew of threats just came on.

00:21:03.616 --> 00:21:05.386 A:middle
Now this-- that's
weird too, you know,

00:21:05.386 --> 00:21:08.586 A:middle
I'm and I think I just wrote
the set Rotation method,

00:21:08.586 --> 00:21:10.816 A:middle
I'm going to go back
and take a look at it.

00:21:17.236 --> 00:21:20.926 A:middle
So here's where I noticed the
rotation changes or I cut it

00:21:20.926 --> 00:21:25.286 A:middle
down and I set a flag,
this method right here.

00:21:25.606 --> 00:21:30.026 A:middle
So when I wrote the method,
it was necessary for me

00:21:30.026 --> 00:21:32.596 A:middle
to call this method to get--

00:21:32.656 --> 00:21:34.666 A:middle
fill that image so
that I can rotate it.

00:21:35.376 --> 00:21:37.966 A:middle
This method that uses a dispatch
cue so that work is done

00:21:37.966 --> 00:21:41.116 A:middle
on a different threat; they'll
by explaining why we saw a lot

00:21:41.116 --> 00:21:44.546 A:middle
of activities on threats,
but we have a better way now,

00:21:44.696 --> 00:21:49.296 A:middle
we're keeping-- I'm
keeping instance variable

00:21:49.296 --> 00:21:50.166 A:middle
to filtered image.

00:21:50.666 --> 00:21:54.166 A:middle
So this method is not necessary,
now I must have missed it

00:21:54.166 --> 00:21:55.756 A:middle
in my refactoring early on.

00:21:55.756 --> 00:21:58.046 A:middle
So let's get rid
of it, recompile.

00:21:58.046 --> 00:22:05.636 A:middle
And I'm going to bring up the
report, scroll to the bottom,

WEBVTT
X-TIMESTAMP-MAP=MPEGTS:181083,LOCAL:00:00:00.000

00:21:58.046 --> 00:22:05.636 A:middle
And I'm going to bring up the
report, scroll to the bottom,

00:22:06.216 --> 00:22:08.836 A:middle
try the rotation again.

00:22:08.836 --> 00:22:11.276 A:middle
And this time you see that,

00:22:11.276 --> 00:22:14.236 A:middle
there are no new
threats coming in.

00:22:15.206 --> 00:22:16.516 A:middle
So I'm pretty happy
with that as well.

00:22:17.776 --> 00:22:20.676 A:middle
CPU like what Troy says
or what you have heard

00:22:20.676 --> 00:22:22.466 A:middle
over the last few days.

00:22:23.136 --> 00:22:26.476 A:middle
Now we want you to do use
as much CPU as possible

00:22:26.476 --> 00:22:28.716 A:middle
to get the work done in
the shortest possible time,

00:22:29.056 --> 00:22:31.836 A:middle
so that the rest of the
course can go to rest,

00:22:32.586 --> 00:22:34.306 A:middle
thereby saving you
battery power.

00:22:35.366 --> 00:22:38.656 A:middle
So do not be afraid to
make used of the CPU

00:22:38.656 --> 00:22:39.676 A:middle
to get real work done.

00:22:40.856 --> 00:22:43.506 A:middle
So that concludes about my
demo and I have this one thing,

00:22:43.506 --> 00:22:47.246 A:middle
I want you to take out from
here is that, whenever you--

00:22:47.246 --> 00:22:49.286 A:middle
a new feature, a new
enhancement and you're--

00:22:49.286 --> 00:22:51.626 A:middle
in the process of testing
it, please remember

00:22:51.626 --> 00:22:54.556 A:middle
to consult the performers,
the debug edges

00:22:54.556 --> 00:22:57.496 A:middle
to make sure you don't add
any performance regressions

00:22:57.746 --> 00:22:58.836 A:middle
to your application, thank you.

00:22:59.516 --> 00:23:07.216 A:middle
[ Applause ]

WEBVTT
X-TIMESTAMP-MAP=MPEGTS:181083,LOCAL:00:00:00.000

00:22:59.516 --> 00:23:07.216 A:middle
[ Applause ]

00:23:07.716 --> 00:23:08.756 A:middle
>> Thank you, Han Ming.

00:23:10.106 --> 00:23:13.556 A:middle
As you can see these debugging
reports give a great high level

00:23:13.556 --> 00:23:15.326 A:middle
overview on what's going
on in your application.

00:23:16.306 --> 00:23:17.676 A:middle
But as debuggers, we--

00:23:17.746 --> 00:23:20.256 A:middle
they can't always rely
on a high level overview.

00:23:20.256 --> 00:23:23.146 A:middle
Sometimes, we need to go down
deep, sometimes we need to look

00:23:23.396 --> 00:23:25.866 A:middle
at the specific state
of our application

00:23:26.166 --> 00:23:29.726 A:middle
in a specific instance variables
that make up our application.

00:23:30.406 --> 00:23:34.116 A:middle
And so for that, I'd like to
talk about the new data tips

00:23:34.166 --> 00:23:35.126 A:middle
and Quick Look features.

00:23:35.816 --> 00:23:39.096 A:middle
If you're gone programming
for a while,

00:23:39.146 --> 00:23:40.446 A:middle
you know that you're
getting into the cycle,

00:23:40.756 --> 00:23:42.946 A:middle
you write a little bit
a code, you hit run,

00:23:42.946 --> 00:23:45.066 A:middle
and you do some debugging,
and then you go back

00:23:45.066 --> 00:23:46.116 A:middle
and do some more coding.

00:23:47.306 --> 00:23:49.876 A:middle
And in Xcode, it's
going to look like this.

00:23:49.906 --> 00:23:52.506 A:middle
You have your big code editor
and you're writing code.

