viewPager not displaying fragment - java

for this project, I have tabs that have to display something under them and i'm using view pager but for some reason, the fragment layout isn't showing up on screen. I get a blank screen but there is no error or anything. I have been googling and searching for hours now and even started a new project just to make sure it was not a build error but still no luck in finding a solution to my problem.
I have done examples like this many times and used the exact same steps but for some reason, it just isn't working this time. Any help would be greatly appreciated
Here is my mainActivity class
public class MainActivity extends ActionBarActivity {
Toolbar toolbar;
ViewPager myViewPager;
SlidingTabLayout mySlidingTabs;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
myViewPager = (ViewPager) findViewById(R.id.viewPager);
myViewPager.setAdapter(new MyPagerAdapter(getSupportFragmentManager(), this));
mySlidingTabs = (SlidingTabLayout) findViewById(R.id.sliding_tabs);
mySlidingTabs.setViewPager(myViewPager);
}
}
Here is my custom adapter class
public class MyPagerAdapter extends FragmentPagerAdapter {
private Context context;
private String[] tabNames = {"Beverages", "Deli & Bakery", "Fresh Produce", "Health & Beauty", "Meat & Seafood", "Natural Foods", "Pet Care"};
public MyPagerAdapter(FragmentManager fm, Context context) {
super(fm);
this.context = context;
}
#Override
public Fragment getItem(int position) {
if (position == 0) {
return new Beverages();
}
else if (position == 1) {
return new DeliBakery();
}
return null;
}
#Override
public int getCount() {
return 2;
}
#Override
public CharSequence getPageTitle(int position) {
return tabNames[position];
}
}
Here is my main activty.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:orientation="vertical">
<include
android:id="#+id/toolbar"
layout="#layout/toolbar_layout"
android:layout_height="wrap_content"
android:layout_width="match_parent" />
<!-- The Sliding tab -->
<bello.myapplication.SlidingTabLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/sliding_tabs"/>
<!-- The pager that allows us to swipe between fragments -->
<android.support.v4.view.ViewPager
android:id="#+id/viewPager"
android:layout_width="match_parent"
android:layout_height="0px"
android:layout_weight="1"
android:background="#android:color/white" />
</LinearLayout>
and here is one of my tab's xml file
<?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">
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Tab fragment 1"
android:textSize="50dp"
android:padding="5dp" />
</RelativeLayout>
Here is one of my fragment classes
public class Beverages extends Fragment {
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.beverages_tab, container, false);
return view;
}
}

When something strange like this happens, try to use Log.i("title", "message") to track if every class/methods are being called.
In your case, it seens that your viewpager isn't in the screen.
If I understood your code, your <include> tag is including the second xml code you posted right?
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Tab fragment 1"
android:textSize="50dp"
android:padding="5dp" />
</RelativeLayout>
It looks like your layout_height="match_parent" is filling all the space on your screen, giving no space to your ViewPager being inflated by the system, try to change it to layout_height="wrap_content and you should be done.
If not, try to change the background of your ViewPager to check if it is on the screen and is not being hided by something else.

Figured out the problem. The viewpager background color and the background color of the tabs where the same so it made it look like there was a black activity. So for anyone else out there with the same problem, try changing either the text color of your tabs.xml or change the background of your viewpager

