1 00:00:00,270 --> 00:00:04,610 So as you can see here these are the lines of code that I actually pasted here. 2 00:00:04,800 --> 00:00:10,240 So for example I want to actually delete of the first elements inside our list view. 3 00:00:10,320 --> 00:00:10,930 OK. 4 00:00:11,100 --> 00:00:16,590 So first of all we need to check that if you have actually any of the computer objects in sight are 5 00:00:16,650 --> 00:00:18,520 all computer at least OK. 6 00:00:18,600 --> 00:00:19,980 So if all computers. 7 00:00:19,980 --> 00:00:23,930 This is actually a list that holds all the computer objects in sight. 8 00:00:23,970 --> 00:00:25,030 It's too late. 9 00:00:25,080 --> 00:00:28,660 So if all computers start size is greater than zero. 10 00:00:28,740 --> 00:00:35,560 And this means that if we have at least one computer object in sight are all computers these are ok. 11 00:00:35,790 --> 00:00:41,670 If the number of objects in sight are all computers at least is actually greater than zero. 12 00:00:41,730 --> 00:00:46,980 Then if this expression evaluates to true then it's going to execute these lines of code here inside 13 00:00:46,980 --> 00:00:49,670 the curly braces of this statement. 14 00:00:49,710 --> 00:00:55,830 First of all it's going to actually remove the first element that exists inside these computers name 15 00:00:55,860 --> 00:00:57,550 at least as you can see here. 16 00:00:57,570 --> 00:01:03,420 Computers name that remove the first element is actually the index the value that we specify for the 17 00:01:03,420 --> 00:01:04,850 index 0 OK. 18 00:01:04,950 --> 00:01:11,190 And it's going to actually delete the value that is inside of the index 0 of these are a list and then 19 00:01:11,190 --> 00:01:16,100 we want to actually delete that object that computer object inside our school. 20 00:01:16,140 --> 00:01:19,710 OK so a database handler that deletes computer. 21 00:01:19,830 --> 00:01:24,270 Ok this is actually a method that we put inside our school I'D handler class. 22 00:01:24,270 --> 00:01:24,860 Right. 23 00:01:25,170 --> 00:01:29,770 So they tell us handler that deletes computer on here as you can see. 24 00:01:29,930 --> 00:01:34,990 I referred to the name of these all computers least that get zero. 25 00:01:35,040 --> 00:01:41,400 So you can actually delete the first object the first computer or object that we have inside of all 26 00:01:41,400 --> 00:01:43,760 computers at least as you can see here. 27 00:01:43,800 --> 00:01:44,430 OK. 28 00:01:44,580 --> 00:01:47,620 So here I specified the Index index zero. 29 00:01:47,640 --> 00:01:53,740 So it's going to delete the computed object that we have inside the index zero of all computers. 30 00:01:53,740 --> 00:01:54,860 At least here. 31 00:01:55,080 --> 00:01:55,590 OK. 32 00:01:55,770 --> 00:01:57,300 So it's going to delete that computer. 33 00:01:57,310 --> 00:02:03,030 So as you can see here I put this piece of code here in order in order to get the first computer object 34 00:02:03,030 --> 00:02:09,390 that we have inside our all computers list and it's going to actually delete that computer inside our 35 00:02:09,750 --> 00:02:10,440 database. 36 00:02:10,530 --> 00:02:11,210 OK. 37 00:02:11,610 --> 00:02:14,240 And here in line one hundred and six as you can see. 38 00:02:14,310 --> 00:02:20,130 I want to actually delete that value with that computer object from our all computers list. 39 00:02:20,160 --> 00:02:22,470 OK so all computers that remove. 40 00:02:22,470 --> 00:02:25,180 And here I specified the index zero. 41 00:02:25,290 --> 00:02:30,680 OK so it's going to remove that object computer object from our all computers list. 42 00:02:31,050 --> 00:02:32,810 And here we have an else statement. 43 00:02:32,910 --> 00:02:39,570 As you can see here statement means we don't have any of the computer objects inside our computers. 44 00:02:39,690 --> 00:02:43,280 So if this expression here evaluates to false. 