Constraintlayout Vertical Bias not working in two views Android - android

I am using constraint layout with a vertical bias to fill view in recycler view. I successfully did that.
<?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"
android:background="#color/white">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recylerview"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingStart="10dp"
android:paddingEnd="10dp"
android:paddingBottom="10dp"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0" />
</androidx.constraintlayout.widget.ConstraintLayout>
My recyclerview items showing me in reverse order because I want to make chat application. So I added reverseLayout and stackFromEnd true. So it look like this.
If my item is single my ui convert into like this by above xml code
Now I want to add edittext and button in bottom. Its not working vertical bias. Does any one know how to fix. Any suggestion to what can i use
Expected Output
Scenerio 1
Scenerio 2
Actual Output
I tried this code
<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"
android:background="#color/white">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingStart=10dp"
android:paddingEnd="10dp"
android:paddingBottom="10dp"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
app:layout_constraintBottom_toTopOf="#+id/inputContainer"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0" />
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/inputContainer"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingBottom="20dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/crecyclerView">
<EditText
android:id="#+id/editTextContainer"
android:layout_width="200dp"
android:layout_height="match_parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="#+id/button"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="#+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="button"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="#+id/editTextContainer"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
UPDATE
After adding #MartinMarconcini answer it fixed my Scenario 2. I want to fix as Scenario 1 as well.

The idea is that your RV will handle its own item size and space by itself. You don't need to worry about this.
The Remainder of the space, will be used by ConstraintLayout.
So you need to pin the RV and the "Bottom Container" together. This would by default cause the CL to try to pull and balance layouts, so you have to tell the bottom container to be biased at the bottom.
In pseudo-XML:
<ConstraintLayout>
<RecyclerView
width=0dp
height=0dp
start/end = parent
TopToTop=parent
BottomToTopOf=BottomContainer
>
<BottomContainer>
width=0dp
height=wrap_content
TopToBottomOf=RecyclerView
BottomToBottomOf=parent
start/end = parent>
</ConstraintLayout>
Now this needs one more thing, because the RV would take all the space, you want to ensure the BottomContainer has more information about where it wants to be placed.
So you add:
app:layout_constraintVertical_bias="1.0"
to the Bottom Container.
This means, vertically, as "bottom" as you can. (0.0 would be the opposite).
The end result is:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recylerview"
android:layout_width="0dp"
android:layout_height="0dp"
android:paddingStart="10dp"
android:paddingEnd="10dp"
android:paddingBottom="10dp"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:listitem="#android:layout/simple_list_item_2" />
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="0dp"
app:layout_constraintVertical_bias="1.0"
android:layout_height="wrap_content"
android:id="#+id/bottomContainer"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="#id/recylerview"
app:layout_constraintBottom_toBottomOf="parent">
<EditText
android:id="#+id/editTextContainer"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="#+id/button"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="#+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="button"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="#+id/editTextContainer"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
Which looks like this:
UPDATE
If you add both
app:stackFromEnd="true"
app:reverseLayout="true"
It works the same way, except the item "0" is at the bottom, and the "last" item is at the top. Adding another item would add it at the top but the BottomContainer has no participation (or influence) over this:

Related

RecyclerView in scrollview cut last items

I have fragment with 2 RecyclerView.
I get some data from api and add it for RecyclerViews in ArrayLists, then notify view that data was changed. For some reason, the last element(s) of the RecyclerViews is getting cut-off. When i get 8 object - RVs show only 5 of them. On small screens even less. I am disable RVs scrolling, and want use one ScrollView for all fragment content.
This is the XML of the fragment:s
<?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=".screens.view.MainFragment">
<androidx.swiperefreshlayout.widget.SwipeRefreshLayout
android:id="#+id/onDutyMainRefreshLayout"
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">
<ScrollView
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">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingHorizontal="#dimen/margin_m"
android:paddingVertical="#dimen/margin_m">
<TextView
android:id="#+id/requestTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:fontFamily="#font/sfprotext_semibold"
android:textStyle="bold"
android:textSize="#dimen/on_duty_main_subtitle_font_size"
android:textColor="#color/dark_liver"
android:text="Requests"
tools:text="Requests"/>
<Button
android:id="#+id/showAllRequestsButton"
style="#style/ShowAllButtonDark"
app:layout_constraintBottom_toBottomOf="#+id/requestTitle"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="#+id/requestTitle"
tools:ignore="TouchTargetSizeCheck"
android:text="Show All"
tools:text="Show All" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/requestsRecyclerView"
android:layout_width="match_parent"
android:layout_marginTop="#dimen/on_duty_recycler_view_margin_top"
android:layout_height="wrap_content"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/requestTitle" />
<TextView
android:id="#+id/groupTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:fontFamily="#font/sfprotext_semibold"
android:textColor="#color/dark_liver"
android:textSize="#dimen/on_duty_main_subtitle_font_size"
android:textStyle="bold"
android:layout_marginTop="#dimen/margin_m"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/requestsRecyclerView"
android:text="Groups"
tools:text="Groups" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/groupsRecyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="#dimen/on_duty_recycler_view_margin_top"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/groupTitle" />
</androidx.constraintlayout.widget.ConstraintLayout>
</ScrollView>
</androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
I try found solution in other question like that, but nothing helped me.
For examle, i tryed some solution from RecyclerView is cutting off the last item

