As any mobile platform evolves and its application offerings improve, quality becomes paramount to success. These days, users demand responsiveness and reasonable performance from the Android applications they choose to install on their devices. And if those applications fail to deliver both exciting functionality and a stable user experience, then the application is quickly uninstalled.
Although Android smartphones and tablets are getting faster every day, developers need to remember that their applications are still running in a resource-constrained environment powered primarily by battery and processors that do not rival the latest desktops or laptops. Here are some ways to slim down your applications so they run optimally on the Android devices of today and tomorrow.
Let's start with some coding tips for responsive applications.
Android App Performance Tip #1: Start with Good Coding Practices
Be a good steward and use common sense, well-established algorithms and standard design patterns. Resource-wise, if you open it, close it. Acquire late, release early. These long-standing coding mantras apply to your Android applications as well, especially if they use underlying device services.
For example, let's say you've written an application that relies upon location-based services. Don't start register for location updates until you absolutely have to, and make sure you un-register for updates as soon as you no longer need the information. This will help you not drain the device battery or hog the system unnecessarily.
Android App Performance Tip #2: Keep Blocking Operations Off the Main UI Thread
Keep your applications nimble by using an AsyncTask, thread, IntentService, or custom background service to do the dirty work. Use loaders to simplify state management of long loading data, such as cursors. You cannot afford for your application to lag or freeze while some processing is going on.
If an operation takes time and resources, offload that processing and perform it asynchronously so that your application remains responsive and the user can go about their business. This applies to operations such as: reading and writing to disk, accessing content providers, databases and the Internet, as well as parsing and other lengthy tasks.
Android App Performance Tip #3: Use the Latest Android SDK Versions, APIs and Best Practices
Keep your applications up-to-date and using the latest that the Android platform has to offer. As the Android platform evolves, it is improved. Some features may be retired, or replaced with better options. Core APIs receive bug fixes and performance improvements. New APIs like loaders have been introduced to help developers write more stable and responsive applications.
Did you know you can enable hardware acceleration in your Android 3.0 apps? Do it! Understand that best practices change over time. Smart developers stay on top of what's new in the platform and what's no longer recommended.
Android App Performance Tip #4: Check Out Strict Mode
You can use an Android API called StrictMode to help you track down violations in several good coding practices. StrictMode will help you identify if your application is leaking memory, as well as detect whether or not your application is trying to perform lengthy blocking operations that should be offloaded to threads or otherwise (see #2).
The StrictMode class (android.os.StrictMode) was introduced in Android 2.3.
Android App Performance Tip #5: Disable or Minimize Debugging and Diagnostics Prior to Publication
If your Android application has taken more than a few minutes to develop, you've probably got some logging and debugging code built into your application. Writing to logs and other such output comes at a performance hit. Make sure these features are minimized or completely disabled prior to release.