Level Up - Android Dev: The default emulator is horrendously slow, use Genymotion!

Many years back when I built and published my first Android apps, I only tested them on the default emulator provided by Google. And, even now, the default emulator is still too slow for my liking. It doesn't allow me to properly test apps. So, I purchased physical devices so that I would never have to touch the Android emulator again.

Genymotion provides a different take on the Android emulator. I've known about it for at least a year, but never got around to trying it because of my really bad experience with the default emulator. I've always heard that it was much faster than Google's implementation, but I didn't think an Android emulator could ever be fast enough for me compared to my physical devices.

I'm always learning something new, and today was finally time for me to learn more about Genymotion and test just how much better it is.

Results: Excellent! So much of a great experience that I had to write this blog post about it! I should have tried Genymotion when I first heard about it, and this is my message to all Android devs to also try it out now!

Sidenote: I was going to compare the default emulator with the Genymotion emulator side-by-side, but it was taking too long to load for me, whereas Genymotion startup was a breeze of fresh air. It runs without any lag. It runs faster than my old API 17 device.

Another great benefit is that Genymotion provides system images for many of the most popular devices, including Samsung Galaxy, Samsung Note, HTC One, Nexus, and more. And, they have a very convenient plugin for Android Studio to launch the emulator.

TLDR: It's fast. I have to make sure I stress that because I didn't believe how fast it would be. Genymotion's Android emulator is much faster and better experience than the default Android emulator.



Here, I even saved enough time to write a quick walkthrough for getting started. ;)

1. Go to Genymotion.com, click "Get Genymotion".
2. Download the free version, you'll have to sign up and confirm your email. (It's quick and it's worth it!)
3. Install it along with VirtualBox. For Windows users, they can bundle the two together in the download. For other, you'll have to install VirtualBox separately.
4. If you try to run it now, you might get an error that says "genymotion virtualization engine not found. Unable to load VirtualBox engine". So, just restart your computer and that fixed it for me. Some others had to enable the virtualization feature in the BIOS.
5. Run! Fast!
6. Now, you can click run in Android Studio and you will see an option to load the app in the Genymotion emulator that is running.

Bonus: How to Install the Genymotion Plugin for Android Studio (and, the first time you click on the installed plugin button, you'll have to add the path to where you installed it. Windows default is "C:\Program Files\Genymobile\Genymotion". Mac default is "/Applications/Genymotion.app")

~ Danial Goodwin ~

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My Android Apps | My Windows Phone Apps | My Developer Blog

Level Up - Android Studio: How to Boost Productivity By Auto-Generating Getters and Setters

A best practice in Java is to encapsulate field variables by making them private and creating a "getter" and "setter" for each of them, as needed. Doing this with many fields can be a lot of boilerplate code to write. But, thankfully, modern IDEs, like Android Studio provide ways to auto-generate code so that you don't have to manually write it.

For example, if you have a class like the following:

public class MyClass {
    private int mId;
    private String mName;
}

Instead of manually writing each accessor (getter) and mutator (setter), go to the menu and click Code->Generate.. (hotkey `alt+insert), then choose the "Getter and Setter" option.

Done. That was fast. And, it will be just as fast with 20+ fields also.

But, wait! By default, Android Studio will include that "m" prefix (stands for "member" variable) in each of the generated method names, so you'll have method names like "setmId" and "getmId". There is a quick permanent fix for this also!

Go to File->Settings->Code Style->Java->Code Generation, then type a single "m" into the "Field", "Name prefix" field. Hit apply, then you are gone. All future code generations will take those "m" prefixes for field into account. Here's a screenshot to what this sentence means visually.

