1 00:00:04,200 --> 00:00:05,200 Welcome back. 2 00:00:05,560 --> 00:00:09,160 All right we've created the adapter for our reports. 3 00:00:09,560 --> 00:00:11,560 Now we need to check if it works. 4 00:00:12,360 --> 00:00:14,660 We'll be using a ViewModel eventually, 5 00:00:15,060 --> 00:00:19,060 but it's easier to test the adapter by creating an activity to use it. 6 00:00:19,560 --> 00:00:22,060 We need to create the activity anyway. 7 00:00:22,060 --> 00:00:24,360 And if we write our functions correctly, 8 00:00:24,360 --> 00:00:27,960 we can just move them into the ViewModel when we're ready to create it. 9 00:00:29,160 --> 00:00:31,660 We've already created the layouts for the activity, 10 00:00:31,660 --> 00:00:34,660 but we can still use the activity wizard for this class, 11 00:00:35,160 --> 00:00:37,660 we'll just delete the layouts that the wizard creates. 12 00:00:38,460 --> 00:00:39,960 Right click the package name, 13 00:00:42,360 --> 00:00:45,960 and choose new, activity, basic activity. 14 00:00:51,760 --> 00:00:54,120 Call the class DurationsReport. 15 00:00:58,480 --> 00:01:02,280 Remember to set the hierarchical parent to main activity. 16 00:01:07,980 --> 00:01:09,780 It's not the end of the world if you forget, 17 00:01:10,280 --> 00:01:13,480 you'll just have to edit the manifest and add the parent activity. 18 00:01:13,880 --> 00:01:15,380 Click finish to continue. 19 00:01:18,580 --> 00:01:22,580 You may get a dialogue like this one with some warnings about conflicts. 20 00:01:22,980 --> 00:01:26,180 I suspect this is a minor fault with the template code. 21 00:01:26,540 --> 00:01:28,900 Because if you check this class carefully, 22 00:01:29,260 --> 00:01:33,060 the one that's wanted is the same as the one that it already is. 23 00:01:33,720 --> 00:01:36,020 If you do get this, you can make a note of it 24 00:01:36,270 --> 00:01:38,170 and refer to it if you get problems. 25 00:01:38,720 --> 00:01:42,520 I think it popped up because there's no space before the closing 26 00:01:42,520 --> 00:01:45,820 backslash in the already is style. 27 00:01:46,620 --> 00:01:49,120 Xml doesn't require a space there, 28 00:01:49,480 --> 00:01:51,680 but it looks like the template codes 29 00:01:51,680 --> 00:01:55,280 just performed a basic search, which hasn't allowed for that. 30 00:01:55,640 --> 00:01:59,640 Anyway enough speculation. Let's proceed anyway. 31 00:02:02,940 --> 00:02:07,340 When android studio has finished creating the activity, close the layout. 32 00:02:11,000 --> 00:02:15,100 We're going to delete contentdurationsreport.xml soon 33 00:02:15,100 --> 00:02:18,600 because we've already created the layout that we'll use for the reports. 34 00:02:19,260 --> 00:02:21,860 All right. This is going to be a bit quick and dirty. 35 00:02:22,360 --> 00:02:24,560 The code we'll reuse will be fine, 36 00:02:24,810 --> 00:02:28,800 but the oncreate function probably isn't how you should write the code 37 00:02:28,800 --> 00:02:29,900 in a production app. 38 00:02:30,300 --> 00:02:33,400 I'll mention that when we get to it. When we do this properly, 39 00:02:33,400 --> 00:02:36,700 we'll want to allow the data to be sorted on the various columns. 40 00:02:37,250 --> 00:02:39,910 I'll create an enum for the column names 41 00:02:39,910 --> 00:02:42,110 to make it easier to see what we're doing. 42 00:02:42,510 --> 00:02:44,810 I'll also add the usual log tag. 43 00:02:59,510 --> 00:03:02,810 Next, we need to declare a variable for our adapter 44 00:03:03,210 --> 00:03:05,810 and also the cursor that will hold the data. 45 00:03:06,010 --> 00:03:09,310 I'll make the sort order default to the name column. 46 00:03:24,010 --> 00:03:27,510 We're also going to display records between a range of dates 47 00:03:28,310 --> 00:03:31,910 that will either be for an entire week or a single day. 48 00:03:32,410 --> 00:03:35,290 We'll do that by changing the selection arguments 49 00:03:35,290 --> 00:03:37,490 that we pass to the content resolver. 50 00:03:46,990 --> 00:03:49,190 I've hard coded the date range there. 