I am using an external library in my app. The first argument used in the example is "this". Which refers to an appcompat activity. However I am using this in a fragment shich obviously doesn't extend appcompat activity.
This is the library:
https://github.com/TouchBoarder/weekdays-buttons-bar
I am not sure whether there is anything I can do. Can I extend the fragment to something compatible (right now it just extends fragment).
Below is a screenshot of the issue:
EDIT:
This is what I extend in my MainActivity:
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
The Fragment that is called innside Main activity is extended like this:
public class AddAlarmFragment extends Fragment {
And I am trying to create the data source in the oncreate method of the fragment like this:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_add_alarm, container, false);
WeekdaysDataSource wds = new WeekdaysDataSource(, R.id.weekdays_stub)
.start(this);
new WeekdaysDataSource.Callback() {
#Override
public void onWeekdaysItemClicked(int attachId,WeekdaysDataItem item) {
// Do something if today is selected?
Calendar calendar = Calendar.getInstance();
if(item.getCalendarDayId()==calendar.get(Calendar.DAY_OF_WEEK)&&item.isSelected())
Toast.makeText(getActivity(),"Carpe diem",Toast.LENGTH_SHORT).show();
}
#Override
public void onWeekdaysSelected(int attachId,ArrayList<WeekdaysDataItem> items) {
//Filter on the attached id if there is multiple weekdays data sources
if(attachId==R.id.weekdays_stub){
// Do something on week 4?
}
}
};
Thanks in advance for your help.
Have you tried casting getActivity()?
((AppCompatActivity) getActivity(), R.id.weekdays_stub)
Read the Android API, you can see AppCompatActivity does extend FragmentActivity and getActivity() does return a FragmentActivity, not an AppCompatActivity, as expected by your library.
I do find it odd that a AppCompatActivity is even the defined parameter rather than a Context
Related
Unlike typical android projects starting with MainActivity with all the code of the layout object in it. This architecture requires me to have the initial code in a custom object. Here's a structure for better understanding.
java/MainActivity.java
java/User.java
layout/activity_main.xml
layout/user.xml
Now I also need a reference to User object within MainActivity and it looks like this.
public class MainActivity extends AppCompatActivity {
public Users users; // instantiate custom class and show
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
}
My User class looks like this.
public class User extends AppCompatActivity {
ListView userList;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.user_list, container, false); // Inflate the layout for this fragment
userList = view.findViewById(R.id.userList);
return view;
}
}
layout/user.xml
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="org.puremvc.java.demos.android.employeeadmin.view.components.UserList">
<ListView
android:id="#+id/userList"
android:layout_width="395dp"
android:layout_height="715dp"
tools:layout_editor_absoluteX="8dp"
tools:layout_editor_absoluteY="8dp" />
</FrameLayout>
So, in other words, MainActivity just acts like a stage doing nothing except just providing a reference to the Initial object. Now I do need MainActivity to be there, can't point User to be a launcher in the manifest. Responsibilities are to be taken care of by User class.
Question: How to instantiate CustomClass User and show.
Context: The MainActivity class has to be minimalistic and clean, no User related code (ListView), all logic lies in the custom class.
P.S. There can be lateral approaches, as long as I have a reference to user Object in MainActivity and it's displayed on launch, I'll accept the answer.
As per my understanding: there should be two approaches.
First, by using the Fragment inside your Activity. Write all initialize and data flow codes inside the fragment and just initialize and start the fragment from the Activity. So when the Activity will start, it will give all its tasks to the fragment with its Context and rest thing Fragment will do.
Like below:
public class MainActivity extends AppCompatActivity {
public Users users; // instantiate custom class and show
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//the fragment stuff
FragmentManager fm= getFragmentManager() //or get SupportFragmentManager when the Fragment comes from Support lib
FragmentTransaction ft= fm.beginTransaction();
Fragment fragment= new UserListFragment();
ft.add(R.id.fragment_container, fragment);
ft.commit();
}
}
OR, the second approach should by using Interface and communicate both Activity and the Custom Class (or you can call it Controller) with it.
