Develop Reference

Make ViewPager Fill The Remaining Space In a ConstraintLayout

I have the following XML code , I couldn't make 'summaryViewPager' fill the remaining space vertically, until the bottom of the screen :
<?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">
<com.google.android.material.card.MaterialCardView
android:id="#+id/mainCardView"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="10dp"
android:layout_marginLeft="10dp"
android:layout_marginTop="10dp"
android:layout_marginEnd="10dp"
android:layout_marginRight="10dp"
android:background="#666266"
android:padding="10dp"
app:cardCornerRadius="20dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="3dp"
android:layout_marginLeft="3dp"
android:layout_marginTop="2dp"
android:text="#string/category"
android:textColor="#FFBA93"
android:textSize="20sp"
android:textStyle="bold"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</com.google.android.material.card.MaterialCardView>
<com.google.android.material.card.MaterialCardView
android:id="#+id/cardView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="10dp"
android:layout_marginLeft="10dp"
android:layout_marginTop="10dp"
android:layout_marginEnd="10dp"
android:layout_marginRight="10dp"
android:background="#666266"
android:padding="10dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#id/mainCardView">
<Button
android:id="#+id/shareButton"
android:layout_width="30dp"
android:layout_height="30dp"
android:layout_marginStart="5dp"
android:layout_marginLeft="5dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="5dp"
android:layout_marginRight="5dp"
android:background="#drawable/ic_share"
app:layout_constraintEnd_toStartOf="#+id/copyButton"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ImageView
android:id="#+id/seenImageView"
android:layout_width="20dp"
android:layout_height="20dp"
android:layout_marginStart="3dp"
android:layout_marginLeft="3dp"
android:layout_marginTop="15dp"
android:layout_marginEnd="5dp"
android:layout_marginRight="5dp"
android:contentDescription="#string/todo"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toEndOf="#+id/favoriteButton"
app:layout_constraintTop_toTopOf="parent"
app:srcCompat="#drawable/unseen" />
</com.google.android.material.card.MaterialCardView>
<androidx.viewpager2.widget.ViewPager2
android:id="#+id/summaryViewPager"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_marginTop="2dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#id/cardView2" />
</androidx.constraintlayout.widget.ConstraintLayout>
The above code doesn't show the PageViewer at all below cardView2 , however when I set android:layout_height="500dp it does show PageViewer, but it doesn't fill the whole screen.

