Develop Reference

Save items added to scroll view android studios

I have created and been able to label items that have been added to a scroll view. I want to find a way to save and store the items created so that when the user clicks off the page they still remain there.
I wanted to do this through the use of sharedprefs however I am not sure how and where the best place would be to add code. Would appreciate any suggestions.
public class Editscreen extends AppCompatActivity {
// https://codevedanam.blogspot.com/2021/04/dynamic-views-in-android.html
Button add;
AlertDialog dialog;
LinearLayout layout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_editscreen);
add = findViewById(R.id.button7);
layout = findViewById(R.id.container);
buildDialog();
add.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
dialog.show();
}
});
}
private void buildDialog() {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
View view = getLayoutInflater().inflate(R.layout.dialog,null);
EditText name = view.findViewById(R.id.nameEdit);
name.getText().clear();
builder.setView(view);
builder.setTitle("Enter Quiz name");
builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
addCard(name.getText().toString());
}
})
.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
}
});
dialog = builder.create();
}
private void addCard(String name) {
View view = getLayoutInflater().inflate(R.layout.cardlayout,null);
TextView nameView = view.findViewById(R.id.name);
Button delete = view.findViewById(R.id.deletequiz);
nameView.setText(name);
delete.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
layout.removeView(view);
}
});
layout.addView(view);
}

I believe you can add this file to your project and you can call this static functions to save your data to pref. This is the compact way.
public class PrefUtil {
private static SharedPreferences getPrefs(Context context) {
return context.getSharedPreferences(context.getPackageName() + "_preferences",Context.MODE_PRIVATE);
}
public static void setStringPref(Context context,String key,String deger){
getPrefs(context).edit().putString(key,deger).apply();
}
public static String getStringPref(Context context,String key){
return getPrefs(context).getString(key,"");
}
public static void setIntPref(Context context,String key,int deger){
getPrefs(context).edit().putInt(key,deger).apply();
}
public static int getIntPref(Context context,String key){
return getPrefs(context).getInt(key, -1);
}
}

Can't change the value of integer variable

#RequiresApi(api = Build.VERSION_CODES.O)
public class MainActivity extends AppCompatActivity {
TextSwitcher textSwitcherage, textSwitcherGender;
Button nextButton, previousButton, nextButton2, previousButton2;
String[] age = {"U-4","Kid","Teen","Adult","Old"};
String[] gender = {"Male","Female","Other"};
TextView textView;
Typeface typeface;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
defVars();
}
public void defVars()
{
textSwitcherGender = findViewById(R.id.textSwitcherGender);
textSwitcherage = findViewById(R.id.textSwitcherage);
nextButton = findViewById(R.id.nextButton1);
nextButton2 = findViewById(R.id.nextButton2);
previousButton = findViewById(R.id.previousButton1);
previousButton2 = findViewById(R.id.previousButton2);
typeface = getResources().getFont(R.font.lettersforlearners);
nextAndPreviousButtons(nextButton,previousButton,textSwitcherage,age,0);
nextAndPreviousButtons(nextButton2, previousButton2, textSwitcherGender, gender,0);
}
public void nextAndPreviousButtons(Button buttonNext, Button buttonPrevious, final TextSwitcher textSwitcher, final String[] data, final Integer stringIndex)
{
buttonNext.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if(stringIndex == data.length - 1)
{
stringIndex = 0;
textSwitcher.setText(data[stringIndex]);
}
else
{
textSwitcher.setText(data[++stringIndex]);
}
}
});
buttonPrevious.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if(stringIndex==0)
{
stringIndex = data.length-1;
textSwitcher.setText(data[stringIndex]);
}
else
{
textSwitcher.setText(data[--stringIndex]);
}
}
});
textSwitcher.setFactory(new ViewSwitcher.ViewFactory() {
#Override
public View makeView() {
textView = new TextView(MainActivity.this);
textView.setTypeface(typeface);
textView.setTextColor(Color.BLACK);
textView.setTextSize(40);
textView.setGravity(Gravity.CENTER_HORIZONTAL);
return textView;
}
});
textSwitcher.setText(data[stringIndex]);
}
}
I have an error:
"error: cannot assign a value to final variable stringIndex"
I set the stringIndex final but still got that problem. I don't know. Am i have to define Integer variables for stringIndex? Or should I delete the stringIndex final? I need to define separate stringIndex variables for each function

if you declare final Integer stringIndex... then you are done! that is the idea and meaning of the reserved word final... is an object you cannot re assign after...
public void nextAndPreviousButtons(Button buttonNext, Button buttonPrevious,
final TextSwitcher textSwitcher, final String[] data, Integer stringIndex)

