If you enable everything and you’re still not getting output, make sure the DDMS device monitor is not running. The file in our main layout is backgroundwhile, so you can remove the white background of ListView. Using lint to Optimize Your UI. The video was recorded, produced, and transcribed by Realm, and is published here with the permission of the conference organizers. Hierarchy Viewer is used to detect rendering efficiency and remove unnecessary nesting. Cosmos features 3 separate tools bundled into one complete package. The ImageView that the red arrow is pointing to is wrapped with one RelativeLayout and then three LinearLayout’s. Since the entire rendering pipeline has to occur between VSync boundaries, if we drop a frame and rendering crosses over that 16-millisecond threshold, then another frame buffer is allocated so that we can immediately start rendering the next frame without having to wait for that back buffer to become available. Or you can lean on a trusted image library where these things have been taken into consideration before. Android utilizes triple buffering in Jelly Bean and up. On slide 23 we have that flat layout. Most of the attributes of the viewstub tag are similar to those of the include tag. Time：2020-6-3. Try to avoid bad performing patterns like doing work on the UI thread and learn how to write fast and responsive apps. Now let's look at the principle: 16ms means 1000/60hz, equivalent to 60fps. It means that process, rendering, and update with the new frame were all achieved in 16 milliseconds or less; What happens if VSync is turned off? For custom views that override the onDraw method, there’s clipRect and quickReject. If you don’t see the purple vertical bars, on my display they show up purple but here they’re showing as blue. It’s important to choose the right view for the right job and know the pros and cons. Save View lookups with the ViewHolder pattern If all you needed was a root ViewGroup, you can remove those extra parents that are wasting time and space by swapping the root with the merge tag instead. Even if you’re doing all the right things, the most important is staying within those VSync ticks. Remember that we said before that our Activity requires the background color to be white, and we did set the background color to be white in the layout, so here's to note that the layout of our Activity will eventually be added to DecorView, the background in the View meeting is not necessary, so we hope to call mDecor. On the Android side, that would mean an Android phone such as the Nexus One, or most phones that run Android 2.3 Gingerbread. The above code will show you that the background color is set for each icon (mainly when there is no icon map), and then a head image is set. There is a row labeled Alerts, or you can click on one of the red or yellow frame dots to see the alert for it. The problem of Overdraw is easy to find. By optimizing your layouts you will be able to implement smooth scrolling interfaces with a minimum memory footprint. If you run Hierarchy Viewer, you’d quickly spot that mistake. Performance optimization of Android UI in real-world recognition rendering In fact, due to different configurations and long iteration history, there may be many time-consuming operations in the UI thread in the code, so we hope to have a simple detection mechanism to help … Again, I can’t stress how important it is that because it’s a RecyclerView row, every mistake or, conversely, optimization is multiplied by the number of rows that are inflated. They will affect your app’s UI performance and you can certainly write your own code to handle all of these things. With the vigorous development of mobile market in recent years, a large number of people have been involved in it. Anything that falls outside of this area will not be drawn, and quickReject returns true if the area is completely outside of the clipping rectangle. It is measured in Hertz. Android performance optimization launch Optimization Practice. iOS, Origin: http://blog.csdn.net/qq_23191031. When they can, there is no guarantee to get the exact number of frames. android UI optimization. 1. Space-wise, double is 2x larger. There’s Glide, Fresco, and Picasso, to name a few. The most common problem with the < include > tag is that findViewById can't find the following layout of the < include > incoming control, and the premise of this problem is to set the ID when include. The green horizontal bar is the 16-millisecond reference bar. Personally, I feel that this idea and React The idea of component-oriented programming in Native has the same merits and demerits. Out of the app-hungry market, these devices are the older, slower portion, but they should be supported because they represent a large portion of the market… Performance matters if you want to be able to provide buttery smooth, exceptional user experiences. If your bar is tall in the blue section area, you’re likely doing too much work in your onDraw method. • Hierarchy Viewer: Used to analyze the layout of your UI. That is the tree overview of that deeply nested layout that I showed earlier. You can see an example on slide 9, where we have frames 0, 1, and 2 displaying on the screen when a VSync pulse happens. Performance Optimization Related Examples But having said that, using an image library is not a silver bullet and all of your problems are solved suddenly. For the meaning of each color block, see the following picture: Blue, light green, light red and dark red represent four different degrees of Overdraw. At this point, we’ve skipped a frame and a third buffer is allocated, and we can start drawing to it immediately. Dark red: It means overdraw four times. Optimize hierarchy and layouts: Layout is an important part of an app that, if applied poorly, can result in an application that constantly exhausts the phone memory by its sluggish UI. That’s where you