Develop Reference

Android programming: How to make language change permanent in onItemSelected adapter in a spinner

I'm new to android programming and I would like to do the following:
I have a spinner which lets you change language. I have set it up and it works quite well. However the issue is that it does not remember the chosen language (in the spinner). So if you were to close the app and restart it, it will revert to the first item on the spinner which is english.
I want to change the function in such a way that once you select an item, it remembers it.
I've set up a shared preference which remembers which language is picked. However I can't make the shared preference the lead since then I could never change the chosen language, and if I make the chosen language the lead then the preference will always follow the chosen language even at the start where the chosen language should actually follow the preference. Here's the code that I have now. I hope anyone can help me we this since I've been breaking my brain over it for a while now
pref_language = pref.getString("language", "en");
//pref_language_begin = pref.getBoolean("language_begin", false);
final Spinner spinner_languages = (Spinner) findViewById(R.id.spinner_languages);
spinner_languages.setAdapter(new CustomSpinnerAdapter(MainActivity.this, R.layout.customspinneritem, languages, language_flags));
spinner_languages.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
parent.getItemAtPosition(position);
language_chosen = (String) parent.getItemAtPosition(position);
if (!pref_language.equals(language_chosen)) {
SetLocale(language_chosen);
pref_language = language_chosen;
edit.putString("language", pref_language);
//edit.putBoolean("language_begin", true);
edit.apply();
recreate();
}
else{
}
}
The customspinneradapter is just there to let me select both a language and a flag for it.
I think I might need a second preference but I have no idea on how to implement it. The leading language at start up should be the preference but the language after choosing one in the spinner should be the chosen language. I was thinking about using an onclick listener but I'm not sure I should with spinners.
Surely there must be a more simpler way and I'm just not thinking straight.
Hope you guys can help me out!

I will give you couple suggestions..
Name your variables with the "cammel case" technique. For example:
spinner_languages shoud be named spinnerLanguages . Be a pro :)
Make a key for languages in shared preferences as a global and constant variable to use it everywhere in a class or classes and prevent typo mistake (if you don't know what is 'global variable" please google it):
static final String LANGUAGES_KEY = "languages";
Just when you start your activity ( onCreate() method but before super.onCreate(savedInstanceState); ) read your shared preferences and set language to the app:
// language from android system
String langSystem = Locale.getDefault().getLanguage();
String lang = sharedPreferences.getString(LANGUAGES_KEY, langSystem);
// update language
SetLocale(lang);
After that find the right language index for spinner (for example by using for loop)
and use:
spinnerLanguages.setSelection(languageIndex)

just use setSelection method for initial selecting item after setting adapter (position must be smaller than list items count, without adapter set spinner have 0 items)
spinner_languages.setSelection(position);
position may be picked e.g. by iterating through languages array (passed to adapter) and comparing each lang to pref_language
int position = -1;
for(int i=0; i < languages.size(); i++) {
if(pref_language.equals(languages.get(i))){
position = i;
break;
}
}
if (position >=0) { // found
spinner_languages.setSelection(position);
}
check out THIS topic about spinner selection

