diff --git a/packages/DocumentsUI/src/com/android/documentsui/dirlist/Model.java b/packages/DocumentsUI/src/com/android/documentsui/dirlist/Model.java
index 68b1bcc411fce..c5ee59237fb08 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/dirlist/Model.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/dirlist/Model.java
@@ -20,9 +20,10 @@ import static com.android.documentsui.Shared.DEBUG;
 import static com.android.documentsui.State.SORT_ORDER_DISPLAY_NAME;
 import static com.android.documentsui.State.SORT_ORDER_LAST_MODIFIED;
 import static com.android.documentsui.State.SORT_ORDER_SIZE;
+import static com.android.documentsui.model.DocumentInfo.getCursorLong;
+import static com.android.documentsui.model.DocumentInfo.getCursorString;
 
 import android.database.Cursor;
-import android.database.MergeCursor;
 import android.os.Bundle;
 import android.provider.DocumentsContract;
 import android.provider.DocumentsContract.Document;
@@ -61,17 +62,34 @@ public class Model {
     private String mIds[] = new String[0];
     private int mSortOrder = SORT_ORDER_DISPLAY_NAME;
 
-    private int mAuthorityIndex = -1;
-    private int mDocIdIndex = -1;
-    private int mMimeTypeIndex = -1;
-    private int mDisplayNameIndex = -1;
-    private int mColumnSizeIndex = -1;
-    private int mLastModifiedIndex = -1;
-
     @Nullable String info;
     @Nullable String error;
     @Nullable DocumentInfo doc;
 
+    /**
+     * Generates a Model ID for a cursor entry that refers to a document. The Model ID is a unique
+     * string that can be used to identify the document referred to by the cursor.
+     *
+     * @param c A cursor that refers to a document.
+     */
+    private static String createModelId(Cursor c) {
+        // TODO: Maybe more efficient to use just the document ID, in cases where there is only one
+        // authority (which should be the majority of cases).
+        return createModelId(
+                getCursorString(c, RootCursorWrapper.COLUMN_AUTHORITY),
+                getCursorString(c, Document.COLUMN_DOCUMENT_ID));
+    }
+
+    /**
+     * Generates a Model ID for a cursor entry that refers to a document. The Model ID is a unique
+     * string that can be used to identify the document referred to by the cursor.
+     *
+     * @param c A cursor that refers to a document.
+     */
+    static String createModelId(String authority, String docId) {
+        return authority + "|" + docId;
+    }
+
     private void notifyUpdateListeners() {
         for (UpdateListener listener: mUpdateListeners) {
             listener.onModelUpdate(this);
@@ -109,13 +127,6 @@ public class Model {
         mCursor = result.cursor;
         mCursorCount = mCursor.getCount();
         mSortOrder = result.sortOrder;
-        mAuthorityIndex = mCursor.getColumnIndex(RootCursorWrapper.COLUMN_AUTHORITY);
-        assert(mAuthorityIndex != -1);
-        mDocIdIndex = mCursor.getColumnIndex(Document.COLUMN_DOCUMENT_ID);
-        mMimeTypeIndex = mCursor.getColumnIndex(Document.COLUMN_MIME_TYPE);
-        mDisplayNameIndex = mCursor.getColumnIndex(Document.COLUMN_DISPLAY_NAME);
-        mColumnSizeIndex = mCursor.getColumnIndex(Document.COLUMN_SIZE);
-
         doc = result.doc;
 
         updateModelData();
@@ -162,30 +173,22 @@ public class Model {
         for (int pos = 0; pos < mCursorCount; ++pos) {
             mCursor.moveToNext();
             positions[pos] = pos;
+            mIds[pos] = createModelId(mCursor);
 
