Develop Reference

Android RecyclerView height problem inside view pager2 inside NestedScrollView with TabLayout [duplicate]

There are a few posts on getting ViewPager to work with varying height items that center around extending ViewPager itself to modify its onMeasure to support this.
However, given that ViewPager2 is marked as a final class, extending it isn't something that we can do.
Does anyone know if there's a way to make this work out?
E.g. let's say I have two views:
View1 = 200dp
View2 = 300dp
When the ViewPager2 (layout_height="wrap_content") loads -- looking at View1, its height will be 200dp.
But when I scroll over to View2, the height is still 200dp; the last 100dp of View2 is cut off.

The solution is to register a PageChangeCallback and adjust the LayoutParams of the ViewPager2 after asking the child to re-measure itself.
pager.registerOnPageChangeCallback(object : ViewPager2.OnPageChangeCallback() {
override fun onPageSelected(position: Int) {
super.onPageSelected(position)
val view = // ... get the view
view.post {
val wMeasureSpec = MeasureSpec.makeMeasureSpec(view.width, MeasureSpec.EXACTLY)
val hMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED)
view.measure(wMeasureSpec, hMeasureSpec)
if (pager.layoutParams.height != view.measuredHeight) {
// ParentViewGroup is, for example, LinearLayout
// ... or whatever the parent of the ViewPager2 is
pager.layoutParams = (pager.layoutParams as ParentViewGroup.LayoutParams)
.also { lp -> lp.height = view.measuredHeight }
}
}
}
})
Alternatively, if your view's height can change at some point due to e.g. asynchronous data load, then use a global layout listener instead:
pager.registerOnPageChangeCallback(object : ViewPager2.OnPageChangeCallback() {
private val listener = ViewTreeObserver.OnGlobalLayoutListener {
val view = // ... get the view
updatePagerHeightForChild(view)
}
override fun onPageSelected(position: Int) {
super.onPageSelected(position)
val view = // ... get the view
// ... IMPORTANT: remove the global layout listener from other views
otherViews.forEach { it.viewTreeObserver.removeOnGlobalLayoutListener(layoutListener) }
view.viewTreeObserver.addOnGlobalLayoutListener(layoutListener)
}
private fun updatePagerHeightForChild(view: View) {
view.post {
val wMeasureSpec = MeasureSpec.makeMeasureSpec(view.width, MeasureSpec.EXACTLY)
val hMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED)
view.measure(wMeasureSpec, hMeasureSpec)
if (pager.layoutParams.height != view.measuredHeight) {
// ParentViewGroup is, for example, LinearLayout
// ... or whatever the parent of the ViewPager2 is
pager.layoutParams = (pager.layoutParams as ParentViewGroup.LayoutParams)
.also { lp -> lp.height = view.measuredHeight }
}
}
}
}
See discussion here:
https://issuetracker.google.com/u/0/issues/143095219

In my case, adding adapter.notifyDataSetChanged() in onPageSelected helped.

Just do this for the desired Fragment in ViewPager2:
override fun onResume() {
super.onResume()
layoutTaskMenu.requestLayout()
}
Jetpack: binding.root.requestLayout() (thanks #syed-zeeshan for the specifics)

Stumbled across this case myself however with fragments.
Instead of resizing the view as the accepted answer I decided to wrap the view in a ConstraintLayout. This requires you to specify a size of your ViewPager2 and not use wrap_content.
So Instead of changing size of our viewpager it will have to be minimum size of the largest view it handles.
A bit new to Android so don't know if this is a good solution or not, but it does the job for me.
In other words:
<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"
>
<!-- Adding transparency above your view due to wrap_content -->
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
>
<!-- Your view here -->
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

For me this worked perfectly:
viewPager2.registerOnPageChangeCallback(object : ViewPager2.OnPageChangeCallback() {
override fun onPageScrolled(
position: Int,
positionOffset: Float,
positionOffsetPixels: Int
) {
super.onPageScrolled(position,positionOffset,positionOffsetPixels)
if (position>0 && positionOffset==0.0f && positionOffsetPixels==0){
viewPager2.layoutParams.height =
viewPager2.getChildAt(0).height
}
}
})

