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Only able to navigate to the extra layout for the first click

The following code is trivial but simulates the problem.
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<Button
android:id="#+id/btnGoToExtra"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="266dp"
android:text="Go To Extra"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
layout_extra.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<Button
android:id="#+id/btnBackToMain"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="186dp"
android:text="Back To Main"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
MainActivity.java
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.btnGoToExtra)
.setOnClickListener(v -> {
setContentView(R.layout.layout_extra);
findViewById(R.id.btnBackToMain)
.setOnClickListener(vv -> {
setContentView(R.layout.activity_main);
});
});
}
}
Question
I can navigate to the layout_extra from activity_main and return to activity_main. Unfortunately, after this round trip, I can no longer be able to navigate to layout_extra anymore.
What causes this problem and how to fix it?

Explanation will follow in chat but that is not how it is supposed to be done, For views to change, You have other options like using Fragments or using new activity entirely, I would also like to suggest moving to kotlin.
public class MainActivity extends AppCompatActivity {
View mainView;
View extraView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mainView = getLayoutInflater().inflate(R.layout.activity_main, null);
extraView = getLayoutInflater().inflate(R.layout.layout_extra, null);
setContentView(mainView);
mainView.findViewById(R.id.btnGoToExtra)
.setOnClickListener(v -> {
setContentView(extraView);
});
extraView.findViewById(R.id.btnBackToMain)
.setOnClickListener(vv -> {
setContentView(mainView);
});
}
}

Reading through the snippet above, here's how everything went
The line
findViewById(R.id.btnGoToExtra)
.setOnClickListener
Registers Button with id btnGoToExtra for click events and when that happens you have the nested
findViewById(R.id.btnBackToMain)
.setOnClickListener
Which registers the element with id backToMain for click events and that's all
Calling setContentView() multiple times is not recommended. The normal way to switch between layouts in the same activity is to use a ViewFlipper or FrameLayout
From here
You then have:
XML
<FrameLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android">
<ImageView
android:src="#drawable/icon"
android:scaleType="fitCenter"
android:layout_height="fill_parent"
android:layout_width="fill_parent"/>
<TextView
android:text="Learn-Android.com"
android:textSize="24sp"
android:textColor="#000000"
android:layout_height="fill_parent"
android:layout_width="fill_parent"
android:gravity="center"/>
</FrameLayout>
code
private void SwitchLayout2() {
RelativeLayout Layout1 = (RelativeLayout)findViewById(R.id.layout1);
RelativeLayout Layout2 = (RelativeLayout)findViewById(R.id.layout2);
// Enable Layout 2 and Disable Layout 1
Layout1 .setVisibility(View.GONE);
Layout2.setVisibility(View.VISIBLE);
}
private void SwitchLayout1() {
RelativeLayout Layout1 = (RelativeLayout)findViewById(R.id.layout1);
RelativeLayout Layout2 = (RelativeLayout)findViewById(R.id.layout2);
// Enable Layout 1 & Disable Layout2
Layout1.setVisibility(View.VISIBLE);
Layout2.setVisibility(View.GONE);
}

First fragment remains in the background after transition

I am currently trying to create an app having a splash screen, a login screen and a register screen.
The only way to achieve exactly what I need is through fragments. Though when I try to transition from the splash screen to the login fragment the text view which was part of the splash screen remains. The same happens after transitioning from the login fragment to the register fragment as well as from the register fragment back to the login fragment. It is important to note that there is no issue during transitioning between login and register or between register and login - except the fact that the edit text stays there.
My MainActivity.java
public class StartActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_start);
}
#Override
public void onBackPressed(){
Toast.makeText(getApplicationContext(), "Back button is disabled", Toast.LENGTH_SHORT).show();
}
}
My layout for MainActivity
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".StartActivity"
android:background="#mipmap/background">
<fragment
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/viewpagerstart"
android:layout_centerInParent="true"
android:name="com.example.distributedsystemsui.SplashFragment">
</fragment>
</RelativeLayout>
The SplashScreen.java
public class SplashFragment extends Fragment {
LinearLayout linearLayout;
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_splash, container, false);
linearLayout = (LinearLayout) view.findViewById(R.id.f_linearsplash);
Animation animation_fadein = AnimationUtils.loadAnimation((StartActivity)getActivity(), R.anim.fade_in);
linearLayout.startAnimation(animation_fadein);
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
public void run() {
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.setCustomAnimations(R.anim.slide_enter_left, R.anim.slide_exit_left,
R.anim.slide_enter_right, R.anim.slide_exit_right);
LoginFragment loginFragment = LoginFragment.newInstance();
ft.replace(R.id.viewpagerstart, loginFragment);
ft.commit();
}
}, 3000);
return view;
}
}
And the layout for the SplashScreen fragment.
<?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=".LoginFragment"
android:background="#color/Tranparent"
android:id="#+id/frame_splash">
<LinearLayout
android:id="#+id/f_linearsplash"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ImageView
android:id="#+id/f_splashlogo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:layout_marginTop="70dp"
android:background="#FFFFFF"/>
<TextView
android:id="#+id/f_splashtext"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/app_name"
android:layout_gravity="center_horizontal"
android:layout_marginTop="100dp"
android:background="#FFFFFF"/>
</LinearLayout>
</FrameLayout>
All my search led back to nothing.
I can only assume that either the below contained in the MainActivity.xml creates a confusion (which I tried to change but no luck):
android:name="com.example.distributedsystemsui.SplashFragment"
or that I am doing a mistake in the SplashScreen.java that I cannot locate, even though I tried for more than 5 hours to make it work.

