I am looking for some practices to follow for making my startup's app performant.
Please share the tips/tricks and practices that you follow for making Flutter apps smoother. I have shared some practices that I currently follow. Thank you!
Flutter apps are very performant if some of the performance optimisations are kept in mind while developing the apps. No doubt, apps can become laggy and janky.
1: Use smaller image files:
No doubt, images are essential for any mobile application. And this is the area where performance gets the hit by a good margin, if not managed correctly. I started my journey as an Android Developer and I soon experienced lot of lag and poor performance in my apps. Later, I found that I was using the images which were of several MBs each. The resolution of image assets was much higher than required.
This took lot of time for device to load the assets and draw pixels, increasing CPU & GPU’s work. Sometimes, images even failed to load, making app completely unresponsive.
Here are some tips to follow to avoid performance issues related to image assets.
Try reducing size of you images from tinypng.
Lower the resolution of image here. Make sure the resolution is not more than any higher end device’s resolution.
2: Avoid Unnecessary Animations
Animation is a foe of performance, using animations may cause your device resources to constantly work (since the animation values are generated again & again). CPU constantly needs to generate values & GPU has to redraw widgets.
3: Remove Redundant Widgets
Personally, I used lot of redundant widgets like useless containers & other widgets which did not contribute to overall UI feel of the app. Gradually, I realised that this was becoming my habit. Although this can be subjective. Make sure to use only those widgets which are necessary.
4: Proper State Management
A proper state management solution can make your app very efficient & avoid computational overhead. A typical Flutter app may contain hundreds of widgets. Updating these widgets & redrawing them again & again may cause your device to work more. The proper state management allows only necessary widgets to update their state or redraw. Let’s assume that you are using Provider as your state management tool for the app, Provider will only notify its listeners i.e consumer widgets. Only widgets listening to that Change Notifier Provider will update.
Image description
5: Use Dart Dev Tools (Flutter Dev Tools)
Dart Dev Tools is a combination of some useful profiling tools which can help to determine which widget or functionality is taking much processing power and cause lag or jank. Dev Tools illustrate a clear picture of things happening at main & UI thread.
Image description
6: Use Const Widgets Wherever Possible
It is good practice to use the keyword const for constants that we can initialise at compile time. Let's also not forget to use const as much as possible for our widgets, this allows us to catch and reuse widgets to avoid unnecessary rebuilds that are caused by their ancestors.
7: Avoid Functional Components
Flutter is all about widgets, creating a custom widget can be done in two popular ways. Either create a function returning respective widget (functional approach) or create a whole new widget. It is highly recommended to create either Stateless or Stateful widget rather than creating a function.
this question is more for looking advices
I've developed an almost full user interface in pure c++ and opengl es 2, currently I'm developing that the click/touch events be propagate as in HTML, I can't remember why I decided do a UI in opengl, but now I realize that I'm reinventing the wheel.
so currently I have many "elements", buttons, containers, scrolls, pictures, animated pictures, borders, text, drag-drop's, I can set easily where I want each element, set sounds, and I really don't know how fast and effective it is right now, but I've maked all the fast and memory effective that I can, and I planning to use multi-threading in the future. And my goal is to approach a system like html.
And now that I'm looking for how to implement my UI in native Android (java), I realized that I was in the correct way, all the properties and methods all the structure I'm implementing in c++ and opengl is almost the same as in android, even I think my implementation is easier to use the images and sounds because I've automatized all and I can put it in the assets folder, and in the code only put the name of the file and the program returns it, with and effective memory managment.
the current elements are elements that I need for a game interface, so if I need other kind of element I'd have to write it, but right now, I have all elements that I need, I think so.
maybe my code in c++ is faster than java.
but even with all this, I know I have a lot to do to have a full UI, so can you give some advices or experience, advantages, disadvantages, it worth to continue with the UI, or better learn (beacuse I just know a llitle bit of UI Android) UI Android, modify all my game for use the new arquitecture/system, What do you think?
I have build a pinball game in unity 3d for android and for some low mobile devices it is running slowly. I was thinking about hiring a unity expert to lighten up the code so it would run better on all devices.
But I wonder if this is possible. Can you make a game preform better by changing the code? I have to add this was my first unity project and it's very messy.
Thanks for helping
Absolutely, there are plenty of ways that changes to code could yield significant increases in performance, depending on how you're currently doing things.
One of them is object pooling when dealing with frequent creation/destruction of objects, another is caching component references when they are used often every frame. And if you're still using OnGui for your interface, probably avoid it in favour of the new (as of 4.6) GUI system. But you haven't included your code in your question, so I can't give a definite solution for optimizing your code.
Chances are though, not all of your code is problematic, just key scripts. My suggestion is to take a look at the Unity Profiler to determine which areas in your code are slowing down your game the most, then take steps to try reducing the execution time. You should also take into consideration non-code problems (eg. With lighting, geometry, materials, textures). Take a look at the guide Unity provides for ideas on how to address those
If you're still having problems, then you can bring that specific code to StackOverflow and see if it can be further improved. Hope this helps! Let me know if you have any questions.
