1 00:00:00,480 --> 00:00:06,630 So as you can see here this is the line of code that I pasted here and here I referred to the name of 2 00:00:06,630 --> 00:00:08,890 this class preference manager. 3 00:00:09,000 --> 00:00:13,310 OK so this class is going to actually manage the preferences in our Android application. 4 00:00:13,390 --> 00:00:19,200 OK so for example example when a user wants to actually change the settings of the application we need 5 00:00:19,200 --> 00:00:24,180 to actually use this class free France manager in order to manage these sitting. 6 00:00:24,180 --> 00:00:27,570 So this is very important that we actually use this glass. 7 00:00:27,690 --> 00:00:31,110 So prevents manager that set default values. 8 00:00:31,110 --> 00:00:32,940 So what does this method do this. 9 00:00:33,000 --> 00:00:39,990 If it actually is going to actually specify the default values for the first time that our application 10 00:00:39,990 --> 00:00:43,490 is actually installed inside our application. 11 00:00:43,530 --> 00:00:49,740 So unhallowed majorly closed this application and now let's actually uninstall and install this application 12 00:00:49,740 --> 00:00:50,330 here. 13 00:00:53,370 --> 00:00:54,030 OK. 14 00:00:54,270 --> 00:00:58,460 And let's actually run our project again and let's install our project here. 15 00:00:58,470 --> 00:01:01,090 Our application on this emulator here again. 16 00:01:01,170 --> 00:01:07,740 So as you can see here this is our application and this is for the first time that our application is 17 00:01:07,740 --> 00:01:09,810 actually running on this emulator. 18 00:01:10,110 --> 00:01:18,510 So now we need to actually read some of the actually preferences some of the settings that we initially 19 00:01:18,540 --> 00:01:22,180 assigned to this quiz underline preferences that exempt. 20 00:01:22,200 --> 00:01:24,750 So insight is always underlying prefer preferences that is. 21 00:01:24,770 --> 00:01:30,800 And as you can see we have a list preference or multi multi-select preference and other and other less 22 00:01:30,810 --> 00:01:31,350 preference. 23 00:01:31,380 --> 00:01:33,550 And finally another list preference. 24 00:01:33,570 --> 00:01:39,620 So as you can see here for each of these components as you can see I provided a default value right. 25 00:01:39,720 --> 00:01:45,130 A default value for example for the colors are provided the black color for the font. 26 00:01:45,180 --> 00:01:50,880 I provide the default font and for other components I also provided a default value. 27 00:01:51,210 --> 00:01:52,410 So why do they do that. 28 00:01:52,410 --> 00:01:59,820 Because for the first time that our application is actually running on the user's device or application 29 00:01:59,880 --> 00:02:06,740 the Android device is going to actually read the default values for the components for these radio buttons 30 00:02:06,780 --> 00:02:13,230 or for these for these checkboxes and the default values is going to be for example determine the background 31 00:02:13,230 --> 00:02:14,440 color of the quiz. 32 00:02:14,530 --> 00:02:15,030 OK. 33 00:02:15,060 --> 00:02:20,430 So that default value for the first time is really important because the user is actually running the 34 00:02:20,430 --> 00:02:21,900 application for the first time. 35 00:02:22,170 --> 00:02:28,860 And we must actually specify the default value for example for the backend on color or for the front 36 00:02:28,920 --> 00:02:36,270 of the text of the buttons or for example how many options we want to show to the user in order to actually 37 00:02:36,360 --> 00:02:44,430 guess the name of the animal or for example we may we may want to we may want to specify the type of 38 00:02:44,430 --> 00:02:48,140 the animals that we want to actually put inside the squeeze. 39 00:02:48,150 --> 00:02:53,070 So this is very important that we specify a default value and inside this main activity that double 40 00:02:53,070 --> 00:02:58,900 file here as you can see that Savoye we use this class your preference manager in order to set those 41 00:02:58,950 --> 00:03:04,900 default values inside this uncreate method of this main activity that Java class as you can see. 42 00:03:04,920 --> 00:03:10,200 So preference manager that set default values and dismiss that as she accepts free arguments. 43 00:03:10,200 --> 00:03:10,730 Right. 44 00:03:10,800 --> 00:03:13,510 The first argument is is going to be the context. 