So easy to save a lot of time with Android Studio

That's it for this post. There are lots of other useful code generators also. If you are doing mindless work, it's probably been automated (or should be). ;)

~ Danial Goodwin ~

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Level Up - Android: How to Root Nexus 4 on Android Lollipop 5.0 (Easy)

In my last post, I explained how to flash Android Lollipop 5.0 system image to Nexus 4. After I did that to my own device, the next thing I did was root it, using fewer steps than that other post. ;)

Rooted Nexus 4 on Android Lollipop 5.0

This will be a quick walk-through for the steps I took to root my Nexus 4. These directions are extended from the site with the great "CF-Auto-Root" tool that we will use.

Prerequisites:

1. I assume that your bootloader is unlocked. If not, please see my previous post for how to unlock the bootloader.
2. I assume you have `adb` added to your environment variable PATH. If not, please see my previous post.
3. I assume you are running Windows, but Max and Linux users will be able to use these general directions also.

Walk-though for rooting the Nexus 4:

1. Download the LGE Nexus 4 Android 5.0 file from http://autoroot.chainfire.eu/#fastboot
2. Unzip the file. You should see two folders and three files in that folder, one should be called "root-windows.bat".
3. Connect your Nexus 4 device to computer, then run `adb reboot-bootloader` in your computer's terminal. This will bring your device to the "fastboot" mode.
4. Make sure again that your bootloader is unlocked before proceeding (label found at bottom-left).
5. Open your computer's terminal to where you downloaded and unzipped the file, and run `root-windows` (Mac and Linux users use your own variant). You should see a red Android if the process is working.

Congrats! When the script is done, it will reboot your device and your Nexus 4 will be rooted!

This process will install the Root Check app so that you can verify a successful root.

More info:

• I didn't have any trouble using these directions for rooting my Nexus 4, so if you have any troubles with the steps, then I'll try to help in my limited capacity.
• Previously, when I was running Android 4.4 rooted, I used ES File Explorer to browse the root directories. But, it didn't work in Android 5.0, so instead I am now using the Root Browser app successfully.

~ Danial Goodwin ~

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Level Up - Android: How to Flash (Upgrade) Nexus 4 to Android Lollipop 5.0 (Easy)

If you have a Nexus 4, then you can have Android Lollipop now! Google recently released the factory image, and I'm now successfully running it (with root, which will be explained in a later post).

Nexus 4 running Android Lollipop 5.0

This will be a short walk-through because I assume you already have the tools needed, but just need the steps to get the flash done. If you have any questions, then please write a comment and I will update as necessary.

1. Download Android Lollipop 5.0 factory image: https://developers.google.com/android/nexus/images#occam
2. Uncompress the file, possibly twice. I used 7-zip. You should see six files there, including a zip, which you do not have to unzip.
3. Make sure `adb` is in your PATH environment variable, which can be found in %android-sdk%/platform-tools/. Also, you will need `fastboot.exe` from that same folder in your PATH. (I assume you already have the Android SDK and you know what I mean by "Advanced system settings"->Environment Variables->PATH.)
4. Connect your Nexus 4 device to computer, then run `adb reboot-bootloader` in your computer's terminal. This will bring your device to the "fastboot" mode.
5. At the very bottom-left, you should be able to see whether your bootloader is locked or unlocked. It must be unlocked to flash a new system image. If unlocked, you're good, go to the next step. If locked, then run `fastboot oem unlock`. WARNING: Unlocking will erase all data.
6. Open your computer's terminal to where you downloaded and uncompressed the files, and run `flash-all`. That command will run the "flash-all.bat" script which will setup the new system image for you!

Congrats! When the script is done, it will reboot your device and Lollipop will be running. It may take a bit for it to boot the first time.

More info: There sure is a lot more information you could read about this entire process, but that's not what this post is for. These are the minimal instructions (with appropriate warning) for most people wanting to do this. If anybody has some good resources to share, then please add them to the comments.

Now, are you ready to root your Nexus 4?

:)
~ Danial Goodwin ~

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My Android Apps | My Windows Phone Apps | My Developer Blog

Level Up - Java: What is Vararg?

