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Android Java Use a cardview to display the items of a gridview

Hi everyone I'm trying to show with a GridView some items that show the contents of an array of strings. This is the CardView I want to set as item:
So when I click on a button, the layout of the choice of the type of film becomes visible and I set an adapter:
cTBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
postaCardVIew.setVisibility(View.GONE);
cT.setVisibility(View.VISIBLE);
GridView simpleGridView = findViewById(R.id.simpleGridView);
String genrelist[] = {"Commedia", "Animazione", "Anime", "Avventura", "Azione", "Biografico", "Documentario", "Drammatico", "Fantascienza","Fantasy",
"Guerra", "Horror", "Musical", "Storico", "Thriller", "Western", "Giallo", "Sentimentale",
};
final ArrayAdapter<String> adapter = new ArrayAdapter<String> (posta.this,android.R.layout.simple_list_item_1, genrelist);
simpleGridView.setAdapter(adapter);
}
But this is what I am getting:
I want to inflate this layout though:
<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="150dp"
android:layout_height="150dp"
xmlns:app="http://schemas.android.com/apk/res-auto"
app:cardCornerRadius="30dp"
android:layout_marginLeft="5dp"
android:layout_marginTop="5dp"
>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/type"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Type"
android:layout_centerInParent="true"
android:textSize="20dp"
android:textStyle="bold"
/>
</RelativeLayout>
</androidx.cardview.widget.CardView>
To get such a thing:
Can anyone help me figure out how I could inflate the desired layout?

In order to use a custom item layout, you need to create a custom adapter that extends from the BaseAdapter or ArrayAdapter
Then inflate and build your item layout in the getView() method:
public class CustomAdapter extends BaseAdapter {
String genrelist[] = {"Commedia", "Animazione", "Anime", "Avventura", "Azione", "Biografico", "Documentario", "Drammatico", "Fantascienza", "Fantasy",
"Guerra", "Horror", "Musical", "Storico", "Thriller", "Western", "Giallo", "Sentimentale",
};
// create a new ImageView for each item referenced by the Adapter
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = LayoutInflater.from(parent.getContext()).inflate(R.layout.item, parent, false);
holder = new ViewHolder();
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.title = convertView.findViewById(R.id.type);
holder.title.setText(genrelist[position]);
return convertView;
}
static class ViewHolder {
TextView title;
}
public int getCount() {
return genrelist.length;
}
public Object getItem(int position) {
return null;
}
public long getItemId(int position) {
return 0;
}
}
And use it as the GridView adapter:
cTBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
postaCardVIew.setVisibility(View.GONE);
cT.setVisibility(View.VISIBLE);
GridView simpleGridView = findViewById(R.id.simpleGridView);
simpleGridView.setAdapter(new CustomAdapter());
}
});
I had to manipulate the margin and cared width and wrap the CardView with a FrameLayout in order to force the margin among cards:
<?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="wrap_content"
android:layout_height="wrap_content"
android:layout_marginHorizontal="4dp"
android:layout_marginVertical="4dp">
<androidx.cardview.widget.CardView xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="120dp"
android:layout_height="120dp"
app:cardCornerRadius="30dp">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/type"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:text="Type: 1"
android:textSize="18sp"
android:textStyle="bold" />
</RelativeLayout>
</androidx.cardview.widget.CardView>
</FrameLayout>
Result:

How to increase the number of text in Android programmatically

I have a page in which I'm taking the START TIME and END TIME from DATABASE.
Let's say the START TIME is 7:00 and END TIME is 22:00
I want to use this START TIME and END TIME to show in my page as textview like 7:00 8:00 9:00 and sooo on till 22:00 as textview
Also I have an imageview that will also increase when the text increases.
How can I achieve this?
Also I want the result text in Horizontal Scroll View with Imageview at top and text view as bottom of each imageview
char first = StartTime.charAt(0);
int StartTimeint = Integer.parseInt(String.valueOf(first));
int l;
for( l = StartTimeint; l<=22; l++){
Log.d("SeatsPage", "Time is "+l);
}
timeofseats.setText(Integer.toString(l));
This is I have done so far but I'm getting 23 as a result, the textview is not increasing
This is my XML File
<?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:layout_width="match_parent"
android:id="#+id/llMain"
android:layout_height="match_parent"
tools:context=".SeatsPagewithDB.SeatsPage">
<ImageView
android:id="#+id/imageView11"
android:layout_width="150px"
android:layout_height="150px"
android:layout_marginStart="28dp"
android:layout_marginEnd="326dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:srcCompat="#drawable/seat" />
<TextView
android:id="#+id/timeofseats"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="40dp"
android:layout_marginTop="12dp"
android:layout_marginEnd="334dp"
android:background="#FF0000"
android:paddingLeft="10dp"
android:paddingRight="10dp"
android:text="7:00"
android:textColor="#fff"
android:textSize="20dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/imageView11" />
</android.support.constraint.ConstraintLayout>
This is the result I am getting as layout
This what I want programmatically