Related

Pageviewer in a NestedScrollView not displaying text

I am using a PageViewer to display fragment's data, and whenever I put a TextView into the fragment's xml, it doesn't display when the app is being run. I put it in a NestedScrollView to put more widgets in then I could without it. I tried putting an ImageView in to see if it was removing everything but that worked fine, except it was a little laggy when changing fragments.
My code for my activity is
public class MainActivity extends AppCompatActivity {
private Toolbar toolbar;
private TabLayout tabLayout;
private ViewPager viewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
viewPager = (ViewPager) findViewById(R.id.view_pager);
setupViewPager(viewPager);
tabLayout = (TabLayout) findViewById(R.id.tabLayout);
tabLayout.setupWithViewPager(viewPager);
}
private void setupViewPager(ViewPager viewPager) {
ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
adapter.addFragment(new VolleyballFragment(), "Volleyball");
adapter.addFragment(new SoftballFragment(), "Softball");
viewPager.setAdapter(adapter);
}
class ViewPagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();
public ViewPagerAdapter(FragmentManager manager) {
super(manager);
}
#Override
public Fragment getItem(int position) {
return mFragmentList.get(position);
}
#Override
public int getCount() {
return mFragmentList.size();
}
public void addFragment(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
#Override
public CharSequence getPageTitle(int position) {
return mFragmentTitleList.get(position);
}
}
}
my fragment codes are the nearly same so I will only provide 1
public class VolleyballFragment extends Fragment{
public VolleyballFragment() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_volleyball, container, false);
}
}
and the activity xml file is
<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.google.android.material.appbar.AppBarLayout
android:id="#+id/appbar"
android:layout_height="wrap_content"
android:layout_width="match_parent">
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_scrollFlags="scroll|enterAlways"></androidx.appcompat.widget.Toolbar>
<com.google.android.material.tabs.TabLayout
android:id="#+id/tabLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.google.android.material.tabs.TabItem
android:id="#+id/softballFragment"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Softball" />
<com.google.android.material.tabs.TabItem
android:id="#+id/volleyballFragment"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Vollyball" />
</com.google.android.material.tabs.TabLayout>
</com.google.android.material.appbar.AppBarLayout>
<androidx.core.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true">
<androidx.viewpager.widget.ViewPager
android:id="#+id/view_pager"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
</androidx.core.widget.NestedScrollView>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
If you need any of the xml files or anything else please let me know.
I fallowed an older tutorial online since this is my first time using fragments and tabs, so I'm a little confused to begin with
Also sorry for the code being cut off and replaced as normal text
I tried your code everything else is fine but you're just missing layout_behavior on NestedScrollView.
After adding this property your code would look like this.
<androidx.core.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="com.google.android.material.appbar.AppBarLayout$ScrollingViewBehavior"
android:fillViewport="true">
<androidx.viewpager.widget.ViewPager
android:id="#+id/view_pager"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
</androidx.core.widget.NestedScrollView>

How to update fragment data using RecyclerView?

I have a ViewPager with 12 fragments. I need to get data from API and update the fragments when scrolling. How do I update the contents of fragment, with only one fragment updating for 12 pages?
My fragment layout fragment_item:
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/surface">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginEnd="20dp"
android:layout_marginStart="20dp"
android:orientation="vertical">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/khaire"
android:gravity="center"
android:text="Overal Working Hour"
android:textColor="#color/colorPrimary"
android:textSize="20sp"
android:textStyle="bold" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/colorPrimary"
android:gravity="center"
android:padding="15dp"
android:text="January"
android:textColor="#color/white"
android:textSize="20sp"
android:textStyle="bold" />
My main activity code:
public class MainActivity extends AppCompatActivity {
private static final int num_pages = 12;
private ViewPager mPager;
private PagerAdapter mPagerAdapter;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mPager = findViewById(R.id.pager);
mPagerAdapter = new ScreenAdapter(getSupportFragmentManager());
mPager.setAdapter(mPagerAdapter);
private class ScreenAdapter extends FragmentStatePagerAdapter {
public ScreenAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int i) {
return new SliderFragment();
}
#Override
public int getCount() {
return num_pages;
}
}
My SlideFragment class:
public class SliderFragment extends Fragment {
Toolbar toolbar;
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
ViewGroup rootView = (ViewGroup) inflater.inflate(R.layout.fragment_item,container,false);
return rootView;
}
Now I want to have same fragment while scrolling the page but with diff texts how could I do that... And if possible use RecyclerView also.
You could create a new Class (UpdatingFragment) with public abstract updateView(); that extends Fragment.
Create your SliderFragment by extending UpdatingFragment instead of Fragment
In the SliderFragment in onCreateView() at the end call updateView().
Write an overwrite method in your SliderFragment for what you need to update (anything you want to show on the UI)
Adjust your screenAdapter to return and take UpdatingFragment’s instead of Fragments.
Now whenever your fragments onCreateView gets called all their UI data gets updated, and if you create a list of SliderFragments and pass that into your adapter instead of creating new ones, you can just run a for loop over that list and call updateView() for each fragment.

How to change the layout with different markup when device rotation?

