1 00:00:00,590 --> 00:00:06,410 ‫Hello and welcome to this lecture and this lecture, we're going to implement the Caps lock, this will 2 00:00:06,410 --> 00:00:11,460 ‫allow us to easily use capital and lowercase letters in our shell. 3 00:00:12,110 --> 00:00:15,220 ‫Currently, you will notice we can only use uppercase letters. 4 00:00:15,230 --> 00:00:18,840 ‫There's no way to turn that to lowercase letters. 5 00:00:19,280 --> 00:00:25,350 ‫So after implementing caps, Lock will be able to use both uppercase and lowercase letters. 6 00:00:25,760 --> 00:00:27,660 ‫So let's let's begin. 7 00:00:28,460 --> 00:00:30,320 ‫Head over to Keyboardists C. 8 00:00:31,710 --> 00:00:40,260 ‫Which is in the keyboard directory and keyboard that s. so we're going to go void's keyboard set caps 9 00:00:40,260 --> 00:00:44,930 ‫lock and we're going to say Buhle State. 10 00:00:45,960 --> 00:00:49,230 ‫OK, so the state will be true or false. 11 00:00:49,260 --> 00:00:52,050 ‫OK, so what we should say is keyboard set, caps lock. 12 00:00:54,780 --> 00:00:55,020 ‫Yeah. 13 00:00:55,020 --> 00:00:56,000 ‫I'll tell you what we'll do. 14 00:00:56,010 --> 00:00:57,560 ‫Actually this should be an integer. 15 00:00:57,660 --> 00:01:00,910 ‫OK, keyboard set caps lock and state. 16 00:01:00,930 --> 00:01:10,680 ‫OK, now go to keyboard Hajj and we're just going to go to fine keyboard caps lock on and that'll be 17 00:01:10,680 --> 00:01:13,560 ‫one to find keyboard caps lock 18 00:01:16,890 --> 00:01:18,390 ‫off and that'll be zero. 19 00:01:18,420 --> 00:01:20,580 ‫OK, so that's just a bit cleaner, right. 20 00:01:21,680 --> 00:01:23,580 ‫We can even have its own type if you want. 21 00:01:23,880 --> 00:01:24,950 ‫So yeah, we'll do that too. 22 00:01:24,960 --> 00:01:25,560 ‫Let's go. 23 00:01:26,430 --> 00:01:27,540 ‫Typedef in it. 24 00:01:28,810 --> 00:01:36,090 ‫Keyboard caps lock state if you find they are having a lot of these different things. 25 00:01:36,090 --> 00:01:42,210 ‫So caps lock on them lock on and all of this, then you might want to have Flagg's instead and just 26 00:01:42,210 --> 00:01:42,860 ‫toggle them. 27 00:01:43,770 --> 00:01:48,300 ‫But just to keep things simple for you all, we're not going to do that here, we're just going to have 28 00:01:48,300 --> 00:01:49,570 ‫a caps lock state. 29 00:01:49,640 --> 00:01:56,070 ‫OK, so keyboard set caps lock and they provide us keyboard caps, lock state, OK, which can either 30 00:01:56,070 --> 00:02:02,130 ‫be on or off and you can make that an enumeration if you prefer. 31 00:02:02,730 --> 00:02:08,670 ‫So we're now going to want to go to keyboard that Hajj and we're just going to say keyboard caps lock 32 00:02:08,670 --> 00:02:10,170 ‫state key. 33 00:02:10,170 --> 00:02:11,520 ‫Uh, caps lock step. 34 00:02:15,950 --> 00:02:16,890 ‫Just like that. 35 00:02:16,910 --> 00:02:17,360 ‫OK. 36 00:02:17,600 --> 00:02:22,510 ‫And that'll stop the state of the keyboard, whether whether the caps locks on or off. 37 00:02:22,970 --> 00:02:28,970 ‫No, obviously if you have multiple keyboards, then they won't sync with each other with the caps lock. 38 00:02:28,970 --> 00:02:35,510 ‫OK, so you may decide to want to put this in the global scope so that the caps lock state affects every 39 00:02:35,510 --> 00:02:35,950 ‫keyboard. 