Just call .requestLayout() to the root view of layout in the onResume() of your Fragment class which is being used in ViewPager2

Just Add this small code in your all fragments of ViewPager2
#Override
public void onResume() {
super.onResume();
binding.getRoot().requestLayout();
}
This is working for me perfectly (If you are not using binding then Just get a root layout instance in place of binding)

I had a similar problem and solved it as below.
In my case I had ViewPager2 working with TabLayout with fragments with different heights.
In each fragment in the onResume() method, I added the following code:
#Override
public void onResume() {
super.onResume();
setProperHeightOfView();
}
private void setProperHeightOfView() {
View layoutView = getView().findViewById( R.id.layout );
if (layoutView!=null) {
ViewGroup.LayoutParams layoutParams = layoutView.getLayoutParams();
if (layoutParams!=null) {
layoutParams.height = ViewGroup.LayoutParams.WRAP_CONTENT;
layoutView.requestLayout();
}
}
}
R.id.layout is layout of particular fragment.
I hope I helped.
Best regards,
T.

No posted answer was entirely applicable for my case - not knowing the height of each page in advance - so I solved different ViewPager2 pages heights using ConstraintLayout in the following way:
<androidx.constraintlayout.widget.ConstraintLayout
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/appBarLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
>
<!-- ... -->
</com.google.android.material.appbar.AppBarLayout>
<!-- Wrapping view pager into constraint layout to make it use maximum height for each page. -->
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/viewPagerContainer"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintBottom_toTopOf="#id/bottomNavigationView"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#id/appBarLayout"
>
<androidx.viewpager2.widget.ViewPager2
android:id="#+id/viewPager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
/>
</androidx.constraintlayout.widget.ConstraintLayout>
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="#+id/bottomNavigationView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:menu="#menu/bottom_navigation_menu"
/>
</androidx.constraintlayout.widget.ConstraintLayout>

#Mephoros code works perfectly when swiped between views but won't work when views are peeked for first time. It works as intended after swiping it.
So, swipe viewpager programmatically:
binding.viewpager.setCurrentItem(1)
binding.viewpager.setCurrentItem(0) //back to initial page

I'm using the ViewPager2ViewHeightAnimator from here

I got stuck with this problem too. I was implementing TabLayout and ViewPager2 for several tabs with account information. Those tabs had to be with different heights, for example: View1 - 300dp, View2 - 200dp, Tab3 - 500dp. The height was locked within first view's height and the others were cut or extended to (example) 300dp. Like so:
So after two days of searches nothing helped me (or i had to try better) but i gave up and used NestedScrollView for all my views. For sure, now i don't have effect, that the header of profile scrolls with info in 3 views, but at least it now works somehow.
Hope this one helps someone! If you have some advices, feel free to reply!
P.s. I'm sorry for my bad english skills.

Only adapter.notifyDataSetChanged() worked for me in ViewPager2. Used below code in Kotlin.
viewPager2.registerOnPageChangeCallback(object : ViewPager2.OnPageChangeCallback() {
override fun onPageSelected(position: Int) {
super.onPageSelected(position)
adapter.notifyDataSetChanged()
}
})

why don't you do it by replacing not using ViewPager2.
like code in below:
private void fragmentController(Fragment newFragment){
FragmentTransaction ft;
ft = mainAct.getSupportFragmentManager().beginTransaction();
ft.replace(R.id.relMaster, newFragment);
ft.addToBackStack(null);
ft.commitAllowingStateLoss();
}
Where relMaster is RelativeLayout.

