Develop Reference

Android - ActivityMainBinding shows me wrong activity

everyone. I'm trying to display a line chart in a full-screen activity. Unfortunately I can't do that. I always get to see my activity_main.xml layout. I also have my LineChart in it, within a CardView. Everything works fine in this activity. But as soon as I switch to activity_details_vitali.xml via a button, I don't see a line chart, just my main_activity. I think I have a wrong binding here. However, I can't find the error
class DetailsVitali : AppCompatActivity() {
private lateinit var binding: ActivityMainBinding
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_details_vitali)
binding = ActivityMainBinding.inflate(layoutInflater)
setContentView(binding.root)
setLineChartData()
}
private fun setLineChartData() {
val linevalues = ArrayList<Entry>()
linevalues.add(Entry(20f, 0.0F))
linevalues.add(Entry(30f, 3.0F))
linevalues.add(Entry(40f, 2.0F))
linevalues.add(Entry(50f, 1.0F))
linevalues.add(Entry(60f, 8.0F))
linevalues.add(Entry(70f, 10.0F))
linevalues.add(Entry(80f, 1.0F))
linevalues.add(Entry(90f, 2.0F))
linevalues.add(Entry(100f, 5.0F))
linevalues.add(Entry(110f, 1.0F))
linevalues.add(Entry(120f, 20.0F))
linevalues.add(Entry(130f, 40.0F))
linevalues.add(Entry(140f, 50.0F))
val linedataset = LineDataSet(linevalues, "First")
//We add features to our chart
linedataset.color = resources.getColor(R.color.purple_200)
linedataset.circleRadius = 5f
linedataset.setDrawFilled(true)
linedataset.valueTextSize = 10F
linedataset.fillColor = resources.getColor(R.color.purple_500)
linedataset.setMode(LineDataSet.Mode.CUBIC_BEZIER);
//We connect our data to the UI Screen
val data = LineData(linedataset)
binding.getTheGraph.data = data
binding.getTheGraph.setBackgroundColor(resources.getColor(R.color.white))
binding.getTheGraph.animateXY(2000, 2000, Easing.EaseInCubic)
}
layout
<?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="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
tools:context=".DetailsVitali">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<androidx.cardview.widget.CardView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="10dp"
app:cardCornerRadius="10dp"
android:elevation="20dp"
android:layout_gravity="center_horizontal">
<com.github.mikephil.charting.charts.LineChart
android:id="#+id/graphDetail"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.cardview.widget.CardView>
</LinearLayout>
</LinearLayout>
EDIT
And I also don't have access to the ID of my LineChart in the DetailsVitali.class. binding.ID.data = data is the ID is from the activity_main.xml.

From your comment that your desired layout is defined in activity_details_vitali.xml, you should be loading ActivityDetailsVitaliBinding, not ActivityMainBinding.
And as mentioned by #ARiF, you can remove the first call to setContentView since you are overwriting it with the second call to setContentView.

Android View Binding: Custom View shows duplicate SwipeRefreshLayout progress indicators