The XML code that you write in your layout.xml file to create the UI is for static UI only. What you are asking is to create views dynamically during runtime. Although you can definitely create views using java code on a click of a button or something. But it is better to code less for the UI whenever possible and keep it separated from the program code. Instead use the tools given to us by the framework we are using.
In Android those tools include stuff like ListView, GridView and the newer and better RecyclerView. These views help you add other views dynamically to your UI in runtime. You define one of them or more (depending on your UI needs) once in your layout.xml and configure them using java code like any other view.
This is how you can use RecyclerView to achieve your goal. I can't explain everything how RecyclerView works and what each line of code does as it will make a very long post but I have tried to highlight main things briefly.
1. Add RecyclerView in your layout file.
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">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
2. Create another layout file and define the template UI of the item that the RecyclerView is going to display. RecyclerView will populate each item that it holds with this layout.
item_view.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
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="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
android:orientation="vertical">
<ImageView
android:id="#+id/imageView_alarm"
android:layout_width="90dp"
android:layout_height="90dp"
android:src="#drawable/alarm" />
<TextView
android:id="#+id/textView_Time"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="8dp"
android:background="#FF0000"
android:paddingLeft="8dp"
android:paddingRight="8dp"
android:text="Time"
android:textColor="#android:color/background_light"
android:textSize="24sp" />
</LinearLayout>
3. Create a ViewHolder class that extends from RecyclerView.ViewHolder. View holder is a RecyclerView related concept. In short it works as a wrapper around the view of a single item and aids in binding new data to the view of the item. Create a bind() function inside view holder to make your life easier.
EDIT: I have updated the class by implementing the View.OnClickListener interface, modified the constructor to pass in the context from onCreateViewHolder() and adding a setItemPosition() just for the sake to pass the item position number from onBindViewHolder() all over to here so we can use this position number in our onClick() method of the interface
MyViewHolder.java [UPDATED]
public class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
private TextView textView;
private int itemPosition;
private Context mContext;
public MyViewHolder(#NonNull View itemView, Context context) {
super(itemView);
itemView.setOnClickListener(this);
mContext = context;
textView = itemView.findViewById(R.id.textView_Time);
}
void bind(String timeText)
{
textView.setText(timeText);
}
void setItemPosition(int position)
{
itemPosition = position;
}
#Override
public void onClick(View v) {
Toast.makeText(mContext, "You clicked item number: " + itemPosition , Toast.LENGTH_SHORT).show();
}
}
4. Create an Adapter class that extends from RecyclerView.Adapter. Adapter works as a bridge between the UI data and RecyclerView itself. An Adapter tells the RecyclerView what layout file to inflate and how many to inflate. RecyclerView job is to deal with how to inflate it on the UI.
EDIT : Just changed myViewHolder in onCreateViewHolder() to match the modified constructor of MyViewHolder. Added the call to setItemPosition() in the onBindViewHolder().
MyAdapter.java [UPDATED]
public class MyAdapter extends RecyclerView.Adapter {
List<String> timeIntervalList = new ArrayList<>();
#NonNull
#Override
public RecyclerView.ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_view, parent, false);
MyViewHolder myViewHolder = new MyViewHolder(view , parent.getContext());
return myViewHolder;
}
#Override
public void onBindViewHolder(#NonNull RecyclerView.ViewHolder holder, int position) {
MyViewHolder viewHolder = (MyViewHolder) holder;
viewHolder.setItemPosition(position);
viewHolder.bind(timeIntervalList.get(position));
}
#Override
public int getItemCount() {
return timeIntervalList.size();
}
public void addItem (String timeText)
{
timeIntervalList.add(timeText);
notifyItemInserted(getItemCount());
}
}
In this adapter you will see two functions. OnCreateViewHolder() inflates the view using the template layout file for a single item and OnBindViewHolder() binds new data to the default values of the of the view just created. The data used for binding is stored in a list inside this Adapter called the timeIntervalList. This list will hold your time interval strings so they can be updated on the view.
5. Finally, use this RecyclerView where you want to use it. Like in your MainActivity.java. RecyclerView needs to be told in what fashion to display the items (e.g list , grid etc ) using a LayoutManager. LinearLayoutManager will display items either vertically or horizontally. You can see I am using your logic to increment time from string and adding new views to RecyclerView using the addItem() function of the MyAdapter class.
MainActivity.java
public class MainActivity extends AppCompatActivity {
private RecyclerView myRecyclerView;
private MyAdapter myAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myRecyclerView = findViewById(R.id.recyclerView);
myAdapter = new MyAdapter();
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this , LinearLayoutManager.HORIZONTAL, false);
myRecyclerView.setLayoutManager(linearLayoutManager);
myRecyclerView.setAdapter(myAdapter);
// This is how you will populate the recycler view
String START_TIME = "7:00";
String END_TIME = "22:00";
char first = START_TIME.charAt(0);
int StartTimeint = Integer.parseInt(String.valueOf(first));
int l;
for( l = StartTimeint; l<=22; l++){
// This is where new item are added to recyclerView.
myAdapter.addItem(l + ":00");
}
}
}
This is the final result.

