I have read through some posts on here regarding activity-fragment communication but my problem is unique; i will try state it as clear as possible for you to understand. In my app there is a Mainactivity and 2 fragments(we call these fragment1 and fragment2) which are in sliding tab layout. The main activity contains a navigation drawer, and fragment1 contains a TextView and other fragment2 contains EditText. Heres problem now, there option on drawer called share:- when it is clicked, i want to access string value in Textview of Fragment1 or value in EditText of Fragment2; depends on which fragment is active in tablayout. now i want to pass string value to text message argument of intent in order for it to be shared with whatever client the user chooses.
#Override
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
int id = item.getItemId();
if (id == R.id.nav_share) {
//Inside the onNavigationItemSelected
String value = " ";
Fragment currentFragment= getActiveFragment();
if(currentFragment instanceof SpeechToText){
value = ((SpeechToText)currentFragment).getText1();
}else if(currentFragment instanceof TTS){
//This one has the edittext
value = ((TTS)currentFragment).getText2();
}
//Then create the intent
//Intent shareIntent ...
Intent shareIntent = new Intent(Intent.ACTION_SEND);
shareIntent.setType("text/plain");
shareIntent.putExtra(Intent.EXTRA_TEXT,value);
shareIntent.putExtra(Intent.EXTRA_SUBJECT, "Message");
startActivity(Intent.createChooser(shareIntent, "Share via"));
}
I have this function from the post you provided to return current active fragment in tab layout.
public Fragment getActiveFragment() {
if (getSupportFragmentManager().getBackStackEntryCount() == 0) {
return null;
} String tag = getSupportFragmentManager().getBackStackEntryAt(getSupportFragmentManager().getBackStackEntryCount() - 1).getName();
return getSupportFragmentManager().findFragmentByTag(tag);
}
I have implementation for methodForGettingTextViewValue() in SpeechToText fragment which is Fragment1:
public String getText1()
{
return resultTEXT.getText().toString();
}
I have implementation for methodForGettingEditTextValue() in TTS fragment which is Fragment2
public String getText2()
{
return return editText.getText().toString();
}
You need to keep track of the active fragment in your tab layout, then check the class of the fragment, and depending on which one it is, call the method that would return either the content of the TextView or that of the EditText.
To keep track of the current fragment, check out this question.
Once you have that part sorted, inside the onNavigationItemSelected implementation, before you create the Intent you'd do something like this, assuming currentFragment is being updated, and that you've implement the needed methods in each of the two fragments:
//Inside the onNavigationItemSelected
String value = "";
if(currentFragment instanceof MyCustomFragment1){
value = ((MyCustomFragment1)currentFragment).methodForGettingTextViewValue();
}else if(currentFragment instanceof MyCustomFragment2){
//This one has the edittext
value = ((MyCustomFragment2)currentFragment).methodForGettingEditTextValue();
}
//Then create the intent
//Intent shareIntent ...
In case it's not clear enough, let me insist that you'd need to implement methodForGettingEditTextValue and methodForGettingTextViewValue. The method should access the view by id, get the value and return it.
Related
I am completely new to Android and just learned Object-oriented programming. My project requires me to build something on open-source code. I am really struggling with this special case. Two fragments are under activity_main, one of them is TerminalFragment. If TerminalFragment is active under activity_main, data from a BLE device will keep flowing into activity_main. Is it possible to keep passing the data to the next activity without clicking a button (in this case, menuItem(R.id.plot))? I added a recyclerview on activity_main2 and want it display the data which is flowing in activity_main.
