1 00:00:00,750 --> 00:00:05,430 So now let's actually run our project and see what happens. 2 00:00:05,430 --> 00:00:10,850 So as you can see here our application is actually running on this emulator here. 3 00:00:11,040 --> 00:00:11,730 Okay. 4 00:00:12,090 --> 00:00:15,050 And now we can't we can see these images here. 5 00:00:15,090 --> 00:00:15,620 OK. 6 00:00:15,750 --> 00:00:23,250 If I scroll down I can see these images but my application is actually taking too much memory because 7 00:00:23,250 --> 00:00:28,300 of these images that I actually assigned to these image views here. 8 00:00:28,380 --> 00:00:31,550 As you can see here and it's crashed. 9 00:00:31,620 --> 00:00:37,730 So as you can see it's actually to go inside this log here in order to see the cause of this error. 10 00:00:37,980 --> 00:00:43,600 And it says that's failed as he has it's Java that land that out of memory error. 11 00:00:43,640 --> 00:00:52,980 Ok failed to allocate this value by its location with this value of free bytes and eight megabyte until 12 00:00:53,730 --> 00:00:59,400 this value as you can see here is the cause of this error is that our application is taking too much 13 00:00:59,400 --> 00:01:06,580 memory because of those high quality images and we cannot just type I animals animal that image resource. 14 00:01:06,600 --> 00:01:10,590 And the name of that image we need to actually do something with those images. 15 00:01:10,630 --> 00:01:13,930 OK you need to actually reduce the size of those images. 16 00:01:13,950 --> 00:01:15,080 So how we can do that. 17 00:01:15,150 --> 00:01:20,810 So in order to do that let's actually that its design code here and now and when I actually pasting 18 00:01:20,850 --> 00:01:24,290 some lines of code here and then I'm going to explain to you what's going on here. 19 00:01:24,300 --> 00:01:25,000 OK everybody. 20 00:01:25,020 --> 00:01:29,490 Now I'm going to actually paste in some lines of code here and then I'm going to explain to you what's 21 00:01:29,490 --> 00:01:30,820 going on here. 22 00:01:30,840 --> 00:01:34,860 So as you can see here first about in line are fifty one. 23 00:01:34,980 --> 00:01:38,940 I actually created a bitmap factory that options object. 24 00:01:38,940 --> 00:01:39,540 OK. 25 00:01:39,930 --> 00:01:42,270 So what is actually a bitmap. 26 00:01:42,300 --> 00:01:48,300 Let's actually go to the Android documentation in order to see what's what what are bitmaps as you can 27 00:01:48,300 --> 00:01:56,160 see here it says bitmaps bitmap objects innovate that keeps your user interface components responsive 28 00:01:56,610 --> 00:02:02,320 and avoids exceeding your application memory really be ok if you are not careful. 29 00:02:02,430 --> 00:02:08,400 Bitmaps can quickly consume your available memory budget leading to an application crash due to the 30 00:02:08,520 --> 00:02:10,480 dreaded exception OK. 31 00:02:10,530 --> 00:02:14,570 Mobile devices typically have constrained system resources. 32 00:02:14,580 --> 00:02:15,020 OK. 33 00:02:15,180 --> 00:02:22,050 Android devices can have as little as 16 megabytes of memory available to a single application. 34 00:02:22,200 --> 00:02:23,640 OK and this is very important. 35 00:02:23,640 --> 00:02:30,590 OK and bitmaps as you can see here take up a lot of memory especially for rich images like photographs. 36 00:02:30,600 --> 00:02:32,500 OK on here. 37 00:02:32,640 --> 00:02:34,570 Let's actually go click on this. 38 00:02:34,580 --> 00:02:37,850 Lot loading large bitmaps efficiently. 39 00:02:37,890 --> 00:02:40,890 So I already opened that here in a new tab. 40 00:02:40,950 --> 00:02:44,990 As you can see here it says images come in all shapes and sizes. 41 00:02:45,240 --> 00:02:49,680 In many cases they are larger than required for a typical application user interface. 42 00:02:49,680 --> 00:02:56,580 Ok for example the system Gallerie application displays photos taken using your Andray devices camera 43 00:02:56,610 --> 00:03:01,080 which are typically much higher resolution than the screen density of your device. 44 00:03:01,090 --> 00:03:05,050 OK and here it says Arete bitmap dimensions and type. 45 00:03:05,350 --> 00:03:09,270 OK we can actually read the bitmap dimensions and type. 46 00:03:09,280 --> 00:03:10,380 Both are here. 47 00:03:10,380 --> 00:03:12,560 This is very important as you can see here. 48 00:03:12,780 --> 00:03:15,380 I skate down version into memory. 49 00:03:15,430 --> 00:03:20,680 Ok so here as you can see it says now that the image dimensions are known. 50 00:03:20,790 --> 00:03:27,360 They can be used to decide if the full image should be loaded into memory or if a sub sampled version 51 00:03:27,510 --> 00:03:29,100 should be loaded instead. 