Change your activity layout XML code as follows,
<?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:layout_width="match_parent"
android:id="#+id/llMain"
android:layout_height="match_parent"
tools:context=".SeatsPagewithDB.SeatsPage">
<HorizontalScrollView
android:layout_width="match_parent"
android:layout_height="wrap_content"
...
...>
<LinearLayout
android:id="#+id/container"
android:orientation="horizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</HorizontalScrollView>
</android.support.constraint.ConstraintLayout>
Move the textview and imageview to another XML file let's call it item_view.xml (you can name it whatever you wish). we are doing so because the root view of this file will be reused.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="wrap_content"
android:layout_height="wrap_content">
<ImageView
android:id="#+id/imageView11"
android:layout_width="150px"
android:layout_height="150px"
app:srcCompat="#drawable/seat"/>
<TextView
android:id="#+id/timeofseats"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#FF0000"
android:paddingLeft="10dp"
android:paddingRight="10dp"
android:text="7:00"
android:textColor="#fff"
android:textSize="20dp"/>
</LinearLayout>
Now make following changes in your Java file
LinearLayout container = findViewById(R.id.container); // or rootView.findViewById() for custom View and Fragment
char first = StartTime.charAt(0);
int StartTimeint = Integer.parseInt(String.valueOf(first));
for(int l = StartTimeint; l<=22; l++){
Log.d("SeatsPage", "Time is "+l);
View view = LayoutInflater.from(container.getContext()).inflate(R.layout.item_view, null);
TextView timeofseats = view.findViewById(R.id.timeofseats);
timeofseats.setText(Integer.toString(l));
container.addView(view);
}