see part of the old frame and part of the new frame. When pixels are drawn over top of pixels, this is called “overdraw”. merge can be used instead, because the parent of the Activity content view The Android system helps us out with overdraw by not drawing views that are completely hidden, but this won’t work for views that are partially showing or custom views that override onDraw. Add the below and check the performance. Another big chapter in Unity Android Optimization, is the UI optimization. After opening Show GPU Overdraw:  Also on slide 28, you may notice that the upper part of the cat images are darker than the lower part. When you notice APP Carton, you can look at the logcat console. Because people are very sensitive to graphics, the rendering speed of UI is very important. I set the number of seconds I wanted to trace to collect date to 10 seconds. When I first started my development career, I had no idea there were tools out there that could help me identify problems in my software. If possible, we should avoid a nested view and try to create a flat view wherever possible. So there will be no redundant Relative Layout nodes. Now there are only 13 views, and some of the views were eliminated just by converting that text and heart icon into a single compound drawable. In my deeply nested layout, I was setting white backgrounds on all of the views. The information here assumes hardware around the level of the Apple A4 chipset, which is used on the original iPad, the iPhone 3GS, and the third generation iPod Touch. recyclerView.setHasFixedSize(true) What this effectively does is it disables that heartbeat that syncs up your GPU’s buffer swap to your screen’s refresh interval. That extra flexibility comes to you at a cost. Since these images are much larger than the images are actually drawn on the screen, a good optimization would be to resample these images so that we’re pushing fewer pixels through the pipeline. When VSync occurs, the image drawn on the back buffer gets flipped over to the front buffer, and that becomes the image that the user sees on the display now. The main.mxl code is as follows: Where network_error.xml is the layout that needs to be displayed only when network errors occur. Generally speaking, storage space and cost for Android on Intel Atom processors is not a bottleneck, so this chapter focuses on performance optimization that makes applications run faster. Android devices come in a vast array of hardware unlike ios and windows devices. (Because the company's project is still in the stage of secrecy, so extract Performance optimization of Android UI in real-world recognition rendering Some examples) Pixels are drawn three times. Android does a lot of things to show what you are seeing on the screen. • VSync stands for Vertical Synchronization. Android studio has built-in monitors to show the performance in areas of network, GPU, CPU, and memory. Flat View improves performance. You won't need the NDK. setWindows Background (drawable); then we can use Acti. * Unnecessary Background 6. But since this is a list row, our mistakes in the deeply nested layout get multiplied for every row displayed on the screen. Then click on Hierarchy Viewer perspective if you’re not already on it, and select your process on the windows tab on the left. A software is never perfect. You can see a full list at developer.android.com, because there’s a lot more things that you can use this trace to profile on. xml However, frame 2 takes too long to render and the GPU isn’t done drawing to the back buffer. Just add timers to your functions that run in the UI thread and might take a while, and collect some data to see how long things take. The difference is that the layout introduced by ViewStub will not display or occupy the position by default, so it can save cpu, memory and other hardware resources when parsing the layout. This quotation is from: [Android UI performance optimization in battle recognition rendering] (http://blog.csdn.net/lmj623565791/article/details/45556391), For example, as shown in the figure above, if one of your operations takes 24 ms, the system will not be able to render normally when it gets the VSYNC signal, and can only wait for the next VSYNC signal (the second 16ms) to perform the rendering work. Profile GPU rendering is a great first place to get a holistic overview of UI rendering performance. If you plan to set the image in your Java code and you’re only setting the drawable in XML simply for a preview, use the tool named Space instead of Android. By default, it will not be parsed. And take advantage of the many tests and tools described in Evaluating Performance as part of your work getting the most out of Android. As a rule of thumb, floating-point is about 2x slower than integer on Android-powered devices. Here is the performance comparison between constraintlayout and traditional layout, relativelayout and LinearLayout. All the Modification codes are as follows: ok, and the last one, which is also very easy to ignore. This talk was delivered live in July 2016 at 360 AnDev. The optimized layout on the right looks no different than the one on the deeply nested on the left. First, click on the Android icon to launch the DDMS Android device monitor. encoding When inflate, the View and its word View will be parsed. On slide 34 you can see a side-by-side screenshot with Profile GPU Rendering on screen enabled, running on a Marshmallow device. Fluid UI also uses a number of third party services providers in order to provide the Fluid UI service: Google If you have clicked on one of these ads (on Google.com or on one of Google’s affiliate sites), this information will be tracked so we can attribute your purchase correctly. You can see there’s a lot less going on. Then also you’ll notice that there are three dots that show up on each child view, giving you a quick visual of rendering