1 00:00:00,720 --> 00:00:04,110 So first we created an array of group names. 2 00:00:04,110 --> 00:00:08,590 This is actually a one dimensional array and then we created a two dimensional array. 3 00:00:08,610 --> 00:00:08,920 OK. 4 00:00:08,940 --> 00:00:11,940 And array of arrays and the name of this area. 5 00:00:11,960 --> 00:00:13,180 Each child names. 6 00:00:13,240 --> 00:00:19,170 OK so now let's actually declare our valuable of type context. 7 00:00:19,200 --> 00:00:19,670 OK. 8 00:00:19,680 --> 00:00:24,460 In order to specify the context of our activity of our application. 9 00:00:24,690 --> 00:00:29,330 So if we have this context class and as you can see it actually automatically imported this context 10 00:00:29,330 --> 00:00:35,610 the class to our activity here to our class and the name of this object is context. 11 00:00:35,700 --> 00:00:36,500 OK. 12 00:00:36,990 --> 00:00:41,270 And as you can see I didn't actually instantiate this object yet. 13 00:00:41,370 --> 00:00:47,670 So I want to actually instantiated Venda actually and the constructor of this class of this class is 14 00:00:47,670 --> 00:00:48,230 being called. 15 00:00:48,250 --> 00:00:50,910 Ok so here I can just type in public. 16 00:00:51,180 --> 00:00:56,520 OK expandable at least you adapter. 17 00:00:56,520 --> 00:01:02,020 OK so remember the name of your constructor must be the same as the name of your class. 18 00:01:02,040 --> 00:01:02,630 OK. 19 00:01:02,910 --> 00:01:07,800 And then I put in a pair of brackets here are part of our practices as you can see here. 20 00:01:08,370 --> 00:01:14,570 And here you can see and inside the prentices I can actually specify the arguments of these are constructor. 21 00:01:14,580 --> 00:01:17,320 So here I can just type in context. 22 00:01:17,790 --> 00:01:19,610 OK context. 23 00:01:19,860 --> 00:01:27,150 So remember that context allows you allows this activity to actually interact with other features of 24 00:01:27,240 --> 00:01:29,010 Android outside of this activity. 25 00:01:29,030 --> 00:01:34,860 OK so we can't use context in lots of places in our Android application programming. 26 00:01:34,890 --> 00:01:35,550 OK. 27 00:01:35,970 --> 00:01:37,050 So this is very important. 28 00:01:37,050 --> 00:01:43,350 So context allows this activity this class to interact with other features outside of this activity. 29 00:01:43,380 --> 00:01:52,350 So we need to actually initialize this context so this that context assignment operator context and 30 00:01:52,350 --> 00:01:55,190 then I need to put in a semicolon at the end of my statement here. 31 00:01:55,230 --> 00:02:00,660 So as you can see here we have this great group of Kant here as you can see we are actually over writing 32 00:02:00,660 --> 00:02:02,610 this method in our class. 33 00:02:02,610 --> 00:02:03,150 OK. 34 00:02:03,360 --> 00:02:05,590 So as you can see here it says return 0. 35 00:02:05,700 --> 00:02:11,600 So here we need to actually return the number of elements that are inside of this group names here. 36 00:02:11,610 --> 00:02:13,190 OK inside of this group names Ari. 37 00:02:13,280 --> 00:02:13,810 OK. 38 00:02:14,070 --> 00:02:17,280 So here I can just refer to the name of that a group names. 39 00:02:17,480 --> 00:02:19,420 K Dot lenth. 40 00:02:19,910 --> 00:02:20,710 OK. 41 00:02:21,180 --> 00:02:23,820 And as you can see here you have these get. 42 00:02:23,860 --> 00:02:25,100 She didn't count here. 43 00:02:25,170 --> 00:02:27,620 And we need to actually implement this method here. 44 00:02:27,780 --> 00:02:30,250 So as you can see it says get children out. 45 00:02:30,300 --> 00:02:33,780 So we need to actually read through the name of this child names Ari. 46 00:02:33,930 --> 00:02:34,640 OK. 47 00:02:34,710 --> 00:02:39,520 And we need to actually get the value of the length of this array. 