Allow transparent images

Load PNGs as ARGB_8888 and JPEGs as RGB_565 preferentially.
Also save ARGB_8888 images to disk cache as PNGs and RGB_565
as jpegs. Fixes some quality issues with transparent images

library/src/com/bumptech/glide/presenter/ImagePresenter.java

@@ -56,10 +56,9 @@ public static class Builder<T> {
         private ExceptionHandler<T> exceptionHandler = new ExceptionHandler<T>() {
             @Override
             public void onException(Exception e, T model, boolean isCurrent) {
+                Log.e("IP: onImageLoadException model= " + model);
                 if (e != null) {
                     e.printStackTrace();
-                } else {
-                    Log.e("IP: onImageLoadException model= " + model);
                 }
             }
         };

library/src/com/bumptech/glide/resize/ImageManager.java

@@ -599,7 +599,7 @@ private void putInDiskCache(String key, final Bitmap bitmap) {
         diskCache.put(key, new DiskCache.Writer() {
             @Override
             public void write(OutputStream os) {
-                bitmap.compress(bitmapCompressFormat, bitmapCompressQuality, os);
+                bitmap.compress(bitmap.getConfig() == Bitmap.Config.ARGB_8888 ? Bitmap.CompressFormat.PNG : Bitmap.CompressFormat.JPEG, bitmapCompressQuality, os);
             }
         });
 

library/src/com/bumptech/glide/resize/bitmap_recycle/BitmapPool.java

@@ -4,5 +4,5 @@
 
 public interface BitmapPool {
     public boolean put(Bitmap bitmap);
-    public Bitmap get(int width, int height);
+    public Bitmap get(int width, int height, Bitmap.Config config);
 }

library/src/com/bumptech/glide/resize/bitmap_recycle/BitmapPoolAdapter.java

@@ -3,13 +3,15 @@
 import android.graphics.Bitmap;
 
 public class BitmapPoolAdapter implements BitmapPool {
+
     @Override
     public boolean put(Bitmap bitmap) {
         return false;
     }
 
     @Override
-    public Bitmap get(int width, int height) {
+    public Bitmap get(int width, int height, Bitmap.Config config) {
         return null;
     }
+
 }

library/src/com/bumptech/glide/resize/bitmap_recycle/LruBitmapPool.java

@@ -22,12 +22,6 @@ public LruBitmapPool(int maxSize) {
 
     @Override
     public synchronized boolean put(Bitmap bitmap) {
-        //BitmapFactory.decodeStream can sometimes return bitmaps with null configs, which can't generally be
-        //reused
-        if (bitmap.getConfig() == null) {
-            return false;
-        }
-
         final int size = getSize(bitmap);
 
         pool.put(bitmap);
@@ -45,10 +39,10 @@ private void evict() {
     }
 
     @Override
-    public synchronized Bitmap get(int width, int height) {
-        final Bitmap result = pool.get(width, height);
+    public synchronized Bitmap get(int width, int height, Bitmap.Config config) {
+        final Bitmap result = pool.get(width, height, config);
         if (result == null) {
-            Log.d("LBP: missing bitmap for width=" + width + " height=" + height);
+            Log.d("LBP: missing bitmap for width=" + width + " height=" + height + " config=" + config);
         } else {
             currentSize -= getSize(result);
         }
@@ -77,14 +71,14 @@ private static class GroupedBitmapLinkedMap {
         private static class KeyPool {
             private static final int MAX_SIZE = 20;
 
-            private Queue<Key> keyPool = new LinkedList<Key>();
+            private final Queue<Key> keyPool = new LinkedList<Key>();
 
-            public Key get(int width, int height) {
+            public Key get(int width, int height, Bitmap.Config config) {
                 Key result = keyPool.poll();
                 if (result == null) {
                     result = new Key();
                 }
-                result.init(width, height);
+                result.init(width, height, config);
                 return result;
             }
 
@@ -98,10 +92,12 @@ public void offer(Key key) {
         private static class Key {
             private int width;
             private int height;
+            private Bitmap.Config config; //this can be null :(
 