performance, or what Hierarchy Viewer thinks it was. Big blue is acceptable (if the whole window is blue, you can get rid of one layer). What does it mean having performant UI? Pro Android Apps Performance Optimization reveals how to fine-tune your Android apps, making them more stable and faster. But it’s a touch less convenient than the onscreen version. For example, we often need to add a title bar when editing the Android interface. But your UI does have to operate smoothly enough that the brain can’t perceive much, if any, frame rate difference. I believe that the most commonly used Layout label is . It’s more complicated than that, but this sums it up into one oversimplified sentence. I can also hold the Mac command key down to select multiple slices for inspection. There is no need to draw the background with the avatar. The memory monitor at the top gives a quick view of your memory pressure and roughly when garbage collection occurs. Created with Sketch. 2. VSync is a way to ensure that the GPU’s frame rate is in sync with the display’s refresh rate. Of course, it's not necessary to use more than 60fps. The purpose of is to extract the common parts of the Layout for other Layouts to optimize the Layout. Code talk to different system hardware and libraries to make things what it should look like on the screen. That gets handed off to the GPU to draw to a buffer. Both are part of the canvas API. Always remember, premature optimization is … What users are seeing is code. The dark blue at the top is the allocated space, and the light blue is the free space. I hope that if you haven’t done that already, you will do it today. Light green is two layers. You definitely want to look at what you’re doing in that area. How to fix it Next will be presented common optimization cycle, which you need to go sequentially every time when noticeably low FPS suddenly occurs in your game after next stage of development… Battery Usage Reduction is also an important part of an android development as this optimisation will ultimately lead to retain the user, as many … The blue section is the time spent creating and updating the display list. This buffer frame is commonly referred to as the “back buffer”. The point is that understanding what you’re putting on the screen and ••how you’re doing it is critical**. Once the system is doing a time-consuming operation larger than 16 ms, the system will not be able to respond to VSYNC signal and perform rendering, resulting in frame loss. This Layout is written in a way that greatly facilitates development. At present, the main force of China's IT industry has basically gone through the road of training. However, here is the test data of foreigners. As someone who has always been passionate and excited about technology, she tries to spread that excitement and enthusiasm to others through volunteer teaching in high schools, speaking engagements and Meetup participation. In order to better understand the role VSync plays, we need a basic understanding of how frame buffering works. Is it much better than before? Android VTune provides a user-friendly graphical user interface that does not require you to recompile the application. • Yellow means that you spent a little bit too much time, but you weren’t too far past that 16-millisecond mark. In the multi-level UI structure, if the invisible UI is also rendering operations, this will lead to some pixel areas being drawn many times, which is a great waste of CPU and GPU resources. Blue: It means twice as much as overdraw. However, it can sometimes be difficult to track down and fix these issues. There will be similar warnings for drop frames. To use Hierarchy Viewer, you need to follow the setup instructions on developer.android.com. That’s indicating an extra layer of overdraw. Using include may result in too many nested layouts, too many view nodes and slow down the parsing speed. She is a former Network Engineer specializing in Cisco Networking and Security Appliances who made the leap into software in 2011. NOTE: I'm leaving the previous code example up for historical reasons, but as of Unity 5.5, they've changed the way this works.Apparently the previous behaviour was a bug, and the #define now needs to be set where you *call your method*, not where it's declared. Even though this seems really obvious, extra backgrounds are a really common cause of overdraw. So we have the same layout as we did directly in main.xml, except that there is a problem mentioned above where the more layout id is covered. The blue and purple sections are only present on Android 4 and up. Let's look at a simple example showing ListView: Now the effect is:  Especially shades of red, which are bad. You want to avoid red as much as possible. Note that our requirement is that Activity as a whole is a white background. When I first started my development career, I had no idea there were tools out there that could help me identify problems in my software. It helps to quickly spot costly mistakes that contribute to rendering time. You're signed out. You can either double click it or click on the miniature blue tree icon to obtain a snapshot. You’ve optimized as much as possible and you’re still experiencing jank. It’s the pixel crossing guard and it operates like a heartbeat. Note: The Android layoutopttool has been replaced by the linttool beginning in ADT and SDK Tools revision 16. So using < ViewStub > avoids parsing the specified layout file. This background is hard to find. It's wrong. Most Android devices refresh the screen 60 times a second (there are undoubtedly exceptions—earlier Android devices were sometimes in the 50 or less fps range). (I just feel that the picture given by google is wrong, clearly 32ms, how to mark a 34ms, is there any other implication that I did not understand?). When a layout is include d as a sub-layout by other layouts, merge is used as the top node of