Initial Thoughts
I copy pasted your Layout into Android Studio 4.x, replaced all #string references with "something", and all #drawables with an existing one (from #android:drawable/) so my layout would render.
From what I see, it looks correct:
I noticed some inconsistencies in your Layout.
CardView Number 1 (top)
Careful with Padding on a CardView (don't know your min/max API so, not sure if this applies to you).
Your CardView has no constrain for its BOTTOM, it's left to "whatever size you compute after wrapping" (Height = wrap, Bottom_To = null).
This ^ means that for the CardView to have a height, all its innerwidgets must compute their sizes, so the top card view knows how much size + margin + padding it needs. It doesn't depend on OTHER widgets (that are not children) because its constrains are all to the parent. (rather it only needs its parent).
CardView Number 2 (bottom)
This cardView wraps all its dimensions but has the same issue as the one above, it doesn't constraint its height (except to be pinned at the bottom of the previous one, CardView 1). Again, this is fine, so as long as nobody depends on this (which is not true). This one has to wait on more widgets to know its size, because it has to wait on the CardView1 to know how much space is left, and also needs to know how much its children need. It's not too hard because both (the ImageView and the Button) have fixed sizes (20 and 30 dp respectively) + margins/padding.
The children of a MaterialCardView cannot/should not/must not use constraints because a CardView is not a ConstraintLayout, rather a glorified FrameLayout, which can only hold ONE child (or if it has more, it will put them on on top of the other). So all those constraints (for the shareButton and seenImageView) are ignored.
The solution to the above, is to have an inner ConstraintLayout as the sole child of a CardView, and inside this inner CL, put all your children and their constraints. The inner ConstraintLayout should have its width/height as either wrap_content or match_parent so they use the constraints of the parent. Since htey have fixed sizes, this is not an issue. (and if they didn't it wouldn't be an issue, but would need another measure pass).
Regardless of this, this second CardView is able to calculate its height, because its children are reporting a size of 20+30 (overlapped) + 15 margin top (image) so.. all this combined is likely 45dp~ of height (since they overlap only the biggest numbers apply here).
All the constraints are ignored for these two children.
ViewPager (bottom)
Finally we reach the VPager. This viewPager is match_parent for its width (since you have constraints to the start/end, you should just use 0dp). And it has wrap_content for its height.
layout_height=wrap_content -> this is a problem here. Because the viewPager doesn't (at the time of layout pass/measure) yet know what its contents are going to be. So you probably want this to be 0dp and let the ViewPager use all available space after the above has been calculated.
The marginTop you have here, will not work as it is, because the CardView 1 and 2 have no bottom constrain, so this one would have to create yet another layout/measure pass after it's all said and done to be able to apply a margin (that's how it works).
Ok Enough Rant - what can you do?
I'd "fix" the layout by adding the correct constraints and -if needed- use a VerticalChain and biasing for all widgets.
I'd fix the middle (Cardview 2) contents by wrapping the textview and imageView in a ConstraintLayout.
I'd remove left/right and replace with start/end (unless you target API 16 or below).
I'd set the ViewPager to 0dp on both dimensions.
The children of your CardView2 refer to copyButton and favoriteButton but these don't exist in the Layout you pasted, so I assume you have more buttons there).
Full Version (modified)
And in case you wonder, here's what I did ( I added a color to the VP's background so it was easier to "see").
<?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">
<com.google.android.material.card.MaterialCardView
android:id="#+id/mainCardView"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="10dp"
android:layout_marginTop="10dp"
android:layout_marginEnd="10dp"
app:layout_constraintVertical_chainStyle="packed"
android:background="#666266"
android:padding="10dp"
app:cardCornerRadius="20dp"
app:layout_constraintBottom_toTopOf="#id/cardView2"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="3dp"
android:layout_marginTop="2dp"
android:text="Category"
android:textColor="#FFBA93"
android:textSize="20sp"
android:textStyle="bold" />
</com.google.android.material.card.MaterialCardView>
<com.google.android.material.card.MaterialCardView
android:id="#+id/cardView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="10dp"
android:layout_marginLeft="10dp"
android:layout_marginTop="10dp"
android:layout_marginEnd="10dp"
android:layout_marginRight="10dp"
android:background="#666266"
android:padding="10dp"
app:layout_constraintBottom_toTopOf="#id/summaryViewPager"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#id/mainCardView">
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/innerCardView2Root"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<Button
android:id="#+id/shareButton"
android:layout_width="30dp"
android:layout_height="30dp"
android:layout_marginStart="5dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="5dp"
android:background="#android:drawable/ic_menu_share"
app:layout_constraintEnd_toStartOf="#+id/seenImageView"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ImageView
android:id="#+id/seenImageView"
android:layout_width="20dp"
android:layout_height="20dp"
android:layout_marginStart="3dp"
android:layout_marginTop="15dp"
android:layout_marginEnd="5dp"
android:contentDescription="#null"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="#+id/shareButton"
app:layout_constraintTop_toTopOf="parent"
app:srcCompat="#android:drawable/ic_menu_search" />
</androidx.constraintlayout.widget.ConstraintLayout>
</com.google.android.material.card.MaterialCardView>
<androidx.viewpager2.widget.ViewPager2
android:id="#+id/summaryViewPager"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginTop="2dp"
android:background="#color/colorSecondary"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#id/cardView2" />
</androidx.constraintlayout.widget.ConstraintLayout>

Button overlapping EditText when keyboard is open

I have the following ConstraintLayout in my Android application:
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/white">
<ImageView
android:id="#+id/image_icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/icon"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
/>
<TextView
android:id="#+id/instructions"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="#dimen/spacing_large"
android:text="#string/instruction"
app:layout_constraintTop_toBottomOf="#id/support_ic"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
/>
<Button
android:id="#+id/call_button"
android:layout_marginTop="#dimen/spacing_large"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#null"
android:text="#string/phone"
android:textSize="18sp"
android:textColor="#drawable/button"
app:layout_constraintTop_toBottomOf="#+id/instructions"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
/>
<EditText
android:id="#+id/message_content"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:lines="8"
android:hint="#string/support_message_hint"
android:textColorHint="#color/text_hint"
android:inputType="textCapSentences|textMultiLine"
android:background="#color/background_gray"
android:padding="#dimen/spacing_small"
android:textColor="#color/black"
app:layout_constraintBottom_toTopOf="#+id/send_button"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
android:gravity="top|left"
app:layout_constraintHorizontal_weight="1"
app:layout_constraintVertical_weight="1"
/>
<Button
android:id="#+id/send_button"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="#string/support_send"
android:background="#color/button_blue"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent" />
</android.support.constraint.ConstraintLayout>
When I open the keyboard, the view adjusts and the bottom two widgets (the button and the editText) move with the keyboard. My problem however, is that whenever this happens, the #id/call_button Button lays on top of the editText. I do not want this. I want the editText to overlay the button when the keyboard is open.
Is there any way to make the editText take precedent when overlapping other widgets in this scenario? I tried adding editText.bringToFront() in my onCreate method, but that didn't do anything.
Also, I am trying to avoid nesting the bottom two widgets (the button and the editText) inside of their own layout. I want them all to remain in the same ConstraintLayout. Thank you for the help ahead of time.

