Category: Android

Flutter Initial Impression

Flutter has been getting a lot of positive press in my social media feeds. I listened to an episode of Engineering Daily which interviewed Eric Seidel, one of the founders of Flutter.

I was extremely disappointed that they chose not to implement any hardware interfaces, like accelerometer, GPS, etc. Flutter really just cares about the UI. They are letting “the community” build plug-ins for all the hardware interactions because those vary by and sometimes within a platform. So now Flutter apps will be like PhoneGap and WordPress. Soon (if not already) there will be a dozen GPS plugins, all with slightly different feature sets, wildly different degrees of quality, and patchy support for different devices within a platform (think of the camera in Android devices). Judging between these plugins will be difficult, and in many cases plugins are unable to be used by certain types of clients, like the federal government, due to security concerns and vetting processes. So in those cases you will just write your own. The cost of a cross-platform app is not going to be lessened by using Flutter. At this point I’d say it’s OK for CRUD or brochureware, but not much else. If your app doesn’t interact with the hardware, why not just build a web site?

I’ll still write some code with it, but I’m disappointed with the reach of the platform into the devices it runs on.

Set Up Android Accessibility Tests Using Espresso

Espresso Logo
The Espresso documentation has a good simple example of how to set up Accessibility Tests in Android. By including AccessibilityChecks, your tests run a number of rules against the activity/fragment under test to ensure it’s accessibility. The tests fail if all the rules do not pass. The basic gist is that you add a @BeforeClass annotated method which calls AccessibilityChecks.enable():

@BeforeClass
public static void enableAccessibilityChecks() {
    AccessibilityChecks.enable();
}

You are supposed to enable this in Espresso 3 by adding the following dependencies to your build.gradle file:


androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
androidTestImplementation 'com.android.support.test:runner:1.0.1'
androidTestImplementation 'com.android.support.test.espresso:espresso-accessibility:3.0.1'

Unfortunately, I have not been able to make it work due to an error in the Espresso library.

Espresso 3.0.1 Broken

The setup described in the Android Documentation results in a run-time error if you include the espresso-accessibility library referenced in the documentation:

Error:Error converting bytecode to dex:
Cause: com.android.dex.DexException: Multiple dex files define Landroid/support/test/espresso/accessibility/R$attr;

This issue was reported on Stack Overflow, but the one answer did not work for me. In the Google Issue tracker a response implies the problem is fixed in v3.0.2. I was unable to get my hands on that version to test it out.

In order to solve the problem, I had to roll back the Espresso libraries to version 3.0.0 in build.gradle:

Espresso 3.0.0 Broken

Turns out this version of Espresso is also broken, but in a different way. It’s missing a transitive dependency on Guava. To get Espresso 3.0.0 to work, you need to add the missing dependency on Guava into your build.gradle:


androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.0'
androidTestImplementation 'com.android.support.test:runner:1.0.0'
androidTestImplementation 'com.android.support.test.espresso:espresso-accessibility:3.0.0'
androidTestImplementation 'com.google.guava:guava:20.0'

I published a simple example project demonstrating an Espresso UI test that includes Accessibility checks on Github. The project’s one UI test actually fails, so you can see what the output looks like when an accessibility check fails. There is a comment in activity_main.xml where the accessibility problem lies. The “broken” branch has the project set up for Espresso 3.0.1 so you can see that error. Hopefully Google pushes 3.0.2 soon.

Be Consistent Not Uniform

Android UI is not iPhone UI

A common shortcut often taken is to make one UI work on multiple platforms, and I find myself fighting this misconception often. My thoughts on this were spurred by an article Mobile First, Desktop Worst, which basically takes on mobile first and responsive design as being flawed. I think many of the arguments presented in that article were also relevant to building mobile UIs for an app that exists on both iOS and Android.

UI development is the most time consuming aspect of developing mobile apps. As the app owner you may want your app to be the same on all platforms to try and minimize the work, but this thinking is wrong. Individual users don’t use your app on multiple platforms and expect a common experience, they use your app on their chosen platform and expect it to act like other apps on their chosen platform. An application which does not adopt the UI conventions of the target platform will have diminished success. Users now expect applications to match their platform experience, especially millennials or users who don’t have experience in other platforms.

Each platform has controls, widgets and interaction paradigms that do not exist on other platforms. One UI that works across all platforms will not take advantage of the unique features of each platform, becoming a compromised design that does not meet user’s expectations. The differences in each platform are typically what makes a quality user experience for that platform. The least-common-denominator approach of the sameness across platforms reduces the potential for adoption and success of an app on any given platform. Mobile usability and a fabulous UX are now expected, and your app won’t achieve that goal unless it exploits the platform and device features.

Many of the cross-platform tools make this mistake out of the gate and promise a two-for-one outcome, which is fallacious thinking. Don’t fall into this trap.

Apache HTTP Client in Android API 24+

Google had been telling us for quite some time that the Apache HTTP Client was deprecated and going to be removed, and with the release of Marshmallow (API 24) this came true. For the vast majority of developers, this is a non-issue. The HttpUrlConnection object is more than adequate. But for some enterprise developers, this presented a problem. The HttpUrlConnection does not support NTLM (Microsoft Active Directory) authentication. But the Apache client does. If you are using or want to use the Apache client, it is still possible. Simply add this to the android section of your build.gradle:

android {
    useLibrary 'org.apache.http.legacy'
}

Now when you build the Apache client becomes available again. It’s still marked as deprecated and Android Studio will complain, but it definitely works.

Resources – Android Authentication in the Web World

I am presenting this talk at the Michigan GDG DevFest on April 22nd. It’s an look at understanding and using existing web technologies for authenticating an Android application to web services, to make for a more secure experience for your Android users.

Code

Github repo

Slides

Links

Resources – Apps Users Want to Use

DetroitDevDay

I am presenting this talk at DetroitDevDay on November 12th. It’s a look into some differing views on psychology and app composition and how it affects users of software. As a mobile developer, this kind of work had come to the forefront as the bar for mobile apps continues to rise.

Books

Articles

Videos