52 00:03:29,100 --> 00:03:31,000 Here are some factors to consider. 53 00:03:31,020 --> 00:03:36,660 Estimated memory usage of loading the full image in memory amount of memory you are willing to commit 54 00:03:37,170 --> 00:03:42,360 to loading this image given any other memory requirements of your application. 55 00:03:42,360 --> 00:03:48,020 Dimensions of the target image view or the UAE component that the image is to be loaded into. 56 00:03:48,030 --> 00:03:53,880 So as you can see here the application or the dimensions of image view. 57 00:03:53,910 --> 00:03:55,950 So let's actually find this clear case here. 58 00:03:56,040 --> 00:04:01,470 As you can see is for example for the layout which I assign the value 100 and for the layout height 59 00:04:01,500 --> 00:04:03,650 I again assign the value 100. 60 00:04:03,670 --> 00:04:08,450 OK so these are the important factors that we need to consider. 61 00:04:08,520 --> 00:04:13,590 For anyone to actually output some images to the screen and as you can see here it says for example 62 00:04:13,800 --> 00:04:17,540 it's not warf loading our value pixel image. 63 00:04:17,550 --> 00:04:24,240 As you can see here disvalue pics that image into memory if it will eventually be displayed in disvalue 64 00:04:24,240 --> 00:04:26,530 pixel Formanek Farmdale in an image view. 65 00:04:26,580 --> 00:04:34,410 OK to tell the decoder to subsample the image loading a smaller version into memory sets in sample size. 66 00:04:34,410 --> 00:04:37,680 So this value is valuable. 67 00:04:37,680 --> 00:04:40,000 We need to set this variable to true. 68 00:04:40,310 --> 00:04:43,990 OK in your math factory that options object. 69 00:04:44,050 --> 00:04:45,790 OK for example. 70 00:04:46,320 --> 00:04:54,330 As you can see this is an example for this it bitmap OK but here in our application in a customized 71 00:04:54,350 --> 00:04:55,600 Lisp view as you can see. 72 00:04:55,860 --> 00:04:58,230 I created my file through the options. 73 00:04:58,260 --> 00:05:02,640 OK so that they can actually call this valuable on this object. 74 00:05:02,680 --> 00:05:03,130 OK. 75 00:05:03,260 --> 00:05:05,370 Options start in sample size four. 76 00:05:05,710 --> 00:05:06,370 OK. 77 00:05:06,650 --> 00:05:09,440 And here I created an object of type bitmap. 78 00:05:09,620 --> 00:05:10,210 OK. 79 00:05:10,370 --> 00:05:12,810 Bitmapped factory that the resource. 80 00:05:12,860 --> 00:05:13,440 OK. 81 00:05:13,640 --> 00:05:21,920 So because of you actually have more images in inside of the project as you can see here. 82 00:05:22,140 --> 00:05:25,700 We have these images inside of this adorable folder in our project. 83 00:05:25,700 --> 00:05:31,070 So if we need we needed to actually call this D-CT resource here and on our factory. 84 00:05:31,140 --> 00:05:31,580 OK. 85 00:05:31,730 --> 00:05:34,390 So bitmapped factor that later D-CT resource. 86 00:05:34,400 --> 00:05:39,580 So and this it actually accepts some arguments context that gets resources. 87 00:05:39,680 --> 00:05:46,470 So here we need to actually refers to the resources of our application so context that gets resources. 88 00:05:46,490 --> 00:05:51,250 And the second argument is the specific image state of our animal images. 89 00:05:51,270 --> 00:05:57,050 Ari Okay and here as you can see we have another argument here options. 90 00:05:57,200 --> 00:06:03,080 So these options of with scientists in sample size here as you can see disvalue for our image. 91 00:06:03,470 --> 00:06:07,880 And here I am assigning this bitmap to to my IMJ animal image. 92 00:06:07,940 --> 00:06:08,570 OK. 93 00:06:08,930 --> 00:06:11,780 So let's actually run our project and see what happens. 94 00:06:11,900 --> 00:06:19,480 So now as you can see of we have now this came down version of our images on these images views. 95 00:06:19,580 --> 00:06:24,420 And as you can see the quality of our images are actually a little bit low. 96 00:06:24,500 --> 00:06:26,350 OK low quality images. 97 00:06:26,480 --> 00:06:30,190 And let's actually change this number four to number eight. 98 00:06:30,470 --> 00:06:32,220 And the search you did on our project again. 99 00:06:32,240 --> 00:06:37,460 So as you can see here again our application is running on this emulator and you can see that these 100 00:06:37,760 --> 00:06:42,500 images are actually very low quality OK low quality images. 101 00:06:42,500 --> 00:06:44,200 So let's actually change this. 102 00:06:44,240 --> 00:06:51,500 And as you can see here although our images are actually a little bit low quality but they're not actually 103 00:06:51,500 --> 00:06:55,850 taking too much memory so that our application actually doesn't crash. 