45 00:03:13,510 --> 00:03:17,080 So the context is this class right main activity that this. 46 00:03:17,130 --> 00:03:22,380 So this is going to be the context that we are going to actually set the default values and for the 47 00:03:22,380 --> 00:03:29,220 second argument we need to specify the actual preferences file that we provided inside our project so 48 00:03:29,220 --> 00:03:36,100 that this class is going to read what those default values from this exemplified so are that examine 49 00:03:36,390 --> 00:03:42,750 that cuius underline preferences so this is the name of this class that we of this vitamine file that 50 00:03:42,750 --> 00:03:45,100 we created inside our project right. 51 00:03:45,120 --> 00:03:50,150 So our That is XML that is underlying preferences at the end is deferred argument. 52 00:03:50,160 --> 00:03:52,940 So what does this argument do. 53 00:03:53,070 --> 00:03:59,160 Now let me show you that for example if you actually call this method again a preference manager that 54 00:03:59,340 --> 00:04:04,440 set default values and then as you can see it is going to show us the arguments so as you can see here 55 00:04:04,740 --> 00:04:11,830 the first argument is actually of type Boolean right and the assigned value falls for the first argument. 56 00:04:11,940 --> 00:04:13,460 Now it says read again. 57 00:04:13,470 --> 00:04:15,690 So the name of this argument is read again. 58 00:04:15,690 --> 00:04:16,910 And what does this mean. 59 00:04:16,920 --> 00:04:24,370 This means that that for the first time our application is running on the user's device and our the 60 00:04:24,960 --> 00:04:29,830 and relativize is going to actually delete those default values from this quiz Underland preferences 61 00:04:29,840 --> 00:04:30,840 that is am I right. 62 00:04:31,110 --> 00:04:38,190 So what happens when the user actually is running the application for actually multiple times for the 63 00:04:38,190 --> 00:04:38,970 next time. 64 00:04:39,000 --> 00:04:39,270 Right. 65 00:04:39,270 --> 00:04:43,460 For example one hour later or for example 10 days later. 66 00:04:43,650 --> 00:04:50,430 In that case as you can see we dont want the application we dont want the device the Android device 67 00:04:50,430 --> 00:04:53,640 to lead to Leto's the default values from there. 68 00:04:53,680 --> 00:04:59,550 This is underlined preferences that are similar because they use it may have actually changed those 69 00:04:59,670 --> 00:05:00,380 values. 70 00:05:00,390 --> 00:05:05,390 OK to use it may have actually to change the background color of the query or use that a man may actually 71 00:05:05,430 --> 00:05:06,160 changed. 72 00:05:06,180 --> 00:05:12,300 I mean have actually changed the front of the text of the buttons or the user may have actually changed 73 00:05:12,420 --> 00:05:20,280 kind of animals that he or she wants to be used in say the quiz or the user may have actually specified 74 00:05:20,640 --> 00:05:21,150 that. 75 00:05:21,150 --> 00:05:25,860 How many options how many guesses are going to be inside the quiz. 76 00:05:25,940 --> 00:05:33,570 So those preferences those settings are going to actually are going to be saved in say the shirt preferences 77 00:05:34,270 --> 00:05:35,700 inside another class. 78 00:05:35,700 --> 00:05:41,820 But here as you can see be assigned a value for us and this means that we dont want to read again after 79 00:05:42,360 --> 00:05:47,310 the user has actually installed the application on the device and they use it for example is running 80 00:05:47,550 --> 00:05:49,640 the application on the device. 81 00:05:49,830 --> 00:05:55,430 And for the next time that the user is actually in the application on the device we dont want to read 82 00:05:55,570 --> 00:05:59,350 preferences to settings from these cuius underling preferences again. 83 00:05:59,380 --> 00:06:05,980 So thats why we assign de-value falls for the first argument which is a Boolean read again right. 84 00:06:06,010 --> 00:06:12,100 We just want to read those default values for the first time that the user is actually running the application 85 00:06:12,360 --> 00:06:12,960 and so forth. 86 00:06:13,090 --> 00:06:18,940 And for the next times of you're going to actually provide some other values and then I'm going to show 87 00:06:18,940 --> 00:06:19,260 you that. 88 00:06:19,270 --> 00:06:23,860 But for now I just know that we assign the value false for the read again argument. 89 00:06:23,860 --> 00:06:27,200 So now let me paste in some lines of code here. 90 00:06:27,250 --> 00:06:28,740 Inside this uncreate my feet. 91 00:06:28,750 --> 00:06:31,820 And then I'm going to explain to you what's going on here. 92 00:06:32,760 --> 00:06:37,040 So as you can see here these are the lines of code that I pasted here. 93 00:06:37,080 --> 00:06:45,420 So as you can see here I refer to the name of this class preference manager that get default shirt preferences. 94 00:06:45,570 --> 00:06:45,780 Right. 95 00:06:45,910 --> 00:06:46,300 Right. 