I am new to Android SDK/API environment. It's the first I am trying to draw a plot/chart. I tried running different kinds of sample codes on the emulator using 3 different free libraries, nothing is showing on the layout screen. The logcat is repeating the following message:
W/Trace(1378): Unexpected value from nativeGetEnabledTags: 0
I/Choreographer(1378): Skipped 55 frames! The application may be doing too much work on its main thread.
The problem didn't persist and the chart worked when I ran a sample code pertaining to an evaluation copy of a licensed library.
taken from : Android UI : Fixing skipped frames
Anyone who begins developing android application sees this message on
logcat “Choreographer(abc): Skipped xx frames! The application may be
doing too much work on its main thread.” So what does it actually
means, why should you be concerned and how to solve it.
What this means is that your code is taking long to process and frames
are being skipped because of it, It maybe because of some heavy
processing that you are doing at the heart of your application or DB
access or any other thing which causes the thread to stop for a while.
Here is a more detailed explanation:
Choreographer lets apps to connect themselves to the vsync, and
properly time things to improve performance.
Android view animations internally uses Choreographer for the same
purpose: to properly time the animations and possibly improve
performance.
Since Choreographer is told about every vsync events, I can tell if
one of the Runnables passed along by the Choreographer.post* apis
doesnt finish in one frame’s time, causing frames to be skipped.
In my understanding Choreographer can only detect the frame skipping.
It has no way of telling why this happens.
The message “The application may be doing too much work on its main
thread.” could be misleading.
source :
Meaning of Choreographer messages in Logcat
Why you should be concerned
When this message pops up on android
emulator and the number of frames skipped are fairly small (<100) then
you can take a safe bet of the emulator being slow – which happens
almost all the times. But if the number of frames skipped and large
and in the order of 300+ then there can be some serious trouble with
your code. Android devices come in a vast array of hardware unlike ios
and windows devices. 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. When frames are skipped the UI is slow and
laggy, which is not a desirable user experience.
How to fix it
Fixing this requires identifying nodes where there is or
possibly can happen long duration of processing. The best way is to do
all the processing no matter how small or big in a thread separate
from main UI thread. So be it accessing data form SQLite Database or
doing some hardcore maths or simply sorting an array – Do it in a
different thread
Now there is a catch here, You will create a new Thread for doing
these operations and when you run your application, it will crash
saying “Only the original thread that created a view hierarchy can
touch its views“. You need to know this fact that UI in android can be
changed by the main thread or the UI thread only. Any other thread
which attempts to do so, fails and crashes with this error. What you
need to do is create a new Runnable inside runOnUiThread and inside
this runnable you should do all the operations involving the UI. Find
an example here.
So we have Thread and Runnable for processing data out of main Thread,
what else? There is AsyncTask in android which enables doing long time
processes on the UI thread. This is the most useful when you
applications are data driven or web api driven or use complex UI’s
like those build using Canvas. The power of AsyncTask is that is
allows doing things in background and once you are done doing the
processing, you can simply do the required actions on UI without
causing any lagging effect. This is possible because the AsyncTask
derives itself from Activity’s UI thread – all the operations you do
on UI via AsyncTask are done is a different thread from the main UI
thread, No hindrance to user interaction.
So this is what you need to know for making smooth android
applications and as far I know every beginner gets this message on his
console.
As others answered above, "Skipped 55 frames!" means some heavy processing is in your application.
For my case, there is no heavy process in my application. I double and triple checked everything and removed those process I think was a bit heavy.
I removed Fragments, Activities, Libraries until only the skeleton was left. But still the problem did not go away. I decided to check the resources and found some icons and background I use are pretty big as I forgot to check the size of those resources.
So, my suggestion is if none of the above answers help, you may also check your resource files size.
I too had the same problem.
Mine was a case where i was using a background image which was in drawables.That particular image was of approx 130kB and was used during splash screen and home page in my android app.
Solution - I just shifted that particular image to drawables-xxx folder from drawables and was able free a lot of memory occupied in background and the skipping frames were no longer skipping.
Update Use 'nodp' drawable resource folder for storing background drawables
files.
Will a density qualified drawable folder or drawable-nodpi take precedence?
Another common cause of delays on UI thread is SharedPreferences access. When you call a PreferenceManager.getSharedPreferences and other similar methods for the first time, the associated .xml file is immediately loaded and parsed in the same thread.
One of good ways to combat this issue is triggering first SharedPreference load from the background thread, started as early as possible (e.g. from onCreate of your Application class). This way the preference object may be already constructed by the time you'd want to use it.
Unfortunately, sometimes reading a preference files is necessary during early phases of startup (e.g. in the initial Activity or even Application itself). In such cases it is still possible to avoid stalling UI by using MessageQueue.IdleHandler. Do everything else you need to perform on the main thread, then install the IdleHandler to execute code once your Activity have been fully drawn. In that Runnable you should be able to access SharedPreferences without delaying too many drawing operations and making Choreographer unhappy.
