I'm creating my first game for Android, using Android Studio, and have a design question about choosing and maintaining parameters throughout the application.
From the main menu, the user would select 'New Game', which opens an Activity called 'New Game Parameters', where they would select one option from each of three categories:
Occupation (occupation 1, occupation 2, occupation 3, etc.)
Item taken (item 1, item 2, item 3, etc.)
Action performed (action 1, action 2, action 3, etc.)
Whatever values the user selects will not change again for that specific play-through once the game starts. Depending on the choices, different events will occur, and so I'll need to reference these parameters throughout the game.
My question is, what is the best way to design for that? I've been looking through tons of documentation for BaseAdapter, ArrayAdapter, ListAdapter, Preference, SharedPreference, persistent data, and a lot of it seems viable, but it's been kind of overwhelming and confusing at times. I've gotten a lot of good information from here before, and appreciate any help that you all can provide.
The simplest way to save only a few values (like yours, three parameters with values) is SharedPreferences. There is a good and simple example on this page:
Saving Key-Value Sets
You could also implement some constants to give your key fixed values.
Example of your button (or what you want to let the user choose):
public void onButtonOption1Click(View v){
//Save your value
SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPref.edit();
editor.putInt("Occupation",1);
editor.commit();
}
Example of activity where you want to load the value:
public void getPreference(){
SharedPreferences sharedPref=getActivity().getPreferences(Context.MODE_PRIVATE);
int occupation_value =sharedPref.getInt("Occupation");
}
Related
I am coding using Xamarin and have a question about application settings.
Is it possible to have application wide settings? I will give you an example:
I have a map application. I have a ListView where the user can select if the map is using the Street View, Satellite View or default view.
Depending on the item that is selected in the ListView depends of the map view that is shown.
Where and how can I save this selection such that this value is visible throughout the application and when the user exits the application, this setting can be remembered for when the user starts the application up again?
Thanks in advance
Yes, it's possible and also very easy. Usually you save simple application settings using SharedPreferences. They can be read from anywhere in the app.
For writing.
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(context);
Editor editor = sp.edit();
editor.putBoolean("someBoolean", true);
editor.putString("someString", "string");
editor.commit();
For reading
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(context);
boolean someBoolean = sp.getBoolean("someBoolean", false);
boolean someString = sp.getString("someString", null);
I suppose you are familiar to Java I/O and android basic concepts. So here I go:
For data persistance in Android, you have two main solutions:
SQLite database
File system
I recommend you to use file system, as you don't really need to organize your data with relational constraints and you will probably not have to make a lot of data persist.
Android documentation is very clear on how to save files:
http://developer.android.com/training/basics/data-storage/files.html
I recommend you to create a Setting class that contains a HashMap attribute:
public class Settings implements Parcelable{
public static HashMap<String,String> settings;
public static void readSettings(){
//Here you read your settings file and you fill your hashmap
}
public static void writeSettings(){
//Here you iterate through your hashmap and you write your setting files
}
}
Every activities will have access to the settings, as the attribute/methods are static. Settings will also be synchronized through every activities (if you change a setting in one activity, every other activities will notice).
If you need some clarifications, leave a comment below.
i work on an app and i have this problem.
Example:
i have 4 buttons in the main page:
APPLE,
STRAWBERRY,
CHERRY,
FAVORITES
if i click on APPLE STRAWBERRY OR CHERRY, it will open another activity with 3 more buttons
APPLE HISTORY,
MADE APPLE JUICE,
HOW TO GROW APPLE
Each of this buttons when clicked, open another activity with some data and text
I would like when someone made a long press on APPLE, STRAWBERRY or CHERRY to open a windows that ask if i want to save the selected item to FAVORITES, so it will copy the button inside the activity FAVORITES with the option to delete this choice in the future.
Can someone help me?
Thanks
You can set a listener for a long click to handle it
yourButton.setOnLongClickListener(new OnLongClickListener() {
#Override
public boolean onLongClick(View v) {
// TODO Auto-generated method stub
return true;
}
});
Inside this listener you can open a Dialog, where the user can choose if he wants to add it to Favorites or not. Furthermore save the users choice in SharedPreferences with a boolean or something which indicates that he made his choice. In your Favorite Activity read the SharedPreferences file and handle accordingly.
This could be done by adding Views programatically to have a dynamic setup. Or if the repertory is limited, like your example, set the Visibility of some Views / Buttons in your XML to gone and change it to Visible by reference to the users input.