the layout, so that when introduced, the top node will be automatically ignored, and all its own points will be merged into the main layout. It is the number of times per second that a new image can be produced; • The refresh rate is the number of times per second a device’s display can update. Medium-sized green areas are acceptable, but you should try to optimize and reduce them. If each rendering is successful, the normal frame rate required for a smooth picture can be achieved: 60fps. What it means not to render at FPS. 24fps enables the human eye to perceive continuous linear motion, which is attributed to the motion blurring effect. Schedule, graphics view, and window manager. Not all devices can render at 60 frames per second, though. You can run it from Android studio or via command line. Even though we already skipped a frame, hopefully now we can catch up and only drop one frame instead of always being behind and struggling to catch up. The top node of the layout is FrameLayout and does not need to set properties such as background or padding. Seeing here, students may ask: why is it that 16ms rendering once, and what is the relationship between 60fps? However, the problem is that the so-called 2-3 years of work experience, so that recruitment units mistakenly believe that: 2-3 years of development experience and just concluded training experience, basically equate. By clicking this section of the pipeline, Systrace will provide additional information about it. You can see some screenshots on slide 18 on how to obtain a capture. If you’re using an emulator, then you’re already good to go. ok, compared with reference to Fig. Follow the instructions in this section to ensure your Android devices minimize resource use and optimize performance. I prefer the command line, so that’s what I’m going to show you. Pixels are drawn four times and acceptable in a small range. If your vertical bar goes above that line, then things took too long. Notice here at the top, on slide 14, that the layout editor shows me a list of color coordinated parent containers that wrap the selected ImageView. As with desktop machines, assuming space isn't an issue, you should prefer double to float. You need to look at the Adapter's getView code. view is just a FrameLayout, so you can use merge to eliminate only one. What’s really happening is the user sees the same frame repeatedly, causing a noticeable hiccup in the animation. Because the screen is refreshed every 16 ms (1 s/60 fps = 16 ms per frame), it is crucial to ensure … Now that we know the basic causes of jank, how do we avoid them? A and D, left and right. Next, there are some unnecessary backgrounds. Generally speaking, there are a lot of job opportunities, but enterprises have greatly increased their employer requirements. If for some reason, your GPU is still doing work on the back buffer, and it’s not sitting around waiting for VSync to occur so it can get swapped over to the front frame buffer, then that frame gets skipped and the image the user sees is that same image they saw before for that interval, or for however many VSync intervals, until that back buffer is done being drawn and we’ll see a new image on the next VSync occurrence. Android apps are designed to run at 60 FPS but are the apps running at FPS? In comparison, you can see on slide 20 the tree for the flattened version of the layout. We’ve all experienced poor application performance where you’re going along and things seem okay, and then suddenly it starts to lag and might even come to a halt. Let's take the example of the prompt page network_error.xml when adding network errors to a layout main.xml. In order to get an image on the screen, the CPU’s responsible for updating a display list. On slide 43, you can see a close up of a single frame. Most of the time here was spent on the RenderThread, issuing draw commands, as can be seen by that light green bar labeled DrawFrame. So if possible, you should generally display some content as soon as possible and delay the background checks and updates a bit. You can see that by clicking on the icon with the three circles in the upper right-hand corner, and the view you select will show how many milliseconds it took for a measure, layout, and draw. The GPU is also responsible for swapping these buffers so that the newly drawn image can be displayed when VSync says, “Go.”. Note: At the same time, don't let the animation execute too many times, resulting in CPU or GPU overload. We have more or less encountered the perceptible interface cartoon phenomenon in the development of applications, especially in the case of too many nested layers of layout, unnecessary rendering, or too many time-consuming operations in onDraw method, too many times of animation execution, it is easy to create such a situation. Make sure the UI thread stays lightning fast. The orange section of the bar represents the time that the CPU is waiting on the GPU to finish its work. This article starts with WeChat official account “Android development tour”. * Unnecessary Background 1. This article describes and discusses these techniques. At this time, you can switch to the program and interface that need to be detected. Since then, she has been developing for Android for close to five years and dabbles in other technologies including IoT. Optimization in Android Improving Layout Performance Layouts are a key part of Android applications that directly affect the user experience. There are many techniques for increasing the performance of applications built with Xamarin.Android. The < include > tag simply means that it is equivalent to introducing the layout specified by layout into main.xml as a whole. This session will help developers better understand the rendering architecture used to display UIs, and how that affects performance. The red section of the bar represents the time spent by Android’s 2D renderer