1 files changed, 141 insertions, 0 deletions
diff --git a/java/com/android/dialer/contactphoto/BitmapUtil.java b/java/com/android/dialer/contactphoto/BitmapUtil.java
new file mode 100644
index 000000000..36055e2c1
--- /dev/null
+++ b/java/com/android/dialer/contactphoto/BitmapUtil.java
@@ -0,0 +1,141 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.dialer.contactphoto;
+
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.graphics.PorterDuff.Mode;
+import android.graphics.PorterDuffXfermode;
+import android.graphics.Rect;
+import android.graphics.RectF;
+
+/** Provides static functions to decode bitmaps at the optimal size */
+public class BitmapUtil {
+
+  private BitmapUtil() {}
+
+  /**
+   * Returns Width or Height of the picture, depending on which size is smaller. Doesn't actually
+   * decode the picture, so it is pretty efficient to run.
+   */
+  public static int getSmallerExtentFromBytes(byte[] bytes) {
+    final BitmapFactory.Options options = new BitmapFactory.Options();
+
+    // don't actually decode the picture, just return its bounds
+    options.inJustDecodeBounds = true;
+    BitmapFactory.decodeByteArray(bytes, 0, bytes.length, options);
+
+    // test what the best sample size is
+    return Math.min(options.outWidth, options.outHeight);
+  }
+
+  /**
+   * Finds the optimal sampleSize for loading the picture
+   *
+   * @param originalSmallerExtent Width or height of the picture, whichever is smaller
+   * @param targetExtent Width or height of the target view, whichever is bigger.
+   *     <p>If either one of the parameters is 0 or smaller, no sampling is applied
+   */
+  public static int findOptimalSampleSize(int originalSmallerExtent, int targetExtent) {
+    // If we don't know sizes, we can't do sampling.
+    if (targetExtent < 1) {
+      return 1;
+    }
+    if (originalSmallerExtent < 1) {
+      return 1;
+    }
+
+    // Test what the best sample size is. To do that, we find the sample size that gives us
+    // the best trade-off between resulting image size and memory requirement. We allow
+    // the down-sampled image to be 20% smaller than the target size. That way we can get around
+    // unfortunate cases where e.g. a 720 picture is requested for 362 and not down-sampled at
+    // all. Why 20%? Why not. Prove me wrong.
+    int extent = originalSmallerExtent;
+    int sampleSize = 1;
+    while ((extent >> 1) >= targetExtent * 0.8f) {
+      sampleSize <<= 1;
+      extent >>= 1;
+    }
+
+    return sampleSize;
+  }
+
+  /** Decodes the bitmap with the given sample size */
+  public static Bitmap decodeBitmapFromBytes(byte[] bytes, int sampleSize) {
+    final BitmapFactory.Options options;
+    if (sampleSize <= 1) {
+      options = null;
+    } else {
+      options = new BitmapFactory.Options();
+      options.inSampleSize = sampleSize;
+    }
+    return BitmapFactory.decodeByteArray(bytes, 0, bytes.length, options);
+  }
+
+  /**
+   * Given an input bitmap, scales it to the given width/height and makes it round.
+   *
+   * @param input {@link Bitmap} to scale and crop
+   * @param targetWidth desired output width
+   * @param targetHeight desired output height
+   * @return output bitmap scaled to the target width/height and cropped to an oval. The cropping
+   *     algorithm will try to fit as much of the input into the output as possible, while
+   *     preserving the target width/height ratio.
+   */
+  public static Bitmap getRoundedBitmap(Bitmap input, int targetWidth, int targetHeight) {
+    if (input == null) {
+      return null;
+    }
+    final Bitmap.Config inputConfig = input.getConfig();
+    final Bitmap result =
+        Bitmap.createBitmap(
+            targetWidth, targetHeight, inputConfig != null ? inputConfig : Bitmap.Config.ARGB_8888);
+    final Canvas canvas = new Canvas(result);
+    final Paint paint = new Paint();
+    canvas.drawARGB(0, 0, 0, 0);
+    paint.setAntiAlias(true);
+    final RectF dst = new RectF(0, 0, targetWidth, targetHeight);
+    canvas.drawOval(dst, paint);
+
+    // Specifies that only pixels present in the destination (i.e. the drawn oval) should
+    // be overwritten with pixels from the input bitmap.
+    paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
+
+    final int inputWidth = input.getWidth();
+    final int inputHeight = input.getHeight();
+
+    // Choose the largest scale factor that will fit inside the dimensions of the
+    // input bitmap.
+    final float scaleBy =
+        Math.min((float) inputWidth / targetWidth, (float) inputHeight / targetHeight);
+
+    final int xCropAmountHalved = (int) (scaleBy * targetWidth / 2);
+    final int yCropAmountHalved = (int) (scaleBy * targetHeight / 2);
+
+    final Rect src =
+        new Rect(
+            inputWidth / 2 - xCropAmountHalved,
+            inputHeight / 2 - yCropAmountHalved,
+            inputWidth / 2 + xCropAmountHalved,
+            inputHeight / 2 + yCropAmountHalved);
+
+    canvas.drawBitmap(input, src, dst, paint);
+    return result;
+  }
+}