In my testing with my current method, the recycler view won't update itself, it just captures the data in the recyclerview of activity_main with TerminalFragment once the user clicked the menuItem (id,plot). What kind of thing I need to add in my method? Should I create another Fragment instead of activity_main2? As I looked this up in the internet, it seems not possible to work that way between a fragment and next activity. Much Appreciated.
onOptionsItemSelected of TerminalFragment
if (id == R.id.plot){
Intent intent = new Intent(getActivity(), MainActivity2.class);
intent.putExtra("output",output); //output
startActivity(intent);
return true;
}
receive() of TerminalFragment
private void receive(byte[] data) {
if(hexEnabled) {
receiveText.append("Hello" + TextUtil.toHexString(data) + '\n');
} else {
String msg = new String(data);
if(newline.equals(TextUtil.newline_crlf) && msg.length() > 0) {
// don't show CR as ^M if directly before LF
msg = msg.replace(TextUtil.newline_crlf, TextUtil.newline_lf);
// special handling if CR and LF come in separate fragments
if (pendingNewline && msg.charAt(0) == '\n') {
Editable edt = receiveText.getEditableText();
if (edt != null && edt.length() > 1)
edt.replace(edt.length() - 2, edt.length(), "");
}
pendingNewline = msg.charAt(msg.length() - 1) == '\r';
}
receiveText.append(TextUtil.toCaretString(msg, newline.length() != 0)); //print out data
output = receiveText.getText().toString(); // CharSequence to String
}
}
OnCreate of mainActivity2, *receiveData() is to add data to the recyclerview
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
Toolbar toolbar = findViewById(R.id.toolbar2);
setSupportActionBar(toolbar);
recyclerView = findViewById(R.id.dataflow);
dataList = new ArrayList<>();
String data;
Bundle extras = getIntent().getExtras();
if (extras != null)
{
data = extras.getString("output");
receiveData(data);
}
setAdapter();
}
i think your problems is unknown how to get activity_main data onto activity_main2 dynamically , You can user " EventBus " to solve data updates dynamically , whatever you use another fragment or activity_main2 .
Hello I want to have an Add function that allows me to input items to my GridView
For Background: I have a standard GridView and an XML activity (which contains 2 TextView) that I want to convert to my GridView. I also have a custom ArrayAdapter class and custom Word object (takes 2 Strings variables) that helps me do this.
My problem: I want to have an Add button that takes me to another XML-Layout/class and IDEALLY it input a single item and so when the user goes back to MainActivity the GridView would be updated along with the previous information that I currently hard-coded atm. This previous sentence doesn't work currently
Custom ArrayAdapter and 'WordFolder' is my custom String object that has 2 getters
//constructor - it takes the context and the list of words
WordAdapter(Context context, ArrayList<WordFolder> word){
super(context, 0, word);
}
#Override
public View getView(int position, View convertView, ViewGroup parent){
View listItemView = convertView;
if(listItemView == null){
listItemView = LayoutInflater.from(getContext()).inflate(R.layout.folder_view, parent, false);
}
//Getting the current word
WordFolder currentWord = getItem(position);
//making the 2 text view to match our word_folder.xml
TextView title = (TextView) listItemView.findViewById(R.id.title);
title.setText(currentWord.getTitle());
TextView desc = (TextView) listItemView.findViewById(R.id.desc);
desc.setText(currentWord.getTitleDesc());
return listItemView;
}
}
Here is my NewFolder code. Which sets contentview to a different XML. it's pretty empty since I'm lost on what to do
public class NewFolder extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.new_folder_view);
Button add = (Button) findViewById(R.id.add);
//If the user clicks the add button - it will save the contents to the Word Class
add.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//make TextView variables and cast the contents to a string and save it to a String variable
TextView name = (TextView) findViewById(R.id.new_folder);
String title = (String) name.getText();
TextView descText = (TextView) findViewById(R.id.desc);
String desc = (String) descText.getText();
//Save it to the Word class
ArrayList<WordFolder> word = new ArrayList<>();
word.add(new WordFolder(title, desc));
//goes back to the MainActivity
Intent intent = new Intent(NewFolder.this, MainActivity.class);
startActivity(intent);
}
});
}
In my WordFolder class I made some TextView variables and save the strings to my ArrayList<> object but so far it's been useless since it doesn't interact with the previous ArrayList<> in ActivityMain which makes sense because its an entirely new object. I thought about making the ArrayList a global variable which atm it doesn't make sense to me and I'm currently lost.