You don't have to modify stringIndex
public void nextAndPreviousButtons(Button buttonNext, Button buttonPrevious, final TextSwitcher textSwitcher, final String[] data, final Integer stringIndex)
{
buttonNext.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if(stringIndex == data.length - 1)
{
textSwitcher.setText(data[0]);
}
else
{
textSwitcher.setText(data[stringIndex+1]);
}
}
});
buttonPrevious.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if(stringIndex==0)
{
textSwitcher.setText(data[data.length-1]);
}
else
{
textSwitcher.setText(data[stringIndex-1]);
}
}
});
textSwitcher.setFactory(new ViewSwitcher.ViewFactory() {
#Override
public View makeView() {
textView = new TextView(MainActivity.this);
textView.setTypeface(typeface);
textView.setTextColor(Color.BLACK);
textView.setTextSize(40);
textView.setGravity(Gravity.CENTER_HORIZONTAL);
return textView;
}
});
textSwitcher.setText(data[stringIndex]);

Trying to call method from MainActivity in Another Activity it is me leading to error

I have Recycler ListView which I show in MainActivity and the first item it is as selected, I have done to click for another items but the last stays clicked and when I try to take this recycler view to show me in next Activity it doesn't work.
The first item it is selected but I have a click method which when click an image makes as selected but when I click a new image this works but the first item stays as selected so continues for others images. I want only a image to be selected.
I don't want to write twice the same code.
Is it good if I have a class only for this method which I can use everytime I want.
The id of recycler view list it is the same on both xml's.
If you have any suggestion for my question please let me know.
This is the adapter for the RecyclerView.
public class ListViewAdapter extends RecyclerView.Adapter<ListViewAdapter.ViewHolder>{
private int selectedItem;
private ArrayList<Integer> mImages = new ArrayList<>();
private ArrayList<String> mSearchUrl = new ArrayList<>();
private Context mContext;
public ListViewAdapter(ArrayList<Integer> images, ArrayList<String> SearchUrl, Context context) {
mImages = images;
mContext = context;
mSearchUrl = SearchUrl;
}
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.s_engine_item, viewGroup, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull final ViewHolder viewHolder, final int i) {
selectedItem = 0;
if (selectedItem == i) {
viewHolder.image.setBackgroundColor(Color.parseColor("#30000000"));
}
Glide.with(mContext).load(mImages.get(i))
.into(viewHolder.image);
viewHolder.searchUrl.setText(mSearchUrl.get(i));
viewHolder.image.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
viewHolder.image.setBackgroundColor(Color.parseColor("#30000000"));
selectedItem = i;
}
});
}
#Override
public int getItemCount() {
return mImages.size();
}
public class ViewHolder extends RecyclerView.ViewHolder{
ImageView image;
TextView searchUrl;
public ViewHolder(#NonNull View itemView) {
super(itemView);
image = itemView.findViewById(R.id.ivEngine);
searchUrl = itemView.findViewById(R.id.ivEngineText);
}
}
}
This is the method in MainActivity.class
public void intSearch() {
mImages.add(R.drawable.s_bing);
mSearchUrl.add("https://www.bing.com/search?q=");
mImages.add(R.drawable.s_google);
mSearchUrl.add("https://www.google.com/search?q=");
mImages.add(R.drawable.s_yahoo);
mSearchUrl.add("www.yahoo.com");
mImages.add(R.drawable.amazon_white256);
mSearchUrl.add("www.amazon.com");
mImages.add(R.drawable.amazon_white256);
mSearchUrl.add("www.amazon.com");
mImages.add(R.drawable.amazon_white256);
mSearchUrl.add("www.amazon.com");
initRecyclerView();
}
private void initRecyclerView() {
LinearLayoutManager layoutManager = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
RecyclerView recyclerView = findViewById(R.id.lvEngines);
recyclerView.setLayoutManager(layoutManager);
ListViewAdapter adapter = new ListViewAdapter(mImages, mSearchUrl, this);
recyclerView.setAdapter(adapter);
}
This is the button which takes to another activity.
btnSearch.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String newEntry = searchPlugin.getText().toString();
