Treehouse Android Utilities

This repository holds helpful utility files for Treehouse Android projects. Included are a couple of helper classes that can be used to work with files in Android, like resizing images and converting to byte arrays.

Build a Self-Destructing Message Android App

Download the following files and add them to your project.

*This project also requires the Apache IOUtils library. Download the required JAR here. Choose the latest zip file under "Binaries".

• FileHelper.java
• ImageResizer.java

FileHelper.java

• getByteArrayFromFile(Context context, Uri uri): This method converts a file from a URI to a byte array. It accepts regular URIs as well as content URIs.
• reduceImageForUpload(byte[] imageData): This method is used to reduce a byte array for an image file to a smaller PNG.
• getFileName(Context context, Uri uri, String fileType): This method creates a file name using file type or the MIME type for both regular URIs and content URIs.

ImageResizer.java

• resizeImage(byte[] imageData, int targetWidth, int targetHeight): This resizes an image to a specified width and height.
• resizeImageMaintainAspectRatio(byte[] imageData, int shorterSideTarget): This version resizes an image based on a size for the shorter side of the images (it maintains the aspect ratio).
• getDimensions(byte[] imageData): This is a helper method to get the dimensions of an image.
• calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight): This is a helper method to calculate the appropriate sample size to use for resizing an image.