Sample code would be appreciative but looking for a sense of direction on what to do next. I can provide other code if necessary. Thank you
To pass data between Activities to need to do a few things:
First, when the user presses your "Add" button, you want to start the second activity in a way that allows it to return a result. this means, that instead of using startActivity you need to use startActivityForResult.
This method takes an intent and an int.
Use the same intent you used in startActivity.
The int should be a code that helps you identify where a result came from, when a result comes. For this, define some constant in your ActivityMain class:
private static final int ADD_RESULT_CODE = 123;
Now, your button's click listener should looks something like this:
addButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
Intent intent=new Intent(MainActivity.this, NewFolder.class);
startActivityForResult(intent, ADD_RESULT_CODE);
}
});
Now for returning the result.
First, you shouldn't go back to your main activity by starting another intent.
Instead, you should use finish() (which is a method defined in AppCompatActivity, you can use to finish your activity), this will return the user to the last place he was before this activity - ActivityMain.
And to return some data, too, you can use this code:
Intent intent=new Intent();
intent.putExtra("title",title);
intent.putExtra("desc",desc);
setResult(Activity.RESULT_OK, intent);
where title and desc are the variables you want to pass.
in your case it should look something like this:
public class NewFolder extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.new_folder_view);
Button add = (Button) findViewById(R.id.add);
//If the user clicks the add button - it will save the contents to the Word Class
add.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//make TextView variables and cast the contents to a string and save it to a String variable
TextView name = (TextView) findViewById(R.id.new_folder);
String title = (String) name.getText();
TextView descText = (TextView) findViewById(R.id.desc);
String desc = (String) descText.getText();
//Save it to the Word class
ArrayList<WordFolder> word = new ArrayList<>();
word.add(new WordFolder(title, desc));
Intent intent=new Intent();
intent.putExtra("title",title);
intent.putExtra("desc",desc);
setResult(Activity.RESULT_OK, intent);
//goes back to the MainActivity
finish();
}
});
}
You should probably also take care of the case where the user changed his mind and wants to cancel adding an item. in this case you should:
setResult(Activity.RESULT_CANCELLED);
finish();
In your ActivityMain you will have the result code, and if its Activity.RESULT_OK you'll know you should add a new item, but if its Activity.RESULT_CANCELLED you'll know that the user changed their mind
Now all that's left is receiving the data in ActivityMain, and doing whatever you want to do with it (like adding it to the grid view).
To do this you need to override a method called onActivityResult inside ActivityMain:
// Call Back method to get the Message form other Activity
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
super.onActivityResult(requestCode, resultCode, data);
// check the result code to know where the result came from
//and check that the result code is OK
if(resultCode == Activity.RESULT_OK && requestCode == ADD_RESULT_CODE )
{
String title = data.getStringExtra("title");
String desc = data.getStringExtra("desc");
//... now, do whatever you want with these variables in ActivityMain.
}
}
I have three fragments: FragmentA, FragmentB, FragmentC. All fragments have one TextInputLayout with editText inside and button to go to next fragment. When FragmentA gets called I enter text in editText and go to next fragment (FragmentB) and do the same thing and do the same thing for last fragment (FragmentC). If I go back to FragmentB and type something different in editText and go to FragmentC text that was three is gone. I know that I have to pass bundle to fragment that will be displayed when swipe back on phone usingonDetach() method. I know if I want to pass bundle to fragment that I will call with pressing next button I have to setArguments(bundle).
public void switchFragments(Fragment fragment, Fragment currentFragment, boolean addToBackStack, String tag) {
FragmentTransaction transaction = currentFragment.getActivity().getSupportFragmentManager().beginTransaction();
transaction.add(R.id.fragment_container_sign_up, fragment, tag);
transaction.hide(currentFragment);
if(addToBackStack) {
transaction.addToBackStack(tag);
}
transaction.commit();
}
I am using transaction.add() and transaction.hide() because I am losing text entered in editTexts when I am coming back from previous fragment if I use transaction.replace()
To store and keep values between Fragments, look at SharedPreferences. Use this to pass value between fragments.