Its nothing, but a simple MVC design pattern which I never recommend.
You can write one Interface like below:
public interface IController{
public void initialize(Activity activity, Bundle savedInstanceState);
public void engage();
public void disengage();
}
Then, make an instance of this Controller inside your Activity/BaseActivity and use like below:
public MainActivity(IController controller){
this.controller = controller;
}
Then call each callback methods from their appropriate place to make them work inside the Controller.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//give the priviledge of onCreate to initialize
controller.initialize(this, savedInstanceState);
}
Then in your Controller class, just write the same program which you supposed to write inside Activity:
public class Your_Controller implements IController {
#Override
public void initialize(Activity activity, Bundle savedInstanceState) {
//do super where needed
//make one class level Activity instance to work in other methods
act = activity;
//just initialize views like below
TextView tv = (TextView) activity.findViewById(R.id.abc);
}
I have used fragments in app. When i pass constructor of FragmentActivity class to the fragment it gives an error i.e. "Type mismatch: cannot convert from ReadFragment to Fragment". Thanks in advance for your help
ReadFragment.java
public class ReadFragment extends FragmentActivity {
public ReadFragment(){
}
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.read_layout);
}
}
MainActivity.java
......
Fragment fragment = null;
fragment = new ReadFragment();
......
}
I guess what you want to do is either:
public class ReadFragment extends Fragment {
or (and this should not work because you cannot cast from one to the other):
fragment_activity = new ReadFragment();
fragment = (fragment) fragment_activity;
Now you can chose
FragmentActivity is not a Fragment and thus cant be assigned to a variable of type Fragment. Your ReadFragment should extend Fragment instead. I would suggest doing this tutorial to learn the basics of fragments and probably search the web for Java tutorials, this is the very basics of Java.
public class ReadFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
//For more info how to implement this i highly suggest you read the tutorial.
}
...
}
When extending Fragment you also need to override OnCreateView.
I have created a MainActivity which consists of 3 tabs which are scrollable (by using ViewPager). Now each of these 3 tabs is a Fragment. Also, I am using ActionBarSherlock (ABS).
For the 1st Fragment, I have created the following class:
public class Fragment_1 extends SherlockFragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// TODO Auto-generated method stub
View v = inflater.inflate(R.layout.fragment1, container, false);
return v;
/* R.layout.fragment1 only contains a TextView. */
}
}
For the 2nd Fragment, I want to extend a FragmentActivity as shown below.
public class Fragment_2 extends FragmentActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment2);
}
}
The 3rd Fragment is same as the first one.
But when I launch the app, it crashes. So, am I wrong in extending FragmentActivity for the class Fragment_2? Is it illegal to extend a FragmentActivity or even an Activity to fragment classes? If not, what is the problem here?
Thanks.
EDIT: After #CommonsWare's answer I updated my class as follows:
public class Fragment_2 extends SherlockFragment {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Button send = (Button) findViewById(R.id.bSend); //Error at this line
//some error free code
FragmentTransaction t = getSupportFragmentManager().beginTransaction(); //Error at this line
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// TODO Auto-generated method stub
View v = inflater.inflate(R.layout.fragment2, container, false);
return v;
}
My final two questions are:
How should I access my R.id.bSend Button in the Fragment_2 class.
Eclipse is giving the suggestion to change getSupportFragmentManager() to getFragmentManager(). Is that change all right?
Thanks!
Is it illegal to extend a FragmentActivity or even an Activity to fragment classes?
Fragment is a Java class. Your fragment implementations (for use as pages in your ViewPager) must inherit from Fragment, directly or indirectly.
Activity does not inherit from Fragment. FragmentActivity does not inherit from Fragment. Hence, you cannot inherit from Activity or FragmentActivity and somehow also inherit from Fragment.
Ive asked a similar question before and didn't get an answer and seems many other ppl are searching for an answer. So I am posting this question to hopefully get a clear answer that everyone can benefit from.
