1 00:00:00,760 --> 00:00:08,100 And I actually tested some padding for these values OK for the left padding This is one hundred for 2 00:00:08,100 --> 00:00:11,920 the top zero for the right zero and for the bottom zero. 3 00:00:11,940 --> 00:00:12,610 OK. 4 00:00:12,960 --> 00:00:16,460 And then I actually assign a color to this view. 5 00:00:16,620 --> 00:00:18,270 Ok text color. 6 00:00:18,570 --> 00:00:23,700 And as you can see here the colors of these are actually the color of these group names are actually 7 00:00:23,900 --> 00:00:24,510 blue. 8 00:00:24,750 --> 00:00:26,140 OK color blue. 9 00:00:26,520 --> 00:00:33,230 And actually sets a size to the stakes to view the size of these values is actually 40. 10 00:00:33,480 --> 00:00:34,110 OK. 11 00:00:34,380 --> 00:00:36,720 And I asked you to returned this takes you. 12 00:00:36,900 --> 00:00:37,310 OK. 13 00:00:37,350 --> 00:00:43,460 And as you can see here the Smurfette this gets group view if it actually returns a value of type view. 14 00:00:43,560 --> 00:00:44,060 OK. 15 00:00:44,250 --> 00:00:46,960 And this text is actually a subclass of view. 16 00:00:47,100 --> 00:00:47,490 OK. 17 00:00:47,580 --> 00:00:50,580 So we can actually turn this text view from the Smurfette. 18 00:00:50,700 --> 00:00:55,380 And as you can see here these are the values that this method actually retains. 19 00:00:55,470 --> 00:00:56,050 OK. 20 00:00:56,810 --> 00:00:58,270 So hopefully that makes sense. 21 00:00:58,370 --> 00:01:03,290 And now we need to actually return the children of these group views as you can see here sport class 22 00:01:03,590 --> 00:01:10,250 as you can see this sport view actually has some has our children as you can see here this sport if 23 00:01:10,250 --> 00:01:11,220 you have children. 24 00:01:11,240 --> 00:01:16,450 OK so if anything I should return these values from this good child human effort. 25 00:01:16,550 --> 00:01:17,260 OK. 26 00:01:17,540 --> 00:01:22,250 So this is for actually the returning the children of these group views. 27 00:01:22,250 --> 00:01:25,270 OK Computer as you can see here and other values. 28 00:01:25,310 --> 00:01:32,090 So here let's actually did it is written not here and now we can actually put in our own implementations 29 00:01:32,420 --> 00:01:33,950 inside of this method. 30 00:01:33,950 --> 00:01:38,010 So as you can see here this is actually the return a value of type view. 31 00:01:38,270 --> 00:01:42,550 And we have group position child position is last child. 32 00:01:42,560 --> 00:01:47,060 This is actually a boolean argument and we have this convert view. 33 00:01:47,120 --> 00:01:50,310 So we can actually to change these arguments and into view. 34 00:01:50,480 --> 00:01:53,190 And we have a view called a parent OK. 35 00:01:53,300 --> 00:01:56,900 The players are actually the parent of these children. 36 00:01:56,910 --> 00:02:02,090 OK so now I'm gonna paste in some lines of code here and then I'm going to explain to you what's going 37 00:02:02,090 --> 00:02:02,980 on here. 38 00:02:03,440 --> 00:02:07,400 So as you can see here these are the lines of code that they actually the pace that he had inside of 39 00:02:07,400 --> 00:02:08,130 this method. 40 00:02:08,270 --> 00:02:09,010 OK. 41 00:02:09,350 --> 00:02:13,510 And as you can see first of all again I created an takes object. 42 00:02:13,520 --> 00:02:13,880 OK. 43 00:02:13,910 --> 00:02:15,800 Takes the view assignment operator. 44 00:02:15,800 --> 00:02:22,040 Here I am initializing this object new text view and then for the constructor of this class I need to 45 00:02:22,040 --> 00:02:24,250 assign a value of type context. 46 00:02:24,260 --> 00:02:25,290 So this is context. 47 00:02:25,340 --> 00:02:26,000 OK. 48 00:02:26,390 --> 00:02:33,080 And then as you can see here inside of our emulator we have these techniques the view that takes the 49 00:02:33,080 --> 00:02:34,110 child names. 50 00:02:34,220 --> 00:02:37,820 So these are the child names as you can see we have this as a child names. 51 00:02:37,820 --> 00:02:41,750 This is actually a two dimensional array or an array of arrays. 52 00:02:41,750 --> 00:02:42,380 OK. 53 00:02:42,800 --> 00:02:45,130 So child names girl position. 54 00:02:45,140 --> 00:02:46,850 So if you have this group position here. 55 00:02:46,910 --> 00:02:47,620 OK. 56 00:02:47,650 --> 00:02:49,690 Sup child position. 57 00:02:50,010 --> 00:02:50,480 OK. 58 00:02:50,630 --> 00:02:55,470 So we can as you can see we have this sport boxing kickboxing judo football basketball. 59 00:02:55,670 --> 00:02:56,250 OK. 60 00:02:56,340 --> 00:02:58,610 So the group position is sports. 61 00:02:58,630 --> 00:02:58,940 OK. 62 00:02:58,940 --> 00:03:02,720 For example for their first group position this is zero. 63 00:03:02,720 --> 00:03:03,260 OK. 64 00:03:03,260 --> 00:03:09,060 So the this group position if this group position is zero this value would be sport. 