Unfixed element on top of RecyclerView

I have something like this:
<?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"
android:padding="10dp"
tools:context=".ui.base.core.example">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="hello" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/topicsRecyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:listitem="#layout/item_topics" />
</androidx.constraintlayout.widget.ConstraintLayout>
When I run this, the TextView element is fixed and scrolls when I scroll through my RecyclerView. Is there a way so that I can make it where the TextView element is on top of the RecyclerView and when I scroll it's not fixed? I'm using a TextView to just do testing, but eventually I'd like to have a header on top of the RecyclerView that shouldn't be scrollable with the RecyclerView and just stay on top.
You need to set up constraints.
Approximately like this:
<TextView
android:id="#+id/textView"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toTopOf="#id/topicsRecyclerView" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/topicsRecyclerView"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="#id/textView"
app:layout_constraintBottom_toBottomOf="parent" />

Bottom item cut in reyclerview in android

Hey I am working in constraint layout with recylerview. My bottom item is cut in the screen. I read this stack overflow post. I don't want to use relative layout or linear layout. Can someone guide me how to fix this in constraint layout.
abc.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"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.appcompat.widget.SearchView
android:id="#+id/searchView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="10dp"
android:layout_marginTop="10dp"
android:layout_marginEnd="16dp"
app:closeIcon="#drawable/ic_cancel"
app:layout_constraintBottom_toTopOf="#+id/exploreScroll"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_chainStyle="packed"
app:layout_constraintVertical_bias="0.0" />
<HorizontalScrollView
android:id="#+id/exploreScroll"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="10dp"
android:layout_marginTop="10dp"
android:scrollbars="none"
app:layout_constraintBottom_toTopOf="#+id/exploreList"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/searchView">
<com.google.android.material.chip.ChipGroup
android:id="#+id/exploreChips"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:chipSpacingHorizontal="10dp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:singleLine="true"
app:singleSelection="true" />
</HorizontalScrollView>
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/exploreList"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="20dp"
android:paddingTop="10dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/exploreScroll" />
</androidx.constraintlayout.widget.ConstraintLayout>
My view cut from
UPDATE
#Zain after your suggestion i tried in my xml any my HorizontalScrollView is going behind my RV. I am adding my blueprint and you can see clearly that, HorizontalScrollView is going behind. After removing app:layout_constraintBottom_toTopOf="#+id/exploreList" from the HorizontalScrollView.
2nd suggestion try
Disclaimer Using a wrap_content height with vertical RecyclerView
can have impact on performance in terms of recycling views; specially
if the height is going to change frequently. Check this article
for more illustration.
So, the first step is to designate the RecyclerView height or to constraint it; from the constraints you want it to expand to the bottom; so use 0dp for that. But in order to make the minimum height to wrap content of the RecyclerView (in case that the items don't exceed the screen height); you can set the default height constraint to wrap with app:layout_constraintHeight_default="wrap" constraint.
Then remove app:layout_constraintBottom_toTopOf="#+id/exploreList" from the HorizontalScrollView, this actually made the bottom item of the RV hide (your main issue); because it is an over-constraint; the HorizontalScrollView tends to push the RV to the bottom while the RV tends to push the HorizontalScrollView to the top.
This will solve the main issue; but when the items are fully accommodated by the screen (no scrolling in the RV), then it will be biased in the middle; to fix this use the bias with app:layout_constraintVertical_bias="0.0" to be biased to the top.
Adding this in place into the layout:
<?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">
<androidx.appcompat.widget.SearchView
android:id="#+id/searchView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="10dp"
android:layout_marginTop="10dp"
android:layout_marginEnd="16dp"
app:closeIcon="#drawable/ic_cancel"
app:layout_constraintBottom_toTopOf="#+id/exploreScroll"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0"
app:layout_constraintVertical_chainStyle="packed" />
<HorizontalScrollView
android:id="#+id/exploreScroll"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="10dp"
android:layout_marginTop="10dp"
android:scrollbars="none"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/searchView">
<com.google.android.material.chip.ChipGroup
android:id="#+id/exploreChips"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:chipSpacingHorizontal="10dp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:singleLine="true"
app:singleSelection="true" />
</HorizontalScrollView>
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/exploreList"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_marginBottom="20dp"
android:paddingTop="10dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHeight_default="wrap"
app:layout_constraintVertical_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/exploreScroll" />
</androidx.constraintlayout.widget.ConstraintLayout>

