Bottom Align Floating Action Button - Constraint Layout

Question

I'm simply trying to do this alignment with constraintlayout but I'm not sure It's possible or not.

How can I do it ?

Sample xml

<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">

<ImageView
    android:id="@+id/imageView"
    android:layout_width="match_parent"
    android:layout_height="320dp"
    android:layout_marginEnd="8dp"
    android:layout_marginStart="8dp"
    android:layout_marginTop="8dp"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:srcCompat="@drawable/com_facebook_profile_picture_blank_portrait" />

<android.support.design.widget.FloatingActionButton
    android:id="@+id/floatingActionButton"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_alignParentRight="true"
    app:srcCompat="@android:color/holo_green_light" />

My workaround.

It's generally done with coordinator layout. I meant is it possible and if it's possible is it the right way. — Emre Akcan, Jun 05 '18 at 07:54
Yes everything is possible, it's not wrong until or unless it is completing your requirements. It's possible and I believe you already have achieved it. :) — Umair, Jun 05 '18 at 07:56
@Umair if you meant my workaround it will probably shown different at different screens. — Emre Akcan, Jun 05 '18 at 07:58
@EmreAkcan yes that's because it will adjust itself according to different screen sizes but the layout will remain the same. — Umair, Jun 05 '18 at 08:00
@Umair So floating button's position on imageview will be same at every screen with my second adjustment? — Emre Akcan, Jun 05 '18 at 08:02
@EmreAkcan ah nope it won't why because every screen has a different resolution so on bigger screens it will go down. Your best bet is to use framelayout of use relative layout inside constraintlayout. — Umair, Jun 05 '18 at 08:06
@EmreAkcan Using *Frame Layout* will be effective for all resolutions. — Jay Rathod, Jun 05 '18 at 08:28

Pawel Laskowski · Accepted Answer · 2018-06-05T10:55:50.097

Constraining both the top and the bottom of the FloatingActionButton to the bottom of the ImageView will center it on the edge. Also android:layout_width="match_parent" of the ImageView should be changed to 0dp to enforce horizontal constraints. Example XML looks like this:

<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="0dp"
        android:layout_height="320dp"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:srcCompat="@drawable/com_facebook_profile_picture_blank_portrait" />

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/floatingActionButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="@id/imageView"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/imageView"
        app:srcCompat="@android:color/holo_green_light" />

</android.support.constraint.ConstraintLayout>

score 0 · Answer 2 · edited Jun 06 '18 at 08:06

You can do it with constraint layout with the following code.

<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="match_parent"
        android:layout_height="320dp"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="4dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:srcCompat="@drawable/carrick" />

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/floatingActionButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentRight="true"
        android:layout_marginBottom="176dp"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:srcCompat="@drawable/bcslogo" />
</android.support.constraint.ConstraintLayout>

otherwise you can use relative layout instead of constraint you can place your all content in relative layout like following

    <RelativeLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentRight="true"
        android:layout_marginBottom="20dp"
        android:id="@+id/notesbg"
        android:layout_gravity="bottom|end">
    <android.support.v7.widget.RecyclerView
        android:layout_marginTop="2dp"
        android:id="@+id/myRecyclernote"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>


        <android.support.design.widget.FloatingActionButton
            android:id="@+id/myFAB"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_alignParentBottom="true"
            android:layout_alignParentRight="true"
            android:layout_gravity="end|bottom"
            android:layout_marginEnd="20dp"
            android:layout_marginBottom="50dp"
            app:backgroundTint="#00b4ed"
            android:src="@drawable/floatingbtn"
            app:borderWidth="0dp"
            app:elevation="8dp" />
    </RelativeLayout>

You have used `android:layout_marginBottom="176dp"` so your code looks different on my screen. — Emre Akcan, Jun 05 '18 at 08:22
then you can try with relative layout otherwise your floating button will display just below of image — Vishal Sharma, Jun 05 '18 at 08:30

Bottom Align Floating Action Button - Constraint Layout

2 Answers2