Cursor data = mDatabaseHelper.getData();
AddHistory(newEntry);
getFragmentRefreshListener().onRefresh();
Intent intent = new Intent(MainActivity.this, ActivitySearchEngine.class);
intent.putExtra("name", newEntry);
intent.putExtra("test", mSearchUrl.get(0));
startActivityForResult(intent, 2);
}
});
This is the another activity
public class ActivitySearchEngine extends Activity implements
SwipeRefreshLayout.OnRefreshListener {
public ImageView mHome;
public EditText searchPlugin;
public WebView webView;
Button btnSearch;
public ImageButton clearSearch, exitButton;
public ImageView favIcon;
public ProgressBar loadIcon;
String text;
SwipeRefreshLayout refreshLayout;
DatabaseHelper mDatabaseHelper;
private String selectedName;
private int selectedID;
private String selectedSearchUrl;
RecyclerView mListView;
MainActivity mainActivity = new MainActivity();
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_search_result);
mHome = findViewById(R.id.imgBtnHome);
searchPlugin = findViewById(R.id.etSearch);
webView = findViewById(R.id.webView);
clearSearch = findViewById(R.id.btnClearSearch);
btnSearch = findViewById(R.id.btnSearch);
favIcon = findViewById(R.id.imgViewFavIcon);
loadIcon = findViewById(R.id.progressBarIcon);
exitButton = findViewById(R.id.imgBtnStopLoad);
refreshLayout = findViewById(R.id.refreshLayout);
mListView = findViewById(R.id.lvEngines);
refreshLayout.setOnRefreshListener(this);
mDatabaseHelper = new DatabaseHelper(this);
mainActivity.intSearch(); // Here it is the error
Activity.ActivitySearchEngine}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.Window$Callback android.view.Window.getCallback()' on a null object reference
Intent receivedIntent = getIntent();
selectedName = receivedIntent.getStringExtra("name");
selectedID = receivedIntent.getIntExtra("id",-1); //NOTE: -1 is just the default value
selectedSearchUrl = receivedIntent.getStringExtra("test");
searchPlugin.setText(selectedName);
loadIcon.setVisibility(View.VISIBLE);
webView.setWebViewClient(new WebViewClient());
webView.getSettings().setJavaScriptEnabled(true);
webView.loadUrl("www.bing.com/search?=" + selectedName);
webView.setWebChromeClient(new WebChromeClient() {
#Override
public void onProgressChanged(WebView view, int newProgress) {
super.onProgressChanged(view, newProgress);
}
#Override
public void onReceivedIcon(WebView view, Bitmap icon) {
super.onReceivedIcon(view, icon);
favIcon.setImageBitmap(icon);
}
});
webView.setWebViewClient(new WebViewClient() {
#Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
super.onPageStarted(view, url, favicon);
loadIcon.setVisibility(View.VISIBLE);
favIcon.setVisibility(View.GONE);
}
public void onPageFinished(WebView view, String url) {
try {
if (loadIcon.getVisibility() == View.VISIBLE) {
loadIcon.setVisibility(View.GONE);
favIcon.setVisibility(View.VISIBLE);
btnSearch.setVisibility(View.GONE);
mHome.setVisibility(View.VISIBLE);
exitButton.setVisibility(View.GONE);
clearSearch.setVisibility(View.VISIBLE);
favIcon.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
onRefresh();
}
});
}
} catch (Exception exception) {
exception.printStackTrace();
}
}
});
searchPlugin.addTextChangedListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
#Override
public void afterTextChanged(Editable s) {
processButtonByTextLength();
}
});
mHome.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
searchPlugin.setText(null);
finish();
}
});
clearSearch.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
searchPlugin.setText("");
}
});
public void processButtonByTextLength() {
String inputText = searchPlugin.getText().toString();
if(inputText.length() > 0) {
btnSearch.setVisibility(View.VISIBLE);
mHome.setVisibility(View.GONE);
clearSearch.setVisibility(View.VISIBLE);
favIcon.setVisibility(View.VISIBLE);
loadIcon.setVisibility(View.GONE);
exitButton.setVisibility(View.GONE);
} else if(inputText.length() == 0) {
btnSearch.setVisibility(View.GONE);
mHome.setVisibility(View.VISIBLE);
clearSearch.setVisibility(View.GONE);
}
}
#Override
public void onRefresh() {
webView.reload();
refreshLayout.setRefreshing(false);
}
}
This is the photo with RecyclerView at MainActivity.class
Photo of another Activity

