I am using a preference fragment and replacing the fragment in the id of the root layout of the main xml file. So my problem is that the preferences are displaying alongside with the main activity xml elements.
I have seen in Android apps that the preferences open up separately I am not sure whether they do open up separately or just occupying the entire screen. For opening the preference fragment I am doing a normal fragment transaction(Note: I am not using the support library not sure if this has something to do with my problem but still mentioning it).
Here is what the problem is,
And so here is my code
sampleprefs.xml
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
<CheckBoxPreference
android:defaultValue="false"
android:title="Check box preference"
android:key="check_box_preference_1" />
<EditTextPreference
android:defaultValue="Default value"
android:selectAllOnFocus="true"
android:singleLine="true"
android:title="Edit text preference"
android:key="edit_text_preference_1" />
</PreferenceScreen>
Here is the main layout,
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.random.preferenceexample.MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World!"
android:id="#+id/textView" />
<Button
android:text="Button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/button" />
</LinearLayout>
This is my Main Activity code where the fragment displays on the click of a button,
public class MainActivity extends Activity implements View.OnClickListener {
boolean result;
Button button;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = (Button)findViewById(R.id.button);
button.setOnClickListener(this);
}
#Override
public void onClick(View v) {
FragmentManager fm = getFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
SettingsFragment sf = new SettingsFragment();
ft.add(R.id.activity_main,sf);
ft.commit();
}
This is the fragment class
public class SettingsFragment extends PreferenceFragment {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.sampleprefs);
}
}
It looks the problem seems to be with the background transparency of Fragment. Fragments are transparent backgrounded by default because they can be used to paint only a small portion of the screen but if you want your Fragment to cover fullscreen then just add some background to it, it will work.
Moreover, it's good practice to use a root layout which supports views to be placed one above the other(for ex. FrameLayout) for FragmentTransactions.
Add these in your Fragment :
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = super.onCreateView(inflater, container, savedInstanceState);
view.setBackgroundColor(getResources().getColor(android.R.color.white));
return view;
}
Here is the working example
Related
I'm trying to show an image below a button only after the button has been pressed. My problem is that the fragment is shown immediately when the app is started and not only after the button has been pressed.
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void say_hello(View view){
Fragment fragment = new ExampleFragment();
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.fragment2, fragment).commit();
}
}
public class ExampleFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.news_articles, container, false);
}
}
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:tools="http://schemas.android.com/tools"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:orientation="vertical"
android:layout_height="fill_parent"
tools:context=".MainActivity">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal|center_vertical"
android:text="PRESS THIS"
android:id = "#+id/test_button"
android:background="#drawable/test_button"
android:onClick="say_hello"
/>
<fragment
android:id="#+id/fragment2"
android:name="com.example.tic_tac_toe.ExampleFragment"
android:layout_width="match_parent"
android:layout_height="643dp" />
</LinearLayout>
<ImageView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:src="#drawable/cool_dog">
</ImageView>
I'm guessing the fragment shows up when the app is started because of the name I give to the fragment in the XML, but the fragment needs a name otherwise I only get error. How do I get the fragment to display nothing before I have clicked the button?
Instead of using <fragment /> view in your xml, you can use Framelayout and add your fragment to this Framelayout on button click using the following code -
FragmentTransaction transaction = getFragmentManager().beginTransaction();
transaction.add(R.id.mainframe, fragment);
transaction.commit();
Where mainframe is the id of Framelayout.
You can try doing this
android.app.Fragment fragment = getActivity().getFragmentManager().findFragmentByTag("YOUR_FRAGMENT_TAG");
getActivity().getFragmentManager().beginTransaction().hide(fragment);
inside your click event.
I have a ViewPager which holds multiple base fragments, each base fragment have four more nested fragments and each nested fragment is a combination of 5 imageViews and textView.
(This is what I intended to do)
I have created a sample application but I am not able to implement that properly. I cannot see any view in the nested fragment or the base fragment.
Here's the code for the sample application
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<fragment android:name="com.example.nestedfragments.BaseFragment"
android:id="#+id/left_fragment"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="match_parent"/>
</LinearLayout>
MainActivity.java
package com.example.nestedfragments;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
public class MainActivity extends FragmentActivity {
/**
* Called when the activity is first created.
