AndroidUtilities

Simple utilities I’ve found to be userful in Android apps and libraries.

SUPPORT NOTICE: This library is now STABLE. It is no longer under active development, however pull requests from others are still being accepted.

Dependency

To use the library, add the following to your gradle build file:

repositories {
  jcenter()
}

dependencies {
  implementation 'com.matthew-tamlin:android-utilities:5.1.2'
}

Older versions are available in the maven repo.

Helpers

The helpers package contains the following classes:

• AssetsHelper
• AudioFocusHelper
• BitmapEfficiencyHelper
• ColorHelper
• DimensionHelper
• InternetHelper
• ScreenSizeHelper
• ThemeColorHelper

AssetsHelper

Provides a simple means of copying assets to a file directory.

AssetsManager manager = context.getAssets();
File targetDir = context.getFilesDir();

// You can copy just one asset
AssetsHelper.copyAssetsToDirectory(manager, targetDir, "picture.png");

// Or you can copy multiple assets using var-args
AssetsHelper.copyAssetsToDirectory(manager, targetDir, "db_config.xml", "default_values");

AudioFocusHelper

Reduces boilerplate code when obtaining and abandoning audio focus.

AudioFocusHelper.requestStreamAlarmFocus(context, new OnAudioFocusChangeListener() {
  @Override
  public void onAudioFocusChange(int focusChange) {
    // Do something
  });
    
AudioFocusHelper.abandonFocus(context, new OnAudioFocusChangeListener() {
  @Override
  public void onAudioFocusChange(int focusChange) {
    // Do something else
  });

BitmapEfficiencyHelper

Encapsulates the complexities and boilerplate code of efficiently decoding artwork.

ImageView imageView = (ImageView) context.findViewById(R.id.image_view);

Bitmap image = BitmapEfficiencyHelper.decodeResource(
    context.getResoures(), 
    R.raw.image, 
    imageView.getWidth(), 
    imageView.getHeight());

imageView.setImageBitmap(image);

ColorHelper

Provides several useful methods for working with colors.

To gradually change the color of something:

FrameLayout layout = (FrameLayout) context.findViewById(R.id.layout);

final int startColor = Color.RED;
final int endColor = Color.BLUE;

ValueAnimator animator = ValueAnimator.ofFloat(0, 1);
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
    @Override
    public void onAnimationUpdate(final ValueAnimator animation) {
        ColorHelper.blendColors(
        startColor, 
        endColor, 
        animation.getAnimatedFraction());
    }
});

To generate random colors:

// The transparency can be fixed at fully opaque
int randomColorWithFullOpacity = ColorHelper.createRandomColor(false);

// Or it can be randomised just like the RGB channels
int randomColorWithRandomOpacity = ColorHelper.createRandomColor(true);

To pick the text color to use against a colored background:

// Some view directly behind the text
int backgroundColor = someView.getBackgroundColor();

// Returns white or black, whichever maximises readability of the text
int textColor = ColorHelper.calculateBestTextColor(backgroundColor);

DimensionHelper

Converts complex units such as DP and SP to pixels.

DimensionHelper.dpToPx(context, someDpDimension);
DimensionHelper.spToPx(context, someSpDimension);
DimensionHelper.ptToPx(context, somePtDimension);

InternetHelper

Provides information about the current internet connection (if any).

ConnectionType connType = InternetHelper.getInternetConnectionType(context);

if (connType == null) {
    disableUpload();
} else if (connType == ConnectionType.WIFI) {
    enableFullUpload();
} else {
    enableCompressedUpload();
}

ScreenSizeHelper

Provides information about the device screen.

To get the physical dimensions of the screen:

int screenWidth = ScreenSizeHelper.getScreenWidth(context);
int screenHeight = ScreenSizeHelper.getScreenHeight(context);

To get the screen size bucket:

public int getLayoutResId(Context context) {
    ScreenSize size = ScreenSizeHelper.getScreenSize(context);

    switch (size) {
        case SMALL: return R.layout.this_screen_is_too_small;
        case NORMAL: return R.layout.this_screen_is_just_right;
        case LARGE: return R.layout.this_screen_is_too_large;
        default: return R.layout.dont_play_with_bears;
    }
}

ThemeColorHelper

Makes it easy to get the primary, primary dark and accent colors of the current theme.

int defaultColor = Color.WHITE;

int primaryColor = ThemeColorHelper.getPrimaryColor(context, defaultColor);
int primaryDarkColor = ThemeColorHelper.getPrimaryDarkColor(context, defaultColor);
int accentColor = ThemeColorHelper.getAccentColor(context, defaultColor);

Compatibility

This library is compatible with Android 14 and up.