-            public void init(int width, int height) {
+            public void init(int width, int height, Bitmap.Config config) {
                 this.width = width;
                 this.height = height;
+                this.config = config;
             }
 
             @Override
@@ -113,6 +109,7 @@ public boolean equals(Object o) {
 
                 if (height != key.height) return false;
                 if (width != key.width) return false;
+                if (config != key.config) return false;
 
                 return true;
             }
@@ -121,12 +118,13 @@ public boolean equals(Object o) {
             public int hashCode() {
                 int result = width;
                 result = 31 * result + height;
+                result = 31 * result + (config != null ? config.hashCode() : 0);
                 return result;
             }
         }
 
         public void put(Bitmap bitmap) {
-            final Key key = keyPool.get(bitmap.getWidth(), bitmap.getHeight());
+            final Key key = keyPool.get(bitmap.getWidth(), bitmap.getHeight(), bitmap.getConfig());
 
             LinkedEntry entry = keyToEntry.get(key);
             if (entry == null) {
@@ -140,8 +138,8 @@ public void put(Bitmap bitmap) {
             entry.add(bitmap);
         }
 
-        public Bitmap get(int width, int height) {
-            final Key key = keyPool.get(width, height);
+        public Bitmap get(int width, int height, Bitmap.Config config) {
+            final Key key = keyPool.get(width, height, config);
 
             LinkedEntry entry = keyToEntry.get(key);
             if (entry == null) {

library/src/com/bumptech/glide/resize/load/Downsampler.java

@@ -6,6 +6,7 @@
 import android.os.Build;
 import com.bumptech.glide.resize.RecyclableBufferedInputStream;
 import com.bumptech.glide.resize.bitmap_recycle.BitmapPool;
+import com.bumptech.glide.util.Log;
 
 import java.io.IOException;
 
@@ -39,7 +40,6 @@ protected int getSampleSize(int inWidth, int inHeight, int outWidth, int outHeig
         }
     };
 
-
     /**
      * Load the image at its original size
      *
@@ -71,7 +71,7 @@ public Bitmap downsample(RecyclableBufferedInputStream bis, BitmapFactory.Option
         bis.mark(MARK_POSITION);
         int orientation = 0;
         try {
-            orientation = new ExifOrientationParser(bis).getOrientation();//ImageResizer.getOrientation(bis);
+            orientation = new ExifOrientationParser(bis).getOrientation();
         } catch (IOException e) {
             e.printStackTrace();
         }
@@ -109,11 +109,28 @@ protected Bitmap downsampleWithSize(RecyclableBufferedInputStream bis, BitmapFac
         if (sampleSize > 1) {
             options.inSampleSize = sampleSize;
         } else {
-            setInBitmap(options, pool.get(inWidth, inHeight));
+            setInBitmap(options, pool.get(inWidth, inHeight, getConfig(bis)));
         }
         return decodeStream(bis, options);
     }
 
+    private Bitmap.Config getConfig(RecyclableBufferedInputStream bis) {
+        Bitmap.Config result = Bitmap.Config.RGB_565;
+        bis.mark(1024); //we probably only need 25, but this is safer (particularly since the buffer size is > 1024)
+        try {
+            result = new ExifOrientationParser(bis).hasAlpha() ? Bitmap.Config.ARGB_8888 : Bitmap.Config.RGB_565;
+        } catch (IOException e) {
+            e.printStackTrace();
+        } finally {
+            try {
+                bis.reset();
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        }
+        return result;
+    }
+
     /**
      * Get some id that uniquely identifies the downsample for use as part of a cache key
      * @return A unique String
@@ -163,6 +180,9 @@ private Bitmap decodeStream(RecyclableBufferedInputStream bis, BitmapFactory.Opt
          }
 
         final Bitmap result = BitmapFactory.decodeStream(bis, null, options);
+        if (result == null && !options.inJustDecodeBounds) {
+            throw new IllegalArgumentException("IP: null result, sampleSize=" + options.inSampleSize);
+        }
 
