1
00:00:00,700 --> 00:00:04,340
All right let's take a look at how
to set portrait only mode in code.

2
00:00:04,340 --> 00:00:06,140
Once again, this video is optional,

3
00:00:06,140 --> 00:00:09,410
you don't need to watch this video to
complete the section or the course, but

4
00:00:09,410 --> 00:00:11,850
it's here if you wanna go a bit further,
and try this out.

5
00:00:11,850 --> 00:00:14,790
Don't worry if you don't fully
understand everything we cover here, but

6
00:00:14,790 --> 00:00:18,270
certainly feel free to ask questions and
discuss with our community, right.

7
00:00:18,270 --> 00:00:20,830
So to start, I'm going to get
rid of the screen orientation

8
00:00:20,830 --> 00:00:23,590
attribute we just added, make sure
the angle bracket is still there.

9
00:00:24,700 --> 00:00:27,740
And now, let's take a look at a helpful
stack overflow question about this

10
00:00:27,740 --> 00:00:28,790
exact problem.

11
00:00:28,790 --> 00:00:31,960
So here the question is, how to set an
entire application in portrait mode only?

12
00:00:31,960 --> 00:00:36,940
If we go down to the first answer,
we see a helpful response, this is for

13
00:00:36,940 --> 00:00:41,160
any Android version, but since our
app is targeting API level 16 and up,

14
00:00:41,160 --> 00:00:44,480
we can use this other solution down here,
which I like better.

15
00:00:44,480 --> 00:00:48,150
So, the basic idea is that we wanna create
custom activity lifecycle listeners,

16
00:00:48,150 --> 00:00:50,900
inside of custom application class.

17
00:00:50,900 --> 00:00:55,235
When an activity switched from portrait
to landscape, it goes through a number of

18
00:00:55,235 --> 00:00:59,190
lifecycle methods, it's a actually
destroyed, and then recreated.

19
00:00:59,190 --> 00:01:01,490
And when it's recreated
in this other mode,

20
00:01:01,490 --> 00:01:04,360
it gets a different layout if needed.

21
00:01:04,360 --> 00:01:07,850
So we wanna do,
is attach a listener to those events, and

22
00:01:07,850 --> 00:01:10,770
then when a certain event is called when,
the activity is created,

23
00:01:10,770 --> 00:01:15,050
we want to force it,
into SCREEN_ORIENTATION_PORTRAIT.

24
00:01:15,050 --> 00:01:16,990
All right,
let's see how this works in code.

25
00:01:16,990 --> 00:01:19,710
So we'll start by creating
a custom application class,

26
00:01:19,710 --> 00:01:24,530
right click on our main package here,
select New, Java Class,

27
00:01:24,530 --> 00:01:28,460
let's call this
InteractiveStoryApplication.

28
00:01:28,460 --> 00:01:31,182
By convention,
if we do a custom application class,

29
00:01:31,182 --> 00:01:33,366
we usually end with the word Application.

30
00:01:33,366 --> 00:01:36,107
As a Superclass,
let's start typing Application, and

31
00:01:36,107 --> 00:01:39,610
we can select android.app.Application,
and click OK.

32
00:01:39,610 --> 00:01:43,120
Okay, so here we have our new class, and
it's extending our base application.

33
00:01:43,120 --> 00:01:47,660
The base application class is used
when an app first start ups, and

34
00:01:47,660 --> 00:01:49,900
there are methods there
that happen by default.

35
00:01:49,900 --> 00:01:53,850
Now that we're using a custom one, we need
to specify that in the manifest itself, so

36
00:01:53,850 --> 00:01:57,950
here for the application element,
we want to add a new attribute.

37
00:01:57,950 --> 00:02:00,740
So drop it on a new line,
and type android:name and

38
00:02:00,740 --> 00:02:05,490
then in here we want the value,
we can start typing InteractiveStory, and

39
00:02:05,490 --> 00:02:08,020
from auto complete,
we can select our new class.

40
00:02:08,020 --> 00:02:10,630
So now,
Android knows when our app starts to

41
00:02:10,630 --> 00:02:14,230
use this custom application class
instead of the default one.

42
00:02:14,230 --> 00:02:20,810
Back in our class, we want to override the
onCreate method, so start typing onCreate,

43
00:02:20,810 --> 00:02:24,270
and we can select it from auto complete,
and this is the onCreate method for

44
00:02:24,270 --> 00:02:28,300
the entire application, not an individual
activity like we've seen before.

45
00:02:28,300 --> 00:02:33,110
So back in our sample code we see that,
inside onCreate we want to register a new

46
00:02:33,110 --> 00:02:37,520
ActivityLifeCycleCallBack, and then in
there we're gonna use a specific method.

47
00:02:39,050 --> 00:02:42,250
So, let's add a new line after
super.onCreate, we wanna make sure we call

48
00:02:42,250 --> 00:02:45,890
that, so that it does all
the functionality in the superclass.

49
00:02:45,890 --> 00:02:50,420
And now we wanna type register, and
there it is, ActivityLifecycleCallbacks.

50
00:02:50,420 --> 00:02:54,290
And here we can add a new anonymous
inner class, we can type new

51
00:02:54,290 --> 00:02:59,090
ActivityLifecycleCallbacks, hit Enter, and
we get a bunch of methods we can override.

52
00:02:59,090 --> 00:03:00,400
Now we don't have to do anything here,

53
00:03:00,400 --> 00:03:03,370
we're only going to override this
first one onActivityCreated,

54
00:03:03,370 --> 00:03:07,570
but you can see there are other methods
that we could override for other reasons.

55
00:03:07,570 --> 00:03:12,399
So in here, when an activity is created,
we want to force it to portrait mode,

56
00:03:12,399 --> 00:03:16,204
we do that by referencing
the activity that's passed in, and

57
00:03:16,204 --> 00:03:20,668
on it we call setRequestedOrientation,
and we set it to portrait mode,

58
00:03:20,668 --> 00:03:23,156
which we get through ActivityInfo, and

59
00:03:23,156 --> 00:03:27,663
I just remember this from the stack
overflow question, ActivityInfo.

60
00:03:27,663 --> 00:03:31,008
And here we have a bunch of screen
orientation parameters, and

61
00:03:31,008 --> 00:03:34,670
we want SCREEN_ORIENTATION_PORTRAIT,
there we go.

62
00:03:34,670 --> 00:03:36,840
So, if we run this we
should be able to see,

63
00:03:36,840 --> 00:03:39,520
if we change our emulator to landscape
mode, it should stay portrait.

64
00:03:40,990 --> 00:03:44,490
Okay it loads up, and we can use the
buttons here to switch, and sure enough,

65
00:03:44,490 --> 00:03:45,920
it doesn't change to landscape view.

66
00:03:45,920 --> 00:03:47,220
Cool, that's exactly what we wanted.