issuing commands to OpenGL to draw the display list. The purple section, the bar, is the time spent transferring resources to the render thread. The challenges aren’t any less of the same. Comparing with the above reference map, we can see that a simple ListView shows Item, which has been over-drawn in many places. You can also use M to highlight a section or an entire frame. • Red means that performance was poor and you took far too much time and might have dropped multiple frames as a result. On slide 19, you can see what a capture looks like. Linear Layout's android:background="@android:color/darker_gray" in the Item layout, android:background="@android:color/white" of Relative Layout in the Item layout, android:background="@android:color/white" of TextView with id_msg in the Item layout, These four unnecessary backgrounds are also easy to find, so the effect of removing them is as follows:  In order to enable this feature: One other feature is an accessibility feature for colorblindness. On slide 47, we have a highlighted area, and then I clicked on the section Draw on the UI Thread, and then hit the M key to mark it. Also if there’s no color, it means that there’s no overdraw occurring at all. Calling clipRect in your onDraw allows you to define the drawable boundaries for a view. GPU overdraw is a tool in developer settings that provides color-coded visual feedback to help you avoid drawing things that won’t be seen on the screen. We need to fix them. You can see how mistakes quickly add up. The advantage is frames per second (FPS) is no longer capped at the display’s refresh rate. Green: It means overdraw twice. Tap to unmute. – EboMike Aug 23 '10 at 8:45 Author: Dashengdai. It’s also collecting system activity and other app events, so you want to kill other running apps before starting your trace. ViewStub tags can be used to introduce an external layout just like include tags. • Android No Response – Crashes app when UI is non-responsive • Settings: Developer Options on device – Some basic CPU stats • Lint: Static analysis tool – offers some performance recommendations 7 If you can't smoothly express the gorgeous picture content, you need to use 60fps to achieve the desired effect. Users can be forgiving of this if it’s a one-off that never happens, but if your application does this on a regular basis, be prepared for uninstalls and negative Play Store reviews. This helps to see the depth of the selected child view and where the container views begin and end. AVG M Performance Optimization Guide ott 1 If your smartphone or tablet is suffering from poor performance, battery life and is constantly running out of storage, these 7 tips will help you get it back to its feet. In this book, you'll learn the following: How to optimize your Java code with the SDK, but also how to write and optimize native code using advanced features of the Android NDK such as using ARM single instruction multiple data (SIMD) instructions (in C or assembly) Of course, you can also specify the android:id, android:height, android:width attributes to override the introduced root node attributes. To understand how jank happens, we will review a few terms first: • Frame rate or frames per second is the frequency per second the device’s hardware can draw to a buffer. My hope is that anybody who has never had profiled their code before will have the confidence to do so after they read this. If your frame rate suddenly drops lower than what it was previously for any reason, the user will experience what’s called “jank” – also known as dropped or skipped frames – which means unintentional pauses in motion. On slide 49, you can see the alert says, “Expensive bitmap uploads”, and it provides us with more information about the problem. * Unnecessary Background 5. The rest of it, I cropped out. Hierarchy Viewer also allows the option to get the relative measure layout and draw times for each view or ViewGroup. Layout optimization. For example, realize you may have greater control over relative layout, but understand that that comes with an extra measure in the layout. First, I change directories to Android SDK platform tools. You can see an example on slide 39 displaying memory, CPU, and GPU monitors running. In this 360AnDev talk, I’ll explain what causes jank (dropped frames) to occur while scrolling, tips on how to avoid it and how to profile for problem areas if it happens. I specified that I want the results output to a file named mytrace by using the -o tag. The RAM and CPU varies and if you want a reasonable performance and user experience on all the devices then you need to fix this thing. Transition rendering refers to how many times a pixel on the screen has been rendered in the same frame of time. Then I ran this systrace Python script. Once you enable “On screen as bars”, you’ll see them appear immediately (see slide 33). At the same time, the layout loaded by ViewStub is not allowed to use the < merge > tag. Of course, this is no secret. This XML achieves the exact same results as the one on slide 13, but with a very shallow layout: You can see a side-by-side comparison of the design view screenshots for both layouts on slide 16. Note How often do you perform rendering to make the interface run smoothly? Once you’ve enabled it, you’ll see the immediate effects of it. On the other hand, don’t think your app has to be so perfect that it never drops a frame here or there. In the video, scrolling through our sample app, or on slide 28, you can see a lot of colors. The problem here is that the UI update is performed in the main thread, so when the initialization task and other time-consuming operations occur, the UI will get stuck. The Android SDK includes tools to help you identify problems in your layout performance, which when combined the lessons here, you will be able to implement smooth scrolling interfaces with a minimum memory footprint.