WEBVTT 00:00.080 --> 00:00.880 Welcome back. 00:00.880 --> 00:04.920 We succeeded in geocoding converting an address to lat long. 00:04.920 --> 00:14.040 Here we convert a state to a liberty address into a coordinate and display the Statue of Liberty. 00:14.360 --> 00:18.200 And now let's do a reverse geocoding. 00:18.200 --> 00:20.560 Converting lat long to an address. 00:20.560 --> 00:22.480 So give me a coordinate. 00:22.480 --> 00:24.520 I give you the address. 00:24.680 --> 00:27.080 For example, for the Eiffel Tower. 00:27.120 --> 00:28.400 Give me the coordinates. 00:28.400 --> 00:30.600 I give you the Eiffel Tower. 00:30.800 --> 00:39.440 For this, let me create another function here called reverse, which is of type suspend function. 00:39.520 --> 00:46.160 Reverse geocode takes two parameters a context and a lat. 00:46.200 --> 00:50.160 Long returns a string which is the address found. 00:50.200 --> 00:52.960 Return with context. 00:53.000 --> 00:55.880 dispatchers.io as you know. 00:56.000 --> 00:57.880 Suspend function. 00:58.120 --> 01:07.130 We mark this function as a coroutine function must be called from a coroutine or other suspend function, 01:07.370 --> 01:09.970 and the context is the first parameter. 01:10.010 --> 01:14.250 The left lung is the second parameter containing latitude and longitude. 01:14.290 --> 01:23.730 To convert, returns a string which is the address with context switches the coroutine to I o dispatcher 01:23.770 --> 01:26.730 optimized for disk or network operations. 01:26.890 --> 01:27.290 Why? 01:27.330 --> 01:36.330 Because geocoding involves system APIs that may block threads running it on dispatchers. 01:36.530 --> 01:40.250 IO avoids freezing for the UI. 01:40.490 --> 01:43.210 So here, let me make a new note. 01:43.370 --> 01:46.890 Please pay attention to this and write it down. 01:46.930 --> 01:50.890 Please, please pay attention to this very important note. 01:50.930 --> 01:55.450 Geocoding involves system APIs that may block threads. 01:55.650 --> 02:04.380 Run it on dispatchers.io in background to avoid freezing the main user interface as we did in go code 02:04.380 --> 02:07.980 address, and we run it on the coroutine scope. 02:08.260 --> 02:12.100 Also, we're going to use it with reverse geocoding. 02:12.300 --> 02:15.060 And for this we use the suspend function. 02:15.060 --> 02:22.900 So I'm showing you the two types making a function a normal function and calling it inside a coroutine 02:22.940 --> 02:28.380 scope, as we did here in the search button I used the coroutine scope. 02:28.580 --> 02:38.500 Or you can make it directly a suspend function in order to get the address and fetch the latitude and 02:38.500 --> 02:46.380 convert it to address in background using dispatchers.io start with try val Geocoder. 02:46.540 --> 02:50.580 We can get that default locale in order to get the language. 02:52.660 --> 02:58.340 Then we need to convert the latitude and longitude to an address. 02:58.620 --> 03:05.630 Val addresses equals to Geocoder dot get from location. 03:05.830 --> 03:12.230 In the geocoding function we used get from location name function. 03:12.470 --> 03:15.990 Now we're going to use the get from location. 03:15.990 --> 03:19.550 Give me the location I'll give you the address. 03:19.750 --> 03:30.110 So the lat long that we passed as a parameter lat long dot latitude and lat long dot longitude. 03:30.110 --> 03:31.550 Give me the coordinates. 03:31.550 --> 03:37.870 I give you the address and make the maximum result equals to one. 03:37.870 --> 03:43.630 We need only one one result for the corresponding addresses. 