104 00:06:55,910 --> 00:06:56,870 As you can see here. 105 00:06:57,070 --> 00:06:57,670 OK. 106 00:06:58,010 --> 00:07:04,040 So if we for example change disvalue to number two are the quality of our images are going to be a little 107 00:07:04,040 --> 00:07:04,600 bit high. 108 00:07:04,610 --> 00:07:06,140 High quality images. 109 00:07:06,140 --> 00:07:11,880 So now that's actually on our project again and here as you can see now we have high quality images. 110 00:07:11,900 --> 00:07:12,580 Okay. 111 00:07:12,970 --> 00:07:18,740 But I think this is not the right way to write our coats but here I just wanted to show you what is 112 00:07:18,740 --> 00:07:21,110 this a bit more effectively that options. 113 00:07:21,150 --> 00:07:26,660 OK how and how we can actually use the bitmap factory in order to actually see the images and output 114 00:07:26,660 --> 00:07:27,950 those images to the screen. 115 00:07:27,950 --> 00:07:28,500 OK. 116 00:07:28,760 --> 00:07:32,440 So let's actually comment out these lines of code here. 117 00:07:32,600 --> 00:07:33,450 OK. 118 00:07:33,860 --> 00:07:42,530 And now according to the documentations we can actually use these if it's OK that the Android gives 119 00:07:42,530 --> 00:07:48,090 us the Android documentation gives us as you can see we can't use this method so I just copied the Smurfette 120 00:07:48,110 --> 00:07:49,130 here as you can see. 121 00:07:49,130 --> 00:07:54,980 Now let's actually go to an android studio and after the end in curly brace of this method as you can 122 00:07:54,980 --> 00:07:58,880 see of this get View method I want to paste this method here and then I'm going to explain to you what's 123 00:07:58,880 --> 00:08:00,350 going on here. 124 00:08:00,380 --> 00:08:02,390 So as you can see here this is our method. 125 00:08:02,570 --> 00:08:03,680 OK. 126 00:08:03,740 --> 00:08:08,980 And as you can see the Axis modifier of this and if it is public this method is static. 127 00:08:08,990 --> 00:08:14,840 So it is going to be a class MF'er we can use we can call this an effect on our class and the return 128 00:08:14,840 --> 00:08:19,360 type of this if it is it and the name of this method is calculate in sample size. 129 00:08:19,460 --> 00:08:19,960 OK. 130 00:08:20,060 --> 00:08:26,690 So it's going I should calculate this impulse in sample size variable for us automatically according 131 00:08:26,690 --> 00:08:27,520 to our images. 132 00:08:27,530 --> 00:08:28,440 OK. 133 00:08:28,670 --> 00:08:34,050 So this Biffen actually accepts some arguments between bitmapped fancy options options. 134 00:08:34,130 --> 00:08:34,800 OK. 135 00:08:35,050 --> 00:08:36,440 It requires. 136 00:08:36,830 --> 00:08:38,540 It requires height. 137 00:08:38,720 --> 00:08:39,350 OK. 138 00:08:39,590 --> 00:08:45,740 And as you can see here inside of this it actually created some variables local variables. 139 00:08:45,740 --> 00:08:52,310 The first one is constant int height as you can see and hear it put an assignment operator and then 140 00:08:52,310 --> 00:08:55,740 it referred to this options argument that's outright. 141 00:08:55,740 --> 00:09:00,410 So out how outside is going to actually give us the height of our image. 142 00:09:00,480 --> 00:09:01,120 Okay. 143 00:09:01,580 --> 00:09:03,230 And then here we have a V. 144 00:09:03,330 --> 00:09:03,910 Okay. 145 00:09:04,130 --> 00:09:08,840 And then it actually gives us the outwits for key the Viets of our image. 146 00:09:08,870 --> 00:09:10,440 And then it's going to say that's why you do this. 147 00:09:10,470 --> 00:09:11,390 It's constant. 148 00:09:11,420 --> 00:09:12,030 OK. 149 00:09:12,410 --> 00:09:16,080 And we have these int in sample size variable. 150 00:09:16,160 --> 00:09:16,750 OK. 151 00:09:16,790 --> 00:09:22,420 And it assigned a value in number one to this variable and it actually created an if statement here 152 00:09:22,430 --> 00:09:29,090 as you can see if the value of this height as you can see here this local variable height this constant 153 00:09:29,330 --> 00:09:33,770 is greater than the value of these required height that we have here. 154 00:09:34,010 --> 00:09:42,920 Or if the value of these v as you can see here is greater than the value of these require Veach as you 155 00:09:42,920 --> 00:09:47,950 can see here then it's going to actually execute these lines of code inside of these if statement. 156 00:09:47,960 --> 00:09:48,700 OK. 157 00:09:49,220 --> 00:09:51,920 So as you can see here it's actually created a comment for us. 158 00:09:51,920 --> 00:09:59,200 It says calculate the largest sample size value that is a power of two and keeps both height and weight 159 00:09:59,300 --> 00:10:01,970 larger request that height and if it's OK.