48 00:02:39,730 --> 00:02:40,060 OK. 49 00:02:40,080 --> 00:02:41,200 And then return That's right. 50 00:02:41,220 --> 00:02:45,420 So here I can just type in child names dot Len. 51 00:02:45,800 --> 00:02:46,600 OK. 52 00:02:46,950 --> 00:02:51,280 And here as you can see if you have another MF it gets group OK. 53 00:02:51,390 --> 00:02:55,050 So this method actually returns a value of type Object. 54 00:02:55,050 --> 00:02:55,500 OK. 55 00:02:55,590 --> 00:02:57,550 And the name of this method is get group. 56 00:02:57,750 --> 00:03:02,970 And this if it actually accepts an argument of type integer and the name of this argument is group or 57 00:03:03,020 --> 00:03:03,890 position. 58 00:03:03,990 --> 00:03:10,950 So here we need to actually return the values that are inside of this get group names. 59 00:03:11,010 --> 00:03:15,820 OK so here I can just typing that actually did it this null here. 60 00:03:16,090 --> 00:03:18,380 Return group names. 61 00:03:18,710 --> 00:03:19,520 OK. 62 00:03:20,160 --> 00:03:22,990 Sup group position. 63 00:03:23,250 --> 00:03:29,280 So it's going to actually return the specific value that is inside of the specific position specific 64 00:03:29,340 --> 00:03:31,660 index actually of these Adli. 65 00:03:31,740 --> 00:03:32,410 OK. 66 00:03:32,640 --> 00:03:35,440 First we are referring to the name of this group names Aure. 67 00:03:35,760 --> 00:03:41,880 And then we are actually referring to this specific index or position. 68 00:03:42,270 --> 00:03:44,270 That is actually that is the inside of this at it. 69 00:03:44,280 --> 00:03:47,140 OK for example a sports computer food car or TV. 70 00:03:47,240 --> 00:03:47,790 OK. 71 00:03:47,820 --> 00:03:55,950 So if you are returning that specific value OK from this method get group and we have our Get child 72 00:03:55,950 --> 00:04:02,400 here and this method actually accepts our two arguments and this if actually returns a value of type 73 00:04:02,490 --> 00:04:03,130 Object. 74 00:04:03,180 --> 00:04:10,640 So here as you can see we need to actually return the values that are inside of these type names Ari. 75 00:04:10,690 --> 00:04:11,270 OK. 76 00:04:11,430 --> 00:04:14,550 So as you can see this is actually a two dimensional array. 77 00:04:14,610 --> 00:04:19,200 So here for this method I can just return to the name of that of a child names. 78 00:04:19,320 --> 00:04:20,050 OK. 79 00:04:20,070 --> 00:04:24,830 Stop as you can see we you have two arguments group position type position. 80 00:04:24,990 --> 00:04:27,430 So I can just type in group position. 81 00:04:27,900 --> 00:04:28,970 OK. 82 00:04:29,040 --> 00:04:32,730 Stop Child position. 83 00:04:33,060 --> 00:04:36,110 OK so this is actually the row and this is the column. 84 00:04:36,120 --> 00:04:42,060 So for example if we assigned the value 0 for this group position OK it's going to go inside of these 85 00:04:42,440 --> 00:04:43,200 tightenings. 86 00:04:43,230 --> 00:04:45,930 So this is the element zero. 87 00:04:45,960 --> 00:04:46,510 OK. 88 00:04:46,540 --> 00:04:47,540 Index 0. 89 00:04:47,730 --> 00:04:55,080 And if if we actually assign the value 0 for this child position is going to return this value boxing 90 00:04:55,470 --> 00:04:56,070 to us. 91 00:04:56,070 --> 00:04:56,820 OK. 92 00:04:57,360 --> 00:05:02,300 So in this if you are actually returning the value used other inside of these or child names. 93 00:05:02,310 --> 00:05:03,980 Aure OK good child. 94 00:05:04,250 --> 00:05:08,090 And we have another Meffert as you can see here gets group ID. 95 00:05:08,120 --> 00:05:11,180 So here I could just return to group position. 96 00:05:11,180 --> 00:05:12,050 That's OK. 97 00:05:12,290 --> 00:05:19,700 So at the group position is the group ID the actually the index of our values inside of this group names. 