I added android:elevation="4dp" to the editText's xml and it worked.

Material Design guidelines specify that Buttons use elevation in both their pressed (8dp elevation) and upressed (2dp elevation) states. https://material.io/guidelines/material-design/elevation-shadows.html#elevation-shadows-elevation-android
Which view you see when two are stacked on top of each other at the same elevation is dependent on the ordering of those views in your layout (e.g. why you expected the views written later to overlay the views written earlier), but elevation takes precedence over this.
As you've found, you can add elevation to your other views to make them "higher" than your button, but this is a bit ugly and might have some unwanted side-effects. I think a better choice would be to set the manifest attribute android:windowSoftInputMode="adjustPan" on your activity. This will cause your activity's view to slide up when the keyboard opens, rather than resizing.

Button showing up in top left

The button I made is in the center of the design screen, but when I run the app it is showing up in the top left.
<Button
android:id="#+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button"
tools:layout_editor_absoluteX="148dp"
tools:layout_editor_absoluteY="231dp" />

ZeekHuge is right, here try this:
<Button
android:id="#+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="Button"
tools:layout_editor_absoluteX="148dp"
tools:layout_editor_absoluteY="231dp" />

This view is not constrained, it only has designtime positions, so it will jump to (0,0) unless you add constraints.
The layout editor allows you to place widgets anywhere on the canvas, and it records the current position with designtime attributes (such as layout_editor_absoluteX.) These attributes are not applied at runtime, so if you push your layout on a device, the widgets may appear in a different location than shown in the editor. To fix this, make sure a widget has both horizontal and vertical constraints by dragging from the edge connections.
<Button
android:id="#+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button"
tools:layout_editor_absoluteX="148dp"
tools:layout_editor_absoluteY="231dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
/>

I assume you're using ConstraintLayout? The problem is these attributes:
tools:layout_editor_absoluteX="148dp"
tools:layout_editor_absoluteY="231dp"
tools attributes affect how a view looks in the Android Studio preview, but have no effect on how it looks when you actually run the app. You will need to add constraints to your button if you want it to be centered when you run. Add these:
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintBottom_toBottomOf="parent"

<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Center Btn"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintRight_toRightOf="parent"/>

ConstraintLayout View.GONE usage

I recently started using ConstraintLayout. As I discovered, most of the features are pretty straight forward, and well explained in the docs with samples, text and video tutorials and all.
The thing that got in my mind is how to I solve this 'puzzle' as elegant as possible?
As you can see, in the right section of the layout, I have multiple Views aligned left. On the last but one row, there are 3 Views aligned horizontally (they are also aligned TOP between each other).
Problem is: if I set first View's visibility from that row as GONE, the other two (in the same row), go left as expected, but the one underneath (last row in the vertical alignment) goes over the row before (because its constraintTop property is set as bottom of the View set as GONE).
The only solution I can think of is using a ViewGroup to group those 3 Views and add the constraint to last row View to it.
Am I missing some property on ConstraintLayout which could help my case? Maybe some sort of fallback (or multiple) constraints if one of them is set on a GONE View?
Sorry if my explanation seem quite abstruse, maybe the pictures will help you more :)
LE: Added layout: https://gist.github.com/DoruAdryan/7e7920a783f07b865489b1af0d933570

