Refactor SkBitmapRegionDecoderInterface for Android

tools/SkCodecTools.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkCodecTools_DEFINED
 #define SkCodecTools_DEFINED
 
+#include "SkBitmapRegionDecoderInterface.h"
+
 inline float get_scale_from_sample_size(uint32_t sampleSize) {
     return 1.0f / (float) sampleSize;
 }
 
-enum SubsetType {
-    kFullyInside_SubsetType,
-    kPartiallyInside_SubsetType,
-    kOutside_SubsetType,
-};
-
 /*
  * Corrects image subset offsets and dimensions in order to perform a valid decode.
  * Also indicates if the image subset should be placed at an offset within the
  * output bitmap.
  *
  * Values of output variables are undefined if the SubsetType is kInvalid.
  *
  * @param imageDims Original image dimensions.
  * @param subset    As input, the subset that the client requested.
  *                  As output, the image subset that we will decode.
  * @param outX      The left offset of the image subset within the output bitmap.
  * @param outY      The top offset of the image subset within the output bitmap.
  *
  * @return An indication of how the subset is contained in the image.
  *         If the return value is kInvalid, values of output variables are undefined.
  */
-inline SubsetType adjust_subset_rect(const SkISize& imageDims, SkIRect* subset, int* outX,
-        int* outY) {
+inline SkBitmapRegionDecoderInterface::SubsetType adjust_subset_rect(const SkISize& imageDims,

[scroggo, 2015/10/27 15:00:51]

Should this be a method on SkBitmapRegionDecoderInterface?

+        SkIRect* subset, int* outX, int* outY) {
     // These must be at least zero, we can't start decoding the image at a negative coordinate.
     int left = SkTMax(0, subset->fLeft);
     int top = SkTMax(0, subset->fTop);
 
     // If input offsets are less than zero, we decode to an offset location in the output bitmap.
     *outX = left - subset->fLeft;
     *outY = top - subset->fTop;
 
     // Make sure we don't decode pixels past the edge of the image or past the edge of the subset.
     int width = SkTMin(imageDims.width() - left, subset->width() - *outX);
     int height = SkTMin(imageDims.height() - top, subset->height() - *outY);
     if (width <= 0 || height <= 0) {
-        return SubsetType::kOutside_SubsetType;
+        return SkBitmapRegionDecoderInterface::kOutside_SubsetType;
     }
 
     subset->setXYWH(left, top, width, height);
     if ((*outX != 0) || (*outY != 0) || (width != subset->width()) ||
             (height != subset->height())) {
-        return SubsetType::kPartiallyInside_SubsetType;
+        return SkBitmapRegionDecoderInterface::kPartiallyInside_SubsetType;
     }
 
-    return SubsetType::kFullyInside_SubsetType;
+    return SkBitmapRegionDecoderInterface::kFullyInside_SubsetType;
 }
 
 #endif // SkCodecTools_DEFINED