00:23:52.506 --> 00:23:56.146 A:middle
And when you hit a breakpoint
that debug area comes

00:23:56.146 --> 00:23:57.676 A:middle
up showing you useful
information.

00:23:58.336 --> 00:24:01.426 A:middle
But a lot of times, we get
all of the context we need

WEBVTT
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00:23:58.336 --> 00:24:01.426 A:middle
But a lot of times, we get
all of the context we need

00:24:01.666 --> 00:24:03.726 A:middle
from our code and so it
would be great to be able

00:24:03.726 --> 00:24:06.746 A:middle
to see the whole method that
we're working on and just hide

00:24:06.746 --> 00:24:09.586 A:middle
that debug area for
when we really need it.

00:24:10.706 --> 00:24:12.566 A:middle
And so then, we'd have
a debugging experience

00:24:12.566 --> 00:24:13.496 A:middle
that looks more like this

00:24:14.456 --> 00:24:18.296 A:middle
and so that's exactly what
we have done in Xcode 5.

00:24:19.576 --> 00:24:22.176 A:middle
The first thing we did
was we improve data tips

00:24:22.686 --> 00:24:24.306 A:middle
and how do we improve them,

00:24:24.526 --> 00:24:26.716 A:middle
we strip away all the
extraneous information.

00:24:27.106 --> 00:24:28.566 A:middle
You already have the
variable name there,

00:24:29.486 --> 00:24:31.896 A:middle
I assumed you also know that
this is a size variable,

00:24:31.896 --> 00:24:33.446 A:middle
so you don't need the
type and the name.

00:24:33.696 --> 00:24:37.196 A:middle
All you care about is the width
and height of this size variable

00:24:37.196 --> 00:24:38.516 A:middle
and so that's what we show you.

00:24:39.106 --> 00:24:43.636 A:middle
But you'll notice we added two
more things to this data tip.

00:24:44.586 --> 00:24:48.726 A:middle
And the first one is the Info
button and if you press that,

00:24:48.726 --> 00:24:52.716 A:middle
you get the results as if you
typeed in the LODB console,

00:24:52.906 --> 00:24:54.846 A:middle
PO or print that object.

00:24:56.826 --> 00:25:01.126 A:middle
[applause] It's really
handy because right there

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00:24:56.826 --> 00:25:01.126 A:middle
[applause] It's really
handy because right there

00:25:01.126 --> 00:25:03.136 A:middle
in your code, right
where you need it,

00:25:03.716 --> 00:25:04.866 A:middle
but we didn't stop there.

00:25:06.266 --> 00:25:10.926 A:middle
Variables, even simple ones
like size has visualization

00:25:10.926 --> 00:25:13.096 A:middle
about them that you would
like to see, maybe you want

00:25:13.096 --> 00:25:14.116 A:middle
to see the aspect ratio.

00:25:14.486 --> 00:25:17.006 A:middle
So you can click on this
Quick Look button and see

00:25:17.006 --> 00:25:19.976 A:middle
that size variable
right there in the code

00:25:20.156 --> 00:25:21.366 A:middle
in a visual representation.

00:25:21.916 --> 00:25:26.956 A:middle
[applause] And this
is super helpful.

00:25:27.366 --> 00:25:30.296 A:middle
So to show you a demo of
how this works in practice,

00:25:30.606 --> 00:25:31.976 A:middle
I'd like to invite
Christopher Friesen.

00:25:33.336 --> 00:25:35.846 A:middle
>> So our users loved the new
features, the Han Ming about it.

00:25:36.356 --> 00:25:39.456 A:middle
The filters are great, even my
mom is sending motion blurred

00:25:39.456 --> 00:25:40.996 A:middle
cap-- pictures already,
so, you we know,

00:25:40.996 --> 00:25:42.176 A:middle
that made a great success.

00:25:43.876 --> 00:25:46.176 A:middle
Now there's another
feature they want, you know,

00:25:46.346 --> 00:25:49.436 A:middle
rectangular boarders around
your pictures are, oh,

00:25:49.436 --> 00:25:50.236 A:middle
they're pretty normal,

00:25:50.236 --> 00:25:52.406 A:middle
but they're also kind
of not that exciting.

00:25:52.776 --> 00:25:54.286 A:middle
Our users want something
little more edgy.

00:25:54.286 --> 00:25:56.526 A:middle
So I've been working
on another feature

00:25:56.966 --> 00:25:58.256 A:middle
and let's take a look at that.

00:25:59.516 --> 00:26:05.926 A:middle
[ Pause ]

WEBVTT
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00:25:59.516 --> 00:26:05.926 A:middle
[ Pause ]

00:26:06.426 --> 00:26:08.186 A:middle
So we'll run our
application here

00:26:14.386 --> 00:26:16.476 A:middle
and I've added the
Mask button down here.

00:26:20.476 --> 00:26:24.956 A:middle
So this is creating a mask
for the image which is--

00:26:25.386 --> 00:26:26.546 A:middle
what our users have asked for.

00:26:26.926 --> 00:26:30.326 A:middle
However, what they really wanted
is they want a star shape.

00:26:30.326 --> 00:26:34.176 A:middle
So I'm in the middle of
running this feature and I want

00:26:34.176 --> 00:26:35.936 A:middle
to use the data steps
in Quick Looks to figure

00:26:35.936 --> 00:26:38.206 A:middle
out what's gone wrong
with my implementation.

00:26:38.206 --> 00:26:47.096 A:middle
So I'll go back here and
I'll use the button down here

00:26:47.096 --> 00:26:50.366 A:middle
at the bottom of the Debug bar
to activate our breakpoints

00:26:51.076 --> 00:26:52.706 A:middle
and then we'll exercise
our application

00:26:53.466 --> 00:26:56.036 A:middle
to hit our breakpoint.

