The first time the app is run, I want to have a checkbox list appear where the user selects the list items that they are interested in, and run the program based on that. Every subsequent time the app is run, I want those selected settings to be remembered, or changed with an options menu, in which case the new settings will be remembered. But all I know how to do is make an app go from the beginning every time it is run…
Similarly, my app reads sequentially through all the data in a large, read-only, unchangable database. As of right now, it creates and opens and fetches all the data every time, which takes a few seconds at the start of the program to open up and do anything. Is there a way to get around this, or, is it even a good idea to try to get around this?
To remember the users selection, have a look at SharedPreferences. You can store the selected items there.
To the database: That really depends on your app. If you need all that data at the same time in memory, I guess theres no way around loading it at the start. If you only need parts, it would be a good idea to load a part of the data when required. But without exact knowledge of your app/use case, this is hard to tell.
When you have some sort of “lag” when loading the database: Do you probably load the database in the UI-thread (= without creating a seperate thread for loading)? Thats bad practice since it blocks all UI operations. Have a look at AsyncTasks. Thats a handy class that wraps around a thread and lets you do things in the background without blocking all the UI. After it’s done with its task (loading in this case) it provides you a
onPostExecute()callback where you can update your UI with the loaded data.