Develop Reference

Android Studio onClick not working in BindViewHolder

I want to start an activity when i click on one of the item of my RecyclerView. Unfortunately when i click on an item nothing happens and I'm stuck here.
I think the code into the onClick method is right (But maybe I'm wrong). I tried to add a Log.d to see if the listener works but i can't see it in the logcat when i click on an item. I'm new on programming so it can be a stupid error. Thanks for help :)
public class UsersRecyclerAdapter extends RecyclerView.Adapter<UsersRecyclerAdapter.ViewHolder> {
private Context context;
private List<Users> usersList;
public UsersRecyclerAdapter(Context context, List<Users> usersList) {
this.context = context;
this.usersList = usersList;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.users_row, parent, false);
return new ViewHolder(view, context);
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
final Users users = usersList.get(position);
holder.firstName.setText(users.getFirstName());
holder.lastName.setText(users.getLastName());
holder.classe.setText(users.getClasse());
String avatarURL = users.getAvatar();
Picasso.get().load(avatarURL).into(holder.avatar);
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Log.i("MyApp","I am here");
context = view.getContext();
Intent intent = new Intent(context, PDFPostListActivity.class);
// String userID = users.getUserID();
// intent.putExtra("userID", userID);
context.startActivity(intent);
}
});
}
EDIT. Here is the root view (users_row):
<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView
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="wrap_content"
android:layout_margin="5dp">
<HorizontalScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<ImageView
android:id="#+id/imageViewAVATAR"
android:layout_width="50dp"
android:layout_height="50dp"
android:paddingBottom="10dp"
android:paddingLeft="10dp"
android:paddingTop="10dp" />
<TextView
android:id="#+id/textViewfistName"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_marginEnd="10dp"
android:gravity="center"
android:textSize="21sp"
android:textStyle="italic" />
<TextView
android:id="#+id/textViewlastName"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_marginEnd="10dp"
android:gravity="center"
android:textSize="21sp"
android:textStyle="italic" />
<TextView
android:id="#+id/textViewclass"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:gravity="center"
android:textSize="21sp"
android:textStyle="italic" />
</LinearLayout>
</HorizontalScrollView>
</androidx.cardview.widget.CardView>

What's the root view of the view holder? Set it to be clickable since you set onClickListener on itemView of view holder.

Great thanks to #Mike M. who rapidly answer in the comment below the question. I paste the message:
When you call setOnClickListener() on itemView, it's setting that on the , since that's the outermost View there. The nested within it is preventing it from receiving click events. Assuming that's all that going to be in that layout, then the simplest fix would probably be to simply set the OnClickListener on the instead. You'll need to give it an android:id, find it with findViewById() just like you did the TextViews, and then call setOnClickListener() on that, instead of itemView.

Edit Custom Views programmatically

I created a layout like this:
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/rlMenu"
android:layout_centerHorizontal="true"
android:gravity="center"
android:layout_centerVertical="true">
<RelativeLayout
android:background="#drawable/dark_rectangle_bord"
android:id="#+id/rl1dia"
android:elevation="10dp"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_width="#dimen/sizeCard"
android:layout_height="#dimen/sizeCard"
android:layout_marginBottom="#dimen/padding_bottom_cards"
android:layout_marginEnd="#dimen/padding_end_cards"
android:layout_marginRight="#dimen/padding_end_cards"
android:layout_marginLeft="#dimen/padding_start_cards"
android:layout_marginStart="#dimen/padding_start_cards"
android:layout_marginTop="#dimen/padding_top_cards">
<TextView
android:text="1º Dia"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/tv1dia"
android:textStyle="normal|bold"
android:textColor="#color/Branco"
android:layout_alignParentBottom="true"
android:padding="10dp"
android:textSize="#dimen/texto_pequeno"
android:gravity="center"
android:fontFamily="sans-serif"
android:layout_centerHorizontal="true"/>
<ImageView
app:srcCompat="#drawable/ic_calendario_1"
android:id="#+id/iv1dia"
android:layout_width="#dimen/sizeImage"
android:layout_height="#dimen/sizeImage"
android:layout_centerHorizontal="true"
android:layout_alignParentTop="true"
/>
After that, I had included it on my MainActivity.
<include
android:id="#+id/my_custom_view"
layout="#layout/custom_view></include>
But in this Custom View there are a RelativeLayout, a ImageView and a TextView. I need to create some Custom Views dynamically, sample as below.
How can i create this Custom View Programatically?
Ex.:
Button bt = new Button(MainActivity.this);
And how can I change the TextView, RelativeLayout, background and the ImageView programatically? Like:
CustomView cv = new CustomView(MainActivity.this);
cv.setImage(R.drawable.chips);
cv.setRlBackground(Color.WHITE);
cv.setText("Hello, World!");

