Develop Reference

Can't Access to ExpandablelistView in fragment

MainActivity on startup add a fragment layout to Relativeview, then i send a data to fragment to add it to ExpandablelistView but my app shows me error that couldn't recognize ExpandablelistView.
MainActivity:
public class MainActivity extends AppCompatActivity implements FragmentAddCatergory.onClickButtonListener {
private FragmentManager manager;
private FragmentTransaction transactionShowList;
private FragmentTransaction transactionAddCatergory;
private FragmentAddCatergory addCatergory;
private FragmentShowCategory showCategory;
private boolean addcategory;
private TextView txtAddCategory;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
manager = getFragmentManager();
transactionShowList = manager.beginTransaction();
showCategory = new FragmentShowCategory();
addCatergory=new FragmentAddCatergory();
transactionShowList.add(R.id.Fragment_container, showCategory);
transactionShowList.commit();
addcategory=false;
txtAddCategory = (TextView) findViewById(R.id.txtaddcategory);
txtAddCategory.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
ChangeFragment();
}
});
}
public void ChangeFragment(){
transactionAddCatergory=manager.beginTransaction();
if (addcategory){
transactionAddCatergory.replace(R.id.Fragment_container,addCatergory);
txtAddCategory.setText("Do you want to see your List?Show me!");
addcategory=false;
}else{
transactionAddCatergory.replace(R.id.Fragment_container,showCategory);
txtAddCategory.setText("Do you want to add a Category?Create One");
addcategory=true;
}
transactionAddCatergory.commit();
}
#Override
public void ClickButton(String group, String child) {
FragmentShowCategory a=new FragmentShowCategory();
a.showExpand(this,group,child);
}}
in last above code i make object from first fragment and send a data and in below code is code of first fragment
public class FragmentShowCategory extends Fragment {
private View view;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
view = inflater.inflate(R.layout.activity_expandable_list_view, container, false);
return view;
}
public void showExpand(Context context, String g, String c) {
Toast.makeText(context, g + " is " + c, Toast.LENGTH_LONG).show();
HashMap<String, List<String>> carsDetails = DataProvider.getInfo(g, c);
List<String> carsBrands = new ArrayList<String>(carsDetails.keySet());
ItemClass adapter = new ItemClass(context, carsDetails, carsBrands);
ExpandableListView list = (ExpandableListView) view.findViewById(R.id.expandList);
list.setAdapter(adapter);
}}
but when i ran my app, i get error that i don't know why in line of:
ExpandableListView list = (ExpandableListView) view.findViewById(R.id.expandList);
i'd appreciate to help me.

Your fragment's view hierarchy is not inflated automatically just because you created an instance of your fragment, as you do in ClickButton. The onCreateView() method that has to be called first in order to inflate your views is part of the fragment's lifecycle. You should let Android instantiate your fragment, and acquire it's instance through the FragmentManager.
This tutorial explains basics about fragments very well.

Android pass View as an object to fragment

I'm more googling to find how can i pass simple view as an object to fragment, but i can't.
for example in MainActivity i have simple view as :
TextView text = (TextView) findviewById(R.id.tv_text);
now i want to pass that to fragment. this below code is my attach Fragment on MainActivity
MainActivity :
public void attachFragment() {
fts = getActivity().getFragmentManager().beginTransaction();
mFragment = new FragmentMarketDetail();
fts.replace(R.id.cardsLine, mFragment, "FragmentMarketDetail");
fts.commit();
}
and this is my Fragment:
public class FragmentMarketDetail extends Fragment implements ObservableScrollViewCallbacks {
public static final String SCROLLVIEW_STATE = "scrollviewState";
private ObservableScrollView scrollViewTest;
private Context context;
private int scrollY;
public static FragmentMarketDetail newInstance() {
FragmentMarketDetail fragmentFirst = new FragmentMarketDetail();
return fragmentFirst;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_online_categories, container, false);
scrollViewTest = (ObservableScrollView) view.findViewById(R.id.scrollViewTest);
scrollViewTest.setScrollViewCallbacks(this);
return view;
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
context = getActivity().getBaseContext();
}
}

It wouldn't be good practise to pass a view that way. If you want to access the view in your activity from within your fragment class, use getActivity() to access the activity to which your fragment is attached, and from there you find your TextView.
TextView text = (TextView) getActivity().findViewById(R.id.tv_text);

How about adding a set function in your custom fragment
e.g.
public void setTextView(TextView tv){
this.tv = tv
}
and then calling it after
mFragment = new FragmentMarketDetail();
mFragment.setTextView(textView)

Find fragment by tag and invoke a function on it:
mFragment = (FragmentMarketDetail ) getActivity().getFragmentManager().findFragmentByTag(FragmentMarketDetail .class.getSimpleName());
mFragment.passTextView(textView);
Of course fragment must be added to backstack.