The animation for my programatically created button acts weird in my application

So I am facing a weird bug I cannot explain - I cannot even reproduce it sometimes.
Basic context:
I have an application, which lists objects. Every object has a name and a point value. For every object, the addCustomSpinner function creates a "ticket" (a custom view, kind-of-spinner) and shows them in a scrollview so the user can select the one needed. There are four different 'containers' for four different kind of objects - so the layout can be populated with four kind of "ticket" package.
The data for the objects are collected from a database. The addCustomSpinner is called with a for cycle for every object in the database, and - Important - before the for method, the Layout it populates with the tickets is cleared (removeAllViews).
Inside addCustomSpinner, everything is created as "new" - like the button in question.
addCustomSpinner creates this button and adds a new onClickListener. Inside onClickListener, a new boolean is created - this is used to show a different animation when the button is clicked again. On first click (boolean = true), the arrow turns 180 degrees and faces upwards, on second click (boolean = false) the arrow turns 180 degrees and faces downwards. Works like a charm, until...
The bug I am facing:
Sometimes - as I already mentioned, not every time - if I click the button for one "ticket", then leave it 'opened' and click on an another one, and leave it 'opened' also, THEN I choose to populate the layout with a different kind of "ticket" package - The arrow faces upwards by default on every ticket in every package! Sometimes - again, just sometimes - with the same pattern I can turn it back, but it happens just "by accident".
I don't understand how the animation and state of the buttons can be connected, if every created ticket is new, every button is new, every onClickListener is new, and every boolean inside onClickListener is new. And if these are connected somehow, then why can that be that every behavior is "unique" for the buttons, nothing else shows any connection - even this is just a "sometimes" bug, a pretty rare one.
Can anybody help me why this happens?
What I tried:
Well, tried to trace the issue - but since it happens just by accident, I have no clue, I just searched if I can do anything else than the boolean to add different animation for the clicks. Sadly using ObjectAnimator is not a good solution for me - not the same result at least, since my animated arrow not only rotates, but it also changes its color. Shapeshifter seemed like a good idea to create animations easily, but now as I see it, maybe a simple rotation will be my ultimate solution.
Here's the code for the button:
customButton.setOnClickListener(new View.OnClickListener() {
boolean isCustomButtonClicked = true;
#Override
public void onClick(View v) {
if (isCustomButtonClicked) {
customButton.setImageResource(R.drawable.avd_anim_arrow_blue_back);
Drawable d = customButton.getDrawable();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
if (d instanceof AnimatedVectorDrawable) {
animArrowAnim = (AnimatedVectorDrawable) d;
animArrowAnim.start();
}
}
routeWhoClimbed.setVisibility(View.VISIBLE);
isCustomButtonClicked = false;
} else if (!isCustomButtonClicked) {
customButton.setImageResource(R.drawable.avd_anim_arrow_blue);
Drawable d = customButton.getDrawable();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
if (d instanceof AnimatedVectorDrawable) {
animArrowAnim = (AnimatedVectorDrawable) d;
animArrowAnim.start();
}
}
routeWhoClimbed.setVisibility(GONE);
isCustomButtonClicked = true;
}
}
});
EDIT:
The full addCustomSpinner():
private void addCustomSpinner(Routes mRouteItemToAdd, String placeName) {
//creating a new View for my custom layout created in xml
View customRoutesView = new View(this);
LinearLayout.LayoutParams customViewParams = new LinearLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT,
ViewGroup.LayoutParams.WRAP_CONTENT
);
customRoutesView.setLayoutParams(customViewParams);
customRoutesView = LayoutInflater.from(this).inflate(
R.layout.custom_view_layout, routeLayout, false
);
//Setting up the views inside the custom view
ImageView imageViewDiffImage = customRoutesView.findViewById(R.id.routeDiffImageView);
TextView textViewRouteName = customRoutesView.findViewById(R.id.routeNameTextView);
TextView textViewRouteDiff = customRoutesView.findViewById(R.id.routeDiffTextView);
ImageButton customButton = customRoutesView.findViewById(R.id.customButton);
RadioButton climberNameOne = customRoutesView.findViewById(R.id.climberNameOne);
RadioButton climberNameTwo = customRoutesView.findViewById(R.id.climberNameTwo);
Button climbedItButton = customRoutesView.findViewById(R.id.climbed_it_button);
RadioGroup climberNameRadioGroup = customRoutesView.findViewById(R.id.climberNameRadioGroup);
RadioGroup climbingStyleRadioGroup = customRoutesView.findViewById(R.id.styleNameRadioGroup);
RelativeLayout routeWhoClimbed = customRoutesView.findViewById(R.id.routeWhoClimbedRelativeLayout);
imageViewDiffImage.setImageResource(R.mipmap.muscle);
textViewRouteName.setText(mRouteItemToAdd.name);
textViewRouteDiff.setText("Difficulty: " + (int) mRouteItemToAdd.difficulty);
climberNameOne.setText(climberName1);
climberNameTwo.setText(climberName2);
routeWhoClimbed.setVisibility(GONE);
//Here comes the button with the animated image
customButton.setOnClickListener(new View.OnClickListener() {
boolean isCustomButtonClicked = true;
#Override
public void onClick(View v) {
if (isCustomButtonClicked) {
customButton.setImageResource(R.drawable.avd_anim_arrow_blue_back);
Drawable d = customButton.getDrawable();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
if (d instanceof AnimatedVectorDrawable) {
animArrowAnim = (AnimatedVectorDrawable) d;
animArrowAnim.start();
}
}
routeWhoClimbed.setVisibility(View.VISIBLE);
isCustomButtonClicked = false;
} else if (!isCustomButtonClicked) {
customButton.setImageResource(R.drawable.avd_anim_arrow_blue);
Drawable d = customButton.getDrawable();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
if (d instanceof AnimatedVectorDrawable) {
animArrowAnim = (AnimatedVectorDrawable) d;
animArrowAnim.start();
}
}
routeWhoClimbed.setVisibility(GONE);
isCustomButtonClicked = true;
}
}
});
//Button, works like an 'OK' or something, and I have no
//problem with this
climbedItButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int checkedNameButton = climberNameRadioGroup.getCheckedRadioButtonId();
int checkedStyleButton = climbingStyleRadioGroup.getCheckedRadioButtonId();
RadioButton checkedNameRadioButton = (RadioButton) findViewById(checkedNameButton);
RadioButton checkedStyleRadioButton = (RadioButton) findViewById(checkedStyleButton);
String checkedName = (String) checkedNameRadioButton.getText();
String checkedStyle = (String) checkedStyleRadioButton.getText();
addClimbToDatabase(user.getUid(), checkedName, mRouteItemToAdd, placeName, checkedStyle);
}
});
//And finally, I add this new "ticket" with the custom view to the layout i want to show it. Again, this also works like a charm, no problem here.
routeLayout.addView(customRoutesView);
}

