Bug 783312 - Show empty rows on about:home for customization. r=mfinkle

mobile/android/base/AboutHomeContent.java

@@ -336,8 +336,13 @@ public class AboutHomeContent extends ScrollView
 
             Cursor c = (Cursor) mTopSitesAdapter.getItem(i);
             final String url = c.getString(c.getColumnIndex(URLColumns.URL));
-
-            displayThumbnail(view, thumbnails.get(url));
+            if (TextUtils.isEmpty(url)) {
+                ImageView thumbnailView = (ImageView) view.findViewById(R.id.thumbnail);
+                thumbnailView.setImageResource(R.drawable.abouthome_thumbnail_add);
+                thumbnailView.setScaleType(ImageView.ScaleType.FIT_CENTER);
+            } else {
+                displayThumbnail(view, thumbnails.get(url));
+            }
         }
 
         mTopSitesGrid.invalidate();
@@ -806,6 +811,11 @@ public class AboutHomeContent extends ScrollView
             }
 
             titleView.setText(title);
+            if (TextUtils.isEmpty(title)) {
+                titleView.setVisibility(View.GONE);
+            } else {
+                titleView.setVisibility(View.VISIBLE);
+            }
             return true;
         }
 

mobile/android/base/Makefile.in

@@ -501,6 +501,7 @@ RES_DRAWABLE_BASE = \
   res/drawable/abouthome_promo_logo_sync.png \
   res/drawable/abouthome_thumbnail.png \
   res/drawable/abouthome_thumbnail_bg.png \
+  res/drawable/abouthome_thumbnail_add.png \
   res/drawable/address_bar_bg_shadow.png \
   res/drawable/alert_addon.png \
   res/drawable/alert_app.png \
@@ -592,6 +593,7 @@ RES_DRAWABLE_HDPI = \
   res/drawable-hdpi/abouthome_promo_logo_sync.png \
   res/drawable-hdpi/abouthome_thumbnail.png \
   res/drawable-hdpi/abouthome_thumbnail_bg.png \
+  res/drawable-hdpi/abouthome_thumbnail_add.png \
   res/drawable-hdpi/address_bar_bg_shadow.png \
   res/drawable-hdpi/alert_addon.png \
   res/drawable-hdpi/alert_app.png \
@@ -673,6 +675,7 @@ RES_DRAWABLE_XHDPI = \
   res/drawable-xhdpi/abouthome_promo_logo_sync.png \
   res/drawable-xhdpi/abouthome_thumbnail.png \
   res/drawable-xhdpi/abouthome_thumbnail_bg.png \
+  res/drawable-xhdpi/abouthome_thumbnail_add.png \
   res/drawable-xhdpi/address_bar_bg_shadow.png \
   res/drawable-xhdpi/address_bar_texture_port.png \
   res/drawable-xhdpi/address_bar_texture_port_pb.png \

mobile/android/base/db/BrowserDB.java

@@ -10,6 +10,7 @@ import org.mozilla.gecko.db.BrowserContract.ExpirePriority;
 import android.content.ContentResolver;
 import android.database.ContentObserver;
 import android.database.Cursor;
+import android.database.CursorWrapper;
 import android.graphics.Bitmap;
 import android.graphics.drawable.BitmapDrawable;
 
@@ -115,7 +116,7 @@ public class BrowserDB {
     }
 
     public static Cursor getTopSites(ContentResolver cr, int limit) {
-        return sDb.getTopSites(cr, limit);
+        return new TopSitesCursorWrapper(sDb.getTopSites(cr, limit), limit);
     }
 
     public static void updateVisitedHistory(ContentResolver cr, String uri) {
@@ -243,4 +244,59 @@ public class BrowserDB {
     public static int getCount(ContentResolver cr, String database) {
         return sDb.getCount(cr, database);
     }
+
+    /* Cursor wrapper that forces top sites to contain at least
+     * mNumberOfTopSites entries. For rows outside the wrapped cursor
+     * will return empty strings and zero.
+     */
+    static public class TopSitesCursorWrapper extends CursorWrapper {
+        int mIndex = -1;
+        Cursor mCursor = null;
+        int mSize = 0;
+        
+        public TopSitesCursorWrapper(Cursor cursor, int size) {
+            super(cursor);
+            mCursor = cursor;
+            mSize = size;
+        }
+
+        public int getPosition() { return mIndex; }
+        public int getCount() { return mSize; }
+        public boolean isAfterLast() { return mIndex >= mSize; }
+        public boolean isBeforeFirst() { return mIndex < 0; }
+        public boolean isLast() { return mIndex == mSize - 1; }
+        public boolean moveToNext() { return moveToPosition(mIndex + 1); }
+        public boolean moveToPrevious() { return moveToPosition(mIndex - 1); }
+
+        public boolean moveToPosition(int position) {
+            mIndex = position;
+            if (position > -1 && position < mCursor.getCount())
+                super.moveToPosition(position);
+            return !(isBeforeFirst() || isAfterLast());
+        }
+
+        public long getLong(int columnIndex) {
+            if (mIndex > -1 && mIndex < mCursor.getCount())
+                return super.getLong(columnIndex);
+            return 0;
+        }
+
+        public String getString(int columnIndex) {
+            if (mIndex > -1 && mIndex < mCursor.getCount())
+                return super.getString(columnIndex);
+            return "";
+        }
+
+        public boolean move(int offset) {
+            return moveToPosition(mIndex + offset);
+        }
+
+        public boolean moveToFirst() {
+            return moveToPosition(0);
+        }
+
+        public boolean moveToLast() {
+            return moveToPosition(mSize-1);
+        }
+    }
 }