package org.edx.mobile.third_party.subscaleview.decoder;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Point;
import android.graphics.Rect;
import android.net.Uri;
/**
* Interface for image decoding classes, allowing the default {@link android.graphics.BitmapRegionDecoder}
* based on the Skia library to be replaced with a custom class.
*/
public interface ImageRegionDecoder {
/**
* Initialise the decoder. When possible, initial setup work once in this method. This method
* must return the dimensions of the image. The URI can be in one of the following formats:
* File: file:///scard/picture.jpg
* Asset: file:///android_asset/picture.png
* Resource: android.resource://com.example.app/drawable/picture
* @param context Application context. A reference may be held, but must be cleared on recycle.
* @param uri URI of the image.
* @return Dimensions of the image.
* @throws Exception if initialisation fails.
*/
Point init(Context context, Uri uri) throws Exception;
/**
* Decode a region of the image with the given sample size. This method is called off the UI thread so it can safely
* load the image on the current thread. It is called from an {@link android.os.AsyncTask} running in a single
* threaded executor, and while a synchronization lock is held on this object, so will never be called concurrently
* even if the decoder implementation supports it.
* @param sRect Source image rectangle to decode.
* @param sampleSize Sample size.
* @return The decoded region. It is safe to return null if decoding fails.
*/
Bitmap decodeRegion(Rect sRect, int sampleSize);
/**
* Status check. Should return false before initialisation and after recycle.
* @return true if the decoder is ready to be used.
*/
boolean isReady();
/**
* This method will be called when the decoder is no longer required. It should clean up any resources still in use.
*/
void recycle();
}