OnItemClickListener is not firing

I am making an app that has a list of exercises to do displayed in a ListView. I am trying to let the user select an item from the list to start a new activity, but my OnItemClickListener is not firing. Here is my Activity, (not a listActivity, it is appCompatActivity):
ArrayList<Exercise> myExercises = new ArrayList<>();
AlertDialog.Builder alertDialogBuilder;
ArrayAdapter<Exercise> arrayAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list);
refreshList();
Button newExButton = (Button) findViewById(R.id.newExButton);
arrayAdapter = new ArrayAdapter<Exercise>(
this,
android.R.layout.simple_list_item_1,
myExercises );
ListView lv = (ListView) findViewById(R.id.actList);
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
System.out.println("listener heard");
// selected item
int selection = position;
startExercise(selection);
}
});
lv.setAdapter(arrayAdapter);
}
public void refreshList(){
setContentView(R.layout.activity_list);
ListView lv = (ListView) findViewById(R.id.actList);
lv.setChoiceMode(AbsListView.CHOICE_MODE_SINGLE);
lv.setAdapter(arrayAdapter);
}
public void startExercise(int selection){
Intent exIntent = new Intent(this, CommenceExercise.class);
Exercise chosenEx = myExercises.get(selection);
Bundle info = new Bundle();
info.putLong("duration", chosenEx.getTime());
info.putString("name", chosenEx.getName());
info.putString("description", chosenEx.getDescription());
exIntent.putExtras(info);
startActivity(exIntent);
}
The list is initially empty, but the user adds items by pressing a button. The button creates an alertDialog through the code below:
public void addNewActivity(View view) {
//get prompts.xml view
LayoutInflater li = LayoutInflater.from(context);
View promptsView = li.inflate(R.layout.custom, null);
alertDialogBuilder = new AlertDialog.Builder(
context);
// set prompts.xml to alertdialog builder
alertDialogBuilder.setView(promptsView);
final EditText userInput = (EditText) promptsView
.findViewById(R.id.exNameInput);
final EditText durInput = (EditText) promptsView
.findViewById(R.id.exDurInput);
// set dialog message
alertDialogBuilder
.setCancelable(false)
.setPositiveButton("OK",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int id) {
long duration = 0;
String exName;
exName = userInput.getText().toString();
duration = Integer.valueOf(durInput.getText().toString());
myExercises.add(new Exercise(exName, duration));
// create new exercise with user input
refreshList();
}
})
.setNegativeButton("Cancel",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int id) {
dialog.cancel();
}
});
// create alert dialog
AlertDialog alertDialog = alertDialogBuilder.create();
// show it
alertDialog.show();
}
}
And here is my xml:
<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:layout_width="match_parent"
android:layout_height="match_parent"
android:descendantFocusability="blocksDescendants"
tools:context="com.example.mytimer.ListActivity">
<TextView
android:id="#+id/textView2"
android:layout_width="146dp"
android:layout_height="30dp"
android:layout_marginLeft="16dp"
android:layout_marginRight="16dp"
android:layout_marginTop="16dp"
android:text="Activities"
android:textAlignment="center"
android:textSize="24sp"
app:layout_constraintHorizontal_bias="0.502"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:layout_marginStart="16dp"
android:clickable="false"
android:layout_marginEnd="16dp" />
<Button
android:id="#+id/newExButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="16dp"
android:layout_marginLeft="16dp"
android:layout_marginRight="16dp"
android:layout_marginStart="16dp"
android:layout_marginTop="87dp"
android:onClick="addNewActivity"
android:text="New Exercise"
android:textSize="18sp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="#+id/textView2" />
<ListView
android:id="#+id/actList"
android:layout_width="328dp"
android:layout_height="301dp"
android:layout_marginBottom="16dp"
android:layout_marginEnd="16dp"
android:layout_marginLeft="16dp"
android:layout_marginRight="16dp"
android:layout_marginStart="16dp"
android:layout_marginTop="16dp"
android:descendantFocusability="blocksDescendants"
android:focusable="false"
android:clickable="false"
android:focusableInTouchMode="false"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="#+id/newExButton"
app:layout_constraintVertical_bias="1.0">
<requestFocus/>
</ListView>
<TextView
android:id="#+id/debugText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="36dp"
android:text="TextView"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
android:clickable="false"
app:layout_constraintTop_toBottomOf="#+id/textView2" />
</android.support.constraint.ConstraintLayout>
When I tap an item I've added to the list, nothing happens. I can tell that the OnItemClickListener is not being fired because the System.out line is never printed. I'm at a loss as to why I can't get it to work. Any help would be greatly appreciated. Thanks in advance.

You need to remove below listview attributes from xml:
android:descendantFocusability="blocksDescendants"
android:focusable="true"
android:clickable="true"
android:focusableInTouchMode="true"
Also, there is no need of refreshList() this is actually bad way of doing things, instead in your addNewActivity(), once your model is ready(probably on click of positive button) add that item to arrayAdapter and then do arrayAdapter.notifyDataSetChanged().
I hope this helps you!

I think problem in XML Please set ListView clickable true
please do some changes in XML
<ListView
android:id="#+id/actList"
android:layout_width="328dp"
android:layout_height="301dp"
android:layout_marginBottom="16dp"
android:layout_marginEnd="16dp"
android:layout_marginLeft="16dp"
android:layout_marginRight="16dp"
android:layout_marginStart="16dp"
android:layout_marginTop="16dp"
android:descendantFocusability="blocksDescendants"
android:focusable="true" // change this
android:clickable="true" // change this
android:focusableInTouchMode="true" // change this
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="#+id/newExButton"
app:layout_constraintVertical_bias="1.0">
<requestFocus/>
</ListView>

Change your refreshList method to below one
public void refreshList(){
arrayAdapter.notifyDataSetChanged();
}
What you're doing is, inflating a ListView again and setting new data to it rather than updating old one. And when you assign new value to ListView you forgot to set onClickListener.
It'll work.

