1 00:00:05,500 --> 00:00:09,650 We've got a few more suggestions to sort out before we look at improving our app. 2 00:00:10,640 --> 00:00:13,640 In the CursorRecyclerViewAdapter class, 3 00:00:16,640 --> 00:00:19,940 there's a suggestion that we can inline count 4 00:00:20,300 --> 00:00:21,960 on line 88. 5 00:00:30,760 --> 00:00:32,360 We can use the light bulb to do that. 6 00:00:32,720 --> 00:00:35,120 We've got some unnecessary duplication in the 7 00:00:35,120 --> 00:00:37,120 OnBindViewHolder function. 8 00:00:39,720 --> 00:00:43,710 In the block of code on lines 76 to 82, 9 00:00:43,710 --> 00:00:46,370 we have to repeat cursor on each line. 10 00:00:47,170 --> 00:00:49,770 Kotlin provides the with statement 11 00:00:49,770 --> 00:00:51,770 to let us write that more concisely. 12 00:01:28,070 --> 00:01:29,270 That's a lot tidier. 13 00:01:30,070 --> 00:01:33,570 If your performing repeated property access isn't the same object, 14 00:01:33,870 --> 00:01:37,470 then "with" avoids having to repeat the object name each time. 15 00:01:38,370 --> 00:01:42,030 In durations report, we've got the same warning that we've already seen. 16 00:01:46,930 --> 00:01:50,130 ViewModelProviders has been deprecated. 17 00:01:51,430 --> 00:01:55,790 The import on line 13 should now be provider. 18 00:02:00,290 --> 00:02:03,190 There are two variables that can be inlined. 19 00:02:04,190 --> 00:02:06,290 Click on the ticks that are light gray 20 00:02:06,290 --> 00:02:09,289 in the right margin and use the light bulb to change the code. 21 00:02:20,690 --> 00:02:24,290 And there's an unnecessary cast on line 45. 22 00:02:34,890 --> 00:02:37,390 Finally, we left the commented out 23 00:02:37,390 --> 00:02:39,890 onDestroy function at the end of the class. 24 00:02:40,390 --> 00:02:41,690 This can also be deleted. 25 00:02:48,590 --> 00:02:50,390 These have all been simple changes. 26 00:02:50,940 --> 00:02:54,600 The warning in the DurationsViewModel is a bit more serious. 27 00:03:04,400 --> 00:03:07,400 It's saying that android.preference 28 00:03:07,400 --> 00:03:10,400 .preferencemanager has been deprecated. 29 00:03:10,900 --> 00:03:12,800 We've got those warnings on line 9 30 00:03:14,360 --> 00:03:15,960 and on line 43. 31 00:03:16,760 --> 00:03:18,010 You may not have this. 32 00:03:18,010 --> 00:03:22,410 If you created your project using androidx and didn't convert it to androidx, 33 00:03:23,010 --> 00:03:27,310 ideally, the conversion process would have fixed it to import from androidx. 34 00:03:27,710 --> 00:03:31,710 Before we fix this, we have to add the library to the dependencies 35 00:03:31,710 --> 00:03:35,010 section in the modules build.gradle file. 36 00:04:03,370 --> 00:04:04,470 Sync now, 37 00:04:06,350 --> 00:04:09,150 and we can change the import in DurationsViewModel. 38 00:04:22,150 --> 00:04:24,650 We're also potentially leaking a resource. 39 00:04:25,550 --> 00:04:29,810 Have a look at the LoadData function on line 182. 40 00:04:32,310 --> 00:04:34,510 In there, we create a cursor 41 00:04:34,510 --> 00:04:38,810 and store it in the database cursor MutableLiveData object. 42 00:04:39,060 --> 00:04:42,360 The durations activity does close this cursor 43 00:04:42,360 --> 00:04:43,860 when we add new data, 44 00:04:44,460 --> 00:04:46,460 but the cursor doesn't get closed otherwise. 45 00:04:47,210 --> 00:04:51,110 We really should close it when the ViewModel is no longer needed. 