Calling method in main activity when a variable is changed in dialog box

I have listed the code below, What i am trying to achieve is the int i to be updated from a dialog box (dialog2). I then want to check in the main activity if it has changed and if it has changed then call a method. How would i do this?
Main Activity
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
int i = 0;
Dialog1 dialog1 = new Dialog1(this, i);
dialog1.show();
}
//Want to call this method whenever I is modified
private void iModified(){
}
}
Dialog 1 Class (This dialog just passes it to dialog2)
public class Dialog1 extends Dialog{
int integerI;
Button button;
public Dialog1(final Activity activity, final int i){
super(activity);
setContentView(R.layout.dialog1);
integerI = i;
button = findViewById(R.id.dialog1Button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Dialog2 dialog2 = new Dialog2(activity ,integerI);
dialog2.show();
closeDialog();
}
});
}
private void closeDialog(){
this.dismiss();
}
}
Dialog 2: This is where the integer is going to be changed and then i want it to be sent to the main activity and checked if it has changed and if so then replace the old integer with the new one.
public class Dialog2 extends Dialog {
int newI;
Button button;
public Dialog2(Activity activity, int i) {
super(activity);
setContentView(R.layout.dialog2);
newI= i + 12345;
button = findViewById(R.id.dialog2Button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
close();
}
});
}
private void close(){
this.dismiss();
}
}

You can use interface.
your activity:
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
int i = 0;
Dialog1 dialog1 = new Dialog1(this, i, new ModifiedListener() {
#Override
public void notify(int i) {
iModified();
}
});
dialog1.show();
}
//Want to call this method whenever I is modified
private void iModified(){
}
}
your dialog1:
public class Dialog1 extends Dialog {
int integerI;
Button button;
public Dialog1(final Activity activity, final int i, final ModifiedListener listener) {
super(activity);
setContentView(R.layout.dialog1);
integerI = i;
button = findViewById(R.id.dialog1Button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Dialog2 dialog2 = new Dialog2(activity, integerI);
dialog2.show();
closeDialog();
}
});
}
private void closeDialog() {
this.dismiss();
}
}
your dialog 2:
public class Dialog2 extends Dialog {
int newI;
Button button;
public Dialog2(Activity activity, int i, final ModifiedListener listener) {
super(activity);
setContentView(R.layout.dialog2);
newI = i + 12345;
//when you modify int you have to call
listener.notify(newI);
button = findViewById(R.id.dialog2Button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
close();
}
});
}
private void close() {
this.dismiss();
}
}
define interface similar to class:
public interface ModifiedListener {
public void notify(int i);
}

How to make my app loads the articles from the beginning?

I have a simple app with 50 articles, my previous and next button work good in all choices BUT when the user goes to the end (at 50th article) the app can't load again from the beginning the 1st article.
Thanks for any help, here is my code:
I don't know if needs more cede for to be clear, cause I am a newbie.
public class StoryActivity extends AppCompatActivity {
public static final String TAG = StoryActivity.class.getSimpleName();
private Story mStory = new Story();
private ImageView mImageView;
private TextView mTextView;
private Page mCurrentPage;
private String mName;
private Button mPreviousButton;
private Button mNextButton;
private ScrollView mScrollView;
private Button mStartButton;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_story2);
//Intent intent = getIntent();
//mName = intent.getStringExtra(getString(R.string.key_name));
if(mName == null){
mName = "";
}
Log.d(TAG, mName);
mImageView = (ImageView)findViewById(R.id.storyImageView);
mTextView = (TextView)findViewById(R.id.storyTextView);
mPreviousButton = (Button)findViewById(R.id.previousButton);
mNextButton = (Button)findViewById(R.id.nextButton);
mTextView.setMovementMethod(new ScrollingMovementMethod());
loadPage(0);
}
private void loadPage(int choice){
mCurrentPage = mStory.getPage(choice);
Drawable drawable = getResources().getDrawable(mCurrentPage.getImageId());
mImageView.setImageDrawable(drawable);
String pageText = mCurrentPage.getText();
//add the name if placeholder included.
//pageText = String.format(pageText,mName);
mTextView.setText(pageText);
if(mCurrentPage.isSingle()){
mPreviousButton.setVisibility(View.VISIBLE);
mNextButton.setText("");
mNextButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
loadPage(0);
}
});
}else{
mPreviousButton.setText(mCurrentPage.getChoices().getText1());
mNextButton.setText(mCurrentPage.getChoices().getText2());
mPreviousButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int previousPage = mCurrentPage.getChoices().getPreviousPage();
loadPage(previousPage);
}
});
mNextButton.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View v) {
int nextPage = mCurrentPage.getChoices().getNextPage();
loadPage(nextPage);
}
});
}}
}