You can use LayoutInflater for that
LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View mView = (View) inflater.inflate(R.layout.custom_view, null);
View email = (View) mView.findViewById(R.id.email);
yourParentView.addView(mView);
But make sure when you add view to its parent call removeAllview() method of yourParentView

Maybe you want to create an actual custom View, using include will not create a custom View but will only inject in your layout that particular xml. So, create a class (in this case extends RelativeLayout but you can use whatever suits you here)
public class CustomView extends RelativeLayout {
private TextView textView;
private ImageView imageView;
public CustomView(Context context, AttributeSet attrs) {
super(context, attrs);
inflate(context, R.layout.custom_view, this);
imageView = (ImageView) findViewById(R.id.image_view);
textView = (TextView) findViewById(R.id.text_view);
}
public void setImage(int resId){
imageView.setImageResource(resId);
}
public void setText(String text){
textView.setText(text);
}
}
an xml of the layout of your custom View (custom_view.xml), you might want to use merge instead of include since you already have a parent layout (RelativeLayout in this case)
<?xml version="1.0" encoding="utf-8"?>
<merge xmlns:android="http://schemas.android.com/apk/res/android">
<TextView
android:id="#+id/text_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
<ImageView
android:id="#+id/image_view"
android:layout_width="48dp"
android:layout_height="48dp"
/>
</merge>
add your custom view to the Activity layout like this, please note that you need to use the full name of the custom View class you're using, in this case com.example.lelloman.dummy.CustomView
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
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"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin">
<com.example.lelloman.dummy.CustomView
android:id="#+id/custom_view"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</RelativeLayout>
and in your Activity
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.my_activity);
CustomView customView = (CustomView) findViewById(R.id.custom_view);
customView.setImage(R.drawable.some_icon);
customView.setText("Hello world");
}

viewPager not displaying fragment

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

Android Set Custom Preference Layout

I'm working on it Android project. I have a prefs.xml code, something like this
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
<Preference
android:key="pref_name_color_picker"
android:title="Colour"
android:summary="Colour of the name"
android:defaultValue="#FFFFFF"
android:layout="#layout/custom_name_setting_layout" />
</PreferenceCategory>
</PreferenceScreen>
And I need to custom preference layout. And I created;
custom_name_setting_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:minHeight="?android:attr/listPreferredItemHeight"
android:gravity="center_vertical"
android:paddingRight="?android:attr/scrollbarSize">
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="15dip"
android:layout_marginRight="6dip"
android:layout_marginTop="6dip"
android:layout_marginBottom="6dip"
android:layout_weight="1">
<TextView
android:id="#+android:id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:singleLine="true"
android:textAppearance="?android:attr/textAppearanceLarge"
android:ellipsize="marquee"
android:fadingEdge="horizontal" />
<TextView
android:id="#+android:id/summary"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#android:id/title"
android:layout_alignLeft="#android:id/title"
android:textAppearance="?android:attr/textAppearanceSmall"
android:maxLines="2" />
<ImageView
android:id="#+id/ivNameTextColor"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:minHeight="32dp"
android:minWidth="32dp"
android:layout_alignParentRight="true" />
</RelativeLayout>
</LinearLayout>
And write a SettingActivity.java
public class SettingActivity extends PreferenceActivity implements SharedPreferences.OnSharedPreferenceChangeListener {
int color = 0xffffff00;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.prefs);
LayoutInflater inflater = (LayoutInflater) getApplicationContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View row = inflater.inflate(R.layout.custom_name_setting_layout, null);
ImageView ivNameTextColor = (ImageView) row.findViewById(R.id.ivNameTextColor);
ivNameTextColor.setBackgroundColor(Color.RED);
}
}
My problem is; I write setBackgroundColor method but not working. Not working meanin is, this program is running without error (like NullReferenceException, there is no error). But background color still not changing.
I don't know why. How can i solve this problem?
Thanks