holder.YOURBUTTONCLICKID.setOnClickListener {
val sharedPrefs = context
.getSharedPreferences("PREFS", Context.MODE_PRIVATE)
sharedPrefs.edit().putString("postId", EDITTEXTID).apply()
(context as FragmentActivity)
.supportFragmentManager.beginTransaction()
.replace(R.id.fragment_container, FRAGMENTA/B/C )
.addToBackStack(null).commit()
}
Replace uppercase with relevant Ids.
And get the value on the other Fragment like this
val preference = context?.getSharedPreferences("PREFS", Context.MODE_PRIVATE)
if (preference != null) {
getTextValue = preference.getString("postId", "none").toString()
}
Remember that your putString key and getString has to be the same.
I have a dummy content list containing 3 items but I want each item to open its own activity rather than passing data to the detail fragment. How can I replace the master fragment with a list fragment of my own when a particular list item is clicked? Is it possible to use the if (position == x) statement for each of my items? The code below replaces the detail fragment but I want to replace the master fragment instead. I have not seen any tutorials on this as all the ones I've come across are associated with replacing the detail fragment, NOT the master fragment.
#Override
public void onItemSelected(String id) {
if (mTwoPane) {
Bundle arguments = new Bundle();
arguments.putString(ItemDetailFragment.ARG_ITEM_ID, id);
ItemDetailFragment fragment = new ItemDetailFragment();
fragment.setArguments(arguments);
getSupportFragmentManager().beginTransaction()
.replace(R.id.item_list, fragment)
.commit();
} else {
Intent detailIntent = new Intent(this, ContinentsListActivity.class);
detailIntent.putExtra(ItemDetailFragment.ARG_ITEM_ID, id);
startActivity(detailIntent);
}
}
You may want to use View.setTag() every time you add an item to your list, so later you can retrieve this tag with View.getTag() and identify the selected item.
I am pretty new to Android (3 days), but I have a pretty good background in PHP (which may be the cause of my confusion in a Java based environment). I started building an Android app using Android Studio (Beta). I created the default Android Studio activity with the Navigation Drawer Activity. I edited the activity fragment part to look like this:
#Override
public void onNavigationDrawerItemSelected(int position) {
Bundle bundle = new Bundle();
bundle.putStringArrayList("contacts", arr);
bundle.putStringArrayList("messages", messages);
Fragment fragment = null;
switch (position) {
case 0:
fragment = new FriendsFragment();
break;
case 1:
fragment = new ChatsFragment();
break;
case 2:
fragment = new GroupsFragment();
break;
case 3:
fragment = new LogoutFragment();
break;
default:
break;
}
if (fragment != null) {
fragment.setArguments(bundle);
FragmentManager fragmentManager = getSupportFragmentManager();
fragmentManager.beginTransaction()
.replace(R.id.container, fragment).addToBackStack(null).commit();
}
}
As you can see I am passing a Bundle to my Fragments called "messages" and "contacts" when an item is selected in the Navigation Drawer. The "messages" bundle are XMPP messages received by the aSmack library from an OpenFire server. So basically I'm trying to create a XMPP client. When I run the app I can receive the messages in the "ChatsFragment".
Now my problem:
I have to press the "ChatsFragment" item on the drawer to have my messages updated (re-receive the bundle) everytime I feel like there are new messages received from the server. But I want this to be done automatically by the fragment.
First I would like to know if my procedure is correct (Activity listens to server, creates bundle, send bundle to fragment, bundle updates messages on receive**)
** = This part I haven't been able to understand how to implement.
1- If the procedure is correct tell me how I should get the messages to be updated by the fragment through the activity?
