1 00:00:03,120 --> 00:00:03,390 Okay. 2 00:00:03,390 --> 00:00:06,750 I've got a bit of a problem and solution type lecture for us here. 3 00:00:06,750 --> 00:00:12,570 And along the way we're going to learn about public access modifier and the problem that we've got. 4 00:00:12,660 --> 00:00:15,720 I'm just going to put up my load level delay to one. 5 00:00:15,720 --> 00:00:19,890 So we've got a little bit longer when we bump our head, what happens is when we bump our head, I'll 6 00:00:19,890 --> 00:00:21,930 just spin around and bump. 7 00:00:22,470 --> 00:00:24,570 I can continue to move and wobble. 8 00:00:24,570 --> 00:00:27,630 I can hit the ground again, trigger a sound effect again. 9 00:00:27,630 --> 00:00:30,630 So I've got a few things in here that we want to stop and prevent. 10 00:00:30,630 --> 00:00:35,190 Basically, when the player crashes, I want to say you can't control your player anymore because you 11 00:00:35,190 --> 00:00:36,030 crashed. 12 00:00:36,030 --> 00:00:41,580 And I'm going to go about doing this in a way that allows us to understand public access modifiers. 13 00:00:41,580 --> 00:00:46,410 So looking at this, theoretically, we've got our player controller script, which is saying how we 14 00:00:46,410 --> 00:00:53,220 move our player, giving us the ability to rotate and speed up, etc., and we want to block that control. 15 00:00:53,220 --> 00:00:57,270 However, we've got our crash detector that says, Hey, I know when you crashed. 16 00:00:57,270 --> 00:01:02,190 So at the moment we've got a problem where these two scripts aren't speaking to each other and we're 17 00:01:02,190 --> 00:01:05,670 going to use the public keyword to resolve that. 18 00:01:05,670 --> 00:01:07,350 So let's jump into Visual Studio. 19 00:01:07,350 --> 00:01:09,660 I'm going to close a couple of things here. 20 00:01:09,660 --> 00:01:11,790 I don't need dust trail and I don't need finish line. 21 00:01:11,790 --> 00:01:14,640 We're just working in player, controller and crash detector. 22 00:01:14,640 --> 00:01:19,920 These are the two scripts and we've talked a little bit just very briefly about public versus private. 23 00:01:19,920 --> 00:01:24,300 You've noticed each time Private has appeared, I've got there and said, Oh, I don't need private, 24 00:01:24,300 --> 00:01:25,680 I'm going to delete that. 25 00:01:25,680 --> 00:01:26,790 So what's going on here? 26 00:01:26,790 --> 00:01:34,320 Well, by default, all of our variables and all of our methods are only available within this particular 27 00:01:34,320 --> 00:01:35,160 class. 28 00:01:35,160 --> 00:01:39,240 That is to say the scope of these things is local to this class. 29 00:01:39,240 --> 00:01:42,360 There's some terminology for use scope, in other words, where you can use it. 30 00:01:42,360 --> 00:01:43,980 And local to this class. 31 00:01:43,980 --> 00:01:49,650 We've also talked about how if we've got something within these curly braces, for example, if we were 32 00:01:49,650 --> 00:01:55,500 to go and define a variable within here, declare it and define it, then we can't use it outside of 33 00:01:55,500 --> 00:01:56,580 this scope. 34 00:01:56,580 --> 00:02:01,380 So those curly braces will define you can use something within here, but not elsewhere. 35 00:02:01,380 --> 00:02:05,790 And we've talked a little bit about member variables that we can set up at the top of our class and 36 00:02:05,790 --> 00:02:07,170 then use them anywhere. 37 00:02:07,500 --> 00:02:12,090 As a point of comparison, the scope of these things is throughout our entire class. 38 00:02:12,090 --> 00:02:17,070 However, how do we go about having something accessible from a different class? 39 00:02:17,070 --> 00:02:23,010 So for example, if I'm in crash detector at the moment and I want to have a method in here that in 40 00:02:23,010 --> 00:02:26,880 player controller we can call at the moment, we have no way of doing that. 41 00:02:26,880 --> 00:02:31,890 If I try to call something in here, for example, the reload scene that I've created, if I were to 42 00:02:31,890 --> 00:02:38,220 say call this particular reload scene method from player controller, we won't be allowed to do that 43 00:02:38,220 --> 00:02:40,800 because reload scene is private. 44 00:02:40,800 --> 00:02:42,150 Remember, it's private by default. 45 00:02:42,150 --> 00:02:47,730 Even if you don't see the keyword in there, we would need to use the keyword public in order for us 46 00:02:47,730 --> 00:02:51,810 to be able to call this method from other classes. 47 00:02:51,810 --> 00:02:53,190 And why is it set up like this? 48 00:02:53,190 --> 00:02:54,540 Well, it's safer that way. 49 00:02:54,540 --> 00:02:57,450 It means that we don't accidentally go and call things. 50 00:02:57,450 --> 00:02:59,400 It means that we are very explicit. 