ConstraintLayout, when constraint dependent view is gone, the layout view behave weirdly

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执念已碎
执念已碎 2020-12-16 09:18

I\'m using ConstraintLayout where I will show as below

I would like to hide First (using gone), and which the view I expect to be as below (whe

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  • 2020-12-16 09:36

    One more thing you can use for Visibility.GONE in ConstraintLayout: Barriers.

    If you are not aware of Barriers, then please check this : Barriers

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  • 2020-12-16 09:40

    An answer has already been given linking to Barriers. I will provide an example of how I've actually implemented it:

    <TextView
        android:id="@+id/textView1"
        app:layout_constraintTop_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        android:text="Some text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    
    <TextView
        android:id="@+id/textView2"
        app:layout_constraintTop_toBottomOf="@id/textView1"
        app:layout_constraintLeft_toLeftOf="parent"
        android:text="Some other text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    <androidx.constraintlayout.widget.Barrier
        android:id="@+id/barrier1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:barrierDirection="bottom"
        app:constraint_referenced_ids="textView1,textView2" />
    

    This example shows 2 TextViews either of which can be gone. The Views are on stacked from top to bottom, so barrierDirection is set to bottom. Should you need another direction, just change that line accordingly.

    Setting any of the 2 TextViews to gone, will result in the Barrier shifting to the bottom of the other, and if we set both to gone, it'll just shift up to the element that textView1's top constraint was referencing, in this case, the parent.

    Note: If your textView1's top constraint is something else, i.e. it's below another element, the barrier will end up there if both views are set to gone.

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  • 2020-12-16 09:47

    Say, you want to have a picture like this:

    Here you have indents between the title and "Nice work", between "Nice work" and time, also horizontal indent to "Opinions". They are centered vertically.

    "Opinions" is attached to the star, so that can be multilined and stay centered. I show results for 2 variants: in the first row opinions are multilined, while in the next row it is a single line. In columns you can see 4 variants of showing/hiding 2 labels.

    1. A more simple and preferrable way is to wrap both labels into LinearLayout and insert it into parent ConstraintLayout. Then you can set vertical gravity, show or hide labels, hide the LinearLayout itself.

    2. If you don't want to have nested layouts, use Barriers and Groups. It is a difficult task that can waste many hours. A key is having additional Views for aligning. Here I have 2 hiding labels ("Nice work" and "Opinions"), and I have to add 2 views (spaces).

    The height of the right space is equal to the height of the star (14dp).

    To simplify hiding several views, I joined them into groups.

    You can see horizontal dotted lines - they are Barriers. I align them on tops and bottoms of the most big views (barrier_2 is similar):

    <androidx.constraintlayout.widget.Barrier
        android:id="@+id/barrier_1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:barrierDirection="top"
        app:constraint_referenced_ids="left_text,opinion" />
    

    Vertical aligning is based on these 2 additional Spaces (see marginTop="10dp"):

    <Space
        android:id="@+id/left_text_space"
        android:layout_width="25dp"
        android:layout_height="10dp"
        android:layout_marginTop="10dp"
        app:layout_constraintStart_toEndOf="@id/left_text"
        app:layout_constraintTop_toBottomOf="@id/title" />
    

    It is difficult to cover all situations, so see the following 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"
        android:paddingLeft="15dp"
        android:paddingTop="5dp"
        android:paddingRight="15dp"
        android:paddingBottom="5dp">
    
        <TextView
            android:id="@+id/title"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:ellipsize="end"
            android:lineSpacingExtra="4sp"
            android:lines="1"
            android:paddingBottom="5dp"
            android:text="«Title text»"
            android:textColor="#333333"
            android:textSize="15sp"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
    
        <androidx.constraintlayout.widget.Barrier
            android:id="@+id/barrier_1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:barrierDirection="top"
            app:constraint_referenced_ids="left_text,opinion" />
    
        <TextView
            android:id="@+id/left_text"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="#112233"
            android:paddingLeft="5dp"
            android:paddingTop="4dp"
            android:paddingRight="5dp"
            android:paddingBottom="4dp"
            android:text="Nice work"
            android:textColor="#ffffff"
            android:textSize="13sp"
            app:layout_constraintBottom_toBottomOf="@id/barrier_2"
            app:layout_constraintStart_toStartOf="@id/title"
            app:layout_constraintTop_toTopOf="@id/left_text_space" />
    
        <Space
            android:id="@+id/left_text_space"
            android:layout_width="25dp"
            android:layout_height="10dp"
            android:layout_marginTop="10dp"
            app:layout_constraintStart_toEndOf="@id/left_text"
            app:layout_constraintTop_toBottomOf="@id/title" />
    
        <androidx.constraintlayout.widget.Group
            android:id="@+id/left_text_group"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:visibility="visible"
            app:constraint_referenced_ids="left_text,left_text_space" />
    
        <Space
            android:id="@+id/opinion_space"
            android:layout_width="1dp"
            android:layout_height="14dp"
            android:layout_marginTop="10dp"
            app:layout_constraintStart_toStartOf="@id/left_text_space"
            app:layout_constraintTop_toBottomOf="@id/title" />
    