45 00:02:43,320 --> 00:02:49,980 OK if we have no computer objects in sight are all computers at least then this statement here is going 46 00:02:49,980 --> 00:02:51,110 to be executed. 47 00:02:51,210 --> 00:03:00,330 And here we want to return from are from this case a statement is not going to actually execute the 48 00:03:00,330 --> 00:03:01,590 lines of code after this. 49 00:03:01,620 --> 00:03:02,610 A return statement. 50 00:03:02,610 --> 00:03:03,180 OK. 51 00:03:03,450 --> 00:03:06,450 So it's going to return out of this method. 52 00:03:06,540 --> 00:03:09,950 And it's not going to execute the lines of code after this statement. 53 00:03:09,960 --> 00:03:16,980 As you can see here and if I if I want to actually execute city AT&T that case here I need to click 54 00:03:16,980 --> 00:03:18,730 on that delete button once again. 55 00:03:18,800 --> 00:03:19,350 OK. 56 00:03:19,500 --> 00:03:21,720 So that's the meaning of return here. 57 00:03:21,750 --> 00:03:26,250 All told you about this written statement in the previous tutorial. 58 00:03:26,550 --> 00:03:28,350 And here we have this break statement. 59 00:03:28,350 --> 00:03:28,810 OK. 60 00:03:28,980 --> 00:03:34,040 So after this switch statement here as you can see we have the switch statement here. 61 00:03:34,050 --> 00:03:34,830 Right. 62 00:03:34,860 --> 00:03:35,700 So this is the kernel. 63 00:03:35,730 --> 00:03:39,530 These are the curly braces that are related to the switch statement. 64 00:03:39,540 --> 00:03:46,930 So after this three statement I can just refer to the name of this adapter object Dadds notify data 65 00:03:47,160 --> 00:03:48,260 set change. 66 00:03:48,540 --> 00:03:54,390 So this method is not if I said change is going to actually let the adapter know that we want to actually 67 00:03:55,180 --> 00:03:56,890 that the data is actually changed. 68 00:03:56,940 --> 00:03:57,510 OK. 69 00:03:57,750 --> 00:04:03,690 And it's going to update itself and it's going to actually show the updated values inside our list view. 70 00:04:03,690 --> 00:04:09,840 So if it is going to update the list view so that we can actually see the updated values for example 71 00:04:09,840 --> 00:04:16,890 if we use the phrase as an object into the database and it's that object is going to be for example 72 00:04:16,920 --> 00:04:22,950 added to the computer's name at a we need to call the Smurfette in order to see that object inside our 73 00:04:22,950 --> 00:04:24,330 list view otherwise. 74 00:04:24,360 --> 00:04:28,380 And if we don't call this method here is it after that notify changed. 75 00:04:28,440 --> 00:04:33,450 If it is not going I should update the list view and bitch and we would be not and we would not be able 76 00:04:33,450 --> 00:04:38,540 to actually see the object to see the added objects or the deleted objects. 77 00:04:38,550 --> 00:04:45,180 So this is very important that you actually put this piece of code here and after that notify data set 78 00:04:45,180 --> 00:04:45,680 changed. 79 00:04:45,690 --> 00:04:46,460 OK. 80 00:04:46,830 --> 00:04:51,570 So hopefully that makes sense so remember that here I put this piece of quote He had this line of quote 81 00:04:51,570 --> 00:04:54,100 he had inside this uncle for as you can see here. 82 00:04:54,270 --> 00:04:55,020 OK. 83 00:04:55,380 --> 00:04:57,000 So hopefully that makes sense. 84 00:04:57,030 --> 00:04:59,910 And now let's actually on our project and see what happens. 85 00:05:00,070 --> 00:05:05,680 So as you can see here our application is running on this emulator here and here as you can see we have 86 00:05:05,680 --> 00:05:08,850 these editrix see that and we have this at the bottom. 87 00:05:08,860 --> 00:05:09,910 And this delete button. 88 00:05:10,030 --> 00:05:13,850 So analysis actually assign a value for these computer name. 89 00:05:13,990 --> 00:05:17,470 So for the computer name I can just typing a match. 90 00:05:17,990 --> 00:05:25,490 And for the computer type I can just typing a desktop desktop computer. 