I like to remember vararg as "variable-length arguments". You may see them parameterized as "foo(Object... objects)" or "foo(int... ints)" or maybe "main(String... args)". The triple-dot signifies the vararg, and the method that has them uses it as an array.

Example code:

/** Returns input as a comma-separated list. If input if null

  * or empty, then this returns an empty string. */

public static String convertToString(Object... objects) {

    if (objects == null || objects.length == 0) { return ""; }

    StringBuilder sb = new StringBuilder();

    for (Object object : objects) {

        sb.append(object.toString()).append(", ");

    }

   return sb.substring(0, sb.length() - 2).

}

More info: https://docs.oracle.com/javase/1.5.0/docs/guide/language/varargs.html

~ Danial Goodwin ~

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Level Up - Android: Speed up your Gradle build times with one-line!

Whether or not you are using Android Studio, Gradle build times are slow (especially when you don't have continuous automated builds (another discussion)).

Here's one way to improve the speed Gradle commands like `assembleRelease` is to enable the Gradle daemon. I've sped up my release builds by about 20%!

Level Up - Paint.NET & Android: How to create new color palettes for Android Holo and Material design

If you work in Android and Paint.NET, here's some quick tips and resources to make both easier to work with. When designing graphics in Paint.NET, it would be really useful to have direct access to all of the Android design guide colors. So, here's how to save and load different color palettes in Paint.NET:

Level Up - Android: How to get started with Unit Testing in Android Studio

Recently, I finally got around to implementing the native unit testing that is provided within Android Studio (not third-party programs like Robolectric). So, after reading a few different sources, the following is the bare minimum that I would have needed in order to add the basic testing features.

Level Up - Android: How to get started with Android Wear and the Wearables Emulator

Recently, I started working on Android Wear for the first time. It's been fun playing around with the new platform and form factor. And, of course, the official Android docs that I read could be condensed further for absolute newcomers. So, in the typical fashion, I've created myself a cheat sheet that I would use next time I would want to learn the easiest way for how to best create Wearable apps.

I've open sourced all my code so far on GitHub. It includes how to first set up the virtual Wear device, connect to the handheld device, and how to have the app send and open a notification on the wearable.

https://github.com/danialgoodwin/android-wear

~ Danial Goodwin ~

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My Android Apps | My Windows Phone Apps | My Developer Blog

Level Up - Dev: Abstractions

Abstractions are great!

Except, when they aren't.

We use abstractions everyday in our code, and it's what allows us to create our programs. This post is just going to be a quick blurb on the downside to non-trivial abstractions, as motivated by reading: http://www.joelonsoftware.com/articles/LeakyAbstractions.html

It's a great read. And, in the interest of time, for now:
TLDR:
- All non-trivial abstractions, to some degree, are leaky.
- Abstractions fail, and you have to know the underlying pieces to understand how to fix it.
- Many great examples
- When there is some great new code-generation tool, learn how to do it manually first, then use the tool to save time.

Eventually, I'll write my own informative article about abstractions, but for now, this will have to do. ;)


And, as I like to say, make sure you remember to think for yourself. Don't do something just because somebody else did it. Don't let your excuse be that somebody else told you to do it.

~ Danial Goodwin ~

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Level Up - Dev: Modular Code

Modular code means that the code is easily reusable; It does not mean that the code has to all be in one file. That's what modules and libraries are for. ;)

~ Danial Goodwin ~

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Level Up - Dev: Codestyle Quote

"Any fool can write code that a computer can understand.
Good programmers write code that humans can understand."

--- Martin Fowler, Refactoring: Improving the Design of Existing Code

~ Danial Goodwin ~

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Research says Work and Study Harder to be more Successful

Research shows that people who work and study harder tend to be more successful.


~ Danial Goodwin ~

ps - I have absolutely no sources to back this up, but it's something nice to believe in. ;)

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Book: The Inner Game

The actual title of the book that I just read is called "The Inner Game of Tennis", but this post is not about tennis.