Ultimately, I did not manage to understand the problem throughly, but I was able to eliminate it.
So during my fixing tries I narrowed down the problem to the animated drawable state - credit to #avalerio for his pro tip, but the answer wasn't addig an id to the button. I think somehow and sometime, the state of the first animation (turning the arrow 180 degrees) stuck in the end position - causing the other views using this animatedDrawable showing it in end position on start.
.reset() did not help, since it resets the animatedVectorDrawable object, not the animation xml drawable state. My solution is a kind of workaround, but it is working: when the custom-view 'ticket' is created with the animated-drawable-imagebutton, I set the imageResource of the button to a not-animated xml drawable - this drawable is basically the start position of my animated-drawable. This way, when the 'tickets' are generated, the imagebutton is 'hardcoded' in the start position.
Not elegant, but works. BUT(!) I would really appreciate if someone could explain to me how this weird behavior is possible - just sometimes, randomly, with no pattern I can reproduce intentionally.

Android Studio basic quiz issue

So I'm trying to make a quiz in which I will have 4 buttons for possible answers. I want to check if the right button is pressed, if so I want to change the image for about 2 seconds and load the next question (which will be an image stored in an array) this will be in a for loop the length of the question array I believe?
I'm having some trouble with this, as I'm also unsure on how to load a new question and then it know which button needs to be pressed, for example. question 1 might need button 1 pressing but question 2 might be button 3 but I don't want to change activity.
creating the array and setting image view:
private int[] ImageArr = new int[5];
private ImageView image = (ImageView) findViewById(R.id.Question_ImgView);
filling array:
public void FillImage() {
ImageArr[0] = R.drawable.img1;
ImageArr[1] = R.drawable.img2;
ImageArr[2] = R.drawable.img3;
ImageArr[3] = R.drawable.img4;
ImageArr[4] = R.drawable.img5;}
this is then called in the "onCreate method" to fill array on launch
then i will have a questions method, this is where I want the before mentioned things to happen.
tldr; I need to know how to loop through an image array if correct button is pressed (correct button changes for each question), and change the text on the buttons, till all questions are answered.
any help would be appreciated, thanks in advance. :)