Description
I have one activity in the vertical orinentation with two tabs (TabLayout) and fragments, which change with Viewpager.
MainActivity.java
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewPager viewPager = (ViewPager) findViewById(R.id.pager);
// Assign created adapter to viewPager
viewPager.setAdapter(new TabsExamplePagerAdapter(getSupportFragmentManager()));
TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
// This method setup all required method for TabLayout with Viewpager
tabLayout.setupWithViewPager(viewPager);
}
public class TabsExamplePagerAdapter extends FragmentPagerAdapter {
// As we are implementing two tabs
private static final int NUM_ITEMS = 2;
public TabsExamplePagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
// For each tab different fragment is returned
public Fragment getItem(int position) {
switch (position) {
case 0:
return new TabOneFragment();
case 1:
return new TabTwoFragment();
default:
return null;
}
}
#Override
public int getCount() {
return NUM_ITEMS;
}
#Override
public CharSequence getPageTitle(int position) {
return "Tab " + (position + 1);
}
}
}
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:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
tools:context=".MainActivity">
<android.support.design.widget.TabLayout
android:id="#+id/tab_layout"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:tabTextColor="#ffffff"
app:tabIndicatorColor="#fbff3a"
app:tabSelectedTextColor="#fbff3a"
app:tabIndicatorHeight="5dp"
android:elevation="4dp"
app:tabGravity="fill"
app:tabMaxWidth="0dp" />
<android.support.v4.view.ViewPager
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</RelativeLayout>
In each tabs i have for one fragments.
TabOneFragment.java (TabTwoFragment is similar ):
public class TabOneFragment extends Fragment {
// Required empty public constructor
public TabOneFragment() { }
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_tab_one, container, false);
}
}
fragment_one_tab.xml (fragment_one_tab.xml is similar)
<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="innovatecode.com.tabexample.TabOneFragment">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:textSize="18dp"
android:text="#string/tab_one" />
</FrameLayout>
And i have simply result:
My problem
When my device is rotated to the horizontal position, I want to get the following result:
I create xml for horizontal markup (land):
active_main.xml (land)
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/root"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<FrameLayout
android:id="#+id/fragment_left"
android:layout_weight="2"
android:layout_width="0dp"
android:layout_height="match_parent" />
<FrameLayout
android:id="#+id/fragment_right"
android:layout_weight="2"
android:layout_width="0dp"
android:layout_height="match_parent" />
</LinearLayout>
But I don't know how to change my code to get this result. I'm not very strong in working with fragments.
First, you can improve your landscape layout by adding your fragments directly to the layout file (under "res/layout-land"):
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/root"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<fragment
android:name="innovatecode.com.tabexample.TabOneFragment"
android:id="#+id/fragment_left"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="match_parent" />
<fragment
android:name="innovatecode.com.tabexample.TabTwoFragment"
android:id="#+id/fragment_right"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="match_parent" />
</LinearLayout>
You can read move on the topic here.
For the code part, you could make use of distinct features of your landscape and portrait layouts to switch between the corresponding logic in code. For example:
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (findViewById(R.id.tab_layout) != null) {
setUpPortraitLayout();
} else {
setUpLandscapeLayout();
}
}
private void setUpPortraitLayout() {
ViewPager viewPager = findViewById(R.id.pager);
// Assign created adapter to viewPager
viewPager.setAdapter(new TabsExamplePagerAdapter(getSupportFragmentManager()));
TabLayout tabLayout = findViewById(R.id.tab_layout);
// This method setup all required method for TabLayout with Viewpager
tabLayout.setupWithViewPager(viewPager);
}
private void setUpLandscapeLayout() {
// Note: with the layout definition suggested above you don't
// need any manual processing to set-up your layout for landscape
// but you still may have some extra set-up (initial binding, etc).
tabOneFragment = (TabOneFragment) getSupportFragmentManager().findFragmentById(R.id.fragment_left);
tabTwoFragment = (TabTwoFragment) getSupportFragmentManager().findFragmentById(R.id.fragment_right);
// ...
}
}
You can pass saved parameters to your fragments via "setArguments()" method. Alternatively consider using "onSaveInstanceState()" methods of your fragments (as opposed to activity, which you use now).
Alternative approach: dynamically add fragments in both landscape and portrait cases. It is based on your code. I think some aspects are arguable (I may be wrong), but changing direction would mean rewriting the whole thing. But it should work eventually.
res/layout-land/active_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/root"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<FrameLayout
android:id="#+id/fragment_left"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="match_parent" />
<FrameLayout
android:id="#+id/fragment_right"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="match_parent" />
</LinearLayout>
MainActivity.java (based off the code you shared via gist)
public class MainActivity extends AppCompatActivity {
private Fragment tabOneFragment;
private Fragment tabTwoFragment;
private ViewPager viewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState != null) {
//Restore the fragment's instance
tabOneFragment = (TabOneFragment) getSupportFragmentManager().getFragment(
savedInstanceState, "tabOneFragment");
tabTwoFragment = (TabTwoFragment) getSupportFragmentManager().getFragment(
savedInstanceState, "tabTwoFragment");
} else {
tabOneFragment = new TabOneFragment();
tabTwoFragment = new TabTwoFragment();
}
if (findViewById(R.id.tab_layout) != null) {
setUpPortraitLayout();
} else {
setUpLandscapeLayout();
}
}
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
getSupportFragmentManager().putFragment(outState, "tabOneFragment", tabOneFragment);
getSupportFragmentManager().putFragment(outState, "tabTwoFragment", tabTwoFragment);
}
private void setUpPortraitLayout() {
viewPager = (ViewPager) findViewById(R.id.pager);
// Assign created adapter to viewPager
viewPager.setAdapter(new TabsPagerAdapter(getSupportFragmentManager()));
TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
// This method setup all required method for TabLayout with Viewpager
tabLayout.setupWithViewPager(viewPager);
}
private void setUpLandscapeLayout() {
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.fragment_left, tabOneFragment);
transaction.replace(R.id.fragment_right, tabTwoFragment);
transaction.addToBackStack(null);
transaction.commit();
}
private class TabsPagerAdapter extends FragmentPagerAdapter {
// As we are implementing two tabs
private static final int NUM_ITEMS = 2;
public TabsPagerAdapter(FragmentManager fragmentManager) {
super(fragmentManager);
}
#Override
// For each tab different fragment is returned
public Fragment getItem(int position) {
switch (position) {
case 0:
return tabOneFragment;
case 1:
return tabTwoFragment;
default:
throw new IllegalStateException("Invalid tab index");
}
}
#Override
public int getCount() { return NUM_ITEMS; }
#Override
public CharSequence getPageTitle(int position) { return "Tab " + (position + 1); }
// NOTE: I think you do not really need to override "instantiateItem()", therefore I removed it.
}
}

