I have taken over an Android project from a past employee and am wondering if there is an easy tool to use for profiling an Android application. I have a LinearLayout with a ProgressBar spinner inside of it. Now I am running a network call on a different thread while that spinner is showing. I use a translate animation to show the entire LinearLayout and when the network call returns on the other thread I hide the LinearLayout. Now this works great but I see that the spinner kind of stops spinning while it is showing. Now it kind of looks like if I interact with the screen, such as trying to scroll, the spinner will continue to spin. For a standard ProgressBar spinner do I need to set some command on the spinner to keep it spinning? Any information on this would be great.
Thanks
You could use StrictMode to detect expensive calls that are being done on the UI Thread.
Why not try implementing your network call in an AsyncTask? In the onPostExecute method implementation you can do whatever is necessary on the UI (i.e hide your progressBar, etc.).
Or, if you are using the compatibility / support library, or targeting Honeycomb or later, use a Loader instead.
Related
I have an ImageView. When user presses button I want to change image (it is animation-list) and run this animation. I used to use setImageResource, but it blocks UI thread and causes lags. I can't predict what image I would set befor user presses button. I tried to preload drawables but it causes OOM, because I have about 30 xmls with animation-list. How can I solve It? To sum up, I want to fastly change image in my ImageView and then start frame animation on it.
I think you are performing a fetch operation on the UI thread for the image(either from storage or network call). That is what is causing the lag.
You might look into using a library to load up your images. There is one that is really easy to implement called Picasso. It's been around for a while too, so it should be easy to see some examples.
I am trying to make an App which is going to display Some Images and Videos. So I am planning to add a splash screen of around 2seconds. After 2 seconds the user will be taken to the Main Screen of the App.
I want to start the loading of the Images, Video when then user is at the splash screen itself so that the user should wait for the least time when he is at the Main Screen.
So the loading will be started at the Splash Screen and then after two second the user will be taken to main screen irrespective of the completion of the loading.
Now since this involves two activities should I use a Async task or should I Use a service with an Async Task(For the callback of completion of code) within it?
Which one would be better. Also in Android 8.0 are there any restriction in using Services?
I think using a Async Task between two screens may cause Memory leak if not coded properly.
Any help would be really grateful.
EDIT: My app is having one more feature hence cannot make the user wait in the Splash Screen till the loading is over.
It is not very good to use AsyncTask for sharing results between 2 activities, because AsyncTack created in Splash activity will be destoyed (stopped) when switched to Main activity. Better to use service in this case and Main screen will subscribe for result.
So basically you want to start the download in the splash screen and continue the download in the activity that follows. In this way, you still have to implement a loading animation. In your case, I would recommend finishing your splash screen, as soon as everything is downloaded. In that way, you don't have to download anything anymore inside the app's lifecycle.
AsyncTasks continue to run even after switching to a new activity. You can try the following flow:
1. Splash screen
2. Trigger Async Task
3. Main Activity
4. Show Images/Videos
The only catch is, you will not be able to fix a time for #2 to complete to be able to start #4. This is the nature of AsyncTasks. You can workaround by using the OnPostExecute within AsyncTask.
Example: OnPostExecute call another method that will enable a button. Users can click on the button to view Images/Videos. But then, this might not be a good user experience to see some button suddenly getting enabled.
In that case I would rather create some Singleton with own Handler (that works in separate Thread), that will be started at Splash screen. After Main screen will start, it should ask that Singleton about respective data or should sign himself for receiving that data.
I have an navigation drawer Activity in which I have made 3 fragments using ViewPager. Each of the fragment has an edit Text, Image button and RecyclerView. The RecyclerView is getting data from a local SQLite database.
On opening the app, I get a Log trace that application skipped XX frames.
(Usually 30-50 frames). Is it normal ? If not, then what should I do? Can fragments be made using background thread like AsyncTask? Or should I populate RecyclerView in background thread?
Is it normal?
Nope. Check out Choreographer (start at line 619) if you are eager to find out what's happening behind the scenes.
what should I do? Can fragments be made using background thread like AsyncTask?