         try {
             if (options.inJustDecodeBounds) {
@@ -172,6 +192,7 @@ private Bitmap decodeStream(RecyclableBufferedInputStream bis, BitmapFactory.Opt
                 bis.close();
             }
         } catch (IOException e) {
+            Log.d("Downsampler: exception loading inDecodeBounds=" + options.inJustDecodeBounds + " sample=" + options.inSampleSize);
             e.printStackTrace();
         }
 

library/src/com/bumptech/glide/resize/load/ExifOrientationParser.java

@@ -11,6 +11,8 @@
  * A class for parsing the exif orientation from an InputStream for an image. Handles jpegs and tiffs.
  */
 public class ExifOrientationParser {
+    private static final int GIF_HEADER = 0x474946;
+    private static final int PNG_HEADER = 0x89504E47;
     private static final int EXIF_MAGIC_NUMBER = 0xFFD8;
     private static final int MOTOROLA_TIFF_MAGIC_NUMBER = 0x4D4D;  // "MM"
     private static final int INTEL_TIFF_MAGIC_NUMBER = 0x4949;     // "II"
@@ -32,6 +34,32 @@ public ExifOrientationParser(InputStream is) {
         streamReader = new StreamReader(is);
     }
 
+
+    // 0xD0A3C68 -> <htm
+    // 0xCAFEBABE -> <!DOCTYPE...
+    public boolean hasAlpha() throws IOException {
+        int firstByte = streamReader.getUInt8();
+
+        if (firstByte == EXIF_MAGIC_NUMBER >> 8) { //JPEG
+            return false;
+        }
+
+        final int firstTwoBytes = firstByte << 8 & 0xFF00 | streamReader.getUInt8() & 0xFF;
+        final int firstFourBytes = firstTwoBytes << 16 & 0xFFFF0000 | streamReader.getUInt16() & 0xFFFF;
+        if (firstFourBytes == PNG_HEADER) { //PNG
+            //see: http://stackoverflow.com/questions/2057923/how-to-check-a-png-for-grayscale-alpha-color-type
+            streamReader.skip(25 - 4);
+            int alpha = streamReader.getByte();
+            return alpha > 3;
+        }
+
+        if (firstFourBytes >> 8 == GIF_HEADER) { //GIF from first 3 bytes
+            return true;
+        }
+
+        return false;
+    }
+
     /**
      * Parse the orientation from the image header. If it doesn't handle this image type (or this is not an image)
      * it will return a default value rather than throwing an exception.
@@ -225,6 +253,10 @@ public long skip(long total) throws IOException {
         public int read(byte[] buffer) throws IOException {
             return is.read(buffer);
         }
+
+        public int getByte() throws IOException {
+            return is.read();
+        }
     }
 }
 

library/src/com/bumptech/glide/resize/load/ImageResizer.java

@@ -437,7 +437,7 @@ public static Bitmap rotateImageExif(Bitmap toOrient, BitmapPool pool, int exifO
         final int newWidth = Math.round(newRect.width());
         final int newHeight = Math.round(newRect.height());
 
-        Bitmap result = pool.get(newWidth, newHeight);
+        Bitmap result = pool.get(newWidth, newHeight, toOrient.getConfig());
         if (result == null) {
             result = Bitmap.createBitmap(newWidth, newHeight, toOrient.getConfig());
         }

library/src/com/bumptech/glide/resize/load/Transformation.java

@@ -20,7 +20,7 @@ public Bitmap transform(Bitmap bitmap, BitmapPool pool, int outWidth, int outHei
                 throw new IllegalArgumentException("Cannot center crop image to width=" + outWidth + " and height="
                         + outHeight);
             }
-            return ImageResizer.centerCrop(pool.get(outWidth, outHeight), bitmap, outWidth, outHeight);
+            return ImageResizer.centerCrop(pool.get(outWidth, outHeight, bitmap.getConfig()), bitmap, outWidth, outHeight);
         }
     };