00:26:56.606 --> 00:27:00.356 A:middle
So here we are, we're
creating a Bezier path

WEBVTT
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00:26:56.606 --> 00:27:00.356 A:middle
So here we are, we're
creating a Bezier path

00:27:00.356 --> 00:27:02.166 A:middle
that will become our mask

00:27:03.096 --> 00:27:05.996 A:middle
but we don't know exactly
what's wrong with the shape.

00:27:07.156 --> 00:27:10.026 A:middle
We can use our data
tips to hover over it.

00:27:10.576 --> 00:27:14.506 A:middle
We can click the Info button
to get a description of it.

00:27:15.256 --> 00:27:18.186 A:middle
Well that's all the
stroke information,

00:27:18.566 --> 00:27:20.906 A:middle
I can breakout some graph
paper and plotted out

00:27:20.956 --> 00:27:23.226 A:middle
or I can click Quick Look.

00:27:23.916 --> 00:27:29.966 A:middle
And here we get our
wonderful image Bezier path

00:27:29.966 --> 00:27:31.846 A:middle
that we're using
to mask or image.

00:27:32.816 --> 00:27:34.826 A:middle
That's not what we want.

00:27:35.886 --> 00:27:39.266 A:middle
Let's take a look
at our method here.

00:27:39.266 --> 00:27:44.276 A:middle
So our method is lazily
initializing the Bezier path.

00:27:44.716 --> 00:27:47.086 A:middle
So as you can see, since,
we already have a mask,

00:27:48.546 --> 00:27:49.976 A:middle
it's going to return
out of this function.

00:27:50.896 --> 00:27:53.256 A:middle
We can use our data tips
to actually edit the value.

00:27:53.256 --> 00:27:55.996 A:middle
I can double click
on my address here,

00:27:56.736 --> 00:28:01.186 A:middle
I can enter zero
to nil that out.

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00:27:56.736 --> 00:28:01.186 A:middle
I can enter zero
to nil that out.

00:28:01.536 --> 00:28:04.296 A:middle
And now as we step over
this code, we won't return

00:28:04.296 --> 00:28:06.366 A:middle
out of the method
early and we'll go,

00:28:06.366 --> 00:28:09.126 A:middle
get into the code that's
going to setup the Bezier path

00:28:09.126 --> 00:28:11.026 A:middle
and we can start debugging that.

00:28:12.206 --> 00:28:15.376 A:middle
So I'll continue here
and now we're on the

00:28:15.376 --> 00:28:17.496 A:middle
for loop that's going to
go through and it's going

00:28:17.496 --> 00:28:18.426 A:middle
to construct the shape.

00:28:19.506 --> 00:28:22.086 A:middle
Let's click continue
about three times

00:28:23.456 --> 00:28:26.236 A:middle
and then we'll see how our
Bezier path is coming along.

00:28:26.756 --> 00:28:31.856 A:middle
We can hover over any
reference to mask in this method

00:28:31.856 --> 00:28:34.186 A:middle
and we'll see what
the current value is.

00:28:35.296 --> 00:28:37.736 A:middle
Again, we'll use Quick
Look and we can see

00:28:37.736 --> 00:28:38.976 A:middle
that it's starting
to draw the shape.

00:28:40.696 --> 00:28:42.176 A:middle
Now in order to draw
a star shape,

00:28:42.816 --> 00:28:46.276 A:middle
we need the drawing points
at alternating radiuses.

00:28:48.296 --> 00:28:52.836 A:middle
If you look at our radius,
we see that every other time

00:28:52.836 --> 00:28:55.506 A:middle
through the loop, it should
be using a different radius.

00:28:57.256 --> 00:28:59.806 A:middle
So let's look at R2.

00:28:59.946 --> 00:29:04.196 A:middle
We see that's 200, R1 is 100.

WEBVTT
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00:28:59.946 --> 00:29:04.196 A:middle
We see that's 200, R1 is 100.

00:29:04.246 --> 00:29:05.146 A:middle
So they're both the same,

00:29:05.146 --> 00:29:07.166 A:middle
so that's why we're not getting
the shape that we wanted.

00:29:08.636 --> 00:29:13.086 A:middle
Again, I can use data tips,
double click on the value

00:29:13.656 --> 00:29:18.846 A:middle
and turn new value and now
that value has been changed

00:29:18.846 --> 00:29:19.896 A:middle
in our running program.

00:29:20.686 --> 00:29:22.386 A:middle
We'll continue several
more times

00:29:22.386 --> 00:29:24.576 A:middle
and then we'll check
on the drawing.

00:29:28.016 --> 00:29:30.326 A:middle
Click on Quick Look
and here we go.

00:29:30.456 --> 00:29:33.166 A:middle
So we're starting to get
our star shape, great.

00:29:33.436 --> 00:29:35.546 A:middle
We figured out where
the problem is.

00:29:38.086 --> 00:29:40.286 A:middle
And we'll go ahead and continue.

00:29:40.956 --> 00:29:44.356 A:middle
And here we are in
a drawRect method.

00:29:45.136 --> 00:29:49.236 A:middle
So it will-- we have
completed our Bezier shape,

00:29:49.236 --> 00:29:52.496 A:middle
our Bezier path and here
we see the complete shape,

00:29:53.436 --> 00:29:56.596 A:middle
and as we continue over
in our application,

00:29:56.776 --> 00:29:58.506 A:middle
we've got the distortion
filters been applied

00:29:58.506 --> 00:29:59.556 A:middle
as well as our mask.