You could save all your favorites items in a csv file, in a preference, in a xml file.. There are millions of way to achieve it.
I would personally use a sharedPreference to let the user edit it easily.
Is it possible to add an array or object to SharedPreferences on Android
I have a custom Array Adapter to display a list of items, in this case, highscores. The system sort of mimics a folder scheme; one clicks a folder named "Game 1" and it goes to a new list with the top 10 scorers. When you take a test, it changes a sharedpreferences called isPlayed, and if isPlayed is 1, the image for that Game, Game 1, is green, otherwise, if you never play Game 1, isPlayed is never 0, and therefor the image on the highscore list of games is red. But, SharedPreferences seems to be unknown in a class that extends ArrayAdapter. How can I use data from sharedpreferences here? Post a question if you need more info.
You can access SharedPreferences with -
getContext().getSharedPreferences(String name, int mode)
PreferenceManager.getDefaultSharedPreferences(YourActivity.this)
or, instead of YourActivity.this you can use any Context from your application such as your application context.
I’m a new developer, so my question maybe too much basic.
I look for example of defining preferences of sound. User can choose what kind of sound will start an application, for example. There can be such a RingtonPreference widjet, so user can choose a sound.
As I know, preferences support the primitive types: Boolean, string, float, long and integer. What way is the best to design preferences: store in entryValues the names if sounds (strings), the address of files from Resourse class (integer), or other way.
Please provide a short example of code.
Thanks in advance!
First of all thank you for the quick and detailed answer!
I want to arrange list of sounds: there must be one “None”, list of sounds that contains folder “raw”, option to add a new sound from different locations and two buttons: “set” and “cancel”. When user touches one item from the list – sound starts to play.
There is a little problem with standard widget that provide android library. “ListPreference” isn’t appropriate because on touch on one of the items – item is chosen and list closes, “there are not buttons set and cancel”.
“RingtonPreference” isn’t appropriate as well – I didn’t succeed to add something to list.
How is possible to build a custom preference layout and that is options that were chosen will be saved as well as on standard widgets. Please provide a short code example. Thanks in advance!
I think the best way to store the Resource are by integers. or you could do names.
I think integer is more reliable.
So to use SharedPreference with this you will need to get access to the apps SharedPreference
public class PreferencesDemo extends Activity {
SharedPreferences app_preferences;
private int resourceNumber;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// Get the app's shared preferences
SharedPreferences app_preferences = PreferenceManager.getDefaultSharedPreferences(this);
resourceNumber = app_preferences.getInt("resourceNumber", 0);
if(resourceNumber == 0){
//This means the user hasnt selected a song and you must act accordingly. Or put a resource number where the 0 is do set it to a default song
}
You will probably want to create a method to put the songs in the SharedPreference such as;
private void createSongResouces(){
SharedPreferences.Editor editor = app_preferences.edit();
//Here you can put as many songs as you want just make sure you call editor.commit(); as i do.
editor.putInt("resourceNumber", resourceNumber);
editor.commit(); // Very important
}
Is it possible to use a preference screen as a simple interface to read and write values to a database?
Basically, I like the way the preference screen looks and operates, but preferences aren't a suitable way to store all the data I have.
I know how to get it to display correctly, but I'm unsure on how to access the values represented on the screen, and how to keep it from writing a preference file.
Is this even a good idea?
Thanks.
Just to follow this up for anyone that is interested. I got it working by using a Preference.OnPreferenceChangeListener() to store the value as a int or string or whatever. For example:
et_model.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener(){
public boolean onPreferenceChange(Preference preference, Object newValue) {
String val = (String) newValue;
preference.setSummary(val);
model = val;
return true;
}
});
Then once the user presses done, I add the data to the database in the usual way with my SQLight database helper class.
When I load the values from the database, I simply use Preference.SetText(String), and Preference.SetSummary(String).
I guess it is still writing a preference file because if I don't set the preference's text it will load with whatever was set last, but I don't think this is a problem. I could also delete the preference file when I close the activity or something...
If you want a good example, just look at the source for the AlarmClock (now DeskClock) Look at SetAlarm.java and set_alarm.xml for the layout(Save and cancel keys) and alarm_prefs.xml for the actual preference layout.
I don't think that is such a hot idea, especially if you plan on having a tone of data in your database. How ever if you did want to do it, I would just extend the Preference widgets that you will use and have them interface with the database. For example, lets say you have 10 items in a table and you want to select one item (row in the database), you would override the ListPreference and fill it with the content of the applicable database row.