Develop Reference

get the string resources dynamic for a question app

I am developing a question app. I got some questions in my string resource file. Each time a user touches the textview it changes the question.
I have all the questions stored in an array, but I don't think this is very efficient.
max_Fragen = FragenBeginner.length - 1;
min_Fragen = 0;
//Fragen Nummer
randomFrage = rand.nextInt((max_Fragen - min_Fragen) + 1) + min_Fragen;
fragekatalog = getResources().getString(R.string.fragen_FragenBeginner_ + randomFrage);
frage.setText(fragekatalog);

You can use
public static int getStringIdentifier(Context context, String name) {
return context.getResources().getIdentifier(name, "string", context.getPackageName());
}
to use a variable as a string identifier.

get ID of string from another values

I know the title is confusing,
But I have a persistent problem when trying to get id key of existing string from strings.xml
like this
I have three values folders:
values , values-fr, values-ar;
and I have one string id:
R.id.center
when printed in screen, this id show:
in values
"Center"
in values-fr
"Centre"
in values-ar
"وسط"
My question is:
Is there a way to retrieve the int id by passing `"Center" or "Centre" or "وسط" as parameter
Someting like "وسط".getId, or ("Centre").getId
I know these methods doesn't exist :)`

Edit: Tested and working. Includes locale-support now.
public void listValues() {
Field[] fields = R.string.class.getFields();
String[] locales = Resources.getSystem().getAssets().getLocales();
for (int x = 0; x < locales.length; x++) {
System.out.println("checking for all ressources for the locale=" + locales[x]);
for (int i = 0; i < fields.length; i++) {
try {
System.out.println("name=" + fields[i].getName() + " value=" + getLocalizedResources(this, new Locale(locales[x])).getString(fields[i].getInt(fields[i].getName())));
} catch (IllegalAccessException ex) {
System.out.println(".. catch it if you want it");
} catch (RuntimeException rex) {
}
}
}
}
#NonNull
Resources getLocalizedResources(Context context, Locale desiredLocale) {
Configuration conf = context.getResources().getConfiguration();
conf = new Configuration(conf);
conf.setLocale(desiredLocale);
Context localizedContext = context.createConfigurationContext(conf);
return localizedContext.getResources();
}

Android: Enable certain button with id as index

I have 50 styled buttons with identificators like "level_i", I need to enable button with certain i in id.
I have code to work with indexed aarays in string xml, but I have no proper ideas how to change it for my usage
Class<R.id.array> res;
Field field;
try {
res = R.array.class;
field = res.getField("words_" + fname);
//set myString to the string resource myArray[fname,y]
myString = getResources().obtainTypedArray(field.getInt(null)).getString(y);
}
catch (Exception e) {
e.printStackTrace();
}

I believe you are saying that you have an ID resource named "words_" + fname for example R.id.words_100. If that is correct, then you can first get the ID using the name of the resource with getIdentifier. Then you can get the actual ID, then you can find the view with that ID:
String resName = "words_" + fname";
Resources res = getResources();
int resId = res.getIdentifier(resName, "id", getPackageName());
View button = findViewById(resId);
EDIT:
Modified original answer to fetch resources from R.id rather than R.string-array.

Get a list of filenames in a drawable resource directory

I want to get a list of certain filenames in a drawable resource directory (at runtime, not using XML). I guess, I would need to distinguish certain files from others. So ...
*res/drawable-hdpi/mysubdir
-- x-one.png
-- one.png
-- x-two.png
-- two.png
-- x-three.png
-- three.png
*
I want to put the x-*.png filenames into a List<String>. Is this possible?
Borrowing some code from another question, I can get all the drawables, but I don't see a way to distinguish one from another in a meaningful way.
private void getDrawableResources() {
final R.drawable drawableResources = new R.drawable();
final Class<R.drawable> drawableClass = R.drawable.class;
final Field[] fields = drawableClass.getDeclaredFields();
final List<Integer> resourceIdList = new ArrayList<Integer>();
for (int i = 0, max = fields.length; i < max; i++) {
final int resourceId;
try {
resourceId = fields[i].getInt(drawableResources);
resourceIdList.add(resourceId);
}
catch (Exception e) {
continue;
}
}
Resources resources = this.getActivity().getResources();
for (int i = 0; i < resourceIdList.size(); i++) {
Drawable drawable = resources.getDrawable(resourceIdList.get(i));
resourceIdList.get(i) + "): " + drawable.toString());
}
}

Resource directories do not support subdirectories.

Use FileNameFilter while getting list of files in a directory.
File dir = new File(dirLocation);
if(dir.exists() && dir.isDirectory())
{
File[] files = dir.listFiles(new FilenameFilter()
{
public boolean accept(File dir, String name)
{
return name.contains("X-");
}
});
}

How to do a findViewById (R.id.>> StringVarHere << )?