00:29:59.706 --> 00:30:01.436 A:middle
So we're nearly there.

WEBVTT
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00:29:59.706 --> 00:30:01.436 A:middle
So we're nearly there.

00:30:02.806 --> 00:30:05.446 A:middle
Now another thing you can
do with the data tips is

00:30:05.776 --> 00:30:08.816 A:middle
that you can go ahead
and inspect the values,

00:30:09.316 --> 00:30:10.566 A:middle
you can crawl in
to the variables,

00:30:11.586 --> 00:30:13.416 A:middle
and dive into them will say.

00:30:14.196 --> 00:30:15.856 A:middle
So let's set our
breakpoint again,

00:30:16.146 --> 00:30:19.236 A:middle
exercising our application,
and we can hover

00:30:19.236 --> 00:30:20.366 A:middle
over self for instance.

00:30:21.806 --> 00:30:24.216 A:middle
And here we see that self
doesn't have a nice concise

00:30:24.216 --> 00:30:28.196 A:middle
summary so we show you the
type as well as the address.

00:30:30.076 --> 00:30:33.106 A:middle
So over here on the left,
we can turn it open,

00:30:33.836 --> 00:30:35.796 A:middle
we start seeing the instance
variables and properties,

00:30:36.656 --> 00:30:39.306 A:middle
and we can see the same
for the super class.

00:30:41.056 --> 00:30:45.016 A:middle
Here's a frame, again, Quick
Looks are also available

00:30:45.106 --> 00:30:46.806 A:middle
as you drill down
into these variables.

00:30:49.236 --> 00:30:50.896 A:middle
Here's another URL.

00:30:51.516 --> 00:30:55.086 A:middle
We can do a peel of it.

00:30:55.166 --> 00:30:57.266 A:middle
Again, this is a textual
description of what it is,

00:30:58.166 --> 00:31:01.266 A:middle
not many people know, you
know, can picture the latitude

WEBVTT
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00:30:58.166 --> 00:31:01.266 A:middle
not many people know, you
know, can picture the latitude

00:31:01.266 --> 00:31:04.026 A:middle
and longitude of that, but we
can use our visual Quick Looks

00:31:04.256 --> 00:31:08.046 A:middle
to see exactly where
this is, we'll do that

00:31:09.396 --> 00:31:10.926 A:middle
and here we are, we can zoom-in.

00:31:11.516 --> 00:31:17.556 A:middle
[applause]

00:31:18.056 --> 00:31:22.366 A:middle
And it sure looks like
it's near where we are

00:31:22.546 --> 00:31:23.886 A:middle
and there might some
event happening

00:31:23.886 --> 00:31:25.466 A:middle
in the Yerba Buena Park.

00:31:25.606 --> 00:31:28.956 A:middle
So that's data tips for you.

00:31:29.636 --> 00:31:32.666 A:middle
They now provide concise
data for you as well

00:31:32.666 --> 00:31:34.146 A:middle
as these great visual data tips

00:31:34.656 --> 00:31:36.656 A:middle
and we hope this will hope
keep you in your source code

00:31:36.656 --> 00:31:38.566 A:middle
as you do your debugging,
thank you.

00:31:39.516 --> 00:31:46.056 A:middle
[ Applause ]

00:31:46.556 --> 00:31:47.616 A:middle
>> Thank you, Christopher.

00:31:49.596 --> 00:31:52.466 A:middle
Now that showed a couple of a
data types available and I'd

00:31:52.466 --> 00:31:53.466 A:middle
like to run through some more.

00:31:53.466 --> 00:31:55.776 A:middle
But let's talk a little
bit about how this works

00:31:55.816 --> 00:31:57.956 A:middle
because this is a developer
conference and I trust you guys

00:31:57.956 --> 00:32:01.246 A:middle
with the information about how
these things are put together

WEBVTT
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00:31:57.956 --> 00:32:01.246 A:middle
with the information about how
these things are put together

00:32:01.246 --> 00:32:02.306 A:middle
because it's really interesting.

00:32:02.876 --> 00:32:06.846 A:middle
LODB powers, many of these
simple ones like NSIs

00:32:07.076 --> 00:32:09.446 A:middle
because it has data
formatters that returns

00:32:09.446 --> 00:32:11.186 A:middle
to us the within the height.

00:32:12.276 --> 00:32:15.896 A:middle
But we also support more
complex types like images,

00:32:16.016 --> 00:32:19.026 A:middle
we support UI image in
iOS, NS image on Mac OS.

00:32:19.576 --> 00:32:21.486 A:middle
But also CGImageRef and CIImage.

00:32:22.296 --> 00:32:26.126 A:middle
And CGImageRef as you well
know has a bunch of functions

00:32:26.426 --> 00:32:27.936 A:middle
that get information out of it.

00:32:28.716 --> 00:32:32.056 A:middle
So if we want to get a
CGImageRef off your iOS device,

00:32:33.036 --> 00:32:34.756 A:middle
in Xcode, we construct
the expressions,

00:32:35.166 --> 00:32:38.086 A:middle
and we send those using LODB
to your running application

00:32:38.226 --> 00:32:41.746 A:middle
and we say, CGImageGetWidth,
we do the same with the height,

00:32:42.246 --> 00:32:44.926 A:middle
and the color space, and
even the bytes of the image

00:32:45.216 --> 00:32:47.896 A:middle
that get shipped over
the wire back to Xcode

00:32:47.896 --> 00:32:49.396 A:middle
where we can reconstruct
the image

00:32:49.466 --> 00:32:50.706 A:middle
and show you right inside Xcode.