Constrain max size of RecyclerView

I'm putting together a screen with 3 controls stacked vertically. Specifically, a RecyclerView sandwiched between two TextView. I have two situations I am trying to address.
When few items are displayed in the RecyclerView the 3 items should be packed towards the top of the screen with blank space BELOW them.
When many items are displayed in the RecyclerView the full screen will be used with the last TextView along the bottom of the screen and scrolling in the center RecyclerView.
I'm struggling to get the position of the last TextView correct as it either gets pushed off the screen or buried behind the RecyclerView if there are many items in the RecyclerView. What I need is a way to tell the RecyclerView to wrap contents, but stop growing when it starts to push the TextView off of the screen.
Below is my layout, any suggestions?
<?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">
<TextView
android:id="#+id/topItem"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintBottom_toTopOf="#+id/middleItem"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_chainStyle="packed" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/middleItem"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scrollbars="none"
app:layout_constraintBottom_toTopOf="#+id/bottomItem"
app:layout_constraintTop_toBottomOf="#+id/topItem" />
<TextView
android:id="#+id/bottomItem"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center_horizontal|top"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintTop_toBottomOf="#+id/middleItem" />
</androidx.constraintlayout.widget.ConstraintLayout>
Try the following:
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/topItem"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="This is the top item."
app:layout_constraintBottom_toTopOf="#+id/middleItem"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0"
app:layout_constraintVertical_chainStyle="packed" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/middleItem"
android:layout_width="0dp"
android:layout_height="0dp"
android:scrollbars="none"
app:layout_constrainedHeight="true"
app:layout_constraintBottom_toTopOf="#+id/bottomItem"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/topItem"
tools:itemCount="3" />
<TextView
android:id="#+id/bottomItem"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:gravity="center_horizontal|top"
android:text="This is the bottom item."
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/middleItem" />
</androidx.constraintlayout.widget.ConstraintLayout>
With three items in the RecyclerView:
With 50 items in the RecyclerView:
The key changes are:
Added app:layout_constraintVertical_bias="0.0" to the top TextView to position the chain always at the top;
Added app:layout_constrainedHeight="true" to the RecyclerView to make sure views don't go off-screen;
Changed match_parent to 0dp and set the horizontal constraints for direct children of the ConstraintLayout.
Changed the RecyclerView's height to '0dp'.
Update: Although the above works, it is a little overdone. As noted in the comments, the same effect can be accomplished by simply setting the height of the RecyclerView to 0dp.
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/topItem"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="This is the top item."
app:layout_constraintBottom_toTopOf="#+id/middleItem"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_chainStyle="packed" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/middleItem"
android:layout_width="0dp"
android:layout_height="0dp"
android:scrollbars="none"
app:layout_constraintBottom_toTopOf="#+id/bottomItem"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/topItem"
tools:itemCount="3" />
<TextView
android:id="#+id/bottomItem"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:gravity="center_horizontal|top"
android:text="This is the bottom item."
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/middleItem" />
</androidx.constraintlayout.widget.ConstraintLayout>