2- If this is not the correct way to do things in Android, recommend me a way of doing it.
My code for displaying the messages in fragment:
private void displayListView() {
// Messages array list
List<String> contacts = getArguments().getStringArrayList("messages");
//System.out.println("arr: " + contacts);
//create an ArrayAdaptar from the String Array
ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(getActivity(),
R.layout.url_list, contacts);
ListView listView = (ListView) getView().findViewById(R.id.listView);
// Assign adapter to ListView
listView.setAdapter(dataAdapter);
//enables filtering for the contents of the given ListView
listView.setTextFilterEnabled(true);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// Send the URL to the host activity
//mListener.onURLSelected(((TextView) view).getText().toString());
}
});
}
Thanks in advance.
Typically for long running operations in the background, like listening to a server, incoming messages, etc, you need to use Services. You do so by subclassing the Service class in Android.
Now for your problem - the design approach should be that you have a background service listening to incoming messages. Anytime a message is received (an input stream in your socket operator) you should send a "broadcast" an intent that a message was received. A custom broadcast receiver that you create should wait for this broadcast. Within the onReceive() method of this receiver, you should trigger the creation of the bundle and updating your message.
Remember you should always delegate your long running operations in Android to services. That is exactly what they are for.
So basically if you're already listening for new messages to come in your activity, then you must have some kind of callback like onMessageRecieved() or something like that.
If you do, you can then notify your fragment in this way.
Create a field (goes under your class declaration) called curFrag, so something like this:
public class MyActivity extends Activity {
private Fragment curFrag;
//other code...
}
then in the code you posted you would initialize the curFrag there, but you also need to set a tag for the current fragment. This will be based on your case statement. Make some final string variables as tags.
i.e.
public static final String CHATSTAG = "chatstag";
#Override
public void onNavigationDrawerItemSelected(int position) {
Bundle bundle = new Bundle();
bundle.putStringArrayList("contacts", arr);
bundle.putStringArrayList("messages", messages);
Fragment fragment = null;
String tag = null;
switch (position) {
case 0:
tag = FRIENDSTAG;
fragment = new FriendsFragment();
break;
case 1:
tag = CHATSTAG;... and so on through the switch statement.
fragment = new ChatsFragment();
break;
case 2:
fragment = new GroupsFragment();
break;
case 3:
fragment = new LogoutFragment();
break;
default:
break;
}
if (fragment != null) {
fragment.setArguments(bundle);
FragmentManager fragmentManager = getSupportFragmentManager();
//remember to set the tag.
if(tag != null) {
fragmentManager.beginTransaction()
.replace(R.id.container, fragment, tag).addToBackStack(null).commit();
} else {
fragmentManager.beginTransaction()
.replace(R.id.container,fragment,DEFAULTTAG).addToBackStack(null).commit();
}
//new code
curFrag = fragment;
}
}
Now in your activity when a new message comes in, check the tag of the fragment and then if it matches a certain fragment, notify the fragment that new data has come in and retrieve it in the fragment.
public void onMessageRecieved() {
if(curFrag.getTag().equalsIgnoreCase(CHATSTAG)) {
ChatsFragment frag = (ChatsFragment) curFrag;
frag.notifyDataRecieved();
}
}
Once you have a reference to your fragment in the activity, you have access to any public methods in that fragment.
If your fragment cannot access the data on its own, then you'll need to get a reference to the activity and create a method in the activity that returns the new data.
So in your activity:
public String getMessageData() {
String newData = ...//get stuff from server;
return newData;
}
then in your fragment
public void notifyNewMessage() {
try {
MyActivity activity = (MyActivity) getActivity();
} catch (ClassCastException e) {
e.printStackTrace();
} catch (NullPointerException e) {
e.printStackTrace();
}
String message = activity.getMessageData();
//do something with the message.
}
It's not necessarily pretty but it works pretty well. You should also check to make sure your fragments are attached when you do this so that you avoid null exceptions.
Hope this helps!