Answer by #Mephoros worked for me in the end. I had a Recyclerview with pagination(v3) in one of the fragments and it was behaving really strangely with page loads. Here is a working snippet based on the answer in case anyone has problems getting and cleaning views.
viewPager.registerOnPageChangeCallback(object : ViewPager2.OnPageChangeCallback() {
var view : View? = null
private val layoutListener = ViewTreeObserver.OnGlobalLayoutListener {
view?.let {
updatePagerHeightForChild(it)
}
}
override fun onPageSelected(position: Int) {
super.onPageSelected(position)
// ... IMPORTANT: remove the global layout listener from other view
view?.viewTreeObserver?.removeOnGlobalLayoutListener(layoutListener)
view = (viewPager[0] as RecyclerView).layoutManager?.findViewByPosition(position)
view?.viewTreeObserver?.addOnGlobalLayoutListener(layoutListener)
}
private fun updatePagerHeightForChild(view: View) {
view.post {
val wMeasureSpec = View.MeasureSpec.makeMeasureSpec(view.width, View.MeasureSpec.EXACTLY)
val hMeasureSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED)
view.measure(wMeasureSpec, hMeasureSpec)
if (viewPager.layoutParams.height != view.measuredHeight) {
viewPager.layoutParams = (viewPager.layoutParams)
.also { lp -> lp.height = view.measuredHeight }
}
}
}
})

just add this code to each fragments :
override fun onResume() {
super.onResume()
binding.root.requestLayout()
}

Finally, I can fix this without requestLayout, notifyDataChanged, or the other solutions above!
It's really easy and simple!
You just need to save current height onPause, then load the saved height onResume.
Look at this example code:
public class MyTabbedFragment extends Fragment {
public MyTabbedFragmentViewBinding binding;
String TAG = "MyTabbedFragment";
int heightBeforePause;
// other code
#Override
public void onResume() {
super.onResume();
Log.d(TAG, "lifecycle | onResume | before set height | rec view height: " + binding.recycleView.getHeight() + " | height before pause: " + heightBeforePause);
// load the saved height
if(heightBeforePause > 0) {
FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, heightBeforePause);
binding.recycleView.setLayoutParams(layoutParams);
}
}
#Override
public void onPause() {
super.onPause();
// save the current height
heightBeforePause = binding.recycleView.getHeight();
Log.d(TAG, "lifecycle | onPause | rec view height: " + binding.recycleView.getHeight());
}

viewPager.registerOnPageChangeCallback(object : ViewPager2.OnPageChangeCallback() {
override fun onPageSelected(position: Int) {
super.onPageSelected(position)
val view = (viewPager[0] as RecyclerView).layoutManager?.findViewByPosition(position)
view?.post {
val wMeasureSpec = MeasureSpec.makeMeasureSpec(view.width, MeasureSpec.EXACTLY)
val hMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED)
view.measure(wMeasureSpec, hMeasureSpec)
if (viewPager.layoutParams.height != view.measuredHeight) {
viewPager.layoutParams = (viewPager.layoutParams).also { lp -> lp.height = view.measuredHeight }
}
}
}
})