        <androidx.constraintlayout.widget.Barrier
            android:id="@+id/barrier_2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:barrierDirection="bottom"
            app:constraint_referenced_ids="left_text,opinion" />
    
        <ImageView
            android:id="@+id/opinion_icon"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:contentDescription="@null"
            app:layout_constraintBottom_toBottomOf="@id/barrier_2"
            app:layout_constraintStart_toEndOf="@id/left_text_space"
            app:layout_constraintTop_toTopOf="@id/opinion_space"
            app:srcCompat="@drawable/ic_filled_rate_star" />
    
        <TextView
            android:id="@+id/opinion"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginStart="5dp"
            android:layout_marginLeft="5dp"
            android:lineSpacingExtra="1sp"
            android:text="1. Opinion 1.\n2. Opinion 2.\n3. Opinion 3.\n4. Opinion 4."
            android:textColor="#1122aa"
            android:textSize="12sp"
            app:layout_constraintBottom_toBottomOf="@id/opinion_icon"
            app:layout_constraintHorizontal_weight="1"
            app:layout_constraintStart_toEndOf="@id/opinion_icon"
            app:layout_constraintTop_toTopOf="@id/opinion_icon" />
    
        <androidx.constraintlayout.widget.Group
            android:id="@+id/opinion_group"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:visibility="visible"
            app:constraint_referenced_ids="opinion_icon,opinion,opinion_space" />
    
        <ImageView
            android:id="@+id/time_icon"
            android:layout_width="15dp"
            android:layout_height="15dp"
            android:layout_gravity="center_vertical"
            android:layout_marginTop="8dp"
            android:contentDescription="@null"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@id/barrier_2"
            app:srcCompat="@drawable/ic_time" />
    
        <TextView
            android:id="@+id/time"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginStart="7dp"
            android:layout_marginLeft="7dp"
            android:ellipsize="end"
            android:lineSpacingExtra="1sp"
            android:lines="2"
            android:paddingBottom="7dp"
            android:text="17:00"
            android:textColor="#9e9e9e"
            android:textSize="11sp"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_weight="1"
            app:layout_constraintStart_toEndOf="@id/time_icon"
            app:layout_constraintTop_toTopOf="@id/time_icon" />
    
    </androidx.constraintlayout.widget.ConstraintLayout>
    

    Then in your activity you can show/hide labels. Hide Groups, not views inside, because strangely inside a Group views are always visible.

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.main_activity)
    
        left_text_group.visibility = View.GONE
        opinion_group.visibility = View.VISIBLE
    }
    
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  • 2020-12-16 09:52

    Try following.

    Set the first view's left and top constraints to "parent". After that:

    • set the txt_body textview width to "0dp"
    • set the left constraint to the first view's right side
    • set the right constraint to the tail view's left side.

    So, whenever you set the first view's visibility to "gone", the body view will be stretched like how you want it.

    <android.support.constraint.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="wrap_content"
        android:padding="16dp">
    
        <TextView
            android:id="@+id/txt_first"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="#0ff"
            android:text="First"
            android:textSize="26sp"
            android:visibility="gone"
            app:layout_constraintEnd_toStartOf="@+id/txt_body"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintLeft_toLeftOf="parent" />
    
        <TextView
            android:id="@+id/txt_body"
            android:layout_width="0dp"
            android:background="#f0f"
            android:layout_height="wrap_content"
            android:text="Elastic Body"
            android:textSize="26sp"
            app:layout_constraintRight_toLeftOf="@+id/txt_tail"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintLeft_toRightOf="@+id/txt_first"
            />
    
        <TextView
            android:id="@+id/txt_tail"
            android:background="#ff0"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Tail"
            android:textSize="26sp"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintRight_toRightOf="parent" />
    
    </android.support.constraint.ConstraintLayout>
    

    Update

    If you want to do using barrier then also you can do it.

    <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="wrap_content"
        android:padding="16dp">
    
        <TextView
            android:id="@+id/txt_first"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="#0ff"
            android:text="First"
            android:textSize="26sp"
            android:visibility="gone"
            app:layout_constraintEnd_toStartOf="@+id/barrier"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
    
        <TextView
            android:id="@+id/txt_body"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:background="#f0f"
            android:text="Elastic Body"
            android:textSize="26sp"
            app:layout_constraintStart_toEndOf="@+id/barrier"
            app:layout_constraintEnd_toStartOf="@+id/txt_tail"
            app:layout_constraintTop_toTopOf="parent" />
    
        <TextView
            android:id="@+id/txt_tail"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="#ff0"
            android:text="Tail"
            android:textSize="26sp"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
    
        <androidx.constraintlayout.widget.Barrier
            android:id="@+id/barrier"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:barrierDirection="start"
            app:constraint_referenced_ids="txt_body,txt_first" />
    
        <androidx.constraintlayout.widget.Barrier
            android:id="@+id/barrier1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:barrierDirection="end"
            app:constraint_referenced_ids="txt_body,txt_tail" />
    
    </androidx.constraintlayout.widget.ConstraintLayout>
    
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