Refactor SkBitmapRegionDecoderInterface for Android

dm/DMSrcSink.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "DMSrcSink.h"
 #include "SamplePipeControllers.h"
 #include "SkAndroidCodec.h"
@@ skipping 90 matching lines @@
         case CodecSrc::kGetFromCanvas_DstColorType:
             break;
         case CodecSrc::kIndex8_Always_DstColorType:
             colorType = kIndex_8_SkColorType;
             break;
         case CodecSrc::kGrayscale_Always_DstColorType:
             colorType = kGray_8_SkColorType;
             break;
     }
 
+    // Construct a color table for the decode if necessary
+    SkAutoTUnref<SkColorTable> colorTable(nullptr);
+    if (kIndex_8_SkColorType == colorType) {
+        SkPMColor colors[256];
+        colorTable.reset(new SkColorTable(colors, 256));
+    }
+
     SkAutoTDelete<SkBitmapRegionDecoderInterface> brd(create_brd(fPath, fStrategy));
     if (nullptr == brd.get()) {
         return Error::Nonfatal(SkStringPrintf("Could not create brd for %s.", fPath.c_str()));
     }
 
-    if (!brd->conversionSupported(colorType)) {
-        return Error::Nonfatal("Cannot convert to color type.\n");
-    }
-
     const uint32_t width = brd->width();
     const uint32_t height = brd->height();
     // Visually inspecting very small output images is not necessary.
     if ((width / fSampleSize <= 10 || height / fSampleSize <= 10) && 1 != fSampleSize) {
         return Error::Nonfatal("Scaling very small images is uninteresting.");
     }
     switch (fMode) {
         case kFullImage_Mode: {
-            SkAutoTDelete<SkBitmap> bitmap(brd->decodeRegion(0, 0, width, height, fSampleSize,
-                    colorType));
-            if (nullptr == bitmap.get() || colorType != bitmap->colorType()) {
+            SkImageInfo info;
+            SkIRect subset = SkIRect::MakeXYWH(0, 0, width, height);
+            if (!brd->prepareRegion(subset, fSampleSize, colorType, false, &info)) {
+                return Error::Nonfatal("Cannot set up for subset decode.\n");
+            }
+
+            SkBitmap bitmap;
+            if (SkBitmapRegionDecoderInterface::kOriginal_Strategy != fStrategy) {
+                if (!bitmap.tryAllocPixels(info, nullptr, colorTable)) {
+                    return "Could not allocate pixels.";
+                }
+            }
+            if (!brd->decodeRegion(bitmap)) {
+                return "Failed to decode subset";
+            }
+            if (colorType != bitmap.colorType()) {
                 return Error::Nonfatal("Cannot convert to color type.\n");
             }
-            canvas->drawBitmap(*bitmap, 0, 0);
+            canvas->drawBitmap(bitmap, 0, 0);
             return "";
         }
         case kDivisor_Mode: {
             const uint32_t divisor = 2;
             if (width < divisor || height < divisor) {
                 return Error::Nonfatal("Divisor is larger than image dimension.\n");
             }
 
             // Use a border to test subsets that extend outside the image.
             // We will not allow the border to be larger than the image dimensions.  Allowing
@@ skipping 27 matching lines @@
                     // Increase the size of the last subset in each row or column, when the
                     // divisor does not divide evenly into the image dimensions
                     subsetWidth += (x + 1 == divisor) ? (width % divisor) : 0;
                     subsetHeight += (y + 1 == divisor) ? (height % divisor) : 0;
 
                     // Increase the size of the subset in order to have a border on each side
                     const int decodeLeft = left - unscaledBorder;
                     const int decodeTop = top - unscaledBorder;
                     const uint32_t decodeWidth = subsetWidth + unscaledBorder * 2;
                     const uint32_t decodeHeight = subsetHeight + unscaledBorder * 2;
-                    SkAutoTDelete<SkBitmap> bitmap(brd->decodeRegion(decodeLeft,
-                            decodeTop, decodeWidth, decodeHeight, fSampleSize, colorType));
-                    if (nullptr == bitmap.get() || colorType != bitmap->colorType()) {
+
+                    SkImageInfo info;
+                    SkIRect subset = SkIRect::MakeXYWH(decodeLeft, decodeTop, decodeWidth,
+                            decodeHeight);
+                    if (!brd->prepareRegion(subset, fSampleSize, colorType, false, &info)) {
+                        return Error::Nonfatal("Cannot set up for subset decode.\n");
+                    }
+
+                    SkBitmap bitmap;
+                    if (SkBitmapRegionDecoderInterface::kOriginal_Strategy != fStrategy) {
+                        if (!bitmap.tryAllocPixels(info, nullptr, colorTable)) {
+                            return "Could not allocate pixels.";
+                        }
+                    }
+                    if (!brd->decodeRegion(bitmap)) {
+                        return "Failed to decode subset";
+                    }
+                    if (colorType != bitmap.colorType()) {
                         return Error::Nonfatal("Cannot convert to color type.\n");
                     }
 
-                    canvas->drawBitmapRect(*bitmap,
+                    canvas->drawBitmapRect(bitmap,
                             SkRect::MakeXYWH((SkScalar) scaledBorder, (SkScalar) scaledBorder,
                                     (SkScalar) (subsetWidth / fSampleSize),
                                     (SkScalar) (subsetHeight / fSampleSize)),
                             SkRect::MakeXYWH((SkScalar) (left / fSampleSize),
                                     (SkScalar) (top / fSampleSize),
                                     (SkScalar) (subsetWidth / fSampleSize),
                                     (SkScalar) (subsetHeight / fSampleSize)),
                             nullptr);
                 }
             }
@@ skipping 1165 matching lines @@
             skr.visit<void>(i, drawsAsSingletonPictures);
         }
         SkAutoTUnref<SkPicture> macroPic(macroRec.endRecordingAsPicture());
 
         canvas->drawPicture(macroPic);
         return "";
     });
 }
 
 }  // namespace DM