*/
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}
base_fragment.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center">
<Button
android:id="#+id/button1"
android:text="Launch Nested Fragment"
android:gravity="center"
android:layout_alignParentBottom="true"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:paddingBottom="10dp"/>
</RelativeLayout>
BaseFragment.java
public class BaseFragment extends Fragment {
Button doNestingButton;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// set the view
View root = inflater.inflate(R.layout.base_fragment, container, false);
doNestingButton = (Button) root.findViewById(R.id.button1);
doNestingButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Fragment videoFragment = new NestedFragment();
// we get the 'childFragmentManager' for our transaction
FragmentTransaction transaction = getChildFragmentManager().beginTransaction();
// make the back button return to the main screen
// and supply the tag 'left' to the backstack
transaction.addToBackStack("left");
// add our new nested fragment
transaction.add(getId(), videoFragment, "left");
// commit the transaction
transaction.commit();
}
});
return root;
}
}
nested_fragment.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:layout_width="154dp"
android:layout_height="154dp"
android:id="#+id/imageView" android:layout_gravity="left|center_vertical"
android:src="#drawable/ic_splash"/>
</LinearLayout>
NestedFragment.java
public class NestedFragment extends Fragment {
public NestedFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.nested_fragment, container, false);
ImageView doNestingButton = (ImageView) root.findViewById(R.id.imageView);
return root;
}
Once again this is a sample application, please guide me.
From your above code, you have not used the fragment container layout such as FrameLayout in base_fragment.xml .So add the frame layout for nested fragment inbase_fragment.xml
The Fragments in my app are not re-added to the activity's view when the device is rotated. If i understand the documentation (and similar questions here on SO) correctly, this should be handled be the fragment manager (without having to specify android:configChanges in my manifest).
My Activity looks like:
public class MainActivity extends SherlockFragmentActivity {
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null){
getSupportFragmentManager().beginTransaction()
.add(R.id.main_fragment_placeholder, new DashboardFragment(),"dashboard")
.commit();
}
}
}
And a Fragment looks like (omitted clicklisteners and so on for clarity):
public class DashboardFragment extends SherlockFragment {
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.fragment_dashboard, container, false);
}
}
The layout files look like (activity_main.xml):
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/main.main">
<FrameLayout android:id="#+id/main_fragment_placeholder"
android:layout_height="fill_parent"
android:layout_weight="1"
android:layout_width="0px"
/>
</LinearLayout>
And fragment_layout.xml:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/main.wrapper"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<my.layout.DashboardLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/main.dashboard">
<!-- some buttons here -->
</my.layout.DashboardLayout>
</LinearLayout>
However, when i rotate my device the screen always becomes blank.
Turns out I did a Stupid Thing. I overrode the onSaveInstanceState(...) method in my activity, without calling super.onSaveInstanceState(), which resulted in the fragments not being recreated. Posting the answer here in hopes that I can save somebody else the time!
Fragments usually get recreated on configuration change. If you don't wish this to happen, use
setRetainInstance(true); in the Fragment's constructor(s)
This will cause fragments to be retained during configuration change.
http://developer.android.com/reference/android/app/Fragment.html#setRetainInstance(boolean)
I created a test project that has two different fragments to be shown in the same activity. One fragment is for landscape and the other for portrait.
# My unique activity
public class MainActivity extends FragmentActivity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}
# First Fragment
public class LandscapeFragment extends Fragment {
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
TextView v = (TextView) inflater.inflate(R.layout.fragment, container, false);
v.setText("LANDSCAPE");
return v;
}
}
# Other Fragment
public class PortraitFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
TextView v = (TextView) inflater.inflate(R.layout.fragment, container, false);
v.setText("PORTRAIT");
return v;
}
}
And I have two main.xml, one in layout/ and the other in layout-land/. Each main.xml points to the correct Fragment to be used.
<!-- layout-land/main.xml -->
<?xml version="1.0" encoding="utf-8"?>
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/fragment"
android:name="br.luckcheese.test.LandscapeFragment"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="5dp" />
<!-- layout/main.xml -->
<?xml version="1.0" encoding="utf-8"?>
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/fragment"
android:name="br.luckcheese.test.PortraitFragment"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="5dp" />
<!-- layout/fragment.xml -->
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="30sp" />
When I open the app on landscape the LandscapeFragment is shown, and when I open in Portrait the PortraitFragment is shown. So far, so good.
But if I open in landscape and rotate the device to portrait then the LandscapeFragment is reloaded and shown.
Which is not the predicted behavior. The PortraitFragment should have been loaded.
And the same thing happens the other way around, if the device starts at the portrait orientation and then I rotate it to landscape: the PortraitFragment just gets reloaded, instead of having the LandscapeFragment loaded.
What am I doing wrong?
Make sure that you don't have: android:config="orientation" in your manifest.xml
The problem is in your 2 layouts, the fragment ids are the same.
Just change these fragment ids, like :
fragmentportrait for layout/main.xml
fragmentlanscape for layout-land/main.xml.
(And change also:
Fragment frag = getSupportFragmentManager().findFragmentById(R.id.fragment);
frag.setRetainInstance(false);
)
I would like to use one Activity which holds several fragments and navigate among the fragments. For example, in the activity, there is a list view which is a fragment, when user select one item from the list, the view will navigate to another fragment, How could this be implemented?