Reason for a fragment to not show up

so I know there are a few topics around here that ask about this but none seemed to be the cause of my issue. I have an ActionBarActivity that is going to be switching between a few different fragments, but I'm having a problem getting one of the fragments to show up. The activity does show a fragment when it is first loaded and does that fine. Here is the code that is setting up the initial fragment with the method to switch between fragments that I'm using.
#Override
protected void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_container);
final ActionBar actionBar = getSupportActionBar();
actionBar.setTitle("");
if (savedInstanceState == null) navigateTo(START_SCREEN);
}
public void navigateTo(int sectionNumber, Serializable objectParam) {
Fragment fragment = null;
switch (sectionNumber) {
case START_SCREEN:
fragment = createStartScreenFragment(); //returns an instance of the class for this fragment
break;
case SCREEN_TWO:
fragment = createSecondScreenFragment(); //returns an instance of the class for this fragment
break;
}
if (fragment == null) return;
FragmentManager fm = getSupportFragmentManager();
FragmentTransaction trans = fm.beginTransaction();
trans.add(R.id.activity_container, fragment, fragment.getTag());
trans.commit();
trans.show(fragment);
}
activity_containers.xml
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:id="#+id/activity_container"
android:layout_width="match_parent"
android:layout_height="match_parent">
</FrameLayout>
The first fragment that loads successfuly
<GridLayout
android:id="#+id/fragment_start_screen"
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="com.android.Activity">
<TextView
android:id="#+id/text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:clickable="true"
/>
...
</GridLayout>
And here is the fragment xml that isn't showing up
<TextView android:id="#+id/section_label" android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<ListView
android:id="#+id/list"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:scrollbars="vertical"
android:fadingEdge="vertical"
android:cacheColorHint="#00000000"
android:fastScrollEnabled="true"
android:padding="2dp">
</ListView>
And here is the misbehaving fragments relevant code:
public class SecondFragment extends Fragment {
public final static int SECTION_NUMBER = 1;
private String mTag = "TAG";
private ParentActivity parentActivity;
public SecondFragment() {
}
public static fragment newInstance() {
SecondFragment fragment = new SecondFragment();
Bundle args = new Bundle();
fragment.setArguments(args);
return fragment;
}
#Override
public void onAttach(final Activity activity) {
super.onAttach(activity);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
parentActivity = (ParentActivity) getActivity();
View rootView = inflater.inflate(R.layout.fragment_second_fragment, container, false);
ListView list = (ListView) rootView.findViewById(R.id.list);
return super.onCreateView(inflater, container, savedInstanceState);
}
}
The biggest problem I'm having here is that there is no error message shown. The text view in the first fragment is supposed to trigger the second fragment to show up on the screen. This used to work when I had that fragment as a DialogFragment and just called .show() on an instance of it. I need it to be a regular fragment now and it doesn't show up. There's no error message that I can see, though debugging it does show it running through all of my code successfully and it looks like its properly inflating the view.
So what could I be missing here that is preventing the fragment from displaying?
Your layout
<TextView android:id="#+id/section_label" android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<ListView
android:id="#+id/list"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:scrollbars="vertical"
android:fadingEdge="vertical"
android:cacheColorHint="#00000000"
android:fastScrollEnabled="true"
android:padding="2dp">
</ListView>
Should be within a ViewGroup
<?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:orientation="vertical">
<TextView android:id="#+id/section_label" android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<ListView
android:id="#+id/list"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:scrollbars="vertical"
android:fadingEdge="vertical"
android:cacheColorHint="#00000000"
android:fastScrollEnabled="true"
android:padding="2dp">
</ListView>
</LinearLayout>
And you should return rootView in onCreateView().
Also, you might need to use replace method of Fragment Manager to replace one fragment with another, instead of add.