Searched and working on this a long while - no luck. ( It must be simple ? Thanks for the assist. )
Trying to get / set a screen full of EditTexts' text, but not with the usual, more hard-coded way:
... findViewById (R.id.SomeTextWidgetId) ;
Instead, I'm trying to figure out a reusable way via a variable holding the (String) name_of_widget.
In psuedo code:
findViewById (R.id.>> StringVarHere << ); // how to do that ?
I tried also this findViewById method, but it didn't work (!?)
//// given:
static final String FIELD_TV_FEE = "TextViewFee" ;
static final String FIELD_TV_FOO = "TextViewFoo" ;
static final String FIELD_TV_FUM = "TextViewFum" ;
//// and some arbitrary number more of similar fields
static final String [] ALL_FIELDS = {
FIELD_TV_FEE ,
FIELD_TV_FOO ,
FIELD_TV_FUM // ...
} ;
//// ...
//// this part works
int ResourceID;
String stringVarHere = FIELD_TV_FEE;
//// outputs a correct id, say '0x7f05000f' as in R.id.xxx below
ResourceID = context
.getResources()
.getIdentifier ( stringVarHere,
"id",
context
.getApplicationInfo()
.packageName
) ;
Log.d ("MyClass" , "RESID = " + Integer.toHexString(ResourceID) ) ;
/*
* that's where I'm stuck ^^^ ... how do I do:
*/
String field_name ;
for ( field_name : ALL_FIELDS ) {
(EditText) SomethingLike_a_findViewById(field_name).setText ("Hello Wurld") ;
}
I've tried .setId ...
//// details
<!-- excerpt from working xml layout -->
<EditText
android:id="#+id/TextViewFee"
android:inputType="text"
android:layout ... etc ...
/>
<EditText
android:id="#+id/TextViewFoo"
android:inputType="text"
android:layout ... etc ...
/>
<EditText
android:id="#+id/TextViewFum"
android:inputType="text"
android:layout ... etc ...
/>
As expected, the gen'ed R file has something like this:
// ...
public static final class id {
public static final int TextViewFee=0x7f05000f;
public static final int TextViewFum=0x7f05001c;
public static final int TextViewFoo=0x7f05001d;
// ... etc
Yes, thanks - it makes sense to do it in the activity. I was trying to keep it from getting too code bulky. Here's what I'm doing now, based on your and A-C's helpful suggestions. The intention is to get all the text of fields of a form back in one String[]. (I know I could brute force all the fields too.)
What do you all think about this below - seems very similar to your suggestion, madlymad ? I am wondering if this is a poor design approach ?
public class FoodBar {
private Activity activity;
private Context ctx;
public FoodBar ( Activity _activity ) {
this.activity = _activity;
this.ctx = this.activity.getApplicationContext() ;
}
public String[] getTextFromAllEditTexts () { // the UI views
int res_id = 0;
int i = 0;
String [] retValues = new String [MyClassName.ALL_FIELDS_LENGTH] ;
for (String field : MyClassName.ALL_FIELDS_ALL_VEHICLES) {
res_id = this.ctx.getResources()
.getIdentifier ( field, "id", this.ctx.getPackageName() );
((EditText) this.activity
.findViewById (res_id))
.setText( "Meat and Potatoes" ) ;
// redundant - get it right back to make sure it really went in !
retVal[i++] = ((EditText) this.activity
.findViewById (res_id))
.getText().toString() ;
}
return retVal;
} // end func
} // end class
Then from the Activity class, it's just:
String [] theFields = null;
FoodBar = new FoodBar (this);
try {
theFields = FoodBar.getTextFromAllEditTexts ();
} catch (Exception e) {
Log.d ("OOPS", "There's a big mess in the Foodbar: " + e.toString() );
}

The way you could do it is (as I understand the way you are trying):
This can be in non-Activity (YourClassname.java):
public static int getMyId(Context context, String field) {
return context.getResources().getIdentifier (field, "id", context.getPackageName());
}
in Activity-class:
for ( String field_name : YourClassname.ALL_FIELDS ) {
int resid = YourClassname.getMyId(context, field_name);
if(resid != 0) { // 0 = not found
EditText et = (EditText) findViewById(resid);
if (et != null) {
et .setText ("Hello Wurld") ;
}
}
}
But I think it's better to code in the activity class like:
String packageName = getPackageName();
Resources res = getResources();
for ( String field_name : YourClassname.ALL_FIELDS ) {
int resid = res.getIdentifier (field_name, "id", packageName);
if(resid != 0) {// 0 = not found
EditText et = (EditText) findViewById(resid);
if (et != null) {
et .setText ("Hello Wurld") ;
}
}
}

A-C suggested something along the lines of:
res_id = getResources().getIdentifier (field, "id", getPackageName());
((EditText)findViewById (res_id)).setText("NoLongerFubar");
this DOES work - when I tried it standalone in a test rig. Thanks ! Still not sure what was blowing up, but I suspect it was Context or Resource items not being accessible.

Note that variable names (such as R.id.some_id) are only available at compile time and cannot be accessed from a String value at run time. Since these ids are declared as ints, you might consider using an int[] or List<Integer> to store the ids. Depending on how dynamic your layout is and what you are doing with the Views in it, you might even want to simply create the Views at run time and store an array or List of them without using any ids at all.