46 00:04:51,810 --> 00:04:56,110 The place to do that is in OnCleared, right at the end of the code. 47 00:05:07,410 --> 00:05:09,210 When we're finished with the ViewModel, 48 00:05:09,210 --> 00:05:11,810 we close the cursor before it's destroyed. 49 00:05:12,310 --> 00:05:14,210 I'm being a bit paranoid here. 50 00:05:14,210 --> 00:05:16,410 The cursor is owned by this class 51 00:05:16,410 --> 00:05:19,730 and will be destroyed when the instance of this class is destroyed. 52 00:05:20,130 --> 00:05:23,730 The only thing holding a reference to the cursor is the adapter. 53 00:05:24,430 --> 00:05:27,430 That's created by the durations report activity 54 00:05:27,430 --> 00:05:30,680 and will be destroyed when durations report is destroyed. 55 00:05:31,230 --> 00:05:34,430 A ViewModel outlives its activities and fragments, 56 00:05:34,630 --> 00:05:36,630 that's one of the reasons we use them. 57 00:05:36,930 --> 00:05:40,730 So there should be nothing that can be holding a reference to this cursor 58 00:05:41,030 --> 00:05:43,030 when the ViewModel gets destroyed. 59 00:05:43,430 --> 00:05:46,530 But it's always a good idea to be aware of the life cycles 60 00:05:46,530 --> 00:05:50,030 of the resources you create and tidy up after yourself. 61 00:05:51,230 --> 00:05:53,830 Next, open the SettingsDialog file. 62 00:05:58,330 --> 00:06:02,730 Our SettingsDialog class is also using the deprecated preference manager. 63 00:06:03,530 --> 00:06:07,030 Once again, change the import to come from androidx. 64 00:06:12,390 --> 00:06:16,890 The other change in here also probably happened when I converted the project. 65 00:06:17,390 --> 00:06:20,940 It was mentioned in the video at the time but this one was missed. 66 00:06:26,740 --> 00:06:30,400 We've got a redundant qualifier on line 32 67 00:06:30,400 --> 00:06:31,600 that can be deleted. 68 00:06:34,400 --> 00:06:38,000 Our SettingsDialog is an AppcompatDialogFragment 69 00:06:38,400 --> 00:06:42,000 and there's no need to qualify the reference to style_normal. 70 00:06:42,800 --> 00:06:45,600 And finally, in SettingsDialog, 71 00:06:45,600 --> 00:06:48,600 delete the OnDestroy function at the end of the class. 72 00:06:49,300 --> 00:06:53,100 It's only there so that we could check the dialogue was being destroyed in the logcat. 73 00:06:58,460 --> 00:07:01,260 There's a small change to make in the task file. 74 00:07:03,360 --> 00:07:06,560 We've got an empty class body in the task class 75 00:07:06,860 --> 00:07:08,220 and that can be deleted. 76 00:07:11,520 --> 00:07:16,420 The last class I'll tidy up in this video is the TaskTimerViewModel. 77 00:07:20,520 --> 00:07:23,320 That's also using the deprecated preference manager. 78 00:07:24,980 --> 00:07:26,780 Change the import to fix that. 79 00:07:28,580 --> 00:07:31,380 We can also lift an assignment out of the if 80 00:07:31,740 --> 00:07:33,340 in the TimeTask function. 81 00:07:47,440 --> 00:07:49,100 You can use a light bulb to do that. 82 00:07:50,200 --> 00:07:52,500 Finally, we should close the cursor. 83 00:07:53,160 --> 00:07:56,160 We did that in the DurationsViewModel class, 84 00:07:56,160 --> 00:07:59,660 and we should be consistent and make that same change 85 00:07:59,660 --> 00:08:01,360 in the TaskTimerViewModel. 86 00:08:15,860 --> 00:08:19,160 In the next video, we'll tidy up main activity 87 00:08:19,160 --> 00:08:22,160 and a couple of the contract classes. I'll see you there.