96 00:06:46,300 --> 00:06:51,770 Here we want to get the shirt preferences of our application inside the user's device. 97 00:06:51,780 --> 00:06:57,870 So this is really important because when ever the use that is actually changing the settings of the 98 00:06:57,870 --> 00:07:05,110 quiz animal or get it they're going to actually save those changes to these shared preferences. 99 00:07:05,220 --> 00:07:11,730 So it's very important that we get this shows preferences and as you can see we need to pass this argument 100 00:07:11,790 --> 00:07:12,990 main activity that these. 101 00:07:12,990 --> 00:07:15,150 So this is going to be the context. 102 00:07:15,150 --> 00:07:15,770 Right. 103 00:07:16,110 --> 00:07:21,450 And as you can see I am calling an other method and these are shared preferences. 104 00:07:21,510 --> 00:07:22,200 Right. 105 00:07:22,200 --> 00:07:28,520 So main activity that these dot legis there on shared preferences change the center. 106 00:07:28,710 --> 00:07:30,740 So what that is what does this mean. 107 00:07:30,810 --> 00:07:37,440 This means that we are going to create our listener for the changes of our settings. 108 00:07:37,620 --> 00:07:38,180 Right. 109 00:07:38,190 --> 00:07:44,580 So diskless main activity is going to be notified when ever the user is actually changing the settings 110 00:07:44,580 --> 00:07:45,480 of the application. 111 00:07:45,480 --> 00:07:49,860 So now let me show you Let me show you that in say the emulator. 112 00:07:49,890 --> 00:07:53,520 So now as you can see here our application is running on the simulator. 113 00:07:53,520 --> 00:07:58,860 And if I click on the Settings button here now for example if I want to actually change the background 114 00:07:58,890 --> 00:08:03,110 color of the Queen for example change it to white. 115 00:08:03,120 --> 00:08:09,600 Now as you can see here it says new changes are applied and this means that this class main activity 116 00:08:09,600 --> 00:08:14,070 here is going to be notified when ever the settings is changed. 117 00:08:14,070 --> 00:08:21,090 For example whenever the background color is changed all the fault of the texts of the guest buttons 118 00:08:21,360 --> 00:08:25,800 are actually changed or of for example the types of animal is actually changed. 119 00:08:25,800 --> 00:08:26,420 Right. 120 00:08:26,460 --> 00:08:29,040 Or we can actually change the number of guesses. 121 00:08:29,070 --> 00:08:35,850 So this means that here you are actually creating a listener inside this main activity class to those 122 00:08:35,850 --> 00:08:36,640 changes. 123 00:08:36,640 --> 00:08:42,050 We are going to be notified to those changes so that we can actually respond to those changes. 124 00:08:42,150 --> 00:08:47,610 So now if I click on dispatch button here as you can see now the background color is white and this 125 00:08:47,610 --> 00:08:55,110 means that the main activity class is actually notified to that change and the background color is white 126 00:08:55,260 --> 00:09:03,260 according to that setting according to the change that the user has actually made here in say the settings 127 00:09:03,270 --> 00:09:04,860 activity. 128 00:09:04,860 --> 00:09:11,760 So hopefully that makes sense and its very important that we create our listener for this. 129 00:09:11,880 --> 00:09:14,370 Listen for this shirt preferences. 130 00:09:14,780 --> 00:09:19,840 So preference managers that get default shirt preferences so here we are actually getting the shared 131 00:09:19,860 --> 00:09:24,680 preferences and then we are calling a method on this show preferences. 132 00:09:24,700 --> 00:09:32,100 So that register on shared preferences change listener and then if you are passing this listener to 133 00:09:32,100 --> 00:09:32,870 dismiss it. 134 00:09:33,060 --> 00:09:38,070 So we havent created this listener yet inside this class so we need to create this listener inside this 135 00:09:38,070 --> 00:09:40,660 class settings change listener right. 136 00:09:40,800 --> 00:09:49,020 So now let's actually copy this settings change the center here and now let's scroll down here and then. 137 00:09:49,020 --> 00:09:50,890 Now inside this class. 138 00:09:50,940 --> 00:09:56,190 So before the end in calibrates of these class classes as you can see we have this mean activity the 139 00:09:56,200 --> 00:10:03,220 class and before the end in curly brace of this class now we're going to create a listener for that 140 00:10:03,350 --> 00:10:06,020 for those changes in say the settings activity. 141 00:10:06,050 --> 00:10:06,630 Right. 142 00:10:06,660 --> 00:10:08,990 A shared preferences change listener. 143 00:10:09,000 --> 00:10:10,240 This is really important. 144 00:10:10,260 --> 00:10:20,400 So here just typing private shared preferences dot on shared preferences change listener. 