51 00:03:49,850 --> 00:03:53,650 We'll be allowing the user to choose dates once everything's working properly, 52 00:03:53,650 --> 00:03:57,550 but for now I've just used the timestamps for the 1st 53 00:03:57,550 --> 00:03:59,150 to the 31st of May. In 54 00:03:59,850 --> 00:04:04,840 the oncreate function, we'll delete the floating action button code. 55 00:04:04,840 --> 00:04:09,830 I'll replace it with a call to setDisplayHomeAsUpEnabled 56 00:04:10,030 --> 00:04:11,330 and pass true. 57 00:04:18,990 --> 00:04:23,390 That adds the up bar to the toolbar to let us return to main activity. 58 00:04:23,940 --> 00:04:26,140 The code to initialize the adapter 59 00:04:26,140 --> 00:04:29,140 and associate it with the RecyclerView is standard. 60 00:04:29,500 --> 00:04:31,500 We've done the same thing a few times now. 61 00:04:41,500 --> 00:04:44,360 There's one more change to make to oncreate. 62 00:04:45,020 --> 00:04:47,620 We need to load the data into our cursor. 63 00:04:48,170 --> 00:04:52,470 I'm going to create a function to do that. I'll call it load data 64 00:04:52,970 --> 00:04:54,970 and add it below oncreate. 65 00:05:53,630 --> 00:05:56,510 This is very close to the final version of the function 66 00:05:56,510 --> 00:05:58,710 that we're going to use in our ViewModel class. 67 00:05:59,310 --> 00:06:03,310 It starts by setting order to the appropriate column that we want to order by 68 00:06:03,810 --> 00:06:05,410 using a when expression. 69 00:06:06,110 --> 00:06:09,370 We pass order to the content resolver's query function 70 00:06:09,370 --> 00:06:10,490 to sort the data. 71 00:06:11,590 --> 00:06:14,290 The call to query shouldn't need any explanation. 72 00:06:14,290 --> 00:06:15,790 We've done this a few times now. 73 00:06:16,450 --> 00:06:19,650 Remember that passing null for the projection 74 00:06:19,650 --> 00:06:22,010 will include every column in the data. 75 00:06:22,450 --> 00:06:25,450 That's usually what you want to do when you're using a database view. 76 00:06:25,950 --> 00:06:27,830 If you don't want any of the columns, 77 00:06:27,830 --> 00:06:30,430 you probably wouldn't have included them in the view. 78 00:06:31,090 --> 00:06:34,690 Of course, there are times when you want to use the same view 79 00:06:34,690 --> 00:06:35,890 for different purposes. 80 00:06:36,290 --> 00:06:38,990 In that case, you can provide a projection. 81 00:06:39,490 --> 00:06:41,790 But it's handy not having to bother setting one up. 82 00:06:42,090 --> 00:06:45,990 We wrote our SwapCursor function to return the old cursor 83 00:06:45,990 --> 00:06:48,490 when we provide a new one to the adapter. 84 00:06:49,090 --> 00:06:52,080 That allows us to call close on the old cursor 85 00:06:52,080 --> 00:06:53,680 to avoid leaking the resource. 86 00:06:54,480 --> 00:06:56,380 That's an acceptable thing to do. 87 00:06:57,180 --> 00:07:00,780 The cursor was created by the DurationsViewModel class, 88 00:07:01,280 --> 00:07:02,680 but that class doesn't use it. 89 00:07:03,340 --> 00:07:07,040 This DurationsReport class uses it for the adapter 90 00:07:07,040 --> 00:07:09,640 and knows when the old cursors can be closed. 91 00:07:10,540 --> 00:07:13,240 But what happens when we close the activity 92 00:07:13,600 --> 00:07:17,300 and return to main activity? Will our cursor get closed? 93 00:07:17,960 --> 00:07:19,860 The answer is no, it won't. 94 00:07:20,360 --> 00:07:24,660 It's our responsibility to free up any resources that we create. 95 00:07:25,160 --> 00:07:28,820 You may be tempted to close the cursor in the ondestroy function 96 00:07:29,320 --> 00:07:30,920 but that will cause problems. 97 00:07:31,920 --> 00:07:33,620 If you want to see what they are, 98 00:07:33,620 --> 00:07:36,620 add the ondestroy function at the end of the class. 99 00:07:57,620 --> 00:07:59,980 Calling swap cursor with null 100 00:07:59,980 --> 00:08:02,980 will return a reference to the existing cursor. 101 00:08:03,230 --> 00:08:06,480 If that's not null, we call its closed function 102 00:08:06,480 --> 00:08:07,780 to free up the resource. 103 00:08:08,780 --> 00:08:12,980 If you fully understand the various life cycles, you'll spot the problem here. 104 00:08:13,780 --> 00:08:16,780 Don't worry if you're not quite that comfortable with the life cycles yet, 105 00:08:17,280 --> 00:08:19,280 you'll spot the problem when the app crashes. 