The problem is that you cannot replace fragments added via the <fragment> tag.
Instead, you should either:
1) Switch to FragmentContainerView, which was added in Fragment 1.2.0. It does not suffer from the same issue as the <fragment> tag and lets you do replace operations without issues:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".StartActivity"
android:background="#mipmap/background">
<androidx.fragment.app.FragmentContainerView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/viewpagerstart"
android:layout_centerInParent="true"
android:name="com.example.distributedsystemsui.SplashFragment">
</androidx.fragment.app.FragmentContainerView>
</RelativeLayout>
2) Use a FrameLayout in your layout and manually add the SplashFragment in your activity (this is essentially what FragmentContainerView does for you):
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".StartActivity"
android:background="#mipmap/background">
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/viewpagerstart"
android:layout_centerInParent="true">
</FrameLayout>
</RelativeLayout>
which means you need to add the SplashFragment manually:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_start);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.viewpagerstart, new SplashFragment())
.commit()
}
}

I think it is better to do the fragment transactions from your activity instead of doing it from your fragment. You might consider having functions in your MainActivity as follows.
public class StartActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_start);
}
public void goToLoginFragment() {
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.setCustomAnimations(R.anim.slide_enter_left, R.anim.slide_exit_left,
R.anim.slide_enter_right, R.anim.slide_exit_right);
LoginFragment loginFragment = LoginFragment.newInstance();
ft.replace(R.id.viewpagerstart, loginFragment);
ft.commit();
}
public void goToRegisterFragment() {
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.setCustomAnimations(R.anim.slide_enter_left, R.anim.slide_exit_left,
R.anim.slide_enter_right, R.anim.slide_exit_right);
LoginFragment registerFragment = RegisterFragment.newInstance();
ft.replace(R.id.viewpagerstart, registerFragment);
ft.commit();
}
#Override
public void onBackPressed(){
Toast.makeText(getApplicationContext(), "Back button is disabled", Toast.LENGTH_SHORT).show();
}
}
And then from your SplashFragment call the function that is defined in your activity.
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
public void run() {
((MainActivity) getActivity()).goToLoginFragment();
}
}, 3000);
I hope that solves the problem.

Fragment Debug GPU overdraw

I have MainActivity and added 2 fragments in R.id.container.
The MainActivity looks like the following.
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_activity);
getSupportFragmentManager().beginTransaction()
.add(R.id.container, Fragment1.newInstance())
.commit();
getSupportFragmentManager().beginTransaction()
.add(R.id.container, Fragment2.newInstance())
.commit();
}
}
Fragmnet1 and Fragment2 have the same code with different layouts.
public class Fragment1 extends Fragment {
public static Fragment1 newInstance() {
return new Fragment1();
}
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container,
#Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_1, container, false);
}
}
And the associated layout fragment1.xml is
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#ffffff"
tools:context=".ui.main.Fragment1">
<TextView
android:id="#+id/message"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Test1"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
Layout for Fragment2 is fragmnet2.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#ffffff"
tools:context=".ui.main.Fragment1">
<TextView
android:id="#+id/message"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="32dp"
android:text="Test2"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
Here is the Debug GPU overdraw MainActivity after adding Fragment1 and Fragment2
See this image below. This is the one more drawing of GPU because the layout in Fragment1 remains in the MainActivity.
How can I add fragments without loading/showing the fragment below?

You are adding two fragments in the same container. This is the exact behaviour as per your code. If you need to show the fragment added later only, you need to replace the fragment instead of add.
I do not know the exact use case of yours. However, I guess you are trying to show fragment1 and fragment2 based on some checking. In that case, you might consider having two functions like the following in your MainActivity.
public boolean fragment1Loaded = false;
public void switchToFrag1() {
fragment1Loaded = true;
getSupportFragmentManager().beginTransaction()
.replace(R.id.container, Fragment1.newInstance())
.commit();
}
public void switchToFrag2() {
fragment1Loaded = false;
getSupportFragmentManager().beginTransaction()
.replace(R.id.container, Fragment2.newInstance())
.commit();
}
Now in the onCreate function, you need to call a function based on a condition which is necessary.
if (showFirstFragment) switchToFrag1();
else switchToFrag2();
You can do the switching whenever necessary from MainActivity.
Hope that helps!
Update
You can handle the back button click in your MainActivity and handle the logic by yourself. Override the onBackPressed function and then switch the fragments based on your necessity. For example, see the modified functions above. I am keeping a reference of which fragment is loaded in the screen right now. Then override the onBackPressed function like the following.
#Override
public void onBackPressed() {
if (fragment1Loaded) super.onBackPressed();
else switchToFrag1();
}
Hope you get the idea.

