Android Open Source - dejalist Utils

• Back to App/code  ↑

From Project

Back to project page dejalist.

License

The source code is released under:

Apache License

Java Source Code

package com.luboganev.dejalist;
/* w w  w . j av a  2 s  .  c o  m*/
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.BitmapFactory.Options;
import android.graphics.Point;
import android.util.Log;
import android.util.TypedValue;

public class Utils {
  public static final String TAG = "Dejalist";
  
  /**
   *   Returns the Android API version running on that device
   */
  public static int getApiLevel() {
    return android.os.Build.VERSION.SDK_INT;
  }
  
  /**
   *   Returns the current timestamp in milliseconds since January 1, 1970 00:00:00 UTC
   */
  public static long currentTimestampInMillis() {
    return System.currentTimeMillis();
  }
  
  /**
   *   Returns the current timestamp in seconds since January 1, 1970 00:00:00 UTC
   */
  public static long currentTimestampInSeconds() {
    return System.currentTimeMillis() / 1000;
  }
  
  /**
   * Returns the physical pixels that 
   * corresponds to the input DIPs
   * 
   * @param context
   *     Use application context and not some activity's context to prevent memory leaks
   */
  public static int getPixelsFromDips(Context context, int dips) {
    float result = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dips, context.getResources().getDisplayMetrics());
    return (int)result;
  }
  
  /**
   *   This variable defines the current mode of the application. 
   *   When it is being released, the debug mode will be set to false.
   */
  public static final boolean DEBUG = false;
  
  /**
   *   Prints a debug message in the system log
   * 
   * @param sender
   *     A string with custom name or a class
   * @param message
   *     The message to be logged
   */
  public static void d(Object sender, String message) {
    if(DEBUG) Log.d(TAG,  getSenderString(sender) + ": " + message);
  }
  
  /**
   *   Prints an error message in the system log
   * 
   * @param sender
   *     A string with custom name or a class
   * @param message
   *     The message to be logged
   */
  public static void e(Object sender, String message) {
    if(DEBUG) Log.e(TAG,  getSenderString(sender) + ": " + message);
  }
  
  /**
   * Gets the name of the Class of the input object
   * 
   * @param sender
   *     The input object 
   * @return
   */
  private static String getSenderString(Object sender) {
    if(sender instanceof String) {
      return (String)sender;
    }
    else return sender.getClass().getSimpleName();
  }
  
  /**
   * Calculates a sample size and dimensions of an
   * image with the input width and height so that it can
   * fit inside the required input width and height without
   * changing its aspect ratio
   * 
   * @param width
   *     The width of the image
   * @param height
   *     The height of the image
   * @param reqWidth
   *     The required width of the image
   * @param reqHeight
   *     The required height of the image
   * @return
   *     The calculated sample size and dimensions in the form
   *     of {@link Options}
   */
  public static BitmapFactory.Options calculateSampleSizeAndDimensions(int width, int height, int reqWidth, int reqHeight) {
    BitmapFactory.Options res = new Options();
      
    res.inSampleSize = 1;
    res.outWidth = height;
    res.outHeight = width;
      
      if(height >= reqHeight) {
        float ratio = ((float)height) / ((float)reqHeight);
        int newWidth = (int)(((float)width) / ratio);
        res.inSampleSize = Math.round(ratio);
        if(newWidth > reqWidth) {
          ratio = ((float)width) / ((float)reqWidth);
          int newHeight = (int)(((float)height) / ratio);
          res.inSampleSize = Math.round(ratio);
          res.outWidth = reqWidth;
          res.outHeight = newHeight;
        }
        else {
          res.outWidth = newWidth;
          res.outHeight = reqHeight;
        }
      }
      else if(width > reqWidth) {
        float ratio = ((float)width) / ((float)reqWidth);
        int newHeight = (int)(((float)height) / ratio);
        res.inSampleSize = Math.round(ratio);
        if(newHeight > reqHeight) {
          ratio = ((float)height) / ((float)reqHeight);
          res.inSampleSize = Math.round(ratio);
          int newWidth = (int)(((float)width) / ratio);
          res.outWidth = newWidth;
          res.outHeight = reqHeight;
        }
        else {
          res.outWidth = reqWidth;
          res.outHeight = newHeight;
        }
      }
      return res;
  }
  
  /**
   * Reads the dimensions of a particular drawable 
   * resource without loading the whole thing into memory
   * 
   * @param res
   *     A reference to the resources object
   * @param resId
   *     The id of the resource
   * @return
   *     A {@link Point} containing the width and height as x and y
   */
  public static Point getResourceBitmapDimensions(Resources res, int resId) {
    // First decode with inJustDecodeBounds=true to check dimensions
      final BitmapFactory.Options options = new BitmapFactory.Options();
      options.inJustDecodeBounds = true;
      BitmapFactory.decodeResource(res, resId, options);
      return new Point(options.outWidth,options.outHeight);
  }
  
  /**
   * Decodes a particular drawable resource using the input sample size
   * 
   * @param res
   *     A reference to the resources object
   * @param resId
   *     The id of the resource
   * @param sampleSize
   *     The sample size to be used when decoding the drawable into a bitmap
   * @return
   *     The decoded Bitmap
   */
  public static Bitmap decodeSampledBitmapFromResource(Resources res, int resId, int sampleSize) {    
      // Calculate required inSampleSize and new dimensions
      BitmapFactory.Options options =  new BitmapFactory.Options();
      // Decode bitmap with inSampleSize set
      options.inSampleSize = sampleSize;
      return BitmapFactory.decodeResource(res, resId, options);
  }
  
  /**
   * Helper method to convert Long[] to long[]
   * 
   * @param input
   * @return
   */
  public static long[] objectArrayToPrimitiveLongArray(Object[] input) {
    long[] result = new long[input.length];
    for (int i = 0; i < input.length; i++) {
      result[i] = (Long)input[i];
    }
    return result;
  }
  
  /**
     * Simple extension that uses {@link Bitmap} instances as keys, using their
     * memory footprint in bytes for sizing.
     */
    public static class ThumbnailCache extends android.support.v4.util.LruCache<Long, Bitmap> {
        public ThumbnailCache(int maxSizeBytes) {
            super(maxSizeBytes);
        }
        
        @Override
        protected int sizeOf(Long key, Bitmap value) {
            return value.getRowBytes() * value.getHeight();
        }
    }
}

Java Source Code List

• Back to App/code  ↑