Android DK Trying to show/hide part of the UI via Fragments

So I am very new to the Android DK, and was sailing pretty fine until I started trying to mess with Fragments.
At the core of it, what I'm trying to do is have a series of buttons on my app's screen, and whichever button the user presses will change what text/spinners/buttons display on the screen.
How I decided to implement that was via Fragments. I can't figure out why my Fragment isn't displaying however, this should be a relatively simple example.
I had a activity_main.xml that is relatively simple. I've changed variable names, but see below:
<LinearLayout android:id="#+id/mainActivity"
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"
android:orientation="vertical"
android:animateLayoutChanges="true" >
<Button
android:id="#+id/buttonD"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#string/d_name"
android:onClick="dMenuButton" />
<RelativeLayout
android:id="#+id/fragment_container"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:visibility="gone" />
<Button
android:id="#+id/buttonR"
android:layout_below="#id/fragment_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#string/r_name"
android:onClick="rButton" />
</LinearLayout>
And the corresponding MainActivity.java
public void dMenuButton(View view){
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.show(dFragment);
fragmentTransaction.commit();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// remove title
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
dFragment = new DFragment();
fragmentTransaction.add(R.id.fragment_container, dFragment);
fragmentTransaction.commit();
}
}
And the fragment_d.xml
<RelativeLayout 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"
android:orientation="vertical" >
<TextView
android:id="#+id/text1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginTop="20dp"
android:text="#string/text1"
android:textAppearance="?android:attr/textAppearanceMedium" />
<Spinner
android:id="#+id/numD"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignTop="#id/text1"
android:layout_toRightOf="#id/text1" />
</RelativeLayout>
With its respective DFragment.java
public class DFragment extends Fragment {
static Spinner dSpinner;
ArrayAdapter<CharSequence> dAdapter;
RelativeLayout view;
public static DFragment newInstance() {
DFragment dFragment = new DFragment();
return dFragment ;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
view = (RelativeLayout) inflater.inflate(R.layout.fragment_d,
container, false);
createSpinners();
return view;
}
private void createSpinners() {
dSpinner = (Spinner) view.findViewById(R.id.numD);
dAdapter= ArrayAdapter.createFromResource(getActivity().getBaseContext(),
R.array.numD,
android.R.layout.simple_spinner_item);
}
}
Currently, the fragment layout is covering up the buttons beneath it. Any help in forcing it to push down the components below would be great.
Thanks in advance.
You are definitely on the right track with the visibility of the fragment_container. You could leave that as visible constantly, then allow the fragment transactions to change what is being displayed in that container.
Depending on your requirements, you could simply perform a .replace(R.layout.fragment_container, anotherFragment) to change which fragment is being displayed (code is pseudo only).
As for the buttons, are you adding them to the activity_main.xml or are they being added in the fragment's layout? As long as you add the new buttons/text after the fragment_container layout in the main activity layout, you should be fine. Let me know exactly what you are trying to achieve with the buttons/text!
Good luck!

Categories

Resources