00:32:50.706 --> 00:32:53.916 A:middle
And believe me that's much
easier than any debugging method

00:32:54.166 --> 00:32:56.606 A:middle
for seeing an in-progress image

00:32:56.916 --> 00:33:00.096 A:middle
that you may have had
to use in the past.

WEBVTT
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00:32:56.916 --> 00:33:00.096 A:middle
that you may have had
to use in the past.

00:33:00.256 --> 00:33:03.916 A:middle
We also support NSString and
we support NSAttributedString,

00:33:03.916 --> 00:33:06.296 A:middle
so you can see your fonts and
colors right inside Xcode,

00:33:06.566 --> 00:33:10.216 A:middle
instead of the plain text view
that might be in the console.

00:33:10.886 --> 00:33:12.916 A:middle
And it's really great for
long strings because it--

00:33:12.916 --> 00:33:14.906 A:middle
of course, it doesn't fit
there in the data tip.

00:33:15.116 --> 00:33:17.146 A:middle
So you can scroll
through the whole string

00:33:17.146 --> 00:33:19.036 A:middle
and see it large right
up in your screen.

00:33:19.596 --> 00:33:25.356 A:middle
We support NSPoint, we support
NSData, and this one is great

00:33:25.356 --> 00:33:28.696 A:middle
because data has bytes and we
format the bytes nicely, NSView.

00:33:29.166 --> 00:33:33.606 A:middle
But data also has, as we all
know, it often comes from files

00:33:33.606 --> 00:33:36.106 A:middle
of streams and that's
usually character data.

00:33:36.716 --> 00:33:37.996 A:middle
And so right next to the bytes,

00:33:38.316 --> 00:33:40.196 A:middle
we show what those
bytes would be

00:33:40.536 --> 00:33:41.676 A:middle
if they were ASCII characters.

00:33:41.786 --> 00:33:42.706 A:middle
And so you can see here

00:33:42.706 --> 00:33:50.016 A:middle
that this is probably a Plist
that's been loaded from disk.

00:33:50.016 --> 00:33:53.366 A:middle
We support Core Location and
if you know, Core Location,

00:33:53.366 --> 00:33:55.626 A:middle
it's basically a
pretty bare bones object

00:33:55.626 --> 00:33:57.016 A:middle
that has latitude, longitude.

00:33:58.176 --> 00:34:01.456 A:middle
And so recognizing what that
latitude and longitude is,

WEBVTT
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00:33:58.176 --> 00:34:01.456 A:middle
And so recognizing what that
latitude and longitude is,

00:34:01.636 --> 00:34:04.236 A:middle
is very difficult unless
you have the map right there

00:34:04.236 --> 00:34:04.686 A:middle
in Xcode.

00:34:05.176 --> 00:34:06.156 A:middle
So this is very powerful.

00:34:07.886 --> 00:34:10.976 A:middle
Similar to Core Location,
we have, we support colors.

00:34:11.166 --> 00:34:13.235 A:middle
And so, rather than
looking at that triplet

00:34:13.235 --> 00:34:16.856 A:middle
of RGB values plus alpha, we
show you the color right there.

00:34:17.406 --> 00:34:21.636 A:middle
We support Bezier paths,
both on iOS and Mac OS

00:34:21.636 --> 00:34:23.335 A:middle
as Christopher showed
in his demo.

00:34:23.956 --> 00:34:25.826 A:middle
And we support URLs.

00:34:25.826 --> 00:34:29.606 A:middle
And it's important to
realize that URLs have a path,

00:34:29.786 --> 00:34:32.326 A:middle
that's a string representation,
and we show you

00:34:32.326 --> 00:34:35.536 A:middle
that in the data tip, but we
also show you the contents

00:34:35.536 --> 00:34:38.436 A:middle
of that URL because that's
just as important to you

00:34:38.686 --> 00:34:41.016 A:middle
who is trying to understand
how your code is working.

00:34:41.706 --> 00:34:44.516 A:middle
So we'll render web
pages from the internet

00:34:44.516 --> 00:34:48.786 A:middle
and put those right there
in Xcode or we'll load files

00:34:48.786 --> 00:34:51.366 A:middle
from your local disk
and show those as well.

00:34:51.835 --> 00:34:55.686 A:middle
In this example, I'm
running a program

00:34:55.686 --> 00:34:58.276 A:middle
that has URL that's
referencing a keynote document.

00:34:58.466 --> 00:35:00.036 A:middle
In fact, it's this
keynote document

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00:34:58.466 --> 00:35:00.036 A:middle
In fact, it's this
keynote document

00:35:00.036 --> 00:35:03.186 A:middle
and I can see it right inside
Xcode which is really powerful.

00:35:03.736 --> 00:35:08.966 A:middle
And so Quick Look is
a new powerful way

00:35:09.526 --> 00:35:13.456 A:middle
to debug your applications that
makes it a whole lot easier

00:35:13.456 --> 00:35:14.416 A:middle
and a whole lot more fun

00:35:14.786 --> 00:35:16.706 A:middle
to see what your
value-- the values are.

00:35:19.456 --> 00:35:22.446 A:middle
Visualizing data type is not the
only thing we need to visualize,

00:35:22.446 --> 00:35:25.506 A:middle
especially, if like me,
you work on UI things.

00:35:26.286 --> 00:35:29.396 A:middle
And especially, in your Mac Apps
because your windows have many,

00:35:29.396 --> 00:35:31.556 A:middle
many views and you
want to visualize,

00:35:31.556 --> 00:35:32.926 A:middle
let's say the bounce
of each view.

00:35:33.526 --> 00:35:37.496 A:middle
And so when I would like to
highlight is the Show View

00:35:37.556 --> 00:35:40.546 A:middle
Frames which will
put a colorful rec--

00:35:40.926 --> 00:35:44.896 A:middle
rectangle around every
view in your application.