Adjusting layouts for different screen sizes for API 14-17, 17-30, 30+

EDIT 09.05.2021:
In general, I would like to programatically adjust the LayoutParams of some Buttons depending on the display size of the smartphone by adjusting some geometry values in onCreate(). Apparently it's not quite that simple.
Finally found found an approach for that, which is possibly working between API 14-17, 17-30, 30+.
My goal would be to determine the "real screen size" without insets / navigation bar elements for all APIs between 14-30+.
I still have to adapt the approach for < API 17, as the navigation bar elements may not yet be deducted in this case (I am currently trying to determine the navigation bar size for these use cases).
QUERY OF THE SCREENSIZE (width, height):
//++++++++++++++ DISPLAY SIZES +++++++++++++
DisplayMetrics realDisplayMetrics = new DisplayMetrics();
int realDisplayWidth;
int realDisplayHeight;
//++++++++++++++ GET HORIZONTAL SCREENSIZE +++++++++
public int getRealScreenWidth(){
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
// TARGETING BUILDVERSIONS GREATER EQUAL API:30
WindowMetrics windowMetrics = getWindowManager().getCurrentWindowMetrics();
// HORIZONTAL DISPLAY SIZE INCLUDING INSETS
WindowInsets windowInsets = windowMetrics.getWindowInsets();
Insets insets = windowInsets.getInsetsIgnoringVisibility(WindowInsets.Type.navigationBars()
| WindowInsets.Type.displayCutout());
int insetsWidth = insets.right + insets.left;
// GET THE SIZE OF HORIZONTAL INSETS
Rect bounds = windowMetrics.getBounds();
realDisplayWidth = bounds.width() - insetsWidth;
// HORIZONTAL SCREEN SIZE WITHOUT INSETS
return realDisplayWidth;
}
else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
// TARGETING BUILDVERSIONS ABOVE API:17, UNTIL API:30
Display display = this.getWindowManager().getDefaultDisplay();
display.getRealMetrics(realDisplayMetrics);
realDisplayWidth = realDisplayMetrics.widthPixels;
return realDisplayWidth;
}
else if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
//REFLECTION FOR BUILDVERSIONs ABOVE API:14 UNTIL API:17
Display display = this.getWindowManager().getDefaultDisplay();
try {
Method getHorizontalSize = Display.class.getMethod("getWidth");
realDisplayWidth = (Integer) getHorizontalSize.invoke(display);
} catch (Exception e) {
realDisplayWidth = 1000;
}
return realDisplayWidth;
}
else {
return realDisplayWidth = 1000;
}
}
//++++++++++++++ GET VERTICAL SCREENSIZE +++++++++
public int getRealScreenHeight(){
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
// TARGETING BUILDVERSIONS GREATER EQUAL API:30
WindowMetrics windowMetrics = getWindowManager().getCurrentWindowMetrics();
// VERTICAL DISPLAY SIZE INCLUDING INSETS
WindowInsets windowInsets = windowMetrics.getWindowInsets();
Insets insets = windowInsets.getInsetsIgnoringVisibility(WindowInsets.Type.navigationBars()
| WindowInsets.Type.displayCutout());
int insetsHeight = insets.top + insets.bottom;
// GET THE SIZE OF VERTICAL INSETS
Rect bounds = windowMetrics.getBounds();
realDisplayHeight = bounds.height() - insetsHeight;
// HORIZONTAL SCREEN SIZE WITHOUT INSETS
return realDisplayHeight;
}
else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
// TARGETING BUILDVERSIONS ABOVE API:17, UNTIL API:30
Display display = this.getWindowManager().getDefaultDisplay();
display.getRealMetrics(realDisplayMetrics);
realDisplayHeight = realDisplayMetrics.heightPixels;
return realDisplayHeight;
}
else if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
//REFLECTION FOR BUILDVERSIONs ABOVE API:14 UNTIL API:17
Display display = this.getWindowManager().getDefaultDisplay();
try {
Method getVerticalSize = Display.class.getMethod("getHeight");
realDisplayHeight = (Integer) getVerticalSize.invoke(display);
} catch (Exception e) {
realDisplayHeight = 1500;
}
return realDisplayHeight;
}
else {
return realDisplayHeight = 1500;
}
}
public void getLog(){
Log.i("screenWide:", String.valueOf(getRealScreenWidth()));
Log.i("screenHeight:", String.valueOf(getRealScreenHeight()));
}
CHANGING LAYOUTPARAMS:
//++++++++++++++ EXAMPLE METHOD FOR CHANGING PARAMS IN ONCREATE() ++++++++++
public void changingLayoutParams(){
// EXAMPLE FOR CHANGING HORIZONTAL LAYOUT PARAMS FOR API ABOVE 17:
Button number1 = (Button) findViewById(R.id.number1);
Button sidebar_v_1 = (Button) findViewById(R.id.sidebar_v_1);
if (getRealScreenWidth() >= 1000){
ViewGroup.MarginLayoutParams params = (ViewGroup.MarginLayoutParams) number1.getLayoutParams();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
params.setMarginStart((int) getResources().getDimension(R.dimen.levelSymbolLeftMargin));
params.setMargins(params.getMarginStart(), params.topMargin, params.getMarginEnd(), params.bottomMargin);
}
ViewGroup.MarginLayoutParams params2 = (ViewGroup.MarginLayoutParams) sidebar_v_1.getLayoutParams();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
params2.setMarginStart((int) getResources().getDimension(R.dimen.levelSymbolLeftMargin));
params2.setMargins(params2.getMarginStart(), params2.topMargin, params2.getMarginEnd(), params2.bottomMargin);
}
}
else if (getRealScreenWidth() < 1000){
ViewGroup.MarginLayoutParams params = (ViewGroup.MarginLayoutParams) number1.getLayoutParams();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
params.setMarginStart((int) getResources().getDimension(R.dimen.lockerMarginLeft));
params.setMargins(params.getMarginStart(), params.topMargin, params.getMarginEnd(), params.bottomMargin);
}
ViewGroup.MarginLayoutParams params2 = (ViewGroup.MarginLayoutParams) sidebar_v_1.getLayoutParams();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
params2.setMarginStart((int) getResources().getDimension(R.dimen.lockerMarginLeft));
params2.setMargins(params2.getMarginStart(), params2.topMargin, params2.getMarginEnd(), params2.bottomMargin);
}
}
}
I have built a ConstraintLayout with several nested layouts inside, with the following rough structure (reduced amount of elements inside):
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/outerBlock"
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">
<androidx.core.widget.NestedScrollView
android:id="#+id/scroll"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginRight="#dimen/nestedScroll_mR"
android:layout_marginEnd="#dimen/nestedScroll_mR"
android:layout_marginLeft="#dimen/nestedScroll_mL"
android:layout_marginStart="#dimen/nestedScroll_mL"
android:layout_marginTop="#dimen/nestedScroll_mT"
android:layout_marginBottom="#dimen/nestedScroll_mB"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:fillViewport="true">
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/wrapper"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/innerBlock0"
android:layout_width="match_parent"
android:layout_height="#dimen/firstInnerBlockH"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintRight_toRightOf="parent">
</androidx.constraintlayout.widget.ConstraintLayout>
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/innerBlock1"
android:layout_width="match_parent"
android:layout_height="#dimen/innerBlockH"
app:layout_constraintTop_toBottomOf="#id/innerBlock0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintRight_toRightOf="parent">
<Button
android:id="#+id/number1"
android:layout_width="#dimen/levelSymbol"
android:layout_height="#dimen/levelSymbol"
android:background="#drawable/number1"
android:layout_marginTop="#dimen/numberMarginTop"
android:layout_marginLeft="#dimen/numberMarginLeft"
android:layout_marginStart="#dimen/numberMarginLeft"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintLeft_toLeftOf="parent" />
<Button
android:id="#+id/sidebar_v_1"
android:layout_width="#dimen/sidebarVWidth"
android:layout_height="#dimen/sidebarVHeight"
android:background="#drawable/side_v"
android:layout_marginLeft="#dimen/sideMarginLeft"
android:layout_marginStart="#dimen/sideMarginLeft"
app:layout_constraintTop_toBottomOf="#id/number1"
app:layout_constraintLeft_toLeftOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/innerBlock2"
android:layout_width="match_parent"
android:layout_height="#dimen/innerBlockH"
app:layout_constraintTop_toBottomOf="#id/innerBlock1">
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.core.widget.NestedScrollView>
</androidx.constraintlayout.widget.ConstraintLayout>
By changing the marginLeft and marginStart LayoutParam the layout would better fit into the display. At the beginning i just designed it for 1 screensize.