40 00:02:35,960 --> 00:02:38,540 ‫But personally, I don't think we need to really. 41 00:02:40,040 --> 00:02:46,430 ‫So Justin Keyboard's set, caps lock, we're going to do, uh, struct keyboard keyboard, so they're 42 00:02:46,430 --> 00:02:48,400 ‫also going to have to provide us a keyboard, OK? 43 00:02:48,890 --> 00:02:53,980 ‫And then we're just going to say keyboard caps, lock state equals state just like that. 44 00:02:53,990 --> 00:03:00,140 ‫OK, and now we're going to say in it, keyboard get caps lock 45 00:03:03,290 --> 00:03:10,040 ‫and we're going to put the struct keyboard in here and that's just going to return the keyboard caps 46 00:03:10,040 --> 00:03:11,900 ‫lock state just like that, guys. 47 00:03:11,930 --> 00:03:15,470 ‫OK, so yeah that looks OK. 48 00:03:16,010 --> 00:03:19,700 ‫Let's put these functions in the header files so we can access them outside. 49 00:03:26,900 --> 00:03:31,130 ‫And we also want to return Keibel caps lock state, not an inch. 50 00:03:31,560 --> 00:03:38,420 ‫So that was my mistake just for the keep or get caps lock, OK, and change the one here as well. 51 00:03:38,750 --> 00:03:39,590 ‫Just like that. 52 00:03:40,490 --> 00:03:44,750 ‫And I'll head over to Classic Dot, see, and we're ready to begin using those functions. 53 00:03:45,500 --> 00:03:53,780 ‫OK, so the first thing we're going to do is during initialization, we're just going to go classic 54 00:03:53,780 --> 00:04:05,990 ‫keyboard and we're going to go keyboard set caps lock and we're going to go ampersand, classic keyboarder 55 00:04:06,230 --> 00:04:13,520 ‫and we're going to say keyboard caps lock off and we're just doing this just to test the functionality. 56 00:04:13,530 --> 00:04:16,580 ‫So obviously we want to toggle the caps lock yet. 57 00:04:16,610 --> 00:04:22,310 ‫OK, but we're just going to turn the caps lock off here to check to check if we're able to put things 58 00:04:22,310 --> 00:04:23,470 ‫in lowercase, OK? 59 00:04:23,480 --> 00:04:27,980 ‫And then once we know we can do that, then we can make it so we can toggle the caps, lock on or off, 60 00:04:28,640 --> 00:04:28,980 ‫OK. 61 00:04:29,000 --> 00:04:35,420 ‫So now just by here, after we get the char code from the keyboard scans, that one, we're going to 62 00:04:35,420 --> 00:04:46,340 ‫say if the caps lock is not down, so we go keyboard, get caps lock and we're going to pass in the 63 00:04:46,340 --> 00:04:50,120 ‫classic keyboard the address of the class, the keyboard, I should say. 64 00:04:50,120 --> 00:04:54,690 ‫OK, and we're going to make sure that we check the status down. 65 00:04:54,710 --> 00:04:59,930 ‫OK, so we're going to go equals equals keyboard caps lock off. 66 00:05:00,170 --> 00:05:09,400 ‫And if that's the case, then we need to take the character here and make it lowercase. 67 00:05:09,410 --> 00:05:14,600 ‫So firstly, we need to check that it's actually from A to Z, because if it's not from A to Z, we 68 00:05:14,600 --> 00:05:15,600 ‫shouldn't even change it. 69 00:05:15,620 --> 00:05:19,640 ‫OK, so let's stop again the ASCII table up and you'll understand. 70 00:05:19,640 --> 00:05:23,990 ‫I'm sure all of you have heard of the ASCII table and I'm sure you all understand it very well. 71 00:05:24,860 --> 00:05:26,540 ‫But just in case, will go over it. 72 00:05:27,260 --> 00:05:36,440 ‫So we can see here that capital A's decimal sixty five and the lowercase A is ninety seven. 