I think the best thing you should do is to create a Question class.
public class Question {
#DrawableRes
private int imageId;
private String[] answers;
private int correctAnswerIndex;
public Question(int imageId, int correctAnswerIndex, String... answers) {
this.imageId = imageId;
this.correctAnswerIndex = correctAnswerIndex;
this.answers = answers;
}
#DrawableRes
public int getImageId() { return imageId; }
public String[] getAnswers() { return answers; }
public int getCorrectAnswerIndex() { return correctAnswerIndex; }
}
This class represents a question. It has
an imageId field to store the image of the question
an answers field to store all the possible answers that the user can choose
a correctAnswerIndex to store the correct answer. This actually stores the index of the correct answer in the answers array. Say you have {"blue", "red", "green", "yellow"} as the answers array and the correct answer is blue, you will set the correct answer index to 0.
Don't understand how to use it? Let's see an example.
At the moment, you have an array of image ids. You should change that to an array of Questions.
private Question[] questions = new Question[4];
And your fillQuestion method would be:
questions[0] = new Question(R.drawable.sweeper_is_handsome, 0, "True", "False", "Maybe", "I don't know");
questions[1] = new Question(R.drawable.no_one_can_beat_jon_skeet_in_reputation, 1, "True", "False", "Maybe", "I don't know");
// you get the idea.
As you can see, the answer to the first question is "True" (correctAnswerIndex = 0) and that to the second question is "False" (correctAnswerIndex = 1).
Now you have an array full of questions. How do you display it?
I think you can work out how to display the image yourself, so let's focus on how to get the buttons working.
I guess your buttons will be in an array, right? If it is isn't, then you're totally doing this wrong. Just add four buttons to an array, it's simple.
You can use the same on click handler for each button. It doesn't matter. In the on click listener, you have a view parameter like this right?
public void buttonOnClick(View view) {
// ⬆︎
// here
}
If you are doing this right, view should be an item in your buttons array. You can use the indexOf method to get the index of the button in the array. If this index matches the correctAnswerIndex of the question, the user chose the correct answer!
But how do you know which question is displaying? You create a variable in your activity class called questionIndex to keep track of it! It should start at 0 and each time you display a new question, you increment it!
EDIT:
This is how your button on click handler would look like:
int pressedButtonIndex = btns.indexOf(view);
int correctAnswerIndex = questions[questionIndex].getCorrectAnswerIndex();
if (pressedButtonIndex == correctAnswerIndex) {
// This means the user chose the correct answer
if (questionIndex == 4) {
// This is actually the last question! No need to display the next!
return;
}
// load next question
questionIndex++;
someImageView.setImage(questions[questionIndex].getImageId());
for (int i = 0 ; i < 4 ; i++) {
btns[i].setText(questions[questionIndex].getAnswers()[i]);
}
// YAY! The next question is displayed.
} else {
// User chose the wrong answer, do whatever you want here.
}

I would like to give a general approach to your question, you can or may need to modify according to your needs,
You have an Image Array of questions and would like to know the correct Button was pressed or not, for that you will need the options and a correct answer to compare with the Button clicked to check if the correct Button was pressed or not,
and you do not need to loop through all the questions at once, what you can do is when the button is pressed, compare button text with the correct answer and if its correct then show the next question image, some code example for the same,
if(btnClicked.getText().toString().equals("Correct Answer")){
questionPos++;
imgView.setImageResource(questionPos);
// Update all the buttons as per the new options
btn1.setText(options1);
// .... like wise update other buttons
}
see if this makes sense
Edit
as per you are asking how to know which button is clicked you can do something like this ...
btn1.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View view) {
if(btn1.getText().toString().equals("Correct Answer")){
questionPos++;
imgView.setImageResource(questionPos);
// Update all the buttons as per the new options
btn1.setText(options1);
}
}
});
// Similarly you can do for all other buttons

How to fix ArrayIndexOutOfBoundsException when a activity is reloaded in Android?

I have created programmatically, 5 radio groups with 4 radio buttons each. I set OnClickListener on the reset button that i have created too. I want when someone clicks the button, to restart my activity. How is it even possible? When the app first time starts, it works fine but when i press the button to reload the activity, the emulator crashes. If i comment the lines where i create the radio groups and the radio buttons and i press the button, the activity is reloading fine otherwise i have this error: Unable to start activity ComponentInfo{...}: java.lang.ArrayIndexOutOfBoundsException: length=4; index=4. How can reload the activity without issues?
Here is my code:
answerGroup = new RadioGroup[5];
answer = new RadioButton[4];
int i = 0;
for (Question qn : questions) {
answerGroup[i] = new RadioGroup(this);
answerGroup[i].setOrientation(RadioGroup.VERTICAL);
int j = 0;
for (Answer an : answers) {
if (qn.getID() == an.getQuestion_id_answer()) {
answer[j] = new RadioButton(this);
answer[j].setText(an.getAnswer());
answerGroup[i].addView(answer[j]);
j++;
}
}
linearLayout.addView(answerGroup[i]);
i++;
}
restartButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = getIntent();
intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
finish();
startActivity(intent);
}
});
Thanks!