In my fragment, I am displaying a list of items using a Custom View that contains a SwipeRefreshLayout.
When I swipe to refresh, I can see two refreshing indicators and one of them never disappears.
See it here
I obviously have only one SwipeRefreshLayout in my hierarchy and this appeared when I migrated my code to View Binding.
Here are the details of my code and of the behaviour.
I have a fragment that displays a list of items, I'm using a Custom View com.myapp.ItemsListView I built for this purpose.
<?xml version="1.0" encoding="utf-8"?>
<com.myapp.ItemsListView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/myItems"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
In order to access this custom view, I am using View Binding. In my fragment, that's what it looks like:
// ItemsFragment.kt
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
binding = FragmentItemsBinding.inflate(inflater, container, false)
return binding?.root
}
and I then access anything in this custom view via binding?.myItems.
And my custom view uses a SwipeRefreshLayout as its root and contains a RecyclerView:
<?xml version="1.0" encoding="utf-8"?>
<androidx.swiperefreshlayout.widget.SwipeRefreshLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/swipeToRefresh"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/items"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical" />
<TextView
android:id="#+id/missingContent"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:text="#string/missing_content_message"
app:drawableTopCompat="#drawable/ic_missing_content_24dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
Following this question I'm using this piece of code to inflate the custom view:
// ItemsListView.kt
class ItemsListView(context: Context, attrs: AttributeSet) : SwipeRefreshLayout(context, attrs) {
private var b: ItemsListBinding? = null
init {
b = ItemsListBinding.inflate(LayoutInflater.from(context), this, true)
}
}
From the code, I customized my SwipeRefreshLayout to look different than the default:
b?.swipeToRefresh?.setSize(LARGE)
b?.swipeToRefresh?.setColorSchemeResources(
R.color.colorPrimary,
R.color.colorPrimaryDark
)
And I access b?.swipeToRefresh to set a listener, display or hide the progress indicator.
fun setListener(listener: OnRefreshListener) {
b?.swipeToRefresh?.setOnRefreshListener(listener)
}
fun showProgress() {
b?.swipeToRefresh?.isRefreshing = true
}
fun hideProgress() {
b?.swipeToRefresh?.isRefreshing = false
}
However, as you can see on the video clip, there is a black progress indicator that sticks and never goes away.
I have tried to access the SwipeRefreshLayout via b?.root and it results in the same behaviour.
In the end, I just do not understand why there are two SwipeRefreshLayout displayed on my screen. I noticed this problem when I introduced View Binding (I previously used Kotlin Synthetics). I'd like to inflate only one SwipeRefreshLayout in the hierarchy.

Why does findViewById returning null when searching for the RecyclerView?

Why is val rv: RecyclerView = findViewById(R.id.material_list_rv) returning null?
MainActivity
class MainActivity : AppCompatActivity() {
var adaptor: MaterialListAdaptor = MaterialListAdaptor()
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
if (savedInstanceState == null) {
supportFragmentManager.commit {
setReorderingAllowed(true)
add<MaterialListFragment>(R.id.fragment_container_view)
}
}
initRecyclerView()
setRecyclerViewData()
}
private fun initRecyclerView(){
val rv: RecyclerView = findViewById(R.id.material_list_rv)
rv.layoutManager = LinearLayoutManager(this#MainActivity)
rv.adapter = adaptor
}
private fun setRecyclerViewData(){
val l = DataSource.createMaterialList()
adaptor.setDataSet(l)
}
}
activity_main
<?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.fragment.app.FragmentContainerView
android:id="#+id/fragment_container_view"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
MaterialListFragment
class MaterialListFragment : Fragment() {
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View {
return inflater.inflate(R.layout.fragment_material_list, container, false)
}
}
fragment_material_list
<?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=".MaterialListFragment">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/material_list_rv"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="8dp"
android:layout_marginBottom="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:listitem="#layout/material_list_rv_list_item" />
</androidx.constraintlayout.widget.ConstraintLayout>

The problem
You placed the call to findViewById in MainActivity.onCreate. It's too early for that, the Fragment's view hasn't been created at that point.
You should be looking for the view in your MaterialListFragment. If you call findViewById in onCreateView, it will work. Like this:
val root = inflater.inflate(R.layout.fragment_material_list, container, false)
val rv = root.findViewById(R.id. material_list_rv)
// Do whatever (eg assign rv to a field in the Fragment to use it later)
return root
Some advice
Even if your code worked, try to have Activities, Fragments and custom Views manage their own children.
If the upper containers dive deep into their children, it's very easy to make mistakes (like the one here!) and you lose the ability to update internal details of Fragments and Views without breaking the containing Activity.
Activity/Fragment lifecycle chart
To orient yourself, keep this in mind (though this diagram is EXTREMELY simplified):

You are looking for RecylerView in MainActivity, where it does not exist.
Instead you should try to access it in FragmentActivity.

View Binding - How do I get a binding for included layouts?

While working with view binding, I came across a couple of undocumented cases.
First: How do I get binding for included view layout parts? The main binding only sees items defined in the main layout.
Second: How do I get binding for merged layout parts. Again, the main binding only sees items in the main layout?