You can use the new Barriers feature of ConstraintLayout.
<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="wrap_content">
<android.support.v7.widget.AppCompatImageView
android:id="#+id/iv_item_small_product_image"
android:layout_width="113dp"
android:layout_height="113dp"
android:layout_marginLeft="7dp"
android:layout_marginStart="7dp"
android:background="#android:drawable/btn_radio"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<android.support.v7.widget.AppCompatImageView
android:id="#+id/iv_row_1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:background="#android:drawable/bottom_bar"
app:layout_constraintLeft_toRightOf="#+id/iv_item_small_product_image"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ro.emag.android.views.FontTextView
android:id="#+id/tv_row_2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="3dp"
android:ellipsize="end"
android:maxLines="2"
app:layout_constraintLeft_toRightOf="#+id/iv_item_small_product_image"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="#+id/iv_row_1"
app:layout_goneMarginTop="0dp"
tools:text="Some text long enough to be split on multiple lines on some devices." />
<android.support.v7.widget.AppCompatRatingBar
android:id="#+id/rb_row_3_1"
style="#style/Widget.AppCompat.RatingBar.Small"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="9dp"
android:isIndicator="true"
android:numStars="5"
android:stepSize="0.1"
app:layout_constraintLeft_toRightOf="#+id/iv_item_small_product_image"
app:layout_constraintTop_toBottomOf="#id/tv_row_2" />
<TextView
android:id="#+id/tv_row_3_2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="6dp"
android:layout_marginStart="6dp"
android:layout_marginTop="9dp"
app:layout_constraintLeft_toRightOf="#+id/rb_row_3_1"
app:layout_constraintTop_toBottomOf="#id/tv_row_2"
tools:text="106" />
<TextView
android:id="#+id/tv_row_3_3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="6dp"
android:layout_marginStart="6dp"
android:layout_marginTop="9dp"
app:layout_constraintLeft_toRightOf="#+id/tv_row_3_2"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="#id/tv_row_2"
app:layout_goneMarginLeft="0dp"
app:layout_goneMarginStart="0dp"
tools:text="Options available" />
<android.support.constraint.Barrier
android:id="#+id/barrier"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:barrierDirection="bottom"
app:constraint_referenced_ids="rb_row_3_1, tv_row_3_2, tv_row_3_3" />
<TextView
android:id="#+id/tv_row_4"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="3dp"
android:ellipsize="end"
android:maxLines="1"
app:layout_constraintLeft_toRightOf="#+id/iv_item_small_product_image"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="#+id/barrier"
tools:text="Some text on last row" />
</android.support.constraint.ConstraintLayout>
Now, the last row is depending on the barrier instead of one of the views of the third row. As the barrier is depending on the three views of the second row, you won't have the gone margin problem.
Plus, i noticed that you don't need the guideline. The right segment can depend on the imageview directly.
In case you are not familiar with Barriers, here's a link to help you out.
As this feature is available only in the 1.1.0 beta1 release of ConstraintLayout, don't forget to add this line to your build.gradle file.
compile 'com.android.support.constraint:constraint-layout:1.1.0-beta1'
make sure to include maven { url "https://maven.google.com" }

ImageView changes position in ConstraintLayout when reusing for RecyclerView

I have some issues regarding the new Constraint Layout.
I am using RecyclerView, and the layout for the item is based on a Constraint Layout with 2 TextViews and 1 ImageView inside it.
In the design view, from Android Studio, everything looks fine, but on the actual device (a S5 with Lineage OS), the ImageView changes its position in some activities.
If I scroll down, the items are how they are supposed to be and when scroll back up, everything goes back to normal.
I mention that I am reusing the same layout file for 3 fragments with Recycler view.
This is the layout for 1 list item.
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/cont_item_root"
android:layout_width="match_parent"
android:layout_height="72dp"
android:background="#drawable/bottom_border"
android:paddingRight="16dp"
android:paddingTop="8dp"
android:paddingBottom="8dp"
android:paddingEnd="16dp"
android:paddingStart="16dp"
android:paddingLeft="16dp">
<TextView
android:id="#+id/lbl_item_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="8dp"
android:layout_marginTop="0dp"
android:gravity="center"
android:text="wqewqwewqeqw"
android:textColor="#android:color/black"
android:textSize="16sp"
app:layout_constraintBottom_toTopOf="#+id/lbl_item_desc"
app:layout_constraintHorizontal_bias="0.008"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="1.0" />
<TextView
android:id="#+id/lbl_item_desc"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
android:textSize="14sp"
android:text="weqweweqweweqeweqwe"
android:layout_marginRight="0dp"
android:layout_marginEnd="72dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="#+id/lbl_item_title"
android:layout_marginBottom="7dp"
app:layout_constraintRight_toRightOf="#+id/lbl_item_title"
app:layout_constraintHorizontal_bias="0.0"/>
<ImageView
android:id="#+id/lbl_item_save"
android:contentDescription="#string/bookmarked"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/ic_star_border_black_24dp"
android:layout_marginEnd="8dp"
app:layout_constraintTop_toTopOf="parent"
android:layout_marginTop="8dp"
app:layout_constraintBottom_toBottomOf="parent"
android:layout_marginBottom="8dp"
android:layout_marginStart="8dp"
android:layout_marginRight="24dp"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintLeft_toRightOf="#+id/lbl_item_desc"
android:layout_marginLeft="8dp"
app:layout_constraintHorizontal_bias="1.0" />
On the phone, in the first fragment, everything is fine, no matter in which order I open it. But if I open the second or the third fragment, things are getting messed up.
Does anybody know what could influence the ImageView (the star) to move?
Thank you!

Found out the answer.
The parent layout, that was containing the RecyclerView, was using Constraint Layout as well, and it seems that there were some conflicts between them.
After changing the root layout to RelativeLayout or LinearLayout, everything went back to normal.