From 2c74ee56a44e7a43bda14e88fd2b571fd88952fe Mon Sep 17 00:00:00 2001
From: Marc Blank <mblank@google.com>
Date: Sun, 11 Oct 2009 18:55:45 -0700
Subject: [PATCH] Prevent EmailAddressAdapter from leaking cursors; load in bg

* Relates to a number of bugs related to ANR's and slow behavior
  when addressing mail
* Call changeCursor(null) on the Adapter when the activity is destroyed
* Call getCount() in the background thread to force data there rather
  than in the UI thread
* If this change is accepted, something equivalent should be
  used in the Gmail app as well
* Addresses #2180237 (P1, target Eclair_Sholes) as well as
  #2180976 and #2146926, the latter two of which were fixed
  with workarounds.

Change-Id: I7503c5fbe091dbc5e784d5a7bebeb3d60226d57d
---
 src/com/android/email/EmailAddressAdapter.java    | 11 ++++++++++-
 .../android/email/activity/MessageCompose.java    | 15 +++++++++++----
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/src/com/android/email/EmailAddressAdapter.java b/src/com/android/email/EmailAddressAdapter.java
index fbe78094f..e4d68707c 100644
--- a/src/com/android/email/EmailAddressAdapter.java
+++ b/src/com/android/email/EmailAddressAdapter.java
@@ -69,6 +69,15 @@ public class EmailAddressAdapter extends ResourceCursorAdapter {
     public Cursor runQueryOnBackgroundThread(CharSequence constraint) {
         String filter = constraint == null ? "" : constraint.toString();
         Uri uri = Uri.withAppendedPath(Email.CONTENT_FILTER_URI, Uri.encode(filter));
-        return mContentResolver.query(uri, PROJECTION, null, null, SORT_ORDER);
+        Cursor c = mContentResolver.query(uri, PROJECTION, null, null, SORT_ORDER);
+        // To prevent expensive execution in the UI thread
+        // Cursors get lazily executed, so if you don't call anything on the cursor before
+        // returning it from the background thread you'll have a complied program for the cursor,
+        // but it won't have been executed to generate the data yet. Often the execution is more
+        // expensive than the compilation...
+        if (c != null) {
+            c.getCount();
+        }
+        return c;
     }
 }
diff --git a/src/com/android/email/activity/MessageCompose.java b/src/com/android/email/activity/MessageCompose.java
index 1084becc0..e8837e746 100644
--- a/src/com/android/email/activity/MessageCompose.java
+++ b/src/com/android/email/activity/MessageCompose.java
@@ -148,6 +148,8 @@ public class MessageCompose extends Activity implements OnClickListener, OnFocus
     private AsyncTask mSaveMessageTask;
     private AsyncTask mLoadMessageTask;
 
+    private EmailAddressAdapter mAddressAdapter;
+
     private Handler mHandler = new Handler() {
         @Override
         public void handleMessage(android.os.Message msg) {
@@ -375,6 +377,11 @@ public class MessageCompose extends Activity implements OnClickListener, OnFocus
         cancelTask(mLoadMessageTask);
         mLoadMessageTask = null;
         // don't cancel mSaveMessageTask, let it do its job to the end.
+
+        // Make sure the adapter doesn't leak its cursor
+        if (mAddressAdapter != null) {
+            mAddressAdapter.changeCursor(null);
+        }
     }
 
     /**
@@ -511,18 +518,18 @@ public class MessageCompose extends Activity implements OnClickListener, OnFocus
 
         mQuotedTextDelete.setOnClickListener(this);
 
-        EmailAddressAdapter addressAdapter = new EmailAddressAdapter(this);
+        mAddressAdapter = new EmailAddressAdapter(this);
         EmailAddressValidator addressValidator = new EmailAddressValidator();
 
-        mToView.setAdapter(addressAdapter);
+        mToView.setAdapter(mAddressAdapter);
         mToView.setTokenizer(new Rfc822Tokenizer());
         mToView.setValidator(addressValidator);
 
-        mCcView.setAdapter(addressAdapter);
+        mCcView.setAdapter(mAddressAdapter);
         mCcView.setTokenizer(new Rfc822Tokenizer());
         mCcView.setValidator(addressValidator);
 
-        mBccView.setAdapter(addressAdapter);
+        mBccView.setAdapter(mAddressAdapter);
         mBccView.setTokenizer(new Rfc822Tokenizer());
         mBccView.setValidator(addressValidator);