In case of:
Include with generic layout (not merge node), we need to assign ID to included part, this way in binding we will have access to included sub part
<include
android:id="#+id/your_id"
layout="#layout/some_layout" />
This way in your activity code:
private lateinit var exampleBinding: ActivityExampleBinding //activity_example.xml layout
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
exampleBinding = ActivityExampleBinding.inflate(layoutInflater)
setContentView(exampleBinding.root)
//we will be able to access included layouts view like this
val includedView: View = exampleBinding.yourId.idOfIncludedView
//[...]
}
Include with merge block in external layout. We can't add ID to it because merge block is not a view.
Let's say we have such eternal merge layout (merge_layout.xm):
<?xml version="1.0" encoding="utf-8"?>
<merge 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"
tools:showIn="#layout/activity_example">
<TextView
android:id="#+id/some_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World" />
</merge>
To properly bind such merge layout we need to:
In your activity code:
private lateinit var exampleBinding: ActivityExampleBinding //activity_example.xml layout
private lateinit var mergeBinding: MergeLayoutBinding //merge_layout.xml layout
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
exampleBinding = ActivityExampleBinding.inflate(layoutInflater)
//we need to bind the root layout with our binder for external layout
mergeBinding = MergeLayoutBinding.bind(exampleBinding.root)
setContentView(exampleBinding.root)
//we will be able to access included in merge layout views like this
val mergedView: View = mergeBinding.someView
//[...]
}

Regarding your first question, you can get a view binding for the included layout.
Here is a sample main_fragment.xml file:
<?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">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recycler_view_main"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1" />
<include
android:id="#+id/toolbar"
layout="#layout/toolbar" />
</LinearLayout>
And MainFragment.java can be like this:
public class MainFragment extends Fragment {
private MainFragmentBinding binding;
private ToolbarBinding toolbarBinding;
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
binding = MainFragmentBinding.inflate(inflater, container, false);
toolbarBinding = binding.toolbar;
return binding.getRoot();
}
#Override
public void onDestroy() {
super.onDestroy();
toolbarBinding = null;
binding = null;
}
}
Now you have two bindings: One corresponds to the main layout and the other corresponds to the included layout.

If you want to bind included layout then,
For Activity
YourMainLayoutBinding mainLayoutBinding = MainLayoutBinding.inflate(getLayoutInflater);
View view = mainLayoutBinding.getRoot();
YourIncludedLayoutBinding includedLayoutBinding = YourIncludedLayoutBinding.bind(View);
For Fragment
YourMainLayoutBinding mainLayoutBinding = MainLayoutBinding.inflate(inflater,container,false);
View view = mainLayoutBinding.getRoot();
YourIncludedLayoutBinding includedLayoutBinding = YourIncludedLayoutBinding.bind(View);
Make Sure if your main layout binding parent root is LinearLayout then,
includedLayoutBinding parent layout also be a linear layout

Suppose I included a layout in my activity_main.xml file as follows:
<include
android:id="#+id/ll_layout1"
layout="#layout/layout1"
android:visibility="gone" />
And suppose I wanted to change its visibility. I can do so as follows:
activityMainBinding.llLayout1.root.visibility = View.VISIBLE

In my case, I forgot to assign id to the include tag
Now, when you've assigned the id, you'll be able to get the binding object as,
YourMainLayoutBinding.YourIncludeTagIDLayoutBinding

Follow steps:-
private val binding : FragmentBinding
by viewBinding(FragmentBinding::bind)
make sure to do the following in "onViewCreated(view: View, savedInstanceState: Bundle?)"
val binding2 = binding.root.include_layout_id
e.g. val binding2 = binding.root.tool_bar_layout
Now access your include layout, views here. e.g.
binding2.textView.text = "your text"

Using the data binding library. Then wrap your XML layout with <layout> tag
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<layout>
<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" />
...
</LinearLayout>
</layout>
toolbar.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">
<ImageView
android:id="#+id/ivImage"
... />
<TextView
android:id="#+id/tvTitle"
... />
</LinearLayout>
MainActivity.kt
private lateinit var binding: ActivityMainBinding
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = DataBindingUtil.setContentView(this, R.layout.activity_main)
// Access include layout views
binding.toolbar.rootView.ivImage.setImageResource(R.drawable.ic_back_arrow)
binding.toolbar.rootView.tvTitle.text = getString(R.string.home)
...
}

In the include layout you must create a Container layout and put here the id.
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
xmlns:app="http://schemas.android.com/apk/res-auto">
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/example"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="parent">
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

Why my foreach breaks when I try to draw dynamic buttons in Kotlin?