51 00:02:59,400 --> 00:03:05,040 We're going out of our way to say, I want this thing or whatever we set up to be able to be called 52 00:03:05,040 --> 00:03:06,270 from another place. 53 00:03:06,270 --> 00:03:08,520 The same is true for variables. 54 00:03:08,520 --> 00:03:15,960 So by default our variables are private, so private int whatever is our variable in here. 55 00:03:15,960 --> 00:03:23,070 So there's a variable we could make this public and then we could change update modify this variable 56 00:03:23,070 --> 00:03:25,770 from other classes or other scripts. 57 00:03:25,770 --> 00:03:31,110 So for example, we'll make this ten and then if we're over in, so this is in the crash detector, 58 00:03:31,110 --> 00:03:36,300 then over in player controller, we could access whatever and set whatever to 20. 59 00:03:36,300 --> 00:03:37,740 It's probably not the best name, is it? 60 00:03:37,770 --> 00:03:40,470 Whatever should name it something a little bit cleverer than that. 61 00:03:40,470 --> 00:03:41,700 But this is our variable. 62 00:03:41,700 --> 00:03:47,070 What you might see if you're cruising around on the interwebs, you'll see a lot of people use public 63 00:03:47,070 --> 00:03:49,530 instead of using serialized field. 64 00:03:49,530 --> 00:03:54,420 That is because if we set this to public, I'm just going to save my script here, jump back to Unity 65 00:03:54,420 --> 00:03:56,190 and show you what I'm talking about. 66 00:03:56,190 --> 00:04:00,570 Public is another way to allow us to see this in the inspector. 67 00:04:00,570 --> 00:04:05,130 So if I click on Barry Fine crash detector, you can see here we've got whatever set to ten. 68 00:04:05,130 --> 00:04:06,660 I could modify that in here. 69 00:04:06,660 --> 00:04:13,830 So the public keyword or the public access modifier is another way to allow us to edit in our inspector. 70 00:04:13,830 --> 00:04:20,070 However, I choose not to do it that way because this also means we can modify whatever from other scripts 71 00:04:20,070 --> 00:04:24,570 and that can happen accidentally or it can be something that we modify, change, update and we don't 72 00:04:24,570 --> 00:04:26,220 quite know exactly how it's happening. 73 00:04:26,220 --> 00:04:29,820 So that is why Serialize Field is a safer way of going about doing that. 74 00:04:29,820 --> 00:04:33,510 Now in our situation here, what is it that we would like to make public? 75 00:04:33,510 --> 00:04:39,690 And I think we would like to have something within our player controller that is made public that says 76 00:04:39,690 --> 00:04:41,670 anyone or any script. 77 00:04:41,670 --> 00:04:43,410 I should say the script is not a person. 78 00:04:43,410 --> 00:04:44,280 Rick, calm down. 79 00:04:44,280 --> 00:04:51,060 So anywhere within our code base, within our project, we can call something on player controller to 80 00:04:51,060 --> 00:04:55,020 say, you can't move anymore, we're disabling controls. 81 00:04:55,020 --> 00:04:56,940 Let's go about creating that framework. 82 00:04:56,940 --> 00:04:58,650 I'm going to pop underneath update. 83 00:04:58,650 --> 00:05:02,580 We will add in a new method and I'm going to call this method. 84 00:05:02,710 --> 00:05:06,070 Disable controls because that's what it's doing now. 85 00:05:06,070 --> 00:05:11,560 In front of that, we're going to use our keyword public and we need to say what the return type is 86 00:05:11,560 --> 00:05:13,390 and we don't have any return information. 87 00:05:13,390 --> 00:05:14,290 We're looking to get back. 88 00:05:14,290 --> 00:05:19,930 So we add void in here, we add our parentheses as usual, create our curly braces. 89 00:05:19,930 --> 00:05:26,800 And what is it that we want to have happen when we when someone says, hey, disable the controls, 90 00:05:26,800 --> 00:05:27,460 man. 91 00:05:27,460 --> 00:05:31,390 Well, we want to literally not allow the player to do these things. 92 00:05:31,390 --> 00:05:36,850 So there's a way we can do that by setting ourselves up a ball and using an if statement jump up to 93 00:05:36,850 --> 00:05:39,700 the top of our script, we'll create a ball and we'll call. 94 00:05:39,700 --> 00:05:45,430 This can move and we'll initialize that at true because you should be able to move. 95 00:05:45,430 --> 00:05:46,600 Yes, you can move. 96 00:05:46,600 --> 00:05:48,790 Now, a little micro challenge for you here. 97 00:05:48,790 --> 00:05:54,940 I want you to go about using our ball to say that if you can move, then you can move. 98 00:05:54,940 --> 00:05:56,980 But if you can't move, then you can't move. 99 00:05:56,980 --> 00:06:00,430 So this is a micro challenge for you, see if you know how to do that. 100 00:06:02,700 --> 00:06:03,210 Okay. 101 00:06:03,240 --> 00:06:04,680 Hopefully that wasn't too vague. 