Close cursor properly.

Also, don't issue separate query()s for each recent mailbox.

Bug 4977956

Change-Id: I3ccd437a7efd5c3599c4a1952ba091a7b3b815bf

emailcommon/src/com/android/emailcommon/utility/Utility.java

@@ -1124,4 +1124,27 @@ public class Utility {
         f.dump("", new FileDescriptor(), w, new String[0]);
         return sw.toString();
     }
+
+    /**
+     * Builds an "in" expression for SQLite.
+     *
+     * e.g. "ID" + 1,2,3 -> "ID in (1,2,3)".  If {@code values} is empty or null, it returns an
+     * empty string.
+     */
+    public static String buildInSelection(String columnName, Collection<? extends Number> values) {
+        if ((values == null) || (values.size() == 0)) {
+            return "";
+        }
+        StringBuilder sb = new StringBuilder();
+        sb.append(columnName);
+        sb.append(" in (");
+        String sep = "";
+        for (Number n : values) {
+            sb.append(sep);
+            sb.append(n.toString());
+            sep = ",";
+        }
+        sb.append(')');
+        return sb.toString();
+    }
 }

src/com/android/email/activity/AccountSelectorAdapter.java

@@ -31,6 +31,7 @@ import com.android.emailcommon.provider.Mailbox;
 import com.android.emailcommon.utility.Utility;
 
 import java.util.ArrayList;
+import java.util.Collection;
 
 import android.content.ContentResolver;
 import android.content.ContentUris;
@@ -385,7 +386,7 @@ public class AccountSelectorAdapter extends CursorAdapter {
                 // Do not display recent mailboxes in the account spinner for the two pane view
                 recentMailboxes = mailboxManager.getMostRecent(mAccountId, mUseTwoPane);
             }
-            int recentCount = (recentMailboxes == null) ? 0 : recentMailboxes.size();
+            final int recentCount = (recentMailboxes == null) ? 0 : recentMailboxes.size();
             matrixCursor.mRecentCount = recentCount;
 
             if (!mUseTwoPane) {
@@ -395,9 +396,7 @@ public class AccountSelectorAdapter extends CursorAdapter {
             }
 
             if (recentCount > 0) {
-                for (long mailboxId : recentMailboxes) {
-                    addMailboxRow(matrixCursor, accountPosition, mailboxId);
-                }
+                addMailboxRows(matrixCursor, accountPosition, recentMailboxes);
             }
 
             if (!mUseTwoPane) {
@@ -418,16 +417,23 @@ public class AccountSelectorAdapter extends CursorAdapter {
             MailboxColumns.UNREAD_COUNT, MailboxColumns.MESSAGE_COUNT
         };
 
-        private void addMailboxRow(MatrixCursor matrixCursor, int accountPosition, long mailboxId) {
+        private void addMailboxRows(MatrixCursor matrixCursor, int accountPosition,
+                Collection<Long> mailboxIds) {
             Cursor c = mContext.getContentResolver().query(
-                    ContentUris.withAppendedId(Mailbox.CONTENT_URI, mailboxId),
-                    RECENT_MAILBOX_INFO_PROJECTION, null, null, null);
-            if (!c.moveToFirst()) {
-                return;
+                    Mailbox.CONTENT_URI, RECENT_MAILBOX_INFO_PROJECTION,
+                    Utility.buildInSelection(MailboxColumns.ID, mailboxIds), null,
+                    RecentMailboxManager.RECENT_MAILBOXES_SORT_ORDER);
+            try {
+                c.moveToPosition(-1);
+                while (c.moveToNext()) {
+                    addRow(matrixCursor, ROW_TYPE_MAILBOX,
+                            c.getLong(c.getColumnIndex(MailboxColumns.ID)),
+                            mFolderProperties.getDisplayName(c), null,
+                            mFolderProperties.getMessageCount(c), accountPosition, mAccountId);
+                }
+            } finally {
+                c.close();
             }
-            addRow(matrixCursor, ROW_TYPE_MAILBOX, mailboxId,
-                    mFolderProperties.getDisplayName(c), null,
-                    mFolderProperties.getMessageCount(c), accountPosition, mAccountId);
         }
 
         private void addHeaderRow(MatrixCursor cursor, String name) {

src/com/android/email/activity/RecentMailboxManager.java

@@ -39,6 +39,8 @@ public class RecentMailboxManager {
     @VisibleForTesting
     static RecentMailboxManager sInstance;
 
+    public static String RECENT_MAILBOXES_SORT_ORDER = MailboxColumns.DISPLAY_NAME;
+
     /** The maximum number of results to retrieve */
     private static final int LIMIT_RESULTS = 5;
     /** Query to find the top most recent mailboxes */
@@ -101,7 +103,7 @@ public class RecentMailboxManager {
             EmailContent.ID_PROJECTION,
             selection,
             new String[] { Long.toString(accountId), Integer.toString(LIMIT_RESULTS) },
-            MailboxColumns.DISPLAY_NAME);
+            RECENT_MAILBOXES_SORT_ORDER);
         try {
             while (cursor.moveToNext()) {
                 returnList.add(cursor.getLong(EmailContent.ID_PROJECTION_COLUMN));

tests/src/com/android/emailcommon/utility/UtilityUnitTests.java

@@ -525,4 +525,20 @@ public class UtilityUnitTests extends AndroidTestCase {
         assertFalse(Utility.isServerNameValid("$"));
         assertFalse(Utility.isServerNameValid("  "));
     }
+
+    private static Collection<Long> toColleciton(long... values) {
+        ArrayList<Long> ret = new ArrayList<Long>();
+        for (long v : values) {
+            ret.add(v);
+        }
+        return ret;
+    }
+
+    public void testBuildInSelection() {
+        assertEquals("", Utility.buildInSelection("c", null));
+        assertEquals("", Utility.buildInSelection("c", toColleciton()));
+        assertEquals("c in (1)", Utility.buildInSelection("c", toColleciton(1)));
+        assertEquals("c in (1,2)", Utility.buildInSelection("c", toColleciton(1, 2)));
+        assertEquals("c in (1,2,-500)", Utility.buildInSelection("c", toColleciton(1, 2, -500)));
+    }
 }