import android.annotation.TargetApi;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Build; import com.example.android.common.logger.Log;
import com.example.android.displayingbitmaps.BuildConfig; import java.io.FileDescriptor; /**
* A simple subclass of {@link ImageWorker} that resizes images from resources given a target width
* and height. Useful for when the input images might be too large to simply load directly into
* memory.
*/
public class ImageResizer extends ImageWorker {
private static final String TAG = "ImageResizer";
protected int mImageWidth;
protected int mImageHeight; /**
* Initialize providing a single target image size (used for both width and height);
*
* @param context
* @param imageWidth
* @param imageHeight
*/
public ImageResizer(Context context, int imageWidth, int imageHeight) {
super(context);
setImageSize(imageWidth, imageHeight);
} /**
* Initialize providing a single target image size (used for both width and height);
*
* @param context
* @param imageSize
*/
public ImageResizer(Context context, int imageSize) {
super(context);
setImageSize(imageSize);
} /**
* Set the target image width and height.
*
* @param width
* @param height
*/
public void setImageSize(int width, int height) {
mImageWidth = width;
mImageHeight = height;
} /**
* Set the target image size (width and height will be the same).
*
* @param size
*/
public void setImageSize(int size) {
setImageSize(size, size);
} /**
* The main processing method. This happens in a background task. In this case we are just
* sampling down the bitmap and returning it from a resource.
*
* @param resId
* @return
*/
private Bitmap processBitmap(int resId) {
if (BuildConfig.DEBUG) {
Log.d(TAG, "processBitmap - " + resId);
}
return decodeSampledBitmapFromResource(mResources, resId, mImageWidth,
mImageHeight, getImageCache());
} @Override
protected Bitmap processBitmap(Object data) {
return processBitmap(Integer.parseInt(String.valueOf(data)));
} /**
* Decode and sample down a bitmap from resources to the requested width and height.
*
* @param res The resources object containing the image data
* @param resId The resource id of the image data
* @param reqWidth The requested width of the resulting bitmap
* @param reqHeight The requested height of the resulting bitmap
* @param cache The ImageCache used to find candidate bitmaps for use with inBitmap
* @return A bitmap sampled down from the original with the same aspect ratio and dimensions
* that are equal to or greater than the requested width and height
*/
public static Bitmap decodeSampledBitmapFromResource(Resources res, int resId,
int reqWidth, int reqHeight, ImageCache cache) { // BEGIN_INCLUDE (read_bitmap_dimensions)
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeResource(res, resId, options); // Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
// END_INCLUDE (read_bitmap_dimensions) // If we're running on Honeycomb or newer, try to use inBitmap
if (Utils.hasHoneycomb()) {
addInBitmapOptions(options, cache);
} // Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
return BitmapFactory.decodeResource(res, resId, options);
} /**
* Decode and sample down a bitmap from a file to the requested width and height.
*
* @param filename The full path of the file to decode
* @param reqWidth The requested width of the resulting bitmap
* @param reqHeight The requested height of the resulting bitmap
* @param cache The ImageCache used to find candidate bitmaps for use with inBitmap
* @return A bitmap sampled down from the original with the same aspect ratio and dimensions
* that are equal to or greater than the requested width and height
*/
public static Bitmap decodeSampledBitmapFromFile(String filename,
int reqWidth, int reqHeight, ImageCache cache) { // First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(filename, options); // Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight); // If we're running on Honeycomb or newer, try to use inBitmap
if (Utils.hasHoneycomb()) {
addInBitmapOptions(options, cache);
} // Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
return BitmapFactory.decodeFile(filename, options);
} /**
* Decode and sample down a bitmap from a file input stream to the requested width and height.
*
* @param fileDescriptor The file descriptor to read from
* @param reqWidth The requested width of the resulting bitmap
* @param reqHeight The requested height of the resulting bitmap
* @param cache The ImageCache used to find candidate bitmaps for use with inBitmap
* @return A bitmap sampled down from the original with the same aspect ratio and dimensions
* that are equal to or greater than the requested width and height
*/
public static Bitmap decodeSampledBitmapFromDescriptor(
FileDescriptor fileDescriptor, int reqWidth, int reqHeight, ImageCache cache) { // First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFileDescriptor(fileDescriptor, null, options); // Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight); // Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false; // If we're running on Honeycomb or newer, try to use inBitmap
if (Utils.hasHoneycomb()) {
addInBitmapOptions(options, cache);
} return BitmapFactory.decodeFileDescriptor(fileDescriptor, null, options);
} @TargetApi(Build.VERSION_CODES.HONEYCOMB)
private static void addInBitmapOptions(BitmapFactory.Options options, ImageCache cache) { // inBitmap only works with mutable bitmaps so force the decoder to
// return mutable bitmaps.
options.inMutable = true; if (cache != null) {
// Try and find a bitmap to use for inBitmap
Bitmap inBitmap = cache.getBitmapFromReusableSet(options); if (inBitmap != null) {
options.inBitmap = inBitmap;
}
} } /**
* Calculate an inSampleSize for use in a {@link android.graphics.BitmapFactory.Options} object when decoding
* bitmaps using the decode* methods from {@link android.graphics.BitmapFactory}. This implementation calculates
* the closest inSampleSize that is a power of 2 and will result in the final decoded bitmap
* having a width and height equal to or larger than the requested width and height.
*
* @param options An options object with out* params already populated (run through a decode*
* method with inJustDecodeBounds==true
* @param reqWidth The requested width of the resulting bitmap
* @param reqHeight The requested height of the resulting bitmap
* @return The value to be used for inSampleSize
*/
public static int calculateInSampleSize(BitmapFactory.Options options,
int reqWidth, int reqHeight) {
// BEGIN_INCLUDE (calculate_sample_size)
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1; if (height > reqHeight || width > reqWidth) { final int halfHeight = height / 2;
final int halfWidth = width / 2; // Calculate the largest inSampleSize value that is a power of 2 and keeps both
// height and width larger than the requested height and width.
while ((halfHeight / inSampleSize) > reqHeight
&& (halfWidth / inSampleSize) > reqWidth) {
inSampleSize *= 2;
} // This offers some additional logic in case the image has a strange
// aspect ratio. For example, a panorama may have a much larger
// width than height. In these cases the total pixels might still
// end up being too large to fit comfortably in memory, so we should
// be more aggressive with sample down the image (=larger inSampleSize). long totalPixels = width * height / inSampleSize; // Anything more than 2x the requested pixels we'll sample down further
final long totalReqPixelsCap = reqWidth * reqHeight * 2; while (totalPixels > totalReqPixelsCap) {
inSampleSize *= 2;
totalPixels /= 2;
}
}
return inSampleSize;
// END_INCLUDE (calculate_sample_size)
}
}