I noticed you're trying to change the margin values of 2 buttons in onCreate(). This will have the same effect as changing the margin values in your activity_main.xml file.
If you're trying to do something else, for instance, change these values when you click a button, you can just set an onClickListener to another button, and then put this code in that onClick listener. Hope this helps. Thanks.

How to use CameraX with PreviewView?

I can't find out how to use camerax with previewview.

Here is an example of how to use Camerax with PreviewView, the code uses the latest versions of CameraX, meaning camera-camera2 version 1.1.0-beta01, and camera-view version 1.1.0-beta01.
#Override
public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
previewView = view.findViewById(R.id.preview_view);
setCameraProviderListener();
}
private void setCameraProviderListener() {
ListenableFuture<ProcessCameraProvider> cameraProviderFuture =
ProcessCameraProvider.getInstance(requireContext());
cameraProviderFuture.addListener(() -> {
try {
ProcessCameraProvider cameraProvider = cameraProviderFuture.get();
bindPreview(cameraProvider);
} catch (ExecutionException | InterruptedException e) {
// No errors need to be handled for this Future
// This should never be reached
e.printStackTrace();
}
}, ContextCompat.getMainExecutor(requireContext()));
}
private void bindPreview(ProcessCameraProvider cameraProvider) {
imageAnalyser();
imageCapture();
CameraSelector cameraSelector =
new CameraSelector.Builder().requireLensFacing(CameraSelector.LENS_FACING_BACK).build();
Preview preview = new Preview.Builder().build();
preview.setSurfaceProvider(previewView.getSurfaceProvider());
ViewPort viewPort = previewView.getViewPort();
if (viewPort != null) {
UseCaseGroup useCaseGroup = new UseCaseGroup.Builder()
.addUseCase(preview)
.addUseCase(imageAnalyzer)
.addUseCase(imageCapture)
.setViewPort(viewPort)
.build();
cameraProvider.unbindAll();
Camera camera = cameraProvider.bindToLifecycle(this, cameraSelector, useCaseGroup);
CameraControl cameraControl = camera.getCameraControl();
cameraControl.setLinearZoom((float)0.3);
}
}
<?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:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.camera.view.PreviewView
android:id="#+id/preview_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/Yellow"
android:layout_gravity="center" />
</LinearLayout>

Here is an article that explains PreviewView and how to use it. It's valid up to version 1.0.0-alpha10 of camera-view, I'll try to keep it up to date.

I had set android:hardwareAccelerated="false" while debugging a different error, and had forgotten to remove it (or set it to true). I quickly noticed camera functionality had stopped working.
Make sure there is no android:hardwareAccelerated="false" in your apps manifest. If there is, either remove it, or set it to true. If this is set to false it will affect the camera preview stream.
TL;DR
Remove any android:hardwareAccelerated="false" in your manifest, or set it true.

Back button results in unintended behaviour

I have two activities. Activity A contains a recycler view of card view elements with images in them. On selecting an element in Activity A. The full landscape version of the image is displayed in Activity B.
The layout file for Activity B is a follows:
<?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"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<androidx.appcompat.widget.AppCompatImageView
android:id="#+id/imageView"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
/>
</androidx.constraintlayout.widget.ConstraintLayout>
The codebase for Activity B is as follows:
class PosterViewActivity : AppCompatActivity()
{
private lateinit var imageView: AppCompatImageView
override fun onCreate(savedInstanceState: Bundle?)
{
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_poster_view)
init()
}
private fun init()
{
findViewsByID()
getBundle()
toggleHide()
}
private fun getBundle()
{
if (intent != null)
{
var imageUrl = intent.getStringExtra(ARG_IMAGE_URL)
if (imageUrl != null)
{
Glide.with(this).load(imageUrl).centerInside().into(imageView)
}
}
}
private fun findViewsByID()
{
imageView = findViewById(R.id.imageView)
}
override fun onOptionsItemSelected(item: MenuItem): Boolean
{
if (item.itemId == android.R.id.home)
{
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)
}
return super.onOptionsItemSelected(item)
}
override fun onBackPressed()
{
super.onBackPressed()
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)
}
override fun onWindowFocusChanged(hasFocus: Boolean)
{
super.onWindowFocusChanged(hasFocus)
}
private fun toggleHide()
{
val uiOptions = window.decorView.systemUiVisibility
var newUiOptions = uiOptions
val isImmersiveModeEnabled = uiOptions or View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY == uiOptions
if (isImmersiveModeEnabled)
{
Log.i("PosterViewActivity", "Turning immersive mode mode off. ")
}
else
{
Log.i("PosterViewActivity", "Turning immersive mode mode on.")
}
if (Build.VERSION.SDK_INT >= 14)
{
newUiOptions = newUiOptions xor View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
}
// Status bar hiding: Backwards compatible to Jellybean
if (Build.VERSION.SDK_INT >= 16)
{
newUiOptions = newUiOptions xor View.SYSTEM_UI_FLAG_FULLSCREEN
}
if (Build.VERSION.SDK_INT >= 18)
{
newUiOptions = newUiOptions xor View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
}
window.decorView.systemUiVisibility = newUiOptions
}
}
However, when I press the back button on the device instead of returning to Activity A. The status and navigation buttons are displayed and hidden and it takes 4 presses of the back button to return to Activity A. I have checked the Back stack and two activities are in the stack namely A and B

