Utility.java

package info.papdt.pano.support;

import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.util.DisplayMetrics;
import android.util.Log;

import java.io.File;
import java.util.Arrays;
import java.util.List;

import static info.papdt.pano.BuildConfig.DEBUG;

public class Utility
{
	private static final String TAG = Utility.class.getSimpleName();
	
	public static <T> int arrayContainsEx(T[] list, T[] sub, float threshold) {
		int length = sub.length;
		
		int index = -1;
		for (int i = 0; i < list.length - length; i++) {
			if (arrayCompareEx(list, sub, i, 0, length, threshold)) {
				index = i;
				break;
			}
		}
		
		return index;
	}
	
	public static <T> boolean arrayCompareEx(T[] a, T[] b, int aStart, int bStart, int length, float threshold) {
		int unmatches = 0;
		for (int i = 0; i < length; i++) {
			T valueA = a[aStart + i];
			T valueB = b[bStart + i];
			
			if (valueA == null || !valueA.equals(valueB)) {
				unmatches++;
			}
		}
		
		/*if (DEBUG) {
			Log.d(TAG, "ummatches: " + unmatches + " of " + length);
		}*/
		
		return unmatches <= length * threshold;
	}
	
	
	/*
	 * Find the longest common subarray
	 * Designed for arrays that have common parts at head and tail
	 * @param headArray The array that have a common part with the other at head
	 * @param tailArray The array that have a common part with the other at tail
	 *
	 */
	public static <T> int arrayHeadTailMatch(T[] headArray, T[] tailArray, int length, float threshold) {
		if (headArray.length != tailArray.length) throw new IllegalArgumentException("length differs");
		
		long startTime = -1;
		
		if (DEBUG) {
			startTime = System.currentTimeMillis();
		}
		
		int arrayLength = headArray.length;
		/*int unmatches = 0;
		float thresholdValue = (float) length * threshold;
		*/
		int ret = -1;
		
		for (int i = length; i > 0; i--) {
			int j = arrayLength - i - 1;
			
			if (arrayCompareEx(headArray, tailArray, 0, j, i, threshold)) {
				ret = i;
				break;
			}
			
			/*if (!headArray.get(i).equals(tailArray.get(j))) {
				unmatches++;
				
				if (unmatches > thresholdValue) {
					ret = i - 1;
					break;
				}
			}*/
		}
		
		if (DEBUG) {
			Log.d(TAG, "arrayHeadTailMatch time: " + (System.currentTimeMillis() - startTime));
		}
		
		return ret;
	}
	
	public static void notifyMediaScanner(Context context, String path) {
		Intent i = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
		i.setData(Uri.fromFile(new File(path)));
		context.sendBroadcast(i);
	}
	
	public static int getStatusBarHeight(Context context) {
		int result = 0;
		int resourceId = context.getResources().getIdentifier("status_bar_height", "dimen", "android");
		
		if (resourceId > 0) {
			result = context.getResources().getDimensionPixelSize(resourceId);
		}
		
		return result;
	}
	
	public static int dp2pxY(Context context, int dip) {
		DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
		int px = Math.round(dip * (displayMetrics.ydpi / 160.0f));       
		return px;
	}
}