That's really strange... your code should have worked... I would suggest you to try implementing the in your activity to include lv.setClcickable(true) and
lv.setEnable(true) :
public class MenuActivity extends AppCompatActivity implements
AdapterView.OnItemClickListener{
ArrayList<Exercise> myExercises = new ArrayList<>();
AlertDialog.Builder alertDialogBuilder;
ArrayAdapter<Exercise> arrayAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list);
refreshList();
Button newExButton = (Button) findViewById(R.id.newExButton);
arrayAdapter = new ArrayAdapter<Exercise>(
this,
android.R.layout.simple_list_item_1,
myExercises );
ListView lv = (ListView) findViewById(R.id.actList);
lv.setClickable(true);
lv.setEnabled(true);
lv.setOnItemClickListener(new AdapterView.OnItemClickListener(){
public void onItemClick(AdapterView<?> parent, View view , int
position, long id)
{
startExercise(position);
}
lv.setAdapter(arrayAdapter);
}
public void refreshList(){
setContentView(R.layout.activity_list);
ListView lv = (ListView) findViewById(R.id.actList);
lv.setChoiceMode(AbsListView.CHOICE_MODE_SINGLE);
lv.setAdapter(arrayAdapter);
}
public void startExercise(int selection){
Intent exIntent = new Intent(this, CommenceExercise.class);
Exercise chosenEx = myExercises.get(selection);
Bundle info = new Bundle();
info.putLong("duration", chosenEx.getTime());
info.putString("name", chosenEx.getName());
info.putString("description", chosenEx.getDescription());
exIntent.putExtras(info);
startActivity(exIntent);
}
}
or add these three lines to your xml
android:focusable="false"
android:focusableInTouchMode="false"
android:clickable="true
android:descendantFocusability="blocksDescendants"
If there are any focusable child views then the first click will always be for focus
And I would Suggest You to use Custom ListView with Viewholder Pattern for efficiency or the Recyclerview of support Library this will make your scroll smooth and won't create extra View Objects... It will only create the View Object that's will fit the screen
Here is the Link for RecyclerView https://guides.codepath.com/android/using-the-recyclerview