I have an activity with 2 fragments in it. I want fragment2 to set a boolean variable in Activity when a checkbox is checked so that fragment1 can know if the checkbox was checked.
This is my Code:
Activity:
public class modestab extends Activity{
public static Context appContext;
public boolean lf=false;
public void onCreate(Bundle savedInstanceState){
appContext=this;
super.onCreate(savedInstanceState);
ActionBar tabbar= getActionBar();
tabbar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
ActionBar.Tab ModesTab =tabbar.newTab().setText("Modes");
ActionBar.Tab CatTab =tabbar.newTab().setText("Categories");
Fragment ModesFragment =new modes();
Fragment CatFragment =new cats();
ModesTab.setTabListener(new MyTabsListener(ModesFragment));
CattTab.setTabListener(new MyTabsListener(CatFragment));
tabbar.addTab(ModesTab);
tabbar.addTab(CatTab);
}
Fragment 1:(Where I want to read the boolean lf set in Acitivity above:
#TargetApi(11)
public class tabmodes extends Fragment{
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View V=inflater.inflate(R.layout.tab_modes, container, false);
button1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(lf==false) //lf here is the lf in Activity which I want to get
Fragment 2: Where I want to set lf in Activity
.....
lifecheck.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener(){
#Override
public void onCheckedChanged(CompoundButton buttonView,
boolean isChecked) {
if(lifecheck.isChecked())
getActivity().lf=true;//Where I want to set the lf flag in Activity
;
}
});
The code doesn't compile and I am not knowing how to set lf in the Activity nor how to read it. Someone suggested I do getActivity() but I am not able to see the variable.
I tried to create a function setlf(boolean jk) but also I am not able to see it...
Any help is welcome :)
Many ways :
1) Activity -> Fragment
In your Activity : create a bundle and use fragment.setArguments(bundle)
in your Fragment : use Bundle bundle = getArguments()
2) Activity -> Fragment
In your Fragment : create a public method
In your Activity : call an active fragment public method :
getSupportFragmentManager().findFragmentById(R.id.your_fragment).publicMethod(args)
3) Fragment -> Activity
In your Fragment : create un interface with getter and setter methods (callback methods)
In your Activity : implement the interface
4) Fragment -> Activity
In your Activity : Create public getter and setter or other methods
In your Fragment : called public activity getter, setter or other methods using :
getActivity().getSomething(), getActivity().setSomething(args) or getActivity().someMethod(args)
You can pass data between fragments in two ways,
First, you can do it by using setArguments(...) and getArguments(....)
Second,you can do it using Call back
Also you can use EventBus. It's really simple.
https://github.com/greenrobot/EventBus
Definitely don't use static methods like my old answer :)
Let's say I have this button:
<Button
android:id="#+id/idone"
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="D2"
android:onClick="myMeth"/>
I have several times used this to call methods from a layout xml as it calls the method from the activity that inflated such view.
Recently with DialogFragments, well it does not work at all. I keep getting an error telling me that such method does not exist. Where is it then looking for such method? I have added it to the DialogFragment class:
public class myActivity extends DialogFragment {
public DiceDialog() {
// empty constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.myDialog, container);
getDialog().setTitle("Hello");
return view;
}
public void myMeth(View view) {
//...
}
As well as in the activity that instantiates the FragmentManager and calls the dialog:
public Class MainActiviry Extends FragmentActivity {
//...
public void onCreate(Bundle savedInstanceState) {
// ..
FragmentManager fm = getSupportFragmentManager();
MyActivity dialog = new AddDiceDialog();
dialog.show(fm, "tag");
}
public void myMeth(View view){
//...
}
And still the messag is that MyMeth is not found.
I have already read that using interfaces and listeners is the correct way to communicate between activity and dialog fragments, but what I am trying to figure out here is where that myMeth call is being made, because well,it is called.
You can implement public myMeth(View view) in your Activity, which will then check for the currently visible Fragment, and call its method.
If you want to use more then one callable method in your Fragment, you can utilize the id's of the calling views and implement a switch, calling a different fragment method according to the id of the View.