Using ListView inside ConstraintLayout

I have read on Android Developers that ConstraintLayout can be used to design a responsive layout for an application. There is a parent ConstraintLayout which houses a toolbar and two other ConstraintLayouts. The first child ConstraintLayout is going to act as empty view for my ListView. The second ConstraintLayout holds my listview and a floating action button. Currently, the the listview appears under the Toolbar, rather than below it. Also as seen in the screenshot, the floating action button appears outside visible area.
See the screenshot below:
And this is the app layout when the list is empty:
This is the code for my layout:
<?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"
android:id="#+id/content"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
>
<android.support.v7.widget.Toolbar xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintRight_toRightOf="parent"/>
<android.support.constraint.ConstraintLayout
app:layout_constraintTop_toBottomOf="#id/toolbar"
android:id="#+id/empty_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="?attr/actionBarSize">
<TextView
app:layout_constraintTop_toTopOf="parent"
android:id="#+id/tv_empty_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/list_is_empty"
android:textSize="#dimen/large_text"
android:textStyle="bold"
/>
<ImageView
android:id="#+id/iv_empty_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintTop_toBottomOf="#id/tv_empty_view"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
android:contentDescription="#string/list_is_empty"
android:src="#drawable/emptybox" />
</android.support.constraint.ConstraintLayout>
<android.support.constraint.ConstraintLayout
android:id="#+id/main_area"
android:layout_marginTop="50dp"
android:layout_marginBottom="?actionBarSize"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintTop_toBottomOf="#id/toolbar"
app:layout_constraintBottom_toBottomOf="parent">
<ListView
android:id="#+id/listview"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="?attr/actionBarSize"
android:layout_marginLeft="#dimen/margin_side"
android:layout_marginStart="#dimen/margin_side"
android:layout_marginRight="#dimen/margin_side"
android:layout_marginEnd="#dimen/margin_side"
android:layout_marginTop="?attr/actionBarSize"
/>
<android.support.design.widget.FloatingActionButton
android:layout_below="#+id/listview"
android:id="#+id/fab"
android:layout_width="#android:dimen/notification_large_icon_width"
android:layout_height="#android:dimen/notification_large_icon_height"
android:layout_gravity="end|bottom"
android:src="#drawable/plus"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintRight_toRightOf="parent"
/>
</android.support.constraint.ConstraintLayout>
</android.support.constraint.ConstraintLayout>
While using ConstraintLayout you have to add constraints for 'constraintTop',constraintRight,constraintBottom,constraintLeft or constraintStart and constraintEnd. only if you constraint all your four sides the constraint layout (or Constraint Start or End with other References) works well. Otherwise the layout will not work correctly
For Further Reference https://codelabs.developers.google.com/codelabs/constraint-layout/index.html?index=..%2F..%2Findex#0
https://developer.android.com/training/constraint-layout/index.html
There are a couple of things that you can improve with the XML and make the design easier.
First, the main layout will match the screen, to have the preview correctly simulate that, you can set its width/height to match_parent
<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/content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
>
Then, Android Studio should be giving you warnings/errors and saying The view is not constrained horizontally/vertically. In ConstraintLayout, you have to use constraints to specify how your views are placed. If you don't, by default they will position at 0/0 and most probably will look different when it runs on the device:
<ListView
android:id="#+id/listview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
android:layout_marginBottom="0dp" />
Now, you should be able to that the main_area overlaps with the toolbar. To fix it, you can change main_area height to match the constrains:
android:id="#+id/main_area"
android:layout_height="0dp"
You should be able to obtain a design similar to what you intended.
Here is your desired result, I've made some changes like margins, src just to make it work in my studio, so you'll have to choose whatever you were using, just replace mine with your src's and margins etc...
<?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"
android:id="#+id/content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
>
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="0dp"
android:layout_height="56dp"
android:background="?attr/colorPrimary"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintLeft_toLeftOf="parent"/>
<android.support.constraint.ConstraintLayout
app:layout_constraintTop_toBottomOf="#+id/toolbar"
android:id="#+id/empty_view"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent">
<TextView
app:layout_constraintTop_toTopOf="parent"
android:id="#+id/tv_empty_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
android:text="list_is_empty"
android:textSize="30sp"
android:textStyle="bold"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent" />
<ImageView
android:id="#+id/iv_empty_view"
android:layout_width="20dp"
android:layout_height="20dp"
app:layout_constraintTop_toBottomOf="#+id/tv_empty_view"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
android:background="#fff222" />
</android.support.constraint.ConstraintLayout>
<android.support.constraint.ConstraintLayout
android:id="#+id/main_area"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintTop_toBottomOf="#+id/toolbar"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent">
<ListView
android:id="#+id/listview"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent" />
<android.support.design.widget.FloatingActionButton
android:layout_marginEnd="30dp"
android:layout_marginBottom="30dp"
android:id="#+id/fab"
android:layout_width="64dp"
android:layout_height="64dp"
android:src="#drawable/bg"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintRight_toRightOf="parent"
/>
</android.support.constraint.ConstraintLayout>
</android.support.constraint.ConstraintLayout>
Here's the output:
I was also facing the same issue.
I made a mistake of keeping layout_width of ListView as fixed width. I changed it to match_constraint and it's coming correctly without any cut.
For height I was facing similar issue so I changed it to match_constraint and it worked.

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