00:35:45.436 --> 00:35:48.756 A:middle
I actually used this recently
because I had a toolbar

00:35:48.756 --> 00:35:50.336 A:middle
which I needed to make
a little bit smaller.

00:35:51.136 --> 00:35:52.676 A:middle
And it has-- as you know,

00:35:52.676 --> 00:35:56.656 A:middle
the toolbar will take the
tallest toolbar item in it

00:35:57.116 --> 00:35:59.196 A:middle
to represent the full height.

00:35:59.856 --> 00:36:02.396 A:middle
And I had one icon that
had invisible background

WEBVTT
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00:35:59.856 --> 00:36:02.396 A:middle
And I had one icon that
had invisible background

00:36:02.516 --> 00:36:04.526 A:middle
that was bigger and I didn't
know which one it was.

00:36:05.056 --> 00:36:07.946 A:middle
So I turn on this option and
it was easy to pinpoint exactly

00:36:07.946 --> 00:36:12.106 A:middle
which toolbar item it was and
I could change the, our asset,

00:36:12.106 --> 00:36:17.626 A:middle
debug it, make that item smaller
and fix my bug, it was green.

00:36:18.546 --> 00:36:23.146 A:middle
Now if you're on iOS, we also
have some solutions for you.

00:36:23.146 --> 00:36:27.456 A:middle
Many people don't realize
that LODB accepts expressions

00:36:27.456 --> 00:36:30.686 A:middle
which are fully qualified
Objective-C statements.

00:36:31.446 --> 00:36:33.196 A:middle
And so if you have a method,

00:36:33.196 --> 00:36:35.826 A:middle
let's say the UIViews
recursive description,

00:36:36.456 --> 00:36:39.286 A:middle
you can send a message
to that object,

00:36:39.556 --> 00:36:43.526 A:middle
telling it to return the string
for that recursive description

00:36:43.526 --> 00:36:45.796 A:middle
and print it to the console.

00:36:46.046 --> 00:36:48.296 A:middle
And this allows you to
see what the child views

00:36:48.296 --> 00:36:49.086 A:middle
of that view are.

00:36:49.086 --> 00:36:51.066 A:middle
And many of the properties
that you might need

00:36:51.066 --> 00:36:53.546 A:middle
to debug what's going
wrong with your UIViews.

00:36:54.186 --> 00:36:58.836 A:middle
And so these workflows
are very powerful.

00:36:58.836 --> 00:37:00.166 A:middle
And now I'd like to
switch gears and talk

WEBVTT
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00:36:58.836 --> 00:37:00.166 A:middle
And now I'd like to
switch gears and talk

00:37:00.166 --> 00:37:02.106 A:middle
about the specific
debugging workflow

00:37:02.106 --> 00:37:05.126 A:middle
that we've made really great
and that's XPC Services.

00:37:05.756 --> 00:37:10.026 A:middle
But first, let's talk a little
bit about what XPC Services are.

00:37:10.416 --> 00:37:13.726 A:middle
XPC Services are really
powerful bits of functionality

00:37:13.726 --> 00:37:15.916 A:middle
that you separate from
your main code in order

00:37:15.916 --> 00:37:19.066 A:middle
to have stability
or maybe security.

00:37:19.786 --> 00:37:22.786 A:middle
And Xcode provides a template
if you're writing a Mac App

00:37:22.786 --> 00:37:25.176 A:middle
that will allow you to
create one of these surfaces

00:37:25.586 --> 00:37:29.016 A:middle
which makes a bundle
inside your application

00:37:29.306 --> 00:37:31.566 A:middle
which is a separate process
that gets launched by the system

00:37:31.846 --> 00:37:35.426 A:middle
when you call the
APIs that call it up.

00:37:35.686 --> 00:37:38.556 A:middle
And this bundle can
be communicated too,

00:37:38.766 --> 00:37:43.546 A:middle
you can ask request things
from the bundle and when

00:37:43.546 --> 00:37:46.396 A:middle
that operation is completed,
it will send the message back

00:37:46.636 --> 00:37:49.836 A:middle
with the results
of that procedure.

00:37:52.786 --> 00:37:55.466 A:middle
This is possible to
do in Xcode 4 to--

00:37:55.466 --> 00:37:59.106 A:middle
it is possible to modify
your scheme to wait

00:37:59.146 --> 00:38:02.226 A:middle
for these XPC services
to come up.

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00:37:59.146 --> 00:38:02.226 A:middle
for these XPC services
to come up.

00:38:02.226 --> 00:38:04.246 A:middle
And when they do, your
Xcode will attach to it.

00:38:04.766 --> 00:38:07.386 A:middle
And what does that mean
to attach to XPC Service?

00:38:07.386 --> 00:38:10.366 A:middle
That means it gets its own entry

00:38:10.366 --> 00:38:12.656 A:middle
in the debug navigator
complete with its own gauges.

00:38:13.326 --> 00:38:17.056 A:middle
And if you said breakpoints in
the XPC Service, they'll stop

00:38:17.056 --> 00:38:19.706 A:middle
in those breakpoints
just alongside your Mac

00:38:19.706 --> 00:38:20.746 A:middle
Application breakpoints.

00:38:21.166 --> 00:38:23.906 A:middle
So it's easy to be able
to step through each

00:38:23.906 --> 00:38:26.866 A:middle
of them concurrently just
by switching back and forth

00:38:26.866 --> 00:38:28.656 A:middle
between the process and
the debug navigator.