102 00:06:04,690 --> 00:06:06,170 It kind of felt a little bit vague. 103 00:06:06,180 --> 00:06:08,700 But where we can do this is within update. 104 00:06:08,700 --> 00:06:14,510 So I can type in if can move and by default that means it's true. 105 00:06:14,520 --> 00:06:16,890 You don't have to say equals equals true. 106 00:06:16,890 --> 00:06:23,520 But just know if you're saying if can move is if this thing resolves to true, then hey man, you can 107 00:06:23,520 --> 00:06:28,470 go about rotating, it can go about boosting and then curly brace at the end. 108 00:06:28,470 --> 00:06:30,600 So if you can move, then go about moving. 109 00:06:30,600 --> 00:06:31,120 Great. 110 00:06:31,140 --> 00:06:36,600 However, what we want to do is put some code in here with our disable controls to change that. 111 00:06:36,600 --> 00:06:38,940 So another little micro challenge for you here. 112 00:06:38,940 --> 00:06:46,110 What code can we add to our disable controls method so that if it's called, you can no longer move? 113 00:06:47,820 --> 00:06:52,670 We will simply say can move the variable now equals false. 114 00:06:52,680 --> 00:06:55,530 What is flicking the switch on our ball so it's false. 115 00:06:55,530 --> 00:07:01,800 I'm going to save that and head over to crash detector, which is the place where we want to be calling 116 00:07:01,800 --> 00:07:03,930 our new fancy public method. 117 00:07:03,930 --> 00:07:07,170 And the first thing in here we need to say where the player controller is. 118 00:07:07,170 --> 00:07:11,610 We need a reference to the player controller so we could set up a serialized field and say, this is 119 00:07:11,610 --> 00:07:13,560 the particular player controller. 120 00:07:13,560 --> 00:07:14,520 We could bring that in. 121 00:07:14,520 --> 00:07:19,320 We can manually, manually drag it in the inspector, but we've just learned how to use find objective 122 00:07:19,320 --> 00:07:19,590 type. 123 00:07:19,600 --> 00:07:21,360 So let's use that one more time. 124 00:07:21,360 --> 00:07:26,760 I'm going to under my if statement here, if the thing that I bumped into is the ground I'm going to 125 00:07:26,760 --> 00:07:30,930 find object of type, what type do you think it's going to be? 126 00:07:31,110 --> 00:07:37,290 It's going to be the player controller, which is the script, which is a class, but it's also a type 127 00:07:37,290 --> 00:07:38,190 dot. 128 00:07:38,190 --> 00:07:39,930 And we're going to call something in here. 129 00:07:39,930 --> 00:07:41,100 What will we call? 130 00:07:41,100 --> 00:07:44,040 You can see it listed right out there in all its glory. 131 00:07:44,040 --> 00:07:49,740 This method we've created, which is public disable controls, parentheses, semicolon. 132 00:07:49,740 --> 00:07:52,560 So we're hereby calling a public method. 133 00:07:52,560 --> 00:07:57,630 I'm going to save that and just show you very quickly if I was to jump back in here and remove this 134 00:07:57,630 --> 00:08:03,960 public keyword from disabled controls, save head back to crash detector, it's now like, hey, you 135 00:08:03,960 --> 00:08:04,770 can't do this. 136 00:08:04,770 --> 00:08:09,000 This is inaccessible due to its protection level, which is cool. 137 00:08:09,000 --> 00:08:10,170 Shows that process. 138 00:08:10,170 --> 00:08:13,410 So put public back in here, save it once again. 139 00:08:13,410 --> 00:08:14,910 Crash detector should be cool. 140 00:08:14,910 --> 00:08:16,770 Let us jump into unity. 141 00:08:16,770 --> 00:08:20,520 Click on play and see if we can rotate after we crash. 142 00:08:20,520 --> 00:08:24,570 So crash and I'm banging on the keyboard, but nothing is happening. 143 00:08:24,570 --> 00:08:25,110 Excellent. 144 00:08:25,110 --> 00:08:28,470 So it is successfully disabled our controls. 145 00:08:28,470 --> 00:08:32,580 So just to recap on that, I know it's a new concept, but it's fairly simple. 146 00:08:32,580 --> 00:08:38,309 Once you use it a few times when we have the public keyword, it simply means that we can access methods 147 00:08:38,309 --> 00:08:41,970 from that class in other classes. 148 00:08:41,970 --> 00:08:45,360 We can also do that for variables, but we tend not to do that. 149 00:08:45,360 --> 00:08:49,050 We tend not to make public variables because they can get a little bit dangerous. 150 00:08:49,050 --> 00:08:53,490 It's a lot harder to see if something's been changed as a variable than it is to see if something's 151 00:08:53,490 --> 00:08:55,140 being called as a method. 152 00:08:55,140 --> 00:08:55,860 Well, I think so. 153 00:08:55,860 --> 00:08:56,490 Anyway. 154 00:08:56,490 --> 00:08:57,210 So there we go. 155 00:08:57,210 --> 00:09:01,500 We've learned a new thing which is using the public access modifier keyword. 156 00:09:01,500 --> 00:09:03,120 I will see you in the next lecture.