Fragment does not show up when app starts (onCreate) but does when it resumes (onResume)

I'm having an issue where a fragment in my main activity does not show up when the app is being started initially (during the main apps onCreate method) but does show up when I pause the app and then resume it (during the onResume method)
Here's the important parts of my main activity
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin" />
<FrameLayout
android:id="#+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent">
</FrameLayout>
MainActivity:
public class MainActivity extends Activity {
protected FrameLayout fragment_container;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (findViewById(R.id.fragment_container) != null) {
if (savedInstanceState != null) {
TextViewFragment fragment = new TextViewFragment();
fragment.setArguments(getIntent().getExtras());
getFragmentManager().beginTransaction().add(R.id.fragment_container, fragment).commit();
}
}}
TextViewFragment:
public class TextViewFragment extends Fragment {
#Override
public void onCreate(Bundle savedInstance) {
super.onCreate(savedInstance);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.textview_fragment, container, false);
}
}
textview_fragment:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:text="This is not showing up"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:typeface="sans"
android:textSize="35sp"/>
</LinearLayout>
Any help is appreciated!

When it starts first then if (savedInstanceState != null) { condition gives null.
You may remove the condition then it will load the fragment always.

Why settings.xml layout is overlapping the ActionBar/Toolbar?

I'm developing a material design app.
After adding settings.xml in SettingsActivity.java & running the app, the activity is appearing like this:
Here's SettingsActivity.java file's code:
public class SettingsActivity extends AppCompatActivity {
Toolbar toolbar;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_settings);
SpannableString s = new SpannableString("Settings");
s.setSpan(new TypefaceSpan(this, "Roboto-Medium.ttf"), 0, s.length(),
Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setTitle(s);
// Display the fragment as the main content.
getFragmentManager().beginTransaction()
.replace(android.R.id.content, new SettingsFragment())
.commit();
}
public static class SettingsFragment extends PreferenceFragment implements SharedPreferences.OnSharedPreferenceChangeListener {
public static final String SHARE_APP_PREFERENCE_KEY = "pref_key_share_app";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Load the preferences from an XML resource
addPreferencesFromResource(R.xml.settings);
}
public void onSharedPreferenceChanged(SharedPreferences sharedPreferences,
String key) {
if (key.equals(SHARE_APP_PREFERENCE_KEY)) {
// do something
}
}
}
}
Here's activity_settings.xml file's code:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.abc.xxx.SettingsActivity">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:layout_scrollFlags="scroll|enterAlways"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"
android:elevation="4dp"/>
</RelativeLayout>
Here's settings.xml file's code:
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" >
<PreferenceCategory android:title="#string/pref_notification" >
<CheckBoxPreference
android:defaultValue="true"
android:key="prefNotification"
android:summary="#string/pref_notify_summary" >
</CheckBoxPreference>
</PreferenceCategory>
</PreferenceScreen>
I don't know why the settings.xml layout is overlapping the ActionBar/Toolbar!
Please let me know.
Thanks in advance.

Change your activity_settings.xml to this
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.abc.xxx.SettingsActivity">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:layout_scrollFlags="scroll|enterAlways"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"
android:elevation="4dp"/>
<FrameLayout
android:id="#+id/fragment_container"
android:layout_width="match_parent"
android:layout_below="#id/toolbar"
android:layout_height="match_parent" />
</RelativeLayout>
And change code to this
// Display the fragment as the main content.
getFragmentManager().beginTransaction()
.replace(R.id.fragment_container, new SettingsFragment())
.commit();

When you call the fragment on the activity, don't use
// Display the fragment as the main content.
getFragmentManager().beginTransaction()
.replace(android.R.id.content, new SettingsFragment())
.commit();
Instead use
// Display the fragment as the main content.
getFragmentManager().beginTransaction()
.replace(R.id.Your_Frame_ID_On_xml, new SettingsFragment())
.commit();
I had the same problem for using android.R.id.content so changing it to the ID you use for the frame to hold the fragment on the xml fixed it.

Discovered that PreferenceActivity in Sunny's solution above may crash due to it loads a content view without a ListView. This is fixed by adding it to activity_settings.xml, but the PreferenceFragment will just ignore it. The activity_settings.xml will the look something like this
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<include layout="#layout/common_actionbar" />
<ListView
android:id="#android:id/list"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<FrameLayout
android:id="#+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent" />