You can't do anything with Views on a background Thread since that would cause a CalledFromWrongThreadException, but what you definitely can and should do is moving all performance-heavy operations like DB read/write to worker Threads. Check out the AsyncTask and AsyncTaskLoader chapter from "Android Developer Fundamentals Course", it will give you a good start on background processing.
Also note that the LoaderManager from the support library is not deprecated.
When my program start I would like to do some settings before is really starting. Forexample choose the user, check the updates and so on. After these settings I would like to start the main program with the appropriate.
Which is the best way to do this?
You can run an AyncTask, or multiple if you need one for each check, in your onCreate() and show a ProgressDialog while the data is being fetched then cancel it in onPostExecute() and move on to the rest of the MainActivity depending on the data that is downloaded. If you need help getting started with AsyncTask you can see this SO answer on the basic structure.
If you use a ProgressDialog then the app will still start but the users will see something and know that data is loading so they won't feel like it is freezing or taking too long to load (or at least they will know why it isn't loaded right away).
AsyncTask Docs
Edit after comment
For what you said you want in your comment you can do this easily with an Activity that has a Dialog Theme. This will give you the functionality you need (a couple Buttons and store the values) but it will look like a little popup. You can't use an actual Dialog as they need an Activity, the same with any menus, AFAIK. Just create your Activity and make it the launcher and main using the Intent-filters then also add the following line to that Activity's tag in the manifest
android:theme="#android:style/Theme.Dialog"
This approach should give you what you need
There are numerous ways to do that.
First - your app is doing some heavy stuff and this may be freezing user interface. In that version do:
1. Create and activity on what you will override onCreate method and set some content with a spinner - so something will be alive and user will see that something is being done.
2. after you will compute all the things that your app need and may I suggest write it to some global variables override onStart method in what change layout to what suit you and give a user a great UI!
Second - you app is not heavy lifting here just throw everything into override of onStart method.
Handy material here for educating:
I need some advice for those who are experienced making Android applications. What I would really like to have, for my application's appearance: at the top, a title-bar which is a ImageView (content is a png), and at the bottom a series of custom buttons which make up a tab-bar like thing. In between the title and the tab-bar is the Content, which may be anything... (most likely buttons)
I have been doing this by making a RelativeLayout which specifies LeftMargin and UpperMargin for x,y coordinates--
Currently all of my activities are inheriting a custom MyActivity class, which rebuilds the title and the tab-bar at the time of onCreate. This seems bad to me!
PART1)
---A solution to Persistent data
Since the "tab-bar" and the title are persistent no matter what screen you're on during this application's run-time, it makes the most sense to store them somewhere... How should I do this? Make a singleton object that the Activity's ask for?
I thought a little about the singleton object, and I'm not even sure what I would store, since the Views that are on displayed during Activity A have activity A as context, and not Activity B.
PART2)
---Animation Aesthetics
I would really like to have the "Content" (the view in the middle between title and tabbar) slide out to the left, and the new content slide in from the right. I.e, I'd like the tab-bar and the title to remain fixed while the "activities" change. is this at all possible? What should I do to achieve it?
one idea I had, was to make all of the program in one activity! I would create an animation for the Custom View in the middle, and I would override the "back" button to navigate correctly to the previous Custom View. Is that a horrible idea?
Anyone have any advice?
Read http://developer.android.com/design. Most of the design principles can be applied to apps that run on legacy releases; it's not just limited to Honeycomb and Ice Cream Sandwich. Do consider the Action Bar and Dashboard design patterns.
I don't really recommend using just one Activity -- generally, an Activity should be a separate, encapsulated, pretty well defined chunk of functionality that can execute independently of other Activities.
To avoid duplication of your UI, consider reusing XML layouts.
To avoid duplication of your logic, consider using Fragments. You should be able to mix and match them in your activities.
To achieve the animation you describe, consider implementing a ViewPager.
Using the ActionBarCompat sample app and Android Support Library, you can enjoy modern goodies like Action Bar, fragments, tabs, and horizontal sliding transitions on devices running Android all the way back to Donut (1.6).