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androidlistviewandroid-cursoradapter

How would I use a different row layout in custom CursorAdapter based on Cursor data?


Background: I'm trying to implement a messenging system in my app, and I'm writing a custom CursorAdapter to display the messages in a ListView in the chat window. I want to use a different row layout for incoming and outgoing messages (information that is saved in the SQLite row in the cursor). Each row has the same elements in it with the same IDs, but they are arranged differently.

The Problem: Currently, I have overridden newView() and bindView(). When the ListView is first populated, it creates all of the Views perfectly, checking each row to see if it's either incoming or outgoing, and inflating the proper XML file. However, when I scroll or a new message is added to the window, the adapter recycles Views for the wrong rows. I would override getView(), but it is not passed the Cursor as a parameter, so I have no way of knowing whether the row should be incoming or outgoing.

I'm not looking for code, but rather, some suggestion for an elegant implementation. Thanks in advance!


Solution

  • Here are two possible solutions:

    (1) Use a single layout for all items, which you can adjust when binding to show as desired. The most straight-forward way would just to have the root view be a FrameLayout which contains N children for each of the different states, and you make one of them visible and all others gone when binding. Of course you want to take care to not let this cause your items to explode in the number of views they contain.

    (2) Implement Adapter.getItemViewType() http://developer.android.com/reference/android/widget/Adapter.html#getItemViewType(int) to tell the list view about the different types of items you have so it will recycle the correct one.