65 00:03:09,320 --> 00:03:14,570 And as you can see if you have this Chinese position these are the columns as you can see we have these 66 00:03:14,780 --> 00:03:21,320 values that are inside of the actually index zero of these child names two dimensional array. 67 00:03:21,320 --> 00:03:21,820 OK. 68 00:03:21,920 --> 00:03:25,460 So it's going to return these values to us. 69 00:03:25,460 --> 00:03:25,850 OK. 70 00:03:25,940 --> 00:03:28,350 As you can see here these these are the values. 71 00:03:28,660 --> 00:03:33,870 And here I am actually setting some setting the padding of these a text view. 72 00:03:33,950 --> 00:03:34,270 OK. 73 00:03:34,300 --> 00:03:40,250 One hundred for the left 0 for the top zero for the right and a zero for the bottom. 74 00:03:40,490 --> 00:03:46,640 And as you can see the color of these child children as you can see here this takes views that are inside 75 00:03:46,640 --> 00:03:48,890 of this group as you can see this is red. 76 00:03:48,890 --> 00:03:51,710 These are the colors of these attacks. 77 00:03:51,890 --> 00:03:57,450 It is red as you can see and the size of these text views is actually 50. 78 00:03:57,870 --> 00:03:58,870 OK. 79 00:03:59,120 --> 00:04:00,760 So hopefully that makes sense. 80 00:04:00,890 --> 00:04:10,850 And I actually specified a certain click listen for this text view the view object as you can see here 81 00:04:11,120 --> 00:04:13,990 if I click on these children is going I should respond. 82 00:04:14,060 --> 00:04:14,470 OK. 83 00:04:14,570 --> 00:04:16,340 But there is an error here. 84 00:04:16,550 --> 00:04:23,330 So here I actually created a tossed object toast that make text Our first we need to specify the context 85 00:04:24,260 --> 00:04:29,410 and second we need to actually specify the text that you want to actually show to the user. 86 00:04:29,510 --> 00:04:36,830 And the first argument is actually the length of our applet of the text the duration of the text that 87 00:04:36,830 --> 00:04:38,610 is actually shown to the user. 88 00:04:38,810 --> 00:04:41,570 And then we are calling the shome effect on these toast. 89 00:04:41,600 --> 00:04:45,920 So if I click on this for example each in here it says kickboxing here. 90 00:04:45,920 --> 00:04:46,460 OK. 91 00:04:46,670 --> 00:04:49,650 Boxing boxing basketball. 92 00:04:49,690 --> 00:04:50,880 Basketball OK. 93 00:04:51,170 --> 00:04:53,190 But as you can see here there is an error here. 94 00:04:53,210 --> 00:04:53,780 OK. 95 00:04:53,870 --> 00:04:56,020 And it says that you cannot. 96 00:04:56,020 --> 00:05:02,370 Valuable the view is X is accessed from within a class needs to be declared final. 97 00:05:02,540 --> 00:05:08,270 So as you can see here as I said earlier in this section that are when you create an inner class as 98 00:05:08,270 --> 00:05:13,280 you can see here we are creating an entire class an anonymous inner class and that in a class that anonymous 99 00:05:13,510 --> 00:05:17,540 class is actually implementing this article class in an interface. 100 00:05:17,570 --> 00:05:23,080 And because that class is implementing this interface it can actually overwrite the Smurfette here. 101 00:05:23,300 --> 00:05:30,320 So if we have this anonymous in a class and B inside of this or in a class we cannot refer to a value 102 00:05:30,380 --> 00:05:32,170 to a variable that is not final. 103 00:05:32,210 --> 00:05:32,670 OK. 104 00:05:32,810 --> 00:05:34,260 That is actually not constant. 105 00:05:34,310 --> 00:05:38,340 So here we need to actually declare this text view as final. 106 00:05:38,880 --> 00:05:41,830 OK and now as you can see the error is gone. 107 00:05:42,230 --> 00:05:42,800 OK. 108 00:05:42,800 --> 00:05:47,770 And here after this a Satanical lesson we are returning this TXI the view object. 109 00:05:47,780 --> 00:05:48,770 OK. 110 00:05:49,100 --> 00:05:50,780 And here we have another method. 111 00:05:50,810 --> 00:05:52,710 Is child selectable. 112 00:05:53,090 --> 00:05:56,310 So the default implementation is enough for this Meffert. 113 00:05:56,370 --> 00:06:02,130 If you want to actually find the description about this effort to actually go to the documentation as 114 00:06:02,130 --> 00:06:08,280 you can see here and here inside the search bar I can actually copy the name of this method and put 115 00:06:08,280 --> 00:06:09,250 it here. 116 00:06:09,840 --> 00:06:10,710 OK. 117 00:06:10,710 --> 00:06:11,930 As you can see this is the method. 118 00:06:12,000 --> 00:06:17,900 This is actually an abstract method and the return type of this if it is Boolean is child selectable. 119 00:06:18,030 --> 00:06:22,940 And this method actually accepts two arguments of type integer group position type position. 