android 7.1 默认壁纸拉伸问题

最近编译Android 7.1，编译完后系统中设置的壁纸不能正常显示

修改位置：7.1SDK/packages/apps/WallpaperPicker/src/com/android/wallpaperpicker/WallpaperUtils.java

             // We need to ensure that there is enough extra space in the wallpaper
             // for the intended parallax effects
-            final int defaultWidth, defaultHeight;
+            int defaultWidth, defaultHeight;
             if (res.getConfiguration().smallestScreenWidthDp >= 720) {
                 defaultWidth = (int) (maxDim * wallpaperTravelToScreenWidthRatio(maxDim, minDim));
                 defaultHeight = maxDim;
@@ -145,6 +145,8 @@ public final class WallpaperUtils {
                 defaultWidth = Math.max((int) (minDim * WALLPAPER_SCREENS_SPAN), maxDim);
                 defaultHeight = maxDim;
             }
+            defaultWidth = maxDim;
+            defaultHeight = minDim;
             sDefaultWallpaperSize = new Point(defaultWidth, defaultHeight);
         }
         return sDefaultWallpaperSize;

修改位置：7.1SDK/frameworks/base/core/java/android/app/WallpaperManager.java

@@ -55,6 +55,7 @@ import android.os.SystemProperties;
 import android.os.UserHandle;
 import android.text.TextUtils;
 import android.util.Log;
+import android.view.WindowManager;
 import android.view.WindowManagerGlobal;

 import libcore.io.IoUtils;
@@ -310,7 +311,7 @@ public class WallpaperManager {
                 mCachedWallpaper = null;
                 mCachedWallpaperUserId = 0;
                 try {
-                    mCachedWallpaper = getCurrentWallpaperLocked(userId);
+                    mCachedWallpaper = getCurrentWallpaperLocked(context, userId);
                     mCachedWallpaperUserId = userId;
                 } catch (OutOfMemoryError e) {
                     Log.w(TAG, "No memory load current wallpaper", e);
@@ -342,7 +343,7 @@ public class WallpaperManager {
           }
         }

-        private Bitmap getCurrentWallpaperLocked(int userId) {
+        private Bitmap getCurrentWallpaperLocked(Context context, int userId) {
             if (mService == null) {
                 Log.w(TAG, "WallpaperService not running");
                 return null;
@@ -354,7 +355,14 @@ public class WallpaperManager {
                         params, userId);
                 if (fd != null) {
                     try {
+                        WindowManager mWindowManager = (WindowManager)context.getSystemService(Context.WINDOW_SERVICE);
+                        int wW = mWindowManager.getDefaultDisplay().getWidth();
+                        int wH = mWindowManager.getDefaultDisplay().getHeight();
                         BitmapFactory.Options options = new BitmapFactory.Options();
+                        options.inJustDecodeBounds = true;
+                        BitmapFactory.decodeFileDescriptor(fd.getFileDescriptor(), null, options);
+                        options.inSampleSize = calculateInSampleSize(options, wW, wH);
+                        options.inJustDecodeBounds = false;
                         return BitmapFactory.decodeFileDescriptor(
                                 fd.getFileDescriptor(), null, options);
                     } catch (OutOfMemoryError e) {
@@ -368,6 +376,18 @@ public class WallpaperManager {
             }
             return null;
         }
+
+        private int calculateInSampleSize(BitmapFactory.Options options,int reqWidth, int reqHeight){
+            int width = options.outWidth;
+            int height = options.outHeight;
+            int inSampleSize = 1;
+            if (width > reqWidth && height > reqHeight) {
+                int widthRatio = Math.round((float) width / (float) reqWidth);
+                int heightRatio = Math.round((float) width / (float) reqWidth);
+                inSampleSize = Math.max(widthRatio, heightRatio);
+            }
+            return inSampleSize;
+        }

         private Bitmap getDefaultWallpaper(Context context, @SetWallpaperFlags int which) {
             InputStream is = openDefaultWallpaper(context, which);

修改位置：7.1SDK/frameworks/base/packages/SystemUI/src/com/android/systemui/ImageWallpaper.java

@@ -229,7 +229,7 @@ public class ImageWallpaper extends WallpaperService {
                 surfaceHeight = Math.max(displayInfo.logicalHeight, mBackgroundHeight);
             }

-            if (FIXED_SIZED_SURFACE) {
+            if (false) {
                 // Used a fixed size surface, because we are special.  We can do
                 // this because we know the current design of window animations doesn't
                 // cause this to break.

修改之后，系统默认设置的壁纸可以正常显示。剩下的问题还在探索中。