106 00:08:19,880 --> 00:08:21,080 If you want to try that, 107 00:08:21,080 --> 00:08:24,680 rotate the device while viewing the reports to cause the crash. 108 00:08:26,180 --> 00:08:30,170 Remember that the cursor is created by the DurationsViewModel 109 00:08:30,170 --> 00:08:32,870 and that will survive the configuration change, 110 00:08:33,370 --> 00:08:36,470 that means the database won't be re-queried 111 00:08:36,470 --> 00:08:39,169 and the adapter will try to read from this cursor, 112 00:08:39,720 --> 00:08:41,520 the one that we've just closed. 113 00:08:42,070 --> 00:08:46,060 I'll talk a bit more about this when we tidy the app up in the next section. 114 00:08:46,660 --> 00:08:49,260 For now, I'll just comment out this function. 115 00:08:53,660 --> 00:08:57,260 That will leave us with the resource leak, but we'll fix it later. 116 00:08:57,920 --> 00:09:01,220 Okay. Three more changes, and we're ready to test. 117 00:09:01,820 --> 00:09:05,420 The first is to call load data in our oncreate function. 118 00:09:11,620 --> 00:09:14,820 That's the bit I don't suggest you do in your final code. 119 00:09:15,480 --> 00:09:19,140 We're just testing our adapter here and our layouts too 120 00:09:19,140 --> 00:09:21,140 because we haven't seen them running yet. 121 00:09:21,910 --> 00:09:24,410 If you examine the logcat when we run the app, 122 00:09:24,410 --> 00:09:28,810 you'll see that the database is queried every time the device is rotated, 123 00:09:29,310 --> 00:09:33,860 that's fine for this test, and we're going to move load data into the ViewModel shortly. 124 00:09:34,560 --> 00:09:38,330 Okay. The next change is to use an intent 125 00:09:38,330 --> 00:09:41,330 to launch this activity when the menu item is tapped. 126 00:09:41,990 --> 00:09:44,090 We do that in main activity 127 00:09:44,090 --> 00:09:45,990 because that's where the main menu code is. 128 00:09:46,540 --> 00:09:50,340 We'll add another branch in OnOptionsItemsSelected. 129 00:10:10,000 --> 00:10:13,700 To tidy up, delete the unused content durations report 130 00:10:13,700 --> 00:10:15,700 xml layout file. 131 00:10:25,200 --> 00:10:29,000 That will cause an error in the activity durations report layout. 132 00:10:29,800 --> 00:10:33,200 You need to tell it to include task durations instead. 133 00:10:34,000 --> 00:10:36,500 Open up activities durations report, 134 00:10:39,500 --> 00:10:41,500 and select the include widget 135 00:10:42,380 --> 00:10:43,880 in the component tree. 136 00:10:44,280 --> 00:10:46,280 Using the symbol next to layout, 137 00:10:48,680 --> 00:10:50,680 select task durations. 138 00:10:54,680 --> 00:10:58,340 While we're here, delete the floating action button 139 00:10:58,340 --> 00:10:59,640 from the component tree. 140 00:11:03,300 --> 00:11:05,800 Okay. The app should now run. 141 00:11:10,200 --> 00:11:13,200 Tap the report icon the one that looks like an eye, 142 00:11:13,860 --> 00:11:16,860 that looks good and we've got a load of data for May. 143 00:11:17,410 --> 00:11:20,410 Scrolling the report should show different tasks. 144 00:11:23,910 --> 00:11:25,910 We can't sort the report at the moment, 145 00:11:26,460 --> 00:11:30,860 but the adapter looks to be working and our portrait layout lines up nicely. 146 00:11:31,660 --> 00:11:36,120 Rotate the emulator into landscape to check if landscape is also correct. 147 00:11:39,320 --> 00:11:41,020 If you get any problems, 148 00:11:41,020 --> 00:11:44,620 add logging to the adapter code to work out what's going wrong. 149 00:11:45,120 --> 00:11:47,000 If the data doesn't line up, 150 00:11:47,000 --> 00:11:50,000 check the margins and padding carefully in the layouts. 151 00:11:51,100 --> 00:11:53,300 The last test in this video 152 00:11:53,700 --> 00:11:55,700 is the up button on the toolbar. 153 00:11:56,500 --> 00:11:59,200 Tapping that should take us back to main activity. 154 00:12:01,800 --> 00:12:05,950 In the next video, we'll change the emulator to a different locale 155 00:12:05,950 --> 00:12:08,550 to make sure the dates are displayed correctly. 156 00:12:09,100 --> 00:12:10,100 I'll see you there.