-            // Generates a Model ID for a cursor entry that refers to a document. The Model ID is a
-            // unique string that can be used to identify the document referred to by the cursor.
-            // If the cursor is a merged cursor over multiple authorities, then prefix the ids
-            // with the authority to avoid collisions.
-            if (mCursor instanceof MergeCursor) {
-                mIds[pos] = getString(mAuthorityIndex) + "|" + mCursor.getString(mDocIdIndex);
-            } else {
-                mIds[pos] = mCursor.getString(mDocIdIndex);
-            }
-
-            mimeType = getString(mMimeTypeIndex);
+            mimeType = getCursorString(mCursor, Document.COLUMN_MIME_TYPE);
             isDirs[pos] = Document.MIME_TYPE_DIR.equals(mimeType);
 
-            switch (mSortOrder) {
+            switch(mSortOrder) {
                 case SORT_ORDER_DISPLAY_NAME:
-                    displayNames[pos] = getString(mDisplayNameIndex);
+                    final String displayName = getCursorString(
+                            mCursor, Document.COLUMN_DISPLAY_NAME);
+                    displayNames[pos] = displayName;
                     break;
                 case SORT_ORDER_LAST_MODIFIED:
-                    longValues[pos] = getLastModified();
+                    longValues[pos] = getLastModified(mCursor);
                     break;
                 case SORT_ORDER_SIZE:
-                    longValues[pos] = mColumnSizeIndex != -1
-                            ? mCursor.getLong(mColumnSizeIndex) : 0;
+                    longValues[pos] = getCursorLong(mCursor, Document.COLUMN_SIZE);
                     break;
             }
         }
@@ -361,17 +364,13 @@ public class Model {
         }
     }
 
-    private String getString(int columnIndex) {
-        return columnIndex != -1 ? mCursor.getString(columnIndex) : null;
-    }
-
     /**
      * @return Timestamp for the given document. Some docs (e.g. active downloads) have a null
      * timestamp - these will be replaced with MAX_LONG so that such files get sorted to the top
      * when sorting by date.
      */
-    private long getLastModified() {
-        long l = mCursor.getLong(mLastModifiedIndex);
+    long getLastModified(Cursor cursor) {
+        long l = getCursorLong(mCursor, Document.COLUMN_LAST_MODIFIED);
         return (l == -1) ? Long.MAX_VALUE : l;
     }
 
diff --git a/packages/DocumentsUI/tests/src/com/android/documentsui/dirlist/ModelTest.java b/packages/DocumentsUI/tests/src/com/android/documentsui/dirlist/ModelTest.java
index 3536593564afa..c6ad5116d93bf 100644
--- a/packages/DocumentsUI/tests/src/com/android/documentsui/dirlist/ModelTest.java
+++ b/packages/DocumentsUI/tests/src/com/android/documentsui/dirlist/ModelTest.java
@@ -284,7 +284,7 @@ public class ModelTest extends AndroidTestCase {
             String id = Integer.toString(i);
             row.add(RootCursorWrapper.COLUMN_AUTHORITY, AUTHORITY);
             row.add(Document.COLUMN_DOCUMENT_ID, id);
-            currentDownloads.add(id);
+            currentDownloads.add(Model.createModelId(AUTHORITY, id));
         }
 
         DirectoryResult r = new DirectoryResult();
diff --git a/packages/DocumentsUI/tests/src/com/android/documentsui/dirlist/TestModel.java b/packages/DocumentsUI/tests/src/com/android/documentsui/dirlist/TestModel.java
index 2d819ffcdf07d..d8c29db81a77f 100644
--- a/packages/DocumentsUI/tests/src/com/android/documentsui/dirlist/TestModel.java
+++ b/packages/DocumentsUI/tests/src/com/android/documentsui/dirlist/TestModel.java
@@ -62,7 +62,9 @@ public class TestModel extends Model {
         update(r);
     }
 
+    // Note that model id includes authority qualifier and is distinct
+    // WRT documentId because of this.
     String idForPosition(int p) {
-        return Integer.toString(p);
+        return createModelId(mAuthority, Integer.toString(p));
     }
 }