I had the same problem. Android Emulator worked perfectly on Android < 6.0. When I used emulator Nexus 5 (Android 6.0), the app worked very slow with I/Choreographer: Skipped frames in the logs.
So, I solved this problem by changing in Manifest file hardwareAccelerated option to true like this:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.myapplication">
<application android:hardwareAccelerated="true">
...
</application>
</manifest>
Update Jan 2022. According to the comment from #M.Ed: Hardware acceleration is enabled by default if you're targeting APIs >= 14.
Try to use the following strategies in order to improve your app performance:
Use multi-threading programming if possible. The performance benefits are huge, even if your smart phone has one core (threads can run in different cores, if the processor has two or more). It's useful to make your app logic separated from the UI. Use Java threads, AsyncTask or IntentService. Check this.
Read and follow the misc performance tips of Android development website. Check here.
I am not an expert, but I got this debug message when I wanted to send data from my android application to a web server. Though I used AsyncTask class and did the data transfer in background, for getting the result data back from server I used get() method of the AsyncTask class which makes the UI synchronous which means that your UI will be waiting for too long. So my advice is to make your app do every network oriented tasks on a separate thread.
I had the same problem. In my case I had 2 nested Relative Layouts. RelativeLayout always has to do two measure passes. If you nest RelativeLayouts, you get an exponential measurement algorithm.
Optimize your images ... Dont use images larger than 100KB ... Image loading takes too much CPU and cause your app hangs .
this usually happens when you are executing huge processes in main thread. it's OK to skip frames less than 200. but if you have more than 200 skipped frames, it can slow down your application UI thread. what you can do is to do these processes in a new thread called worker thread and after that, when you want to access and do something with UI thread(ex: do something with views, findView etc...) you can use handler or runOnUiThread(I like this more) in order to display the processing results.
this absolutely solves the problem. using worker threads are very useful or even must be used when it comes to this cases.
https://stacklearn.ir
I had the same problem. When I ran the code on another computer, it worked fine. On mine, however, it displayed "The application may be doing too much work on its main thread".
I solved my problem by restarting Android studio [File -> Invalidated caches / Restart -> click on "Invalidate and Restart"].
My app had same problem. But it was not doing other than displaying list of cards and text on it. Nothing running in background. But then after some investigation found that the image set for card background was causing this, even though it was small(350kb). Then I converted the image to 9patch images using
http://romannurik.github.io/AndroidAssetStudio/index.html.
This worked for me.
In my case, it was because I had accidentally set a breakpoint on a method. Once I cleared it, the message went away and performance improved a lot.
As I did first preferably use SVG images instead of all other types, If not possible compress all of your PNG and JPG resources using some image processing tools such as Adobe Photoshop or Fotosizer. one of the easiest ways is online image compressing tools like this which helped me to decrease all my image files to almost 50% of their initial size.
This is actually not a problem. This happens when you have the debugger for a long time. Remove the brake point and check again.
I got same issue while developing an app which uses a lot of drawable png files on grid layout. I also tried to optimize my code as far as possible.. but it didn't work out for me.. Then i tried to reduce the size of those png.. and guess its working absolutely fine.. So my suggestion is to reduce size of drawable resources if any..
After doing much R&D on this issue I got the Solution,
In my case I am using Service that will run every 2 second and with the runonUIThread, I was wondering the problem was there but not at all.
The next issue that I found is that I am using large Image in may App and thats the problem.
I removed the Images and set new Images.
Conclusion :- Look into your code is there any raw file that you are using is of big size.
First read the warning. It says more load on main thread. So what you have to do is just run functions with more work in a thread.
Have not resolved yet but will do. For my tiny project with one composable function (button) and logic to check if "com.whatsapp" packages exists on device (emulator) i have the following in the same log while starting simulator:
I/Choreographer: Skipped 34 frames! The application may be doing too much work on its main thread.
For me that was RoundedBackgroundColorSpan ! in textview, I remove it so (burn my brain to find it because It doesn't appear in real smartphones like Pixel 4 Xl or Samsung note 10+ also in emulator but in chip device this slow a view).
This is normal if you are using async/await functionalities in your application.
What considerations should one be mindful of when constructing a GLSurfaceView-centric UI?
This is for a game and the bulk of the UI will be an intro screen (start, options, about, exit) and a level selector screen. I've put a lot of time into the rendering/animation for the game using OpenGL, and I'm no graphic artist, so taking the OGL UI route seems to make sense to me. But I'm an Android novice and need some outside input. Thanks for reading.
There is nothing wrong with that, especially for a game. The only problem is that you will have to do everything yourself. Most games seem to be doing this.
Due to the ease from which one activity can start another, I would say it is worthwhile to abstract your options and level selection from the game itself. If you're unfamiliar with starting activities and/or passing information between activities, there are plently of good tutorials and examples to help. You could try the ubiquitous Notepad tutorial if you haven't already ( http://developer.android.com/resources/tutorials/notepad/index.html ).
The advantages of this method would be to leave your OpenGL/game Activity less cluttered, and that you would be able to use tried-and-true Android UI elements instead of building your own from scratch.