Develop Reference

Is it possible to sort data in a textview?

I am using 'Codeofaninja' .
android table scroll code
He generates data. I replaced that with an sqlite database. It works well but...
I need to sort and the displays are textviews with tablerows.
Should I use listviews instead of the textviews/tablerows?
I have seen examples of data being sorted in a collection. I have my data in lists already but I have read that textviews have performance problems.
If the answer is listviews then I have to redesign the views which I am trying to not do. But if technology says I must then so be it.
So I have come up with 2 options:
1:textview gets repopulated with list after any data actions.
2:listview is where data is manipulated then stored back to db. Then I need to put a listview in the relativelayout view?
I have tried deleting the tablerows from the textview and reading data back in but this proves slow.
I searched on textviews and listviews and have seen many examples but it is still not clear as to what method is the preferred.
Thank you for input.

The idea is that the sorting is independent of the view. You sort the data in the collection (list, array, etc.) first, then use the ListAdapter (or ArrayAdapter, .etc) to populate the view.
From what you described, it seems the textviews are re-created every time, i.e, if you have 10 rows, each row has 3 textviews, did you create 30 textviews? In that case, sure it has performance problem. Try reading up on ViewHolder for ListView
Android Viewholder implementation

It is superior to use the idea of loading some data at a time. Both Android ListView and RecyclerView virtually loads data when required, and removes data when they are no longer needed.
One good tutorial about ListView # Populating a ListView With Data. Tell us what you think of it.
The only drawback for these GUI classes is when you only have small amount of data to show, which is not likely, from your post.

Android Adapt Data from a SQLite Database to a Listview

EDIT: After spending almost all day on this OutOfMemory Error I was getting, turns out I simply wasnt advancing a cursor. However, I still wish to obtain an answer for my question below. To clarify, my question is:
Is it faster to make a custom adapter for a listview that hooks directly into the database to retrieve the data, or should an arraylist of that data be made first and then passed into a default arrayadapter?
I am currently working on an application and as a part of one of its functions I need to be able to take data from an internal database and display parts of it in various listviews. These listviews are all linked together in a ViewFlipper to make it easy to move between the views. I am working with about 5000 values maximum at once. (That is the stress size for the data set that I am tasked to work with).
Should I write a custom adapter that directly links to the database and extracts the values, or is there a better way to go about this? I tried to create a sort of wrapper class for the database that would extract all necessary data from the database and place it into a POJO but i keep getting OutOfMemory exceptions (5 string values * 5000 rows = 25000 strings doesnt seem to be nicely accepted in my case).

Not with the same amount of values, 5000 but I had a similar problem.
I ended up using a private arrayList on a ListAdapter, the list will contain only partial lists, for example 100 items.
Your cursor can initially contain the values to fill the firsts 100 items and when you scroll down looking for more items you can launch another cursor to retreive the next 50 items. Controlling a range of 100-150 items at your arrayList by adding/removing new/old items and refreshing the adapter.
I vote up your question because maybe someone find a better way to do it and I would like to know as well.

What's the best way to handle a list view whose cursor gets frequent reads and writes?

I am building an Inventory application. The items are shown in a grid view and each cell of the grid view also has a TextView in the upper right corner that displays the available quantity of the item. The user can single click on the gridview cell to increase the quantity or long click to decrease it.
I am currently using a class derived from SimpleCursorAdapter to display the data, but I am not sure about how to update the quantity in the DB. I am afraid that if I write directly to the DB and then create a new cursor and change cursor that the application might become bogged down if the user clicks repeatedly (say to add 10 items)
I have considered copying the data from the query cursor to an array in the Activity and then using an ArrayAdapter but this seems kludgy.
I have also thought about creating an array in my SimpleCursorAdapter which would cache items that have been modified and then save those items when pausing...
Is there a better way? A more Android way?
I guess this comes down to: what is the best way to make rapid changes in the DB and UI?

I don't know much about Cursors in this regard, but I would create a custom ArrayAdapter based on a model object rather than a Cursor. That's just a personal preference, but by doing this I don't have to make any assumptions about the Cursor implementation or know it inside and out.
Let's say you're displaying a collection of type Item in your grid. I would create a class called ItemsList that derives from ArrayList<Item> and my adapter would derive from ArrayAdapter<Item>. The reason you create a wrapper around the ArrayList is that you can allow the user to interact with it freely and mark it as "dirty" and allow it to update the database asynchronously. This way, you just call notifyDataSetChanged() on your adapter and you don't have to think about the overhead of updating the db...you've separated interacting with the collection being displayed and the process of updating the persistent storage.
Btw...this video is a must when working with ListViews and Adapters if you haven't already seen it:
http://www.youtube.com/watch?v=wDBM6wVEO70

You could use a regular listView and a regular Adapter with a list (arraylist) of items in it. Every time user clicks or long clicks you can edit the list in your adapter and notifyDataChanged() which will reflect the list changes on your listView. If you want to keep your list after user quits your application you can use either database(for bigger amount of data) or preferences (for smaller data amount).

Android Scrolling Autogrow ListView

Hello
I am trying to build a listview based on content from the web.
I have had a look at :
http://androidboss.com/load-listview-in-background-asynctask/
example but it uses a predefined array of months. How can I substitute the known
array of months for an unknown undetermined number of items from the internet?
I want to load a listview with some data from the internet, the user
scrolls the list and it retrieves the next row(s) from the internet etc etc
rather than using a array of predetermined length.
Thanks Ian

You can use my EndlessAdapter for that. The project has a demo/ subproject demonstrating its use.

It sounds like you need to extend an adapter such as ArrayAdapter. Extending an ArrayAdapter so that you can dynamically generate the rows or alter the number of rows, and also notify the Adapter that the underlying data has changed, is a very common exercise in Android.
You'll find quite a few tutorials on this but, very basically, if you implement your own adapter by extending ArrayAdapter you can override getView() to programmatically generate each view, and you can override getCount() to provide the number of rows. You can use notifyDataSetChanged() to trigger a refresh of the list on the screen if some data has changed and you need to refresh.

How to delete checked items in a ListView

I want to have a Button that when clicked, removes all the checked items in the ListView. I already have all the xml items set up, I just don't know how to write the java code.

The ListView displays data that comes from an Adapter. In order to remove items from the view the item needs to be removed from the Adapter and the view notified. In android the Adapter notifies the view by calling notifyDataSetChanged().
How to remove an item from the adapter depends on your particular adapter. The SimpleCursorAdapter gets its data from an underlying Cursor. To remove an item, the item should be removed from the underlying Cursor. For example using a SQLiteCursor a row in the database needs to be deleted.
If you use the ArrayAdapter just call remove(T object) on the adapter. It will automagically call notifyDataSetChanged() for you.
update:
I saw the code at git hub. Here are some pointers as how to get your app working as soon as possible.
Try refactoring your code in to smaller graspable parts. Start with extracting some methods to give parts of the large method understandable names.
The problem is that there might by hundreds of rows in the database and only enough views to fill the screen. Nowhere is it remebered what rows are checked, hence its not possible to remove them. You probably need to extend BaseAdapter or SimpleCursorAdapter to hold the state (checked or not) of the rows. Read up on the excellent android documentation.
My point here is there is a distinction between the view, your CheckBox, and the model containing the data to display. So check out Model-View-Controller. You can ignore the concept of controller for now.