Broaden the filter for wallpaper restore

Tweak the filter parameters so that we now use any restored wallpaper image
that is larger than our ideal size, and will reject any smaller images only
if they are *much* smaller than our ideal size.  The specific threshold used
here will just barely reject Nexus One or Droid sized wallpapers for restore
onto a Xoom, but will pass anything larger.

Bug 4070129

Change-Id: I889bdb3ef5011343b2fccb2f81c6abc2f4603ee2

diff --git a/core/java/android/app/backup/WallpaperBackupHelper.java b/core/java/android/app/backup/WallpaperBackupHelper.java
index 6539711..55368d6 100644 (file)
--- a/core/java/android/app/backup/WallpaperBackupHelper.java
+++ b/core/java/android/app/backup/WallpaperBackupHelper.java
@@ -110,11 +110,16 @@ public class WallpaperBackupHelper extends FileBackupHelperBase implements Backu
                     if (DEBUG) Slog.d(TAG, "Restoring wallpaper image w=" + options.outWidth
                             + " h=" + options.outHeight);
 
-                    // how much does the image differ from our preference?
+                    // How much does the image differ from our preference?  The threshold
+                    // here is set to accept any image larger than our target, because
+                    // scaling down is acceptable; but to reject images that are deemed
+                    // "too small" to scale up attractively.  The value 1.33 is just barely
+                    // too low to pass Nexus 1 or Droid wallpapers for use on a Xoom, but
+                    // will pass anything relatively larger.
                     double widthRatio = mDesiredMinWidth / options.outWidth;
                     double heightRatio = mDesiredMinHeight / options.outHeight;
-                    if (widthRatio > 0.8 && widthRatio < 1.25
-                            && heightRatio > 0.8 && heightRatio < 1.25) {
+                    if (widthRatio > 0 && widthRatio < 1.33
+                            && heightRatio > 0 && heightRatio < 1.33) {
                         // sufficiently close to our resolution; go ahead and use it
                         if (DEBUG) Slog.d(TAG, "wallpaper dimension match; using");
                         f.renameTo(new File(WALLPAPER_IMAGE));