Converter.java

package de.danoeh.antennapod.core.util;

import android.content.Context;
import android.util.Log;

import java.util.Locale;

import de.danoeh.antennapod.core.R;

/** Provides methods for converting various units. */
public final class Converter {
    /** Class shall not be instantiated. */
    private Converter() {
    }

    /** Logging tag. */
    private static final String TAG = "Converter";


    /** Indicates that the value is in the Byte range.*/
    private static final int B_RANGE = 0;
    /** Indicates that the value is in the Kilobyte range.*/
    private static final int KB_RANGE = 1;
    /** Indicates that the value is in the Megabyte range.*/
    private static final int MB_RANGE = 2;
    /** Indicates that the value is in the Gigabyte range.*/
    private static final int GB_RANGE = 3;
    /** Determines the length of the number for best readability.*/
    private static final int NUM_LENGTH = 1024;
    
    private static final int DAYS_MIL = 86400000;
    private static final int HOURS_MIL = 3600000;
	private static final int MINUTES_MIL = 60000;
	private static final int SECONDS_MIL = 1000;

    /** Takes a byte-value and converts it into a more readable
     *  String.
     *  @param input The value to convert
     *  @return The converted String with a unit
     * */
    public static String byteToString(final long input) {
        int i = 0;
        int result = 0;

        for (i = 0; i < GB_RANGE + 1; i++) {
            result = (int) (input / Math.pow(1024, i));
            if (result < NUM_LENGTH) {
                break;
            }
        }

        switch (i) {
            case B_RANGE:
                return result + " B";
            case KB_RANGE:
                return result + " KB";
            case MB_RANGE:
                return result + " MB";
            case GB_RANGE:
                return result + " GB";
            default:
                Log.e(TAG, "Error happened in byteToString");
                return "ERROR";
        }
    }
    
    /** Converts milliseconds to a string containing hours, minutes and seconds */
    public static String getDurationStringLong(int duration) {	
    	int h = duration / HOURS_MIL;
    	int rest = duration - h * HOURS_MIL;
    	int m = rest / MINUTES_MIL;
    	rest -= m * MINUTES_MIL;
    	int s = rest / SECONDS_MIL;
    	
    	return String.format("%02d:%02d:%02d", h, m, s);
    }
    
    /** Converts milliseconds to a string containing hours and minutes */
    public static String getDurationStringShort(int duration) {
    	int h = duration / HOURS_MIL;
    	int rest = duration - h * HOURS_MIL;
    	int m = rest / MINUTES_MIL;
    	
    	return String.format("%02d:%02d", h, m);
    }

    /** Converts long duration string (HH:MM:SS) to milliseconds. */
    public static int durationStringLongToMs(String input) {
        String[] parts = input.split(":");
        if (parts.length != 3) {
            return 0;
        }
        return Integer.parseInt(parts[0]) * 3600 * 1000 +
                Integer.parseInt(parts[1]) * 60 * 1000 +
                Integer.parseInt(parts[2]) * 1000;
    }

    /** Converts short duration string (HH:MM) to milliseconds. */
    public static int durationStringShortToMs(String input) {
        String[] parts = input.split(":");
        if (parts.length != 2) {
            return 0;
        }
        return Integer.parseInt(parts[0]) * 3600 * 1000 +
                Integer.parseInt(parts[1]) * 1000 * 60;
    }

    /** Converts milliseconds to a localized string containing hours and minutes */
    public static String getDurationStringLocalized(Context context, long duration) {
        int h = (int)(duration / HOURS_MIL);
        int rest = (int)(duration - h * HOURS_MIL);
        int m = rest / MINUTES_MIL;

        String result = "";
        if(h > 0) {
            String hours = context.getResources().getQuantityString(R.plurals.time_hours_quantified, h, h);
            result += hours + " ";
        }
        String minutes = context.getResources().getQuantityString(R.plurals.time_minutes_quantified, m, m);
        result += minutes;
        return result;
    }

    /**
     * Converts seconds to a localized representation
     * @param time The time in seconds
     * @return "HH:MM hours"
     */
    public static String shortLocalizedDuration(Context context, long time) {
        float hours = (float) time / 3600f;
        return String.format(Locale.getDefault(), "%.1f ", hours) + context.getString(R.string.time_hours);
    }

    /**
     * Converts the volume as read as the progress from a SeekBar scaled to 100 and as saved in
     * UserPreferences to the format taken by setVolume methods.
     * @param progress integer between 0 to 100 taken from the SeekBar progress
     * @return the appropriate volume as float taken by setVolume methods
     */
    public static float getVolumeFromPercentage(int progress){
        if (progress==100)
            return 1f;
        return (float) (1 - (Math.log(101 - progress) / Math.log(101)));
    }
}