This was a great read, and you should read this book if you play sports and have ever wondered why you play good one day and bad the next. This book may help you have a more consistent and higher gameplay.

I wrote a whole bunch of notes as I read, and you can read them on GitHub.

If it's too much trouble to click a link, then here's the TLDR (Too Long; Didn't Read) that shares just a few of the biggest points:

• There is an inner game and outer game. There are already many great resources on the outer game.
• During practice, analyze your movements (methods includes "feeling" it, mirrors, video playback) and don't try to force any change. During game play, just let it happen naturally; trust yourself.
• Experiment with many different playing styles. The "right" style may be different for different people.
• You still may need some good outer game practice in order to gain more from these inner game tips.
• If you dislike competition, then you have the wrong idea about it.
• When playing, if you have any anxieties or frustrations, then you aren't a player of the inner game.

And, if you have already read this book or any of the other "Inner Game" books, then I'd be happy to hear your biggest take-aways.

~ Danial Goodwin ~

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Level Up - Dev: Integer Overflow Not Overflowing

An integer overflow (or wraparound) occurs when a number larger than the max integer value or smaller than the min integer value is tried to be stored in the integer's memory. You could imagine a circular number line.

Ex: If you have an integer at the max positive value and add one, then the integer will wraparound and be set to the most negative value (if using a signed int. An unsigned int will wraparound to 0). And, vise-versa.

Today, I experienced a bug where I wanted to get a (signed) integer overflow, but unfortunately the int value was just going to zero instead of going to the negative numbers. Thankfully, I knew the memory/bit representation of int and was able to figure out what was going on.

Here is some simplified code, with only one small change:

    // Test #1 - has wraparound
    int wrap = 1;
    for (int i = 0; i < 34; i++) {
        print(i + ": wrap: " + wrap);
        wrap = wrap * 3;
    }

    // Test #2 - no wraparound
    int wrap = 1;
    for (int i = 0; i < 34; i++) {
        print(i + ": wrap: " + wrap);
        wrap = wrap * 2;
    }

Here is the relevant output from running the code above:

// Test #1 - has wraparound
...
13: wrap: 1594323
14: wrap: 4782969
15: wrap: 14348907
16: wrap: 43046721
17: wrap: 129140163
18: wrap: 387420489
19: wrap: 1162261467
20: wrap: -808182895
21: wrap: 1870418611
22: wrap: 1316288537
23: wrap: -346101685
24: wrap: -1038305055
25: wrap: 1180052131
26: wrap: -754810903
27: wrap: 2030534587
28: wrap: 1796636465
29: wrap: 1094942099
30: wrap: -1010140999
31: wrap: 1264544299
32: wrap: -501334399
33: wrap: -1504003197

// Test #2 - no wraparound
...
20: wrap: 1048576
21: wrap: 2097152
22: wrap: 4194304
23: wrap: 8388608
24: wrap: 16777216
25: wrap: 33554432
26: wrap: 67108864
27: wrap: 134217728
28: wrap: 268435456
29: wrap: 536870912
30: wrap: 1073741824
31: wrap: -2147483648
32: wrap: 0

33: wrap: 0

If test #1 were to continue, then the values would keep wrapping. If test #2 were to continue, then the values would stay the same at 0.

The easiest way for me to make sense of this experiment was to know that multiplying by a power of 2 (2, 4, 8, 16, 32..) is the exact same as a bit shift in the binary computer. And, the bits that made up the int were all just getting pushed out of memory in test #2 until there were no more set bits to manipulate. In test #1, more int memory bits are being flipped in order to continue the wraparound.

I would explain this at a lower level, but there are already many great resources for "bit representation of integer".


~ Danial Goodwin ~

ps - This post was mainly for myself and written quickly. If there are any questions about this, then I'd be happy to elaborate.

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