Allow decoding JPEG into A8.

src/images/SkImageDecoder.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkImageDecoder.h"
 #include "SkBitmap.h"
@@ skipping 127 matching lines @@
     return bitmap->allocPixels(fAllocator, ctable);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 void SkImageDecoder::setPrefConfigTable(const SkBitmap::Config pref[6]) {
     if (NULL == pref) {
         fUsePrefTable = false;
     } else {
         fUsePrefTable = true;
-        memcpy(fPrefTable, pref, sizeof(fPrefTable));
+        fPrefTable.fPrefFor_8Index_NoAlpha_src = pref[0];
+        fPrefTable.fPrefFor_8Index_YesAlpha_src = pref[1];
+        fPrefTable.fPrefFor_8Gray_src = SkBitmap::kNo_Config;
+        fPrefTable.fPrefFor_8bpc_NoAlpha_src = pref[4];
+        fPrefTable.fPrefFor_8bpc_YesAlpha_src = pref[5];
     }
 }
 
+void SkImageDecoder::setPrefConfigTable(const PrefConfigTable& prefTable) {
+    fUsePrefTable = true;
+    fPrefTable = prefTable;
+}
+
 SkBitmap::Config SkImageDecoder::getPrefConfig(SrcDepth srcDepth,
                                                bool srcHasAlpha) const {
     SkBitmap::Config config;
 
     if (fUsePrefTable) {
-        int index = 0;
         switch (srcDepth) {
             case kIndex_SrcDepth:
-                index = 0;
+                config = srcHasAlpha ? fPrefTable.fPrefFor_8Index_YesAlpha_src
+                                     : fPrefTable.fPrefFor_8Index_NoAlpha_src;
                 break;
-            case k16Bit_SrcDepth:
-                index = 2;
+            case k8BitGray_SrcDepth:
+                config = fPrefTable.fPrefFor_8Gray_src;
                 break;
             case k32Bit_SrcDepth:
-                index = 4;
+                config = srcHasAlpha ? fPrefTable.fPrefFor_8bpc_YesAlpha_src
+                                     : fPrefTable.fPrefFor_8bpc_NoAlpha_src;
                 break;
         }
-        if (srcHasAlpha) {
-            index += 1;
-        }
-        config = fPrefTable[index];
     } else {
         config = fDefaultPref;
     }
 
     if (SkBitmap::kNo_Config == config) {
         config = SkImageDecoder::GetDeviceConfig();
     }
     return config;
 }
 
@@ skipping 271 matching lines @@
             if (kUnknown_Format == *format) {
                 if (stream->rewind()) {
                     *format = GetStreamFormat(stream);
                 }
             }
         }
         delete codec;
     }
     return success;
 }