I know there is a nice tutorial on the developer site, but it handles the tablet screen in which two pane layout with one list fragment and one detailed fragment showing in one screen. I only want to navigate among fragments without show two fragments in one screen.
Are there tutorials can teach me how to do it?
In the nutshell the answer to your question is to notify your host activity and then have your host activity replace your current fragment container using FragmentManager.
One of the approach is to make an interface in your first fragment, have your host activity register/listen (implement) to this interface and then have your FragmentManager to replace the container content with the second fragment on listener callback.
I'm not sure about tutorial but here is my snippet:
First Fragment
public class First extends Fragment{
private static onMySignalListener listener;
//call this function from whatever you like i.e button onClickListener
public void switchWindow() {
if(listener != null){
listener.onMySignal();
}
}
public interface onMySignalListener {
//customize this to your liking
//plain without argument
void onMySignal();
//with argument
void onMySignalWithNum(int mNum);
}
public static void setOnMySignalListener(onMySignalListener listener) {
First.listener = listener;
}}
Host Activity
public class HostActivity extends FragmentActivity implements onMySignalListener{
private final String ADD_TAG_IF_NECESSARY = "mTag";
#Override
public void onCreate(Bundle ssi) {
setContentLayout(R.layout.main);
FirstFragment.setOnMySignalListener(this);
}
#Override
public void onMySignal() {
//if you're using compat library
FragmentManager manager = getSupportFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
//initialize your second fragment
sfragment = SecondFragment.newInstance(null);
//replace your current container being most of the time as FrameLayout
transaction.replace(R.id.container, fragment, ADD_TAG_IF_NECESSARY);
transaction.commit();
}
#Override
public void onMySignalWithNum(int mNum) {
//you can do the same like the above probably with your own customization
}}
This is only an example on how you'd implement interface, kindly tidy it up by yourself. And please be noted though that this is not effective if you have a lot of fragment wanting to notify your host activity about something. doing so will lead you to implement various listener to your host activity.
I think this will be useful for you. It is example of two fragments in one screen works independently.
MainActivity :
public class MainActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_activity);
Fragment newFragment = new Test();
FragmentTransaction transaction = getFragmentManager().beginTransaction();
transaction.add(R.id.UprLayout, newFragment);
// transaction.addToBackStack(null);
transaction.commit();
Fragment newFragment2 = new TestRight();
FragmentTransaction transaction2 = getFragmentManager().beginTransaction();
transaction2.add(R.id.dwnLayout, newFragment2);
// transaction.addToBackStack(null);
transaction2.commit();
}
}
main_activity.xml :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/LinearLayout2"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center|center_horizontal"
android:orientation="vertical" >
<LinearLayout
android:id="#+id/UprLayout"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:orientation="vertical" />
<LinearLayout
android:id="#+id/dwnLayout"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:orientation="vertical" />
</LinearLayout>
Fragment Test :
public class Test extends Fragment {
TextView tv;
#Override
public void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.test, container, false);
return view;
}
}
Fragment TestRight :
public class TestRight extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.test_right, container, false);
return view;
}
#Override
public void onStart() {
super.onStart();
Button button = (Button)getActivity().findViewById(R.id.button1);
button.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Fragment newFragment = new Right2nd();
FragmentTransaction transaction = getFragmentManager()
.beginTransaction();
transaction.replace(R.id.dwnLayout, newFragment);
transaction.addToBackStack("aa");
transaction.commit();
//transaction.add(R.id.frag, newFragment).commit();
}
});
}
}
test.xml :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical" >
<TextView
android:id="#+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center_horizontal"
android:text="test"
android:textAppearance="?android:attr/textAppearanceLarge"
android:textSize="50sp" />
</LinearLayout>
test_right.xml :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical" >
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Click" />
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Test right"
android:textAppearance="?android:attr/textAppearanceLarge"
android:textSize="45sp" />
</LinearLayout>
Fragment Right2nd :
public class Right2nd extends Fragment{
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View vw = inflater.inflate(R.layout.right_2nd, container, false);
return vw;
}
}
right_2nd.xml :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Right 2nd"
android:textAppearance="?android:attr/textAppearanceLarge"
android:textSize="50sp" />
</LinearLayout>
I know this is quite old question but this is currently implemented in Navigation Component https://developer.android.com/guide/navigation/
Here is a very nice tutorial about it. MULTIPLE FRAGMENTS STACK IN EACH VIEWPAGER TAB
I think ChildFragment
would do the job for you. Ignore the Tab ViewPager. It's performing the same thing in multiple tabs. Hope this helps a bit.