145 00:10:20,880 --> 00:10:24,920 And then here we need to specify a name for this listener right. 146 00:10:24,930 --> 00:10:27,160 So just paste it pistis value here. 147 00:10:27,220 --> 00:10:36,540 Settings change the listener and then put an assignment operator here new again shared preferences that 148 00:10:36,860 --> 00:10:45,420 as you can see should be Finance's dot on shirt preferences change Listen here and now just open and 149 00:10:45,420 --> 00:10:51,400 close the listener by by putting an opening curly brace followed by a closing curly brace. 150 00:10:51,420 --> 00:10:56,780 So now it may actually create a new line here and now we can actually see disvalue here. 151 00:10:56,940 --> 00:11:00,310 Private shared preferences that aren't shared. 152 00:11:00,300 --> 00:11:01,900 Preferences change the listener. 153 00:11:01,980 --> 00:11:05,480 So here we are going to create a listener to those changes. 154 00:11:05,500 --> 00:11:10,190 Inside these shows preferences and in Amy's settings changed the center right. 155 00:11:10,200 --> 00:11:16,270 The same name that be specified here inside is on create Smurfit settings change to listener right. 156 00:11:16,350 --> 00:11:24,180 So now I put an assignment operator here new shared preferences that aren't shared preferences but that 157 00:11:24,220 --> 00:11:26,060 unshipped preference change listener. 158 00:11:26,190 --> 00:11:31,590 Right so now we are inside this inside the curly braces unopen opening curly brace followed by a closing 159 00:11:31,590 --> 00:11:35,710 curly brace and now as you can see here we have an error. 160 00:11:35,730 --> 00:11:39,720 So here we are actually creating an anonymous inner class right. 161 00:11:39,730 --> 00:11:47,040 I told you about anonymous classes in Java in the previous tutorials and now you know what our anonymous 162 00:11:47,180 --> 00:11:47,660 classes. 163 00:11:47,670 --> 00:11:55,130 And here you are creating an anonymous class that actually conforms to this interface. 164 00:11:55,160 --> 00:12:01,820 As you can see here unshared friends change to the center and now you need to actually provide the abstract 165 00:12:01,820 --> 00:12:06,530 method that we have inside this interface and shared to prevent a strange listener. 166 00:12:06,530 --> 00:12:09,520 So what is that an abstract Meffert that abstract. 167 00:12:09,530 --> 00:12:10,600 Is that abstract. 168 00:12:10,610 --> 00:12:13,430 If it is an shared preference change listener. 169 00:12:13,520 --> 00:12:19,720 So if you need to write this move it here and at the end as you can see if we have this incredible piece 170 00:12:19,760 --> 00:12:25,180 of this listener right we need to put up a semicolon here and as you can see here the error is gone 171 00:12:25,520 --> 00:12:26,530 so we override it. 172 00:12:26,530 --> 00:12:29,470 This method here inside these anonymous inner class. 173 00:12:29,470 --> 00:12:32,110 So here we have an anonymous class. 174 00:12:32,180 --> 00:12:40,300 Right and this anonymous class is actually conforming to this on a shared friends change listener interface. 175 00:12:40,640 --> 00:12:46,400 And because that anonymous in a class is actually conforming to this interface we need to actually provide 176 00:12:46,400 --> 00:12:50,080 the abstract method that we have inside this interface right. 177 00:12:50,180 --> 00:12:56,660 So here as you can see we have this method here inside these anonymous class as you can see that it 178 00:12:56,660 --> 00:13:00,720 isn't if it is actually public Woit on shared preference changed. 179 00:13:00,770 --> 00:13:06,500 So this is going to be called whenever it is the use that is actually has changed the preferences of 180 00:13:06,500 --> 00:13:08,030 the application. 181 00:13:08,030 --> 00:13:11,140 So as you can see here we have these preferences. 182 00:13:11,150 --> 00:13:15,040 So for example the user change the format. 183 00:13:15,210 --> 00:13:19,370 And if I click on this back button he had as he can't see the font is changed right. 184 00:13:19,760 --> 00:13:23,960 So this is going to be called when ever the use of changes to preferences. 185 00:13:23,960 --> 00:13:29,900 So on shirtsleeve friends change and the it accepts two arguments the first one is shared preferences 186 00:13:30,230 --> 00:13:32,840 and the second one is the key right. 187 00:13:32,930 --> 00:13:39,680 So now later we will be actually putting more logic's inside this method for now just put these lines 188 00:13:39,680 --> 00:13:40,640 of code here. 189 00:13:40,980 --> 00:13:43,720 And now let's actually scroll to the top here. 190 00:13:43,760 --> 00:13:47,020 As you can see now the error is gone right.