00:38:29.446 --> 00:38:33.046 A:middle
But the difficult part is that
when this communication ends

00:38:33.046 --> 00:38:35.666 A:middle
with your service, the
system is allowed to wreak

00:38:35.756 --> 00:38:39.286 A:middle
that XPC Service to free up
system resources for other apps.

00:38:39.766 --> 00:38:43.566 A:middle
And so to make that even better,

00:38:43.916 --> 00:38:46.156 A:middle
we've improved the
situation in Xcode 5.

00:38:47.156 --> 00:38:50.026 A:middle
When Xcode debugs your
application, it starts listening

00:38:50.256 --> 00:38:52.286 A:middle
for any services in
your application bundle.

00:38:53.906 --> 00:38:57.676 A:middle
And when those services come
up, Xcode automatically attaches

00:38:57.676 --> 00:38:59.716 A:middle
to it, meaning, you can set
breakpoints, you can see it

00:38:59.716 --> 00:39:02.106 A:middle
in the debug navigator,
you can check out the CPU

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00:38:59.716 --> 00:39:02.106 A:middle
in the debug navigator,
you can check out the CPU

00:39:02.106 --> 00:39:04.236 A:middle
and memory reports for those.

00:39:04.916 --> 00:39:07.856 A:middle
And when it goes away, Xcode
automatically detaches.

00:39:08.496 --> 00:39:12.836 A:middle
But Xcode is waiting once again
for that service to come back

00:39:13.366 --> 00:39:16.716 A:middle
and we'll attach to it again,
providing a seamless experience

00:39:16.756 --> 00:39:18.616 A:middle
for you XPC Service debugging.

00:39:22.336 --> 00:39:24.146 A:middle
This works great
in practice and I'd

00:39:24.146 --> 00:39:25.496 A:middle
like to invite Christopher
Friesen

00:39:25.496 --> 00:39:27.626 A:middle
up one more time to
give a final demo.

00:39:28.686 --> 00:39:31.116 A:middle
>> So yet again our users
want another feature.

00:39:31.116 --> 00:39:34.526 A:middle
They want to be able to look
at any image of the internet.

00:39:35.926 --> 00:39:38.326 A:middle
Now this might be kind
of dangerous to do.

00:39:38.326 --> 00:39:41.406 A:middle
So we're going to put this
functionality in an XPC Service

00:39:41.406 --> 00:39:43.766 A:middle
so that it's partition
from our main application.

00:39:44.116 --> 00:39:46.906 A:middle
So we've changed the
input to be a URL

00:39:47.446 --> 00:39:49.126 A:middle
and we put this on our service.

00:39:49.416 --> 00:39:51.386 A:middle
So let's take a look
and see what Xcode does

00:39:51.386 --> 00:39:52.856 A:middle
as we debug this application.

00:39:58.476 --> 00:40:00.976 A:middle
So I'll click the run here,
our application starting up.

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00:39:58.476 --> 00:40:00.976 A:middle
So I'll click the run here,
our application starting up.

00:40:01.176 --> 00:40:05.426 A:middle
Now we've hit a breakpoint where
the main app is now setting

00:40:05.426 --> 00:40:07.836 A:middle
up an XPC connection
to talk to our service.

00:40:09.526 --> 00:40:11.476 A:middle
You'll notice that in
the debug navigator,

00:40:11.916 --> 00:40:14.176 A:middle
we currently have just
a single application.

00:40:14.656 --> 00:40:17.396 A:middle
Our debug gauges and
threads and stacks.

00:40:19.176 --> 00:40:23.566 A:middle
Now as I continue, watch
this area and you'll see

00:40:23.566 --> 00:40:25.816 A:middle
that we automatically
attached to the XPC process.

00:40:26.366 --> 00:40:31.006 A:middle
And there it just showed up.

00:40:32.376 --> 00:40:33.936 A:middle
You'll note that it
has a different icon

00:40:33.936 --> 00:40:34.946 A:middle
in your main application.

00:40:35.086 --> 00:40:36.996 A:middle
It's a black and white
screwdriver and a wrench.

00:40:37.586 --> 00:40:39.866 A:middle
And again, it has
the same debug gauges

00:40:40.136 --> 00:40:43.646 A:middle
and the same capabilities
in this debug area.

00:40:44.246 --> 00:40:48.946 A:middle
As you see in our application,
we've fetched the image

00:40:48.946 --> 00:40:50.546 A:middle
and we're displaying it.

00:40:52.276 --> 00:40:57.566 A:middle
Now in order to debug in your
XPC Service, you simply need

00:40:57.566 --> 00:40:58.696 A:middle
to go set your breakpoints.

WEBVTT
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00:41:00.076 --> 00:41:02.316 A:middle
So we'll go to our breakpoint
that we've already created.

00:41:02.916 --> 00:41:05.366 A:middle
I'll set it in our service
and then I'll go back

00:41:05.366 --> 00:41:06.896 A:middle
and exercise our application.

00:41:07.476 --> 00:41:10.656 A:middle
Here we are.

00:41:11.436 --> 00:41:12.776 A:middle
It's now in the debug navigator,

00:41:12.776 --> 00:41:15.146 A:middle
you can see that we've
got our main application

00:41:15.146 --> 00:41:19.326 A:middle
which is still running, the
gauges are still whirling away,

00:41:19.326 --> 00:41:24.126 A:middle
the UI is still responsive, but
the XPC Service has been paused.

00:41:25.646 --> 00:41:27.196 A:middle
And here you see
that we're stopped

00:41:27.196 --> 00:41:29.636 A:middle
in thread 16 on stack
frame zero.

00:41:34.076 --> 00:41:35.986 A:middle
And we can continue
our application.

