What to set CursorAdapter(Context context, Cursor c, int flags) to in order to make it work with CursorLoader?
android, android-contentprovider, android-cursoradapter, android-cursorloader, android-loadermanager
Solution
I blogged about this topic a couple weeks ago... maybe reading through it will help. You might also consider reading through the sample code on the developers site.
Reaping the Benefits of the LoaderManager Class
Which constructor should I use?
Use `CursorAdapter(Context context, Cursor c, int flags)` (the documentation recommends using this constructor over the former).
What integer do I pass `CursorAdapter(Context context, Cursor c, int flags)`.
Just pass it the integer `0`. You don't want to pass it `FLAG_REGISTER_CONTENT_OBSERVER`, since you are using a `CursorLoader` with your `CursorAdapter` (since the `CursorLoader` registers the `ContentObserver for you), and you definitely don't want to pass it`FLAG_AUTO_REQUERY` since that flag is deprecated.
What's worrying me is how to correctly manage the old cursor. I am not really sure the correct way to do this.
The whole point of the `LoaderManager` is that it does all of the annoying cursor management stuff for you, behind the scenes. The convenience of having your data loaded automatically without having to worry about managing the queried cursor is precisely why the old `startManagingCursor` and `stopManagingCursor` methods were deprecated.
... I could just do `adapter.swapCursor(cursor).close()`
Don't do that. The `LoaderManager` will close the cursor on its own. In fact, if I remember correctly, you will get an error if you attempt to call `close()` on the cursor. It sounds like you shouldn't have to override `onContentChanged()` either.
Problem
The google docs point out not to use the `CursorAdapters` first constructor, ``` CursorAdapter(Context context, Cursor c) ``` There are only two other options, ``` CursorAdapter(Context context, Cursor c, boolean autoRequery) ``` which says Constructor that allows control over auto-requery. It is recommended you not use this, but instead CursorAdapter(Context, Cursor, int). When using this constructor, FLAG_REGISTER_CONTENT_OBSERVER will always be set.` and ``` CursorAdapter(Context context, Cursor c, int flags)` ``` which says it is the recommended constructor. Problem is there are only two flags to use with the last constructor here, `FLAG_AUTO_REQUERY`(int 1) and `FLAG_REGISTER_CONTENT_OBSERVER`(int 2). Using `FLAG_AUTO_REQUERY` doesn't make sense because I am now using a CursorLoader in which to manage it in the background as well as update it. With `FLAG_REGISTER_CONTENT_OBSERVER`, it says its not needed when using `CursorLoader`. Now I ask, what integer do I pass `CursorAdapter(Context context, Cursor c, int flags)` in order to make it work fine with my `CursorAdapter`? Whats worrying me is how to correctly manage the old cursor. I am not really sure the correct way to do this. If I use `FLAG_REGISTER_CONTENT_OBSERVER`, then I must do something with `onContentChanged()`, but when using `swapCursor()` in my `LoaderManager`, since the cursor is not closed, I could just do `adapter.swapCursor(cursor).close()`. But would that conflict with `onContentChanged()` in `CursorAdapter`? Goal is to not cause any memory leaks and be efficient.