120 00:06:22,950 --> 00:06:29,450 And this is the description of this method where there is the child at the specified position is selectable. 121 00:06:29,670 --> 00:06:36,010 OK so we can specify that whether each child of this group use as you can see here are actually two 122 00:06:36,010 --> 00:06:37,250 selectable or not. 123 00:06:37,490 --> 00:06:44,070 OK but for this application it is enough the default implementation implementation is enough return 124 00:06:44,070 --> 00:06:51,180 false and now it's actually to go to the main activity that double file here and now let's actually 125 00:06:51,270 --> 00:06:56,570 create an object of these from these expandable adapter. 126 00:06:56,720 --> 00:06:57,310 OK. 127 00:06:57,720 --> 00:07:04,600 So here I can just type in expandable list view adapter and the name of this object is and expandable 128 00:07:04,600 --> 00:07:05,740 this view adapter. 129 00:07:05,910 --> 00:07:08,980 Or I could just name this object as adapter. 130 00:07:09,120 --> 00:07:15,050 OK it is simple assignment operator new expandable adapter. 131 00:07:15,270 --> 00:07:20,200 And as you can see inside the Prentice's for this constructed I need to specify the context. 132 00:07:20,220 --> 00:07:23,900 So inside is expendible adapter for the constructor of this class. 133 00:07:23,970 --> 00:07:29,810 I specified that this constructor actually accepts an argument of type context. 134 00:07:29,860 --> 00:07:37,750 OK so here of any to actually pass this context and this context with the past to this context instance 135 00:07:37,750 --> 00:07:38,880 worry about OK. 136 00:07:39,150 --> 00:07:45,710 So here again just typing our main activity that this. 137 00:07:46,110 --> 00:07:47,500 OK so this is the context. 138 00:07:47,520 --> 00:07:49,590 I mean I think that this this is our class. 139 00:07:49,890 --> 00:07:52,770 And here I can just type in expandable this view. 140 00:07:52,770 --> 00:07:57,420 So if you have this expandable view OK in say this content underline minute example here. 141 00:07:57,450 --> 00:07:59,340 This is our this view. 142 00:07:59,340 --> 00:08:05,760 Now we want to actually bind to data that we actually get from these expandable adapter and put that 143 00:08:05,820 --> 00:08:08,690 they are inside these expandable view. 144 00:08:08,700 --> 00:08:15,970 So here I can't just type in expandable list view that set adapter. 145 00:08:16,360 --> 00:08:16,990 OK. 146 00:08:17,010 --> 00:08:19,420 So here we need to specify the adapter. 147 00:08:19,500 --> 00:08:22,230 So we have this adapter here adapter. 148 00:08:22,690 --> 00:08:26,490 OK so now let's actually run our project and see what happens. 149 00:08:26,610 --> 00:08:32,020 So now I want to actually show you an important point about two dimensional Olly's. 150 00:08:32,250 --> 00:08:36,810 So here as you can see our application is actually running on the simulator. 151 00:08:36,900 --> 00:08:42,120 And if I actually click on this support group view you can see the children of this group view boxing 152 00:08:42,120 --> 00:08:48,530 kickboxing judo football basketball and if I actually click on these items I can see these tossed here 153 00:08:48,540 --> 00:08:49,590 kickboxing. 154 00:08:49,890 --> 00:08:53,010 And now let's actually click on the computer. 155 00:08:53,010 --> 00:08:54,570 Good view here. 156 00:08:55,170 --> 00:08:58,150 And as you can see here our application crashed. 157 00:08:58,140 --> 00:09:01,200 Unfortunately at 35 has stopped. 158 00:09:01,210 --> 00:09:03,950 So let's let's actually go to the log here at the bottom. 159 00:09:04,260 --> 00:09:12,320 And now we can see that here it says our That land that Arey index out of bounds. 160 00:09:12,330 --> 00:09:15,850 Exception OK lead free index free. 161 00:09:15,980 --> 00:09:21,690 So we actually accessed an index of an array that actually doesn't exist. 162 00:09:22,080 --> 00:09:22,610 OK. 163 00:09:22,770 --> 00:09:27,840 And here as you can see it says expandable view adapter does get Chinese view. 164 00:09:27,840 --> 00:09:33,740 So the error is actually the error is actually happened on this MFL tried to view Meffert. 165 00:09:33,750 --> 00:09:35,960 So if I click on this link here. 166 00:09:36,480 --> 00:09:40,660 Now we can see these are actually line of code. 167 00:09:40,680 --> 00:09:47,070 The error actually happened in this line of code and here I am actually getting the children of this 168 00:09:47,310 --> 00:09:54,220 group of group view here as you can see we have this view and we have these child names at it. 169 00:09:54,300 --> 00:09:59,880 So now as you can see here you have these get group count. 170 00:10:00,180 --> 00:10:00,710 OK. 171 00:10:00,870 --> 00:10:02,790 And we have these kids children challenge.