I need to draw dynamic buttons inside a foreach loop that retrieve data from my anko sqlite, the foreach only enter once and breaks and only draw one button in my layout, what I doing wrong? my code is this:
fun loadZones (ctx: Context, update: String, view: View, layout: LinearLayout) {
val zonesParser = rowParser{idzone: Int, zone: String -> Pair(idzone, zone)}
for (it in ctx.database.use {
select("tableplan")
.distinct()
.column("idzone")
.column("zone")
.orderBy("zone")
.parseList(zonesParser)
}) {
val layoutParams = LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT)
val btnZone = layoutInflater.inflate(R.layout.zones_item, null) as MaterialButton
btnZone.text = it.second
btnZone.id = it.first
layout.addView(btnZone, layoutParams)
Log.e("PAIR", "FIN DEL CICLO")
continue
}
}
The data that retrieves from my query is this:
(2, LARRY)
(1, MADISON)
That's my activity, I need to draw the buttons in "lytZonesButtons" id
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout 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=".TablePlanFragment">
<com.google.android.material.appbar.AppBarLayout android:layout_width="match_parent"
android:layout_height="wrap_content" android:elevation="2dp"
tools:targetApi="lollipop" app:liftOnScroll="true">
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbarTablePlan"
style="#style/com.madison.Toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:title="#string/table_title_module">
</androidx.appcompat.widget.Toolbar>
</com.google.android.material.appbar.AppBarLayout>
<LinearLayout
android:layout_marginTop="56dp"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:orientation="horizontal"
android:background="#color/orangeLighter"
android:gravity="center_vertical"
android:padding="5dp" android:id="#+id/lytZonesButtons" />
<androidx.core.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="112dp"
android:padding="5dp">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rc_tableplan"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
</androidx.core.widget.NestedScrollView>
</FrameLayout>
and that's my button template that I called "zones_item":
<?xml version="1.0" encoding="utf-8"?>
<com.google.android.material.button.MaterialButton
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" style="#style/com.madison.AppButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="#style/TextAppearance.MaterialComponents.Subtitle2"
tools:text="MADISON"
tools:targetApi="lollipop"
android:layout_margin="5dp"
/>
EDIT: I found the solution!
I don't now why my layout instance in the twice iteration of my loop throws NullPointerException but not shows in the log cat, my solution was put the loop code in onCreateView function, this is the code:
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
val view = inflater.inflate(R.layout.activity_tableplan, container, false)
val iActivity = (activity as AppCompatActivity)
iActivity.setSupportActionBar(view.toolbarTablePlan)
iActivity.supportActionBar?.setDisplayShowTitleEnabled(true)
// view.rc_tableplan.setHasFixedSize(true)
// val gridLayoutManager = GridLayoutManager(context, 2, GridLayoutManager.HORIZONTAL, false)
// view.rc_tableplan.layoutManager = gridLayoutManager
val response = loadTablePlan(this.context!!, "no")
if (response.trim().toUpperCase() == "SUCCESS") {
val zonesParser = rowParser{idzone: Int, zone: String -> Pair(idzone, zone)}
for (zone in this.context!!.database.use {
select("tableplan")
.distinct()
.column("idzone")
.column("zone")
.orderBy("zone")
.parseList(zonesParser)
}) {
val layout:LinearLayout = view.lytZonesButtons
layout.let {
val btnZone = layoutInflater.inflate(R.layout.zones_item, layout, false) as MaterialButton
btnZone.text = zone.second
btnZone.id = zone.first
btnZone.requestLayout()
layout.addView(btnZone)
Log.e("PAIR", "FIN DEL CICLO")
}
}
}
return view
}
Thanks a lot for all people that tried help me, some admin can close my question please.

The hint is only one button is showing. Your trying to inflate the same view twice in the same spot.
You need to add an empty linearlayout in your xml. And in your loop change the buttonz..
var btnZone = findViewById(R.layout.btnZone)
button.text = "Pair"
btnZone.addView(button, layoutParams)
That's not the exact code (and probably not even the right syntax) but it shows you how you need to modify your loop.
Basicly you were attempting to inflate the same instance of the same view. When really your not inflating any views this way your just adding views.
Note
If you have a linearlayout in your xml when you add another button view to it it will add it below it. If you set the layout orientation to horizontal the button view then gets added beside the other one.
here's a link to an example.
Sorry I would make sure my code matched your code and variables with proper syntax but I am at work.