00:41:36.656 --> 00:41:40.396 A:middle
And we see that we've
returned back from the service,

00:41:40.396 --> 00:41:45.276 A:middle
applied the filter and
display it in the UI.

00:41:45.426 --> 00:41:46.726 A:middle
Now another thing to note is

00:41:47.216 --> 00:41:48.546 A:middle
that the Stop button
doesn't show

00:41:48.546 --> 00:41:50.006 A:middle
that multiple processes
are running.

00:41:51.396 --> 00:41:53.196 A:middle
This is because we
grouped them together

00:41:54.836 --> 00:41:57.876 A:middle
so that whenever you click stop,
we'll stop your main application

00:41:58.186 --> 00:42:01.136 A:middle
as well as your-- any XPC
processes that you have running,

WEBVTT
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00:41:58.186 --> 00:42:01.136 A:middle
as well as your-- any XPC
processes that you have running,

00:42:01.136 --> 00:42:05.206 A:middle
this is so that you can go
back, change your source code

00:42:05.206 --> 00:42:07.916 A:middle
and then next time you
run, we'll use that--

00:42:07.916 --> 00:42:10.596 A:middle
those changes in
your XPC Services.

00:42:11.906 --> 00:42:16.326 A:middle
So let's watch that debug
area as I click Stop.

00:42:16.476 --> 00:42:19.396 A:middle
I know, it's exciting
when it just works.

00:42:20.486 --> 00:42:27.956 A:middle
So there, so this is, so as we
said, XPC debugging is automatic

00:42:27.956 --> 00:42:31.466 A:middle
and enabled by default, but
there's also a toggle for it.

00:42:31.466 --> 00:42:35.026 A:middle
So let's go to the scheme popup
and we'll choose edit scheme.

00:42:36.506 --> 00:42:38.106 A:middle
Here we see that we're
on the run action.

00:42:39.396 --> 00:42:40.806 A:middle
Currently, we have
the info tab selected.

00:42:40.806 --> 00:42:45.226 A:middle
If we go to the options
tab, we see that the option

00:42:45.226 --> 00:42:47.976 A:middle
to toggle our debugging
XPC services is right here.

00:42:48.166 --> 00:42:49.496 A:middle
So here, you can
just toggle it on

00:42:49.496 --> 00:42:52.876 A:middle
and off should you ever need
to, most likely you won't.

00:42:54.196 --> 00:43:00.636 A:middle
And we hope that the
XPC integration in Xcode

WEBVTT
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00:42:54.196 --> 00:43:00.636 A:middle
And we hope that the
XPC integration in Xcode

00:43:02.026 --> 00:43:05.806 A:middle
for debugging your XPC
Services will entice you to look

00:43:05.806 --> 00:43:11.466 A:middle
at the powerful XPC subsystem
in Mac iOS X and add it

00:43:11.466 --> 00:43:12.976 A:middle
to your application, thank you.

00:43:13.516 --> 00:43:19.236 A:middle
[ Applause ]

00:43:19.736 --> 00:43:22.056 A:middle
>> So today, we've talked
about a lot of new things.

00:43:22.596 --> 00:43:24.576 A:middle
We talked about the
new debugging gauges

00:43:24.576 --> 00:43:26.336 A:middle
and the associated
debug reports.

00:43:27.216 --> 00:43:28.836 A:middle
We talked about data tips

00:43:29.226 --> 00:43:31.986 A:middle
and the improvements they
allow access to Quick Looks

00:43:31.986 --> 00:43:33.696 A:middle
which are also available
in the variable view.

00:43:34.146 --> 00:43:37.246 A:middle
We talked about some
drawing diagnostics

00:43:37.246 --> 00:43:38.166 A:middle
that you have access to.

00:43:38.696 --> 00:43:40.666 A:middle
And we talked about XPC Services

00:43:40.716 --> 00:43:42.576 A:middle
and the debug capabilities
in Xcode.

00:43:43.106 --> 00:43:46.626 A:middle
I know many of you; perhaps
all of you have new features

00:43:46.626 --> 00:43:48.546 A:middle
or new applications that
you're working on right now.

00:43:49.626 --> 00:43:52.836 A:middle
And I really hope that you
use the new features in Xcode,

00:43:53.196 --> 00:43:56.066 A:middle
maybe you take a look
at that debug gauge

00:43:56.066 --> 00:43:58.426 A:middle
and see what your
memory profile is like.

00:43:58.716 --> 00:44:02.976 A:middle
Maybe you look at the CPU,
maybe use the new Quick Looks

WEBVTT
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00:43:58.716 --> 00:44:02.976 A:middle
Maybe you look at the CPU,
maybe use the new Quick Looks

00:44:03.056 --> 00:44:05.036 A:middle
to solve the problem
in your application

00:44:05.946 --> 00:44:08.116 A:middle
because Xcode is
trying really hard

00:44:08.336 --> 00:44:10.306 A:middle
to make sure you ship great Apps

00:44:11.366 --> 00:44:13.666 A:middle
and I hope that's
what you get to do.

00:44:14.486 --> 00:44:16.696 A:middle
We have, of course, if
you have any questions

00:44:16.696 --> 00:44:19.526 A:middle
after the conference, you
can talk to Dave DeLong

00:44:19.596 --> 00:44:21.056 A:middle
or visit the developer forums.

00:44:21.056 --> 00:44:22.656 A:middle
There are some really
great people there.

00:44:23.756 --> 00:44:26.326 A:middle
I've referenced some
related sessions.

00:44:27.596 --> 00:44:29.806 A:middle
Thank you very much
for attending Debugging

00:44:29.806 --> 00:44:31.706 A:middle
in Xcode 5, have a great week.

00:44:32.516 --> 00:44:36.050 A:middle
[ Applause ]