Obviously, if you are hard-coding the color then you can just do it in your XML:
android:background="#android:color/red"
If you want to do it in code then unfortunately it's trickier than it might seem. You can't just set the color of the preference view in onCreate() because the preference views are stored in a list and are created and recycled dynamically as you scroll the list.
You need to set the background color when the view is being created. To do that you'll need to implement a custom preference class and override getView():
public class CustomColorPreference extends Preference
{
int backgroundColor = Color.BLACK;
public CustomColorPreference(Context context) {
super(context);
}
public CustomColorPreference(Context context, AttributeSet attrs) {
super(context, attrs);
}
public void setCustomBackgroundColor(int color)
{
backgroundColor = color;
}
#Override
public View getView(View convertView, ViewGroup parent)
{
View v = super.getView(convertView, parent);
// v.setBackgroundColor(backgroundColor); // set background color of whole view
ImageView ivNameTextColor = (ImageView)v.findViewById(R.id.ivNameTextColor);
ivNameTextColor.setBackgroundColor(backgroundColor);
return v;
}
}
Change your XML to use the CustomColorPreference class:
<com.example.yourapp.CustomColorPreference
android:key="pref_name_color_picker"
android:title="Colour"
android:summary="Colour of the name"
android:defaultValue="#FFFFFF"
android:layout="#layout/custom_name_setting_layout" />
Then in your onCreate you can get the CustomColorPreference and set the color on it using the public method setCustomBackgroundColor():
CustomColorPreference picker = (CustomColorPreference)findPreference("pref_name_color_picker");
picker.setCustomBackgroundColor(Color.RED);

Getting Child from linear layout

I created layout file, consist of one linearlayout and two nested linearlayout inside the main one. When I using getParent method, it select the second nested linearlayout. My target was the first one nested linearlayout. So I gives the first nested linearlayout a ID called linear_top. Then I declared in the onCreateView, test and debug, I have no luck it shows that is null.
My target was AnimatedGifImageView
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<LinearLayout
android:id="#+id/linear_top"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<TextView
android:id="#+id/music_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Love Story"
android:textAppearance="?android:attr/textAppearanceLarge" />
<com.music.flow.lib.AnimatedGifImageView
android:id="#+id/music_anim"
android:layout_width="match_parent"
android:layout_height="76dp"
android:scaleType="fitXY"
android:contentDescription="Animation"
/>
</LinearLayout>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<RatingBar
android:id="#+id/music_rating"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:minHeight="40dp"
android:numStars="4"
android:rating="3.5" />
<ImageView
android:id="#+id/btn_playmusic"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="50dp"
android:src="#drawable/resume" />
</LinearLayout>
OnCreateView
linearTop = (LinearLayout) v.findViewById(R.id.linear_top);
AnimatedGifImageView animatedGifImageView =
(AnimatedGifImageView) linearTop.getChildAt(1); /* Null Exception */

Child views are indexed from 0. In other words, the first child view is 0, the second child view is 1... and so on.
Also, why don't you just get the the ImageView by it's ID?
AnimatedGifImageView musicAnim = (AnimatedGifImageView) findViewById(R.id.music_anim);

#Override
public View onCreateView(View v, String name, Context context,
AttributeSet attrs) {
LinearLayout linearTop = (LinearLayout) v.findViewById(R.id.linear_top);
ImageView animatedGifImageView = (ImageView) linearTop.getChildAt(1); // NullPointer
return super.onCreateView(v, name, context, attrs);
}
Does your code look like this? You are getting a NullPointerException because in onCreateView, the parameter View v may be null, as mentioned in the docs here. Are you using fragments? If not, then don't use onCreateView. Place your code instead in onCreate like this:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
LinearLayout linearTop = (LinearLayout) findViewById(R.id.linear_top);
ImageView animatedGifImageView = (ImageView) linearTop.getChildAt(1);
setContentView(R.layout.activity_nested_linearlayout);
}
also, as what Sound Conception mentioned, you could just try to get the view directly by using its id instead of manually getting it using an index.