73 00:05:36,810 --> 00:05:44,090 ‫OK, we can convert a capital A for example to a lowercase A by doing a simple equation. 74 00:05:44,100 --> 00:05:46,670 ‫So if we want to get a python here. 75 00:05:50,100 --> 00:05:55,120 ‫And we did ninety seven minus sixty five. 76 00:05:55,800 --> 00:06:04,500 ‫We get 32, so all we do is, is we add 32 to any uppercase character and it becomes a lowercase character. 77 00:06:04,890 --> 00:06:07,560 ‫OK, let's take decimal 68. 78 00:06:07,560 --> 00:06:14,040 ‫Ferdy Ferdy, as an example, we're going to go sixty eight plus thirty two and we get one hundred. 79 00:06:14,040 --> 00:06:19,590 ‫And if you look at one hundred decimal hundred that is lowercase D so you can see the ASCII tables arranged 80 00:06:19,590 --> 00:06:21,030 ‫like this in such a way. 81 00:06:21,030 --> 00:06:27,420 ‫So you can do math like this on it and be able to easily convert to lowercase, OK or uppercase. 82 00:06:28,260 --> 00:06:30,450 ‫Now we do need to check that it's in bounds. 83 00:06:30,450 --> 00:06:37,350 ‫So we need to check if the character is between Capital A. and Capital Z and if that's true, then we 84 00:06:37,350 --> 00:06:41,910 ‫can perform that that that mathematical operations. 85 00:06:41,920 --> 00:06:51,780 ‫So if we just go back to Visual Studio Code and we can work with that, so we're going to say if C is 86 00:06:51,780 --> 00:07:00,540 ‫above or equal capital and C is below equal capital Z. 87 00:07:01,460 --> 00:07:05,360 ‫In which case it's a character that should be converted to lowercase. 88 00:07:05,610 --> 00:07:14,160 ‫So we just go C minus equals 32, which is the difference between now plus equals not minus plus equals 89 00:07:14,160 --> 00:07:18,750 ‫32, which is the difference in the ASCII table, as I just showed you with Python just then. 90 00:07:19,410 --> 00:07:19,930 ‫Uh. 91 00:07:20,430 --> 00:07:23,280 ‫So why do we check if the caps lock is off and not on? 92 00:07:24,000 --> 00:07:28,640 ‫Because our entire scan scans, that one is in uppercase. 93 00:07:28,830 --> 00:07:32,040 ‫That's why if it was in lower case, then we'd do the opposite. 94 00:07:32,040 --> 00:07:39,180 ‫We would check if the if the caps lock was on and we check between A and between lowercase, A. and 95 00:07:39,180 --> 00:07:39,720 ‫lowercase. 96 00:07:40,890 --> 00:07:47,700 ‫But because we're checking the caps lock itself and we check between capital and Z because of the way 97 00:07:47,700 --> 00:07:48,840 ‫the scan said one is. 98 00:07:49,080 --> 00:07:49,950 ‫So that should work. 99 00:07:49,950 --> 00:07:50,700 ‫OK guys. 100 00:07:50,880 --> 00:07:52,500 ‫So we're nearly ready to build this. 101 00:07:52,500 --> 00:07:59,580 ‫But before we do, just go to keyboard dot Hajj because we missed the semicolon there on keyboard get 102 00:07:59,580 --> 00:08:00,280 ‫caps lock. 103 00:08:00,300 --> 00:08:01,920 ‫OK, yeah. 104 00:08:01,940 --> 00:08:04,050 ‫So once you've done that, we can go ahead and build this. 105 00:08:04,050 --> 00:08:06,870 ‫Just go make clean build that S.H.. 106 00:08:09,860 --> 00:08:15,860 ‫And we can see that works absolutely fine if you run that, we should see lower case when we type, 107 00:08:16,010 --> 00:08:16,730 ‫which we do. 108 00:08:17,480 --> 00:08:18,560 ‫Hello, how are you? 109 00:08:19,580 --> 00:08:20,220 ‫Excellent. 