The activity is probably trying to reference to old view elements (from before the Activity restart). Try to add your view components:
RadioGroup
RadioButton
As class variables. Can you try that and tell me what it is doing? I will update this answer according to the input you give me.
EDIT:
I assume that you are using a ArrayList<Question> and ArrayList<Answer> as the questions and answers variable.
for (Question qn : questions) {
RadioGroup answerGroup = new RadioGroup(this);
answerGroup.setOrientation(RadioGroup.VERTICAL);
for (Answer an : qn.getAnswers()) {
if (qn.getID() == an.getQuestion_id_answer()) {
RadioButton answer = new RadioButton(this);
answer.setText(an.getAnswer());
answerGroup.addView(answer);
}
}
linearLayout.addView(answerGroup);
}
Maybe you should add a getter method to your question called: getAnswers(); and a variable to your Question model called List<Answer> answers. Ofcourse, these answers need to be set before you try to do anything with them.

You must debug your code, probably not all your questions have 4 answers.
If one of your questions have more than 4 answers (eg: 5), and you try to loop through them you get the ArrayIndexOutOfBoundsException because j>=4.
As a solution: try to use a List for your RadioButtons:
List<RadioButton> answer = new ArrayList<RadioButton>();
And for each iteration add a new RadioButton:
answer.add(new RadioGroup(this));
PS: Also i suggest you to use recreate() method to reload/recreate your activity.

Android ListAdapter start # top

Currently the list when populated is starting with the view # the bottom of the list. Is there a way using listAdapters to force it to the top of the list?
Currently the orientation scrolls to the bottom on create. Is there a way to pin the screen to the top when it creates? http://imgur.com/wGTEy in this example you see that entry 1 on create is shoved upwards to make room for six... Instead I want it to populate like this. http://imgur.com/6Lg6e... entry 1 is the top of the list and 6 is pushed off to the bottom for the scroll.
If you look at the picture above you will notice it starts at the bottom of the list instead of at the top. Any Ideas?
mAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, mStrings);
setListAdapter(mAdapter);
registerForContextMenu(getListView());
populateFields();
private void populateFields() {
if (mRowId != null) {
Cursor note = mDbHelper.fetchDaily(mRowId);
startManagingCursor(note);
String body = note.getString(note.getColumnIndexOrThrow(NotesDbAdapter.KEY_DBODY));
mAdapter.clear();
if (!(body.trim().equals(""))){
String bodysplit[] = body.split(",");
for (int i = 0; i < bodysplit.length; i++) {
mAdapter.add(bodysplit[i].trim());
}
}
}
}
**edited to fix != string error.

You want the items later in the list to be at the top of the ListView? If so, check out this questions: Is it possible to make a ListView populate from the bottom?

You are completely changing the adapter, so the scroll position is lost in the process... You can use:
ListView listView = getListView();
int position = listView.getFirstVisiblePosition();
if (!(body.trim().equals(""))){
String bodysplit[] = body.split(",");
for (int i = 0; i < bodysplit.length; i++) {
mAdapter.add(bodysplit[i].trim());
}
}
listView.setSelection(position);
But this is not perfect as it is, if a row is added before position the index will be off. If your list contains unique values you can use ArrayAdapter#getPosition(), to find the new index.
While I still recommend using a CursorAdapter, because it handles large table data better, I want to address a point on efficiency with your ArrayAdapter code.
By using adapter.clear() and adapter.add() you are asking the ListView to redraw itself on every step... potentially dozens or hundreds of times. Instead you should work with the ArrayList directly and then ask the ListView to redraw once itself with ArrayAdapter#notifyDataSetChanged() after the loop completes.