You should just have to do something similar to this in your PosterViewActivity:
//link instance of menu_main
val mainToolbar = findViewById<androidx.appcompat.widget.Toolbar>(R.id.toolbar)
setSupportActionBar(mainToolbar)
//Enable Up Button to return you to home page
val actionBar = supportActionBar
actionBar?.title = null
actionBar?.setDisplayHomeAsUpEnabled(true)

How do I use a ViewPager with the AHBottomNavigation bar?

I want to use the ViewPager with the BottomNavigation bar from Aurel Hubert https://github.com/aurelhubert/ahbottomnavigation
I have following code:
My 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"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
tools:context="com.aaron.waller.mrpolitik.MainActivity"
android:id="#+id/content_id">
<com.aurelhubert.ahbottomnavigation.AHBottomNavigation
android:id="#+id/myBottomNavigation_ID"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:layout_alignParentBottom="true"/>
</RelativeLayout>
and my MainActivity.java:
public class MainActivity extends AppCompatActivity implements AHBottomNavigation.OnTabSelectedListener {
AHBottomNavigation bottomNavigation;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getSupportActionBar().hide();
bottomNavigation = (AHBottomNavigation) findViewById(R.id.myBottomNavigation_ID);
bottomNavigation.setOnTabSelectedListener(this);
bottomNavigation.setDefaultBackgroundColor(Color.BLUE);
this.createNavItems();
}
//Create items, add them to bar, set propertied and set current item
private void createNavItems() {
//CREATE ITEMS
AHBottomNavigationItem ohnemundItem = new AHBottomNavigationItem("Parteien", R.drawable.parteienicon);
AHBottomNavigationItem grinseItem = new AHBottomNavigationItem("Statistiken", R.drawable.statsicon);
AHBottomNavigationItem lachItem = new AHBottomNavigationItem("Fragen", R.drawable.fragenicon);
//ADD THEM to bar
bottomNavigation.addItem(ohnemundItem);
bottomNavigation.addItem(grinseItem);
bottomNavigation.addItem(lachItem);
//set properties
bottomNavigation.setDefaultBackgroundColor(Color.parseColor("#FEFEFE"));
//set current item
bottomNavigation.setCurrentItem(0);
}
#Override
public void onTabSelected(int position, boolean wasSelected) {
if (position == 0) {
ParteienFragment parteienFragment = new ParteienFragment();
getSupportFragmentManager().beginTransaction().replace(R.id.content_id, parteienFragment).commit();
} else if (position == 1) {
StatistikenFragment statistikenFragment = new StatistikenFragment();
getSupportFragmentManager().beginTransaction().replace(R.id.content_id, statistikenFragment).commit();
} else if (position == 2) {
FragenFragment fragenFragment = new FragenFragment();
getSupportFragmentManager().beginTransaction().replace(R.id.content_id, fragenFragment).commit();
}
}
}
I have no clue how to implement a ViewPager in this case.
I have already googled but have found nothing specific to this NavigationBar.
Is it possible at all to add a swipe effect with this navigation bar?
All I want is that I can wipe left and right between my Fragments.

I know it is a bit late but here goes a way of achieving what you pretend. If you want a swipe behaviour you should make a touch event in your activity to detect a swipe. After you detect a swipe it should be simple, just get the current item, and depending on the swipe set the position on the bottom navigation.
Example:
if(isSwipeRight && bottomNavigation.getCurrentItem() > 0)
bottomNavigation.setCurrentItem(bottomNavigation.getCurrentItem()-1);
else if(isSwipeLeft && bottomNavigation.getCurrentItem() < numTabs-1)
bottomNavigation.setCurrentItem(bottomNavigation.getCurrentItem()+1);