Custom arrayadapter combines lists used in different fragments of same activity

I have MainActivity activity which has 3 fragments. Those 3 fragments use same arrayadapter class MessageListAdapter. When i populate listView in my fragments using different ArrayLists using MessageListAdapter it combines all those ArrayLists and displays in each fragment. I want each fragment to display its own list.
MessageListAdapter:
public class MessageListAdapter extends ArrayAdapter<Message>{
Context context;
public MessageListAdapter(Context c, int resourceId, ArrayList<Message> list) {
super(c, resourceId, list);
this.context = c;
}
//...
}
HomeFragment:
public class HomeFragment extends Fragment {
View view;
ListView listView1;
ArrayList<Message> contactMessages;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
view = inflater.inflate(R.layout.home_layout, container, false);
TextView welcomeMessage = (TextView) view.findViewById(R.id.welcomeMessage);
Account acc = new Account();
welcomeMessage.setText("Welcome " + acc.getName() + "!");
contactMessages = new Message().getContactMessages();
listView1 = (ListView) view.findViewById(R.id.homeList);
MessageListAdapter adapter = new MessageListAdapter(this.getActivity(), R.layout.activity_message, contactMessages);
listView1.setAdapter(adapter);
listView1.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// TODO Auto-generated method stub
}
});
return view;
}
}
ProfileFragment:
public class ProfileFragment extends Fragment implements View.OnClickListener, OnItemClickListener {
View view;
Intent intent;
ListView listView2;
ArrayList<Message> personalMessages;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
view = inflater.inflate(R.layout.profile_layout, container, false);
Button button = (Button) view.findViewById(R.id.addMessage);
button.setOnClickListener(this);
Button addFriendButton = (Button) view.findViewById(R.id.addFriend);
addFriendButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
intent = new Intent(getActivity(), AddFriendActivity.class);
startActivity(intent);
}
});
personalMessages = new Message().getPersonalMessages();
// Log.i("Personal messages ArrayList: ", personalMessages.toString());
listView2 = (ListView) view.findViewById(R.id.profileList);
MessageListAdapter adapter = new MessageListAdapter(this.getActivity(), R.layout.activity_message, personalMessages);
listView2.setAdapter(adapter);
listView2.setOnItemClickListener(this);
return view;
}
}
Also have 3rd fragment which will use this same MessageListAdapter, but i have not implemented it yet due to running into this problem.
I made screenshots to make it easier to understand:
Items with orange pictures are supposed to be shown only in ProfileFragment and item with blue picture is supposed to be shown only in HomeFragment

Problem lies in using static ArrayList inside Message class. addPersonalMessage adds Message object into personalMessages list and addContactMessage adds Message object into contactMessages list. After i built all the messages according to their type and put them inside lists separately, for some reason application combines those 2 lists. This is why i end up with similar content in both listviews in fragments. Solved problem by using SQLite database instead of using static variables.
Message:
public class Message {
private String author;
private String messageTitle;
private Bitmap messageImage;
private static ArrayList<Message> personalMessages = new ArrayList<Message>();
private static ArrayList<Message> contactMessages = new ArrayList<Message>();
public Message() {
}
public Message(String a, String t, Bitmap b) {
this.author = a;
this.messageTitle = t;
this.messageImage = b;
}
public void addPersonalMessage() {
personalMessages.add(this);
}
public void addContactMessage() {
contactMessages.add(this);
}
}

Android : setVisibility not work

I want change view linearlayout from class
But not work this code
main.java
public class MainActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ComNet.readDb();
}
}
And :
ComNet.java
public class ComNet {
public static Context context;
public static void readDb() {
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View viewMain = inflater.inflate(R.layout.main, null);
LinearLayout lnrPart = (LinearLayout) viewMain.findViewById(R.id.lnrPart);
lnrPart.setVisibility(View.GONE);
}
}
How change lnrPart from main.xml in class ( ComNet ) ?

View viewMain = inflater.inflate(R.layout.main, null);
with this line you are creating a new View, with the content of main.xml. This object is different from the one you are seeing at screen in your MainActivity. setVisibility is working. You are calling it on the wrong instance

Send the activities rootView to readDB function.
main.java
public class MainActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ComNet.readDb(findViewById(R.id.main));
}
}
ComNet.java
public static void readDb(View viewMain) {
LinearLayout lnrPart = (LinearLayout) viewMain.findViewById(R.id.lnrPart);
viewMain.setVisibility(View.GONE);
}

How to add one view to another view which is created using java file that extends view/

This is what i am trying to do, this my main class file
private View TicTacStart;
//onCreate
#Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
TicTacStart = new Game(this);
//reference to base layout..
LinearLayout baseView = (LinearLayout)findViewById(R.id.baseView);
//I cant INFLATE THE VIEW SINCE I AM NOT USING XML AND RATHER USING ANOTHER CLASS GAME WHICH EXTENDS VIEW
LayoutInflater vi = (LayoutInflater)thisActivity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View thisScreensView = vi.inflate(TicTacStart, null);
//add the view to the base view...
baseView.addView(thisScreensView);
}
This is game class
public class Game extends View {
private Cell[][] singlesquare = null;
int x = 3;
int y = 3;
private int l;
private int a;
private boolean whatdrawn = false;
private int playerwin = 3;
private Paint caneta;
Data Data MORE classes
}
so basically what I want to do is add Game view class into baseview in my main class file. Is there someway i can make this work as i don't want to use xml's now.

Yuu can directly add GameView into baseview for ex:
#Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
TicTacStart = new Game(this);
//reference to base layout..
LinearLayout baseView = (LinearLayout)findViewById(R.id.baseView);
baseView.addView(TicTacStart );
}