98 00:05:19,700 --> 00:05:20,290 OK. 99 00:05:20,540 --> 00:05:24,120 So these for example this is index 0 1 2 3 4. 100 00:05:24,230 --> 00:05:27,660 So these values would be the ID for these groupings. 101 00:05:27,680 --> 00:05:28,250 OK. 102 00:05:28,640 --> 00:05:36,010 So here as you can see I just returned to this group position and we have a child ID here. 103 00:05:36,050 --> 00:05:41,930 As you can see here and as you can see for the Smurfette get child I.D. You have these child position 104 00:05:41,960 --> 00:05:43,080 as an argument. 105 00:05:43,100 --> 00:05:47,670 So if you could just retain that value returned child position. 106 00:05:47,960 --> 00:05:48,730 OK. 107 00:05:49,130 --> 00:05:49,360 OK. 108 00:05:49,370 --> 00:05:55,290 So at this point he's going to return the specific index that are inside of this tightenings. 109 00:05:55,310 --> 00:05:59,570 Ari for example index 0 1 2 free and other values. 110 00:05:59,570 --> 00:06:00,090 OK. 111 00:06:00,320 --> 00:06:05,810 So these are these are the columns and these are as you can see these arrows are actually the laws that 112 00:06:05,870 --> 00:06:07,910 are inside of these child names Aure. 113 00:06:08,200 --> 00:06:08,580 OK. 114 00:06:08,630 --> 00:06:13,460 So if you are just returning to the index of the child position. 115 00:06:13,460 --> 00:06:14,030 OK. 116 00:06:14,120 --> 00:06:16,290 So these are the children of these. 117 00:06:16,300 --> 00:06:16,550 OK. 118 00:06:16,580 --> 00:06:21,850 These columns boxing kickboxing judo football basketball and other bodies. 119 00:06:22,070 --> 00:06:29,020 So here are as you can see we have this I.D. And here we have these has stable IDs. 120 00:06:29,180 --> 00:06:32,170 So the default implementation for this method is enough. 121 00:06:32,380 --> 00:06:33,230 OK. 122 00:06:33,560 --> 00:06:36,370 We don't need to actually override this method again. 123 00:06:36,590 --> 00:06:43,130 And here we don't and you actually are putting our own implementations. 124 00:06:43,310 --> 00:06:49,390 OK so now and as you can see here we can actually go to the web browser. 125 00:06:49,500 --> 00:06:50,060 OK. 126 00:06:50,280 --> 00:06:55,470 And he had as you can see this is our expandable adapter class and now I can actually search for the 127 00:06:55,470 --> 00:07:01,260 name of that specific Misfit's that I want to actually see the actually the description of that method. 128 00:07:01,260 --> 00:07:01,790 OK. 129 00:07:01,950 --> 00:07:07,340 So here I could just press on hold the command key and then press on the letter F on my keyboard. 130 00:07:07,560 --> 00:07:11,970 If you are using a Windows machine you need to actually hold the control key and and press on the letter 131 00:07:12,000 --> 00:07:13,570 F on your keyboard. 132 00:07:13,620 --> 00:07:19,380 And here inside the search bar as you can see I can get you to test for my specific methods has stable 133 00:07:19,590 --> 00:07:22,340 stable IDs. 134 00:07:22,620 --> 00:07:27,540 And as you can see here this is Meffert and this is actually an abstract method and the return type 135 00:07:28,050 --> 00:07:34,780 of this method actually is boolean and it says indicates there the height and group ids are stable across 136 00:07:34,890 --> 00:07:36,990 changes to the to the underlying data. 137 00:07:37,080 --> 00:07:39,910 OK so this is the description of the Smurfit OK. 138 00:07:39,990 --> 00:07:42,770 Let's actually go to the Android studio your ID. 139 00:07:42,870 --> 00:07:45,320 So we don't need to actually override. 140 00:07:45,390 --> 00:07:48,190 Actually we don't need to put our own implementations here. 141 00:07:48,240 --> 00:07:49,750 OK so let's see what. 142 00:07:49,760 --> 00:07:50,920 What is the other in my. 143 00:07:51,180 --> 00:07:53,350 And we have this great group view. 144 00:07:53,700 --> 00:07:54,280 OK. 145 00:07:55,690 --> 00:08:00,130 And here as you can see if it actually returns a value of type view. 146 00:08:00,260 --> 00:08:00,810 OK. 147 00:08:01,090 --> 00:08:04,410 And this my friend actually accepts some arguments. 