CardView in fragment is invisible

I have a main activity (ActivityMain.java) that I would like to use to navigate between four fragments. In one of these fragments, I'm attempting to place a CardView in conjunction with a RecyclerView to create a vertical list of cards. However, so far I've been unable to get any of the cards to display when I run the app. The CardView will display perfectly in Android Studio's design preview, but when an actual device/emulator is used it disappears.
I've tried to manually set the visibility of the CardView through Java, but it continued to stay invisible. I believe that the fragment's layout could be covering the CardView's layout, but I'm still very new to Android development so I'm not completely sure what the problem could be.
Below I've pasted the classes and XML files that are likely to be associated with my problem.
AdapterMainFeed.java
public class AdapterMainFeed extends RecyclerView.Adapter<AdapterMainFeed.ViewHolderMainFeed> {
private ArrayList<Article> listArticlesMain = new ArrayList<>();
private LayoutInflater inflater;
public AdapterMainFeed(Context context) {
inflater = LayoutInflater.from(context);
}
public void setArticlesMain(ArrayList<Article> listArticlesMain) {
this.listArticlesMain = listArticlesMain;
notifyDataSetChanged();
}
#Override
public ViewHolderMainFeed onCreateViewHolder(ViewGroup container, int i) {
View layout = inflater.inflate(R.layout.view_main_feed, container, false);
Article article1 = new Article("asdf", "ghj", "klm", new Date(0));
Article article2 = new Article("sdfg", "hjk", "lmn", new Date(0));
Article article3 = new Article("dfgh", "jkl", "mno", new Date(0));
listArticlesMain.add(article1);
listArticlesMain.add(article2);
listArticlesMain.add(article3);
return new ViewHolderMainFeed(layout);
}
#Override
public void onBindViewHolder(ViewHolderMainFeed viewHolderMainFeed, int i) {
Article currentArticle = listArticlesMain.get(i);
viewHolderMainFeed.articleTitle.setText(currentArticle.getTitle());
viewHolderMainFeed.articleAuthor.setText(currentArticle.getAuthor());
viewHolderMainFeed.articleWebsite.setText(currentArticle.getWebsite());
DateFormat formatter = DateFormat.getDateTimeInstance();
final String timePosted = formatter.format(currentArticle.getTimePosted());
viewHolderMainFeed.articleTime.setText(timePosted);
}
#Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
super.onAttachedToRecyclerView(recyclerView);
}
#Override
public int getItemCount() {
return listArticlesMain.size();
}
static class ViewHolderMainFeed extends RecyclerView.ViewHolder {
TextView articleTitle;
TextView articleAuthor;
TextView articleWebsite;
TextView articleTime;
public ViewHolderMainFeed(View itemView) {
super(itemView);
articleTitle = (TextView) itemView.findViewById(R.id.mainArticleTitle);
articleAuthor = (TextView) itemView.findViewById(R.id.mainArticleAuthor);
articleWebsite = (TextView) itemView.findViewById(R.id.mainArticleWebsite);
articleTime = (TextView) itemView.findViewById(R.id.mainArticleTime);
}
}
}
view_main_feed.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="8dp"
tools:context="com.convergeapp.converge.ActivityMain">
<android.support.v7.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
card_view:cardCornerRadius="7dp"
card_view:cardBackgroundColor="#color/colorPurpleSeance"
android:id="#+id/mainArticleCard"
android:layout_width="match_parent"
android:layout_height="300dp"
android:padding="8dp"
android:clickable="true">
<RelativeLayout
android:id="#+id/mainArticleLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="16dp">
<TextView
android:id="#+id/mainArticleTitle"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"/>
<TextView
android:id="#+id/mainArticleAuthor"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:layout_below="#id/mainArticleTitle"/>
<TextView
android:id="#+id/mainArticleWebsite"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:layout_below="#+id/mainArticleTime"/>
<TextView
android:id="#+id/mainArticleTime"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"/>
</RelativeLayout>
</android.support.v7.widget.CardView>
</RelativeLayout>

After playing around with some changes, I finally discovered the solution. What I did was add the Article objects to the list in the main fragment's onCreateView method. Additionally, I instantiated CardView in the ViewHolder, though that didn't help me see the cards initially.
So, if you're ever in a similar predicament and can't figure out the solution, try to actually create the objects before setting them.

You need to call notifyDataSetChanged(); inside onCreateViewHolder after adding the new articles so that the itemcount is updated

Create a ListView with selectable rows/change background color of ListView rows when clicked

Problem
I'm trying to create a ListView with selectable items. I want to be able to click on an item in the ListView and have the item change color in the list, and then go on and do something else with the data from the row.
I'm using a SimpleAdapter.
How do I make it so that when I tap on a row, it turns a different color, and then when I tap on a different row, the new row is selected and changed to a new color, and the old row changes back to normal?
Code
Here is my code so far. The DBTools class is has all of the data that I want to be displayed in my ListView organized and taken care of. The getAllReceivers() method returns an ArrayList of HashMap<String, String>s that have all of my data.
MainActivity.java:
public class MainActivity extends ListActivity {
DBTools dbTools = new DBTools(this);
ArrayList<HashMap<String, String>> receiverList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getActionBar().hide();
setContentView(R.layout.activity_main);
receiverList = dbTools.getAllReceivers();
dbTools.close();
ListView listView = getListView();
if(receiverList.size() != 0) {
SimpleAdapter adapter = new SimpleAdapter(MainActivity.this,receiverList, R.layout.receiver_entry, new String[] {"receiverId","receiverName", "fullPath"}, new int[] {R.id.receiverId, R.id.receiverName, R.id.fullPath});
setListAdapter(adapter);
}
}
}
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TableRow
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#android:color/black" >
<TextView
android:id="#+id/titleTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center_horizontal"
android:text="My List" />
</TableRow>
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/black"
android:id="#android:id/list" />
</TableLayout>
receiver_entry.xml
<?xml version="1.0" encoding="utf-8"?>
<TableRow xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="#+id/tableRow" >
<TextView
android:id="#+id/receiverId"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:visibility="gone" />
<TextView
android:id="#+id/receiverName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Robotronics" />
<TextView
android:id="#+id/fullPath"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="123.45.678.910:8088/robtrox/find" />
</TableRow>