110 00:08:20,690 --> 00:08:22,860 ‫So, yeah, congratulations on that. 111 00:08:22,880 --> 00:08:26,680 ‫Guys, we now have the lower case implemented. 112 00:08:27,020 --> 00:08:30,920 ‫We now need to just make the toggling of the caps lock and we are finished. 113 00:08:31,490 --> 00:08:38,570 ‫So just scroll to the top of this file and we're just going to go to find define classic keyboard's 114 00:08:38,570 --> 00:08:39,050 ‫caps. 115 00:08:39,050 --> 00:08:45,710 ‫Lock equals zero x three a system don't the equals sign just type six three A.. 116 00:08:46,250 --> 00:08:48,450 ‫Now that's the code for the caps lock. 117 00:08:48,480 --> 00:08:55,070 ‫OK, so scroll down here and just by here, just above line 75. 118 00:08:56,240 --> 00:09:00,930 ‫No, no, no, below the line 78, where we check the key was released. 119 00:09:01,370 --> 00:09:09,950 ‫We're just going to say if scanned code is equal to a classic keyboard caps lock. 120 00:09:12,260 --> 00:09:18,710 ‫So when I was just going to go keyboard set, caps lock, classic keyboard. 121 00:09:20,390 --> 00:09:29,810 ‫I like Shippen ampersand there, guys, and we're going to say keyboard caps, lock state, all state 122 00:09:30,590 --> 00:09:36,260 ‫equals keyboard get caps, lock ampersand, classic keyboard. 123 00:09:36,260 --> 00:09:40,840 ‫And you could make a toggle function if you wanted, but we'll just do it like this for now. 124 00:09:41,360 --> 00:09:52,700 ‫And we're going to say if the old state is equal to caps, lock on then use keyboard caps lock off. 125 00:09:54,320 --> 00:09:57,740 ‫Otherwise use keyboard caps lock on. 126 00:09:57,770 --> 00:09:59,010 ‫So a bit of a tannery here. 127 00:09:59,030 --> 00:10:04,720 ‫OK, so hold steady because zikos caps lock on, then use caps lock off. 128 00:10:04,730 --> 00:10:06,020 ‫Otherwise caps lock on. 129 00:10:06,020 --> 00:10:06,650 ‫Perfect. 130 00:10:07,370 --> 00:10:08,630 ‫So that should work. 131 00:10:08,630 --> 00:10:12,620 ‫OK, so if we just go make clean bill to Hajj. 132 00:10:17,100 --> 00:10:25,300 ‫Kevin Hyram, you just type something, no press caps, lock and type again, press caps, lock type 133 00:10:25,300 --> 00:10:27,310 ‫again, press caps lock type again. 134 00:10:27,670 --> 00:10:29,050 ‫So you can see that works now. 135 00:10:29,060 --> 00:10:31,630 ‫We now have the ability to use the caps lock. 136 00:10:32,120 --> 00:10:38,120 ‫Now you'll notice if you start the pro, if you start the operating system with your caps lock on it. 137 00:10:38,170 --> 00:10:44,590 ‫It'll still think caps lock is off the mask because we don't care about the actual state of the caps. 138 00:10:44,590 --> 00:10:47,200 ‫Lock one, the OS boots. 139 00:10:47,470 --> 00:10:49,080 ‫We just assume that it's off. 140 00:10:49,480 --> 00:10:54,250 ‫OK, if you want to take this a step further, you can use the keyboard commands to determine if the 141 00:10:54,250 --> 00:10:56,410 ‫caps lock is on or off state. 142 00:10:57,080 --> 00:11:03,700 ‫However, we don't need to get on that because this is a perfectly acceptable implementation.