148 00:08:04,420 --> 00:08:08,100 So the first argument is a group position of type integer. 149 00:08:08,110 --> 00:08:12,020 The second argument is is expanded boolean. 150 00:08:12,190 --> 00:08:14,690 The first argument is convert's view view. 151 00:08:14,710 --> 00:08:21,050 So let's actually change the name of this argument to view and the first argument is the parent. 152 00:08:21,200 --> 00:08:24,810 OK so if we have these values as an argument of the Smurfette. 153 00:08:25,000 --> 00:08:25,530 OK. 154 00:08:25,960 --> 00:08:28,110 So let's actually implement this method here. 155 00:08:28,120 --> 00:08:33,040 So now I would actually pasting some lines of code here and then I'm going to explain to you what's 156 00:08:33,040 --> 00:08:34,530 going on here. 157 00:08:34,570 --> 00:08:38,890 So as you can see here we have actually pasted these lines of code here. 158 00:08:38,920 --> 00:08:39,650 OK. 159 00:08:40,030 --> 00:08:45,720 And as you can see we don't need this line of code written on here and here first about in line sixty 160 00:08:45,740 --> 00:08:46,620 eight. 161 00:08:46,690 --> 00:08:53,790 I actually created an object of type text view and the name of this object is TXI The View assignment 162 00:08:53,830 --> 00:08:54,840 operator new. 163 00:08:54,850 --> 00:08:58,360 Here I am initializing this object takes view context. 164 00:08:58,480 --> 00:09:01,780 So this takes view here as you can see this constructor. 165 00:09:01,780 --> 00:09:06,350 The constructor of this text view class actually needs the context. 166 00:09:06,400 --> 00:09:11,800 OK so I just assigned this context object that I actually declared inside of this class as you can see 167 00:09:11,800 --> 00:09:15,750 here in line 21 and here in line. 168 00:09:15,830 --> 00:09:20,200 I-69 I actually want to set some takes to this text view. 169 00:09:20,280 --> 00:09:20,720 OK. 170 00:09:20,800 --> 00:09:23,980 So takes the view that it takes group names. 171 00:09:24,100 --> 00:09:27,750 So this nymphet gets confused when I try to return to us. 172 00:09:27,940 --> 00:09:32,700 These are the values these group names as you can see here. 173 00:09:32,710 --> 00:09:33,270 OK. 174 00:09:33,610 --> 00:09:35,590 Sports computer TV. 175 00:09:35,590 --> 00:09:36,010 OK. 176 00:09:36,070 --> 00:09:40,740 So this Lifford is actually returning these values to the college of this method. 177 00:09:40,750 --> 00:09:41,280 OK. 178 00:09:41,560 --> 00:09:48,690 So we can see that this method is going to be called on each iteration of these values. 179 00:09:48,910 --> 00:09:49,380 OK. 180 00:09:49,420 --> 00:09:51,930 Sports computer food court TV. 181 00:09:51,940 --> 00:09:55,270 OK so if the name of this is get group view. 182 00:09:55,450 --> 00:09:55,760 OK. 183 00:09:55,780 --> 00:09:57,240 So these are the group views. 184 00:09:57,460 --> 00:09:58,040 OK. 185 00:09:58,270 --> 00:10:01,380 And we actually created a text for you as you can see here. 186 00:10:02,080 --> 00:10:03,460 That said text group names. 187 00:10:03,460 --> 00:10:05,910 So I actually referred to these are group names. 188 00:10:05,960 --> 00:10:12,040 Ari as you can see here these are the values that are inside of this emulator as you can see here and 189 00:10:12,040 --> 00:10:15,950 here I actually put in a pair a pair of brackets. 190 00:10:16,030 --> 00:10:17,950 Group position as you can see here. 191 00:10:17,950 --> 00:10:23,530 So it's going to get you to return the specific value that is inside of this specific index or a specific 192 00:10:23,530 --> 00:10:25,200 position of this group names. 193 00:10:25,600 --> 00:10:27,560 OK so you can see these values here.