03:43.950 --> 03:44.510 Okay. 03:44.830 --> 03:55.430 Also, in order to get rid of the deprecation here, we can use suppress annotation and use deprecation 03:55.470 --> 03:56.030 okay. 03:56.430 --> 03:57.630 It's very simple. 03:57.950 --> 04:04.950 We can get the addresses from get from location and pass the coordinates latitude and longitude and 04:05.050 --> 04:06.810 set the maximum result to one. 04:06.850 --> 04:07.370 Okay. 04:07.610 --> 04:16.370 Also, you can get rid of this press annotation if you want address first, not first or null. 04:16.410 --> 04:26.010 We can get a null dot get address line and set it to zero because we need to get the first ordinal which 04:26.050 --> 04:28.890 the addresses we have many addresses. 04:29.090 --> 04:31.250 We need to get the first one. 04:31.370 --> 04:31.810 Okay. 04:31.850 --> 04:34.570 And we set the maximum result to one. 04:34.610 --> 04:37.890 This is the idea behind using this code. 04:37.930 --> 04:43.930 Catch e exception print stack trace and return null. 04:43.970 --> 04:47.610 Okay this is the reverse geocoding function. 04:47.610 --> 04:52.090 Let's add the last thing here inside the search button. 04:52.090 --> 04:54.210 Here we need to get the address. 04:54.210 --> 04:58.850 So address equals to reverse geocode. 04:58.890 --> 05:04.330 Pass the context and pass it which is the lat long. 05:04.370 --> 05:08.540 Otherwise go and display unknown address. 05:09.340 --> 05:13.740 Set the question mark here and there is a very important note. 05:13.860 --> 05:18.060 Suspension functions can be called only within the coroutine body. 05:18.660 --> 05:24.140 This is the coroutine body, but this is for the geocoding address inside the lat. 05:24.180 --> 05:33.260 Here set another coroutine scoop dot launch and move the address to it. 05:33.260 --> 05:34.180 Run again. 05:34.220 --> 05:36.540 Search for Eiffel Tower. 05:36.580 --> 05:43.700 Click search and you notice that text is displaying eight Avenue Gustave Eiffel. 05:43.740 --> 05:45.620 Paris, France. 05:45.660 --> 05:48.180 Okay, so congratulations guys. 05:48.180 --> 05:49.900 This is the geocoding. 05:50.100 --> 05:56.900 Let me try another, uh, another function, which is the reverse geocoding. 05:56.940 --> 05:58.660 Give me the coordinates. 05:58.660 --> 06:00.300 I'll give you the address. 06:00.340 --> 06:04.300 I'll give you the coordinates of, um. 06:04.740 --> 06:05.340 Love. 06:05.620 --> 06:12.150 A love Lovable and a lovely place in the Arabic word, which is Beirut. 06:12.190 --> 06:12.910 Set three. 06:12.950 --> 06:17.950 3.8938. 06:18.150 --> 06:18.750 Comma. 06:18.830 --> 06:20.190 Space three. 06:20.270 --> 06:24.110 5.5018. 06:24.150 --> 06:25.790 Click search. 06:26.150 --> 06:27.430 And here we go. 06:27.670 --> 06:30.070 You notice the reverse geocoding. 06:30.350 --> 06:32.430 I gave the coordinates. 06:32.470 --> 06:38.350 There is a location and an address which is Beirut, Lebanon. 06:38.670 --> 06:39.270 Okay. 06:39.550 --> 06:43.550 So another um another place. 06:43.550 --> 06:46.190 Let me give you a turkey. 06:46.590 --> 06:48.510 I give you Istanbul. 06:48.950 --> 06:51.870 So let me write Istanbul. 06:52.150 --> 06:53.110 Search. 06:53.270 --> 06:54.830 And here we go. 06:54.910 --> 07:02.590 This is the location and the address of the Istanbul state in Turkey. 07:02.630 --> 07:03.190 Okay. 07:03.550 --> 07:05.550 So congratulations, guys. 07:05.550 --> 07:08.990 This is how we use reverse geocoding.