Solution
The solution to this problem is very simple. We need to add an OnItemClickListener to our ListView to listen for clicks and respond accordingly.
So, in the onCreate() method, once you've made sure that you set of data isn't empty, you're going to want to Override the onItemClick() method to listen for the click and change the color. You're also going to want to keep track of which item you selected for the later steps, so add public int selectionId = -1; at the top of your class. Furthermore, you'll need to let the ListAdapter know that you changed something by calling ((SimpleAdapter) getListAdapter()).notifyDataSetChanged().
if(receiverList.size() != 0) {
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int index, long id) {
view.setBackgroundColor(Color.RED);
TextView receiverIdTextView = (TextView) view.findViewById(R.id.receiverId);
selectionId = Integer.valueOf(receiverIdTextView.getText().toString());
((SimpleAdapter) getListAdapter()).notifyDataSetChanged();
}
});
SimpleAdapter adapter = getNewAdapter();
setListAdapter(adapter);
}
Great! Now we have a working system that will change the color of the row that you tap. But we're not done yet. We need to make sure that the previous selection changes back to the normal color.
For this, we are going to use override the SimpleAdapter's getView() method, which is called everytime the ListView goes to draw the items being displayed in it.
It only actually displays the items it needs to - the ones that you can see. It does not render the ones above or below your screen. So if you have 200 items in a ListView, only 5 or 6, depending on the size of your screen and the size of the items, are being rendered at a time.
To override the getView() method, go up to where you initialize the adapter and change the code to this:
SimpleAdapter adapter = new SimpleAdapter(MainActivity.this,receiverList, R.layout.receiver_entry, new String[] { "receiverId","receiverName", "fullPath"}, new int[] {R.id.receiverId, R.id.receiverName, R.id.fullPath}) {
#Override
public View getView (int position, View convertView, ViewGroup parent) {
View view = super.getView(position, convertView, parent);
TextView receiverIdTextView = (TextView) view.findViewById(R.id.receiverId);
if(receiverIdTextView.getText().toString().equals(String.valueOf(selectionId))) {
view.setBackgroundColor(Color.RED);
} else {
view.setBackgroundColor(Color.WHITE);
}
return view;
}
};
Every time one of the rows is drawn, since the getView() will get called, the ListView will check if the current view has the id of row you selected. If it doesn't, it'll change the background color to white. If it does, it'll change the background color to red.
And voila! That's it! Now you are setting the background color to red when you click on an item in the ListView.
Final Code
MainActivity.java:
public class MainActivity extends ListActivity {
DBTools dbTools = new DBTools(this);
ArrayList<HashMap<String, String>> receiverList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getActionBar().hide();
setContentView(R.layout.activity_main);
receiverList = dbTools.getAllReceivers();
dbTools.close();
ListView listView = getListView();
if(receiverList.size() != 0) {
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int index, long id) {
view.setBackgroundColor(Color.RED);
TextView receiverIdTextView = (TextView) view.findViewById(R.id.receiverId);
selectionId = Integer.valueOf(receiverIdTextView.getText().toString());
((SimpleAdapter) getListAdapter()).notifyDataSetChanged();
}
});
SimpleAdapter adapter = new SimpleAdapter(MainActivity.this,receiverList, R.layout.receiver_entry, new String[] { "receiverId","receiverName", "fullPath"}, new int[] {R.id.receiverId, R.id.receiverName, R.id.fullPath}) {
#Override
public View getView (int position, View convertView, ViewGroup parent) {
View view = super.getView(position, convertView, parent);
TextView receiverIdTextView = (TextView) view.findViewById(R.id.receiverId);
if(receiverIdTextView.getText().toString().equals(String.valueOf(selectionId))) {
view.setBackgroundColor(Color.RED);
} else {
view.setBackgroundColor(Color.WHITE);
}
return view;
}
};
setListAdapter(adapter);
}
}
}
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TableRow
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#android:color/black" >
<TextView
android:id="#+id/titleTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center_horizontal"
android:text="My List" />
</TableRow>
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/black"
android:id="#android:id/list" />
</TableLayout>
receiver_entry.xml
<?xml version="1.0" encoding="utf-8"?>
<TableRow xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="#+id/tableRow" >
<TextView
android:id="#+id/receiverId"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:visibility="gone" />
<TextView
android:id="#+id/receiverName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Robotronics" />
<TextView
android:id="#+id/fullPath"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="123.45.678.910:8088/robtrox/find" />
</TableRow>