91 00:05:26,230 --> 00:05:26,730 OK. 92 00:05:26,890 --> 00:05:29,830 And then here if I click on this add what's in here. 93 00:05:29,830 --> 00:05:33,710 Now as you can see this value is going to be added to our list view. 94 00:05:33,730 --> 00:05:37,220 I imagine Dasch desktop computer right. 95 00:05:37,270 --> 00:05:41,210 And if I click on this delete button here that's value is going to be deleted. 96 00:05:41,230 --> 00:05:47,410 So that may actually at that's about you again here you match and of for the computer type computer 97 00:05:47,500 --> 00:05:48,770 or this computer is. 98 00:05:48,820 --> 00:05:49,340 Excuse me. 99 00:05:49,360 --> 00:05:53,230 Desktop computer. 100 00:05:53,620 --> 00:05:55,000 And then click on Add. 101 00:05:55,480 --> 00:05:59,370 And again I want to actually add an order of audio for the computer name. 102 00:05:59,440 --> 00:06:10,220 So iPhone for example iPhone 7 and for the computer type I can just type in our mobile computer mobile 103 00:06:10,750 --> 00:06:17,560 computer and then if I click on this button here it's going to add value to our list view and for the 104 00:06:17,560 --> 00:06:18,230 computer. 105 00:06:18,300 --> 00:06:27,210 Again I want to add another value for example galaxy galaxy is six. 106 00:06:27,710 --> 00:06:35,610 And for the computer type I can just type in a more wide more wide computer. 107 00:06:36,190 --> 00:06:41,770 And here if I click on this and put in here that value is going to be added to Odlyzko view right. 108 00:06:41,770 --> 00:06:46,870 So now you can actually click on dispatch button here and if you actually click on these background 109 00:06:47,110 --> 00:06:51,340 applications and if I actually close this application now. 110 00:06:51,490 --> 00:06:58,530 Now if I open this application again here at 58 now here as you can see these data are actually deceived. 111 00:06:58,680 --> 00:06:59,180 OK. 112 00:06:59,280 --> 00:07:05,520 I actually added these data to my database and those that are actually being retrieved from the database 113 00:07:06,030 --> 00:07:07,080 and I can see those data. 114 00:07:07,080 --> 00:07:09,640 So those they thought actually saved inside the database. 115 00:07:09,990 --> 00:07:16,560 And if it's for example one of them and here for example I deleted all the computer artex and this one 116 00:07:16,560 --> 00:07:17,270 remains. 117 00:07:17,400 --> 00:07:23,370 And if I click on dispatch button here or if I actually close this application here completely and if 118 00:07:23,370 --> 00:07:25,650 I open the application again here. 119 00:07:25,710 --> 00:07:31,920 Now as you can see here this data is actually saved and those data that I actually deleted a few seconds 120 00:07:31,920 --> 00:07:33,850 ago are actually gone. 121 00:07:33,870 --> 00:07:34,340 OK. 122 00:07:34,470 --> 00:07:37,530 Those They are not here we just can't see the value here. 123 00:07:37,560 --> 00:07:38,400 OK. 124 00:07:38,880 --> 00:07:45,360 And in this way you can actually save your data or delete data from the database here as you can see 125 00:07:45,360 --> 00:07:50,950 in say this is your LATE handler class I actually added some other methods for example updates computer. 126 00:07:51,300 --> 00:07:56,850 You can use this method in order to update a specific item inside your list view. 127 00:07:56,920 --> 00:07:57,170 OK. 128 00:07:57,310 --> 00:08:01,780 Or for example get computers count or other methods. 129 00:08:01,800 --> 00:08:04,110 So this is how you can work with as too late. 130 00:08:04,110 --> 00:08:10,940 So for now just make sure that you actually learn all these concepts that taught you are in this tutorial. 131 00:08:11,000 --> 00:08:15,900 Please if you have any questions please post the discussion in the course and then I'll do my best to 132 00:08:15,900 --> 00:08:17,430 answer all of your questions. 133 00:08:17,490 --> 00:08:18,840 Thank you very much for watching. 134 00:08:18,870 --> 00:08:20,410 And I've seen the next tutorial.