DialogFragment 中的 ViewPager2 内的 EditText 不会显示键盘

Question

I have a layout - let's call it layout A - with some EditText s, which I inflate inside a DialogFragment and all goes well with them. I have another DialogFragment whose layout - let's call it layout B - has a ViewPager2 in it, and I use it with a FragmentStateAdapter which hosts fragments where I reuse layout A for each of them.

Now my problem is that when I tap on the EditText s inside the ViewPager2 , they seem to be getting focus (my grasp of that subject isn't perfect), the cursor starts showing and I can manipulate the text with it ("select", "select all", "cut", etc.), but the soft keyboard won't open up. In the dialog without the viewPager, those same EditText s work flawlessly and the keyboard opens up.

In the Android Manifest I have android:windowSoftInputMode="adjustPan" (I use a single activity in my app).

What could be the problem?

My code:

Layout A:

<?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/title_text_view"
        android:layout_width="60dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="@dimen/double_margin"
        android:layout_marginLeft="@dimen/double_margin"
        android:text="@string/title_colon"
        android:textStyle="bold"
        app:layout_constraintBottom_toBottomOf="@id/title_edit_text"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="@id/title_edit_text" />

    <EditText
        android:id="@+id/title_edit_text"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginEnd="@dimen/double_margin"
        android:layout_marginRight="@dimen/double_margin"
        android:autofillHints="false"
        android:ellipsize="end"
        android:hint="@string/enter_track_title"
        android:inputType="textCapWords|textMultiLine"
        android:maxLines="2"
        android:textSize="14sp"
        app:layout_constraintBottom_toTopOf="@id/position_edit_text"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toEndOf="@id/title_text_view"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/position_text_view"
        android:layout_width="60dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="@dimen/double_margin"
        android:layout_marginLeft="@dimen/double_margin"
        android:text="@string/number_dot"
        android:textStyle="bold"
        app:layout_constraintBottom_toBottomOf="@id/position_edit_text"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="@id/position_edit_text" />

    <EditText
        android:id="@+id/position_edit_text"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="@dimen/margin"
        android:layout_marginEnd="@dimen/double_margin"
        android:layout_marginRight="@dimen/double_margin"
        android:layout_marginBottom="@dimen/margin"
        android:autofillHints="false"
        android:ellipsize="end"
        android:hint="@string/enter_track_position"
        android:inputType="text"
        android:maxLength="6"
        android:maxLines="1"
        android:textSize="14sp"
        app:layout_constraintBottom_toTopOf="@id/duration_text_view"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toEndOf="@id/position_text_view"
        app:layout_constraintTop_toBottomOf="@id/title_edit_text"
        tools:ignore="TextFields" />

    <TextView
        android:id="@+id/duration_text_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/duration_colon"
        android:textStyle="bold"
        android:layout_marginBottom="@dimen/double_margin"
        app:layout_constraintBottom_toTopOf="@id/colon_text_view"
        app:layout_constraintEnd_toEndOf="@id/seconds_picker"
        app:layout_constraintStart_toStartOf="@id/minutes_picker"
        app:layout_constraintTop_toBottomOf="@id/position_edit_text" />

    <NumberPicker
        android:id="@+id/minutes_picker"
        android:layout_width="80dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="@dimen/double_margin"
        android:layout_marginLeft="@dimen/double_margin"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toStartOf="@id/colon_text_view"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/duration_text_view" />

    <TextView
        android:id="@+id/colon_text_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="@dimen/margin"
        android:text="@string/colon"
        android:textSize="42sp"
        app:layout_constraintBottom_toBottomOf="@id/minutes_picker"
        app:layout_constraintEnd_toStartOf="@id/seconds_picker"
        app:layout_constraintStart_toEndOf="@id/minutes_picker"
        app:layout_constraintTop_toTopOf="@id/minutes_picker"
        app:layout_constraintVertical_bias="0.42000002" />

    <NumberPicker
        android:id="@+id/seconds_picker"
        android:layout_width="80dp"
        android:layout_height="wrap_content"
        android:layout_marginEnd="@dimen/double_margin"
        android:layout_marginRight="@dimen/double_margin"
        app:layout_constraintBottom_toBottomOf="@id/minutes_picker"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toEndOf="@id/colon_text_view"
        app:layout_constraintTop_toTopOf="@id/minutes_picker" />


</androidx.constraintlayout.widget.ConstraintLayout>

Layout B:

<?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">

    <View
        android:id="@+id/edit_track_divider_1"
        style="@style/divider"
        android:layout_marginTop="@dimen/double_margin"
        app:layout_constraintBottom_toTopOf="@id/left_arrow"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ImageButton
        android:id="@+id/left_arrow"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="@dimen/quadruple_margin"
        android:layout_marginLeft="@dimen/quadruple_margin"
        android:layout_marginTop="@dimen/double_margin"
        android:background="@android:color/transparent"
        android:contentDescription="@string/left_arrow_image"
        android:scaleX="1.5"
        android:scaleY="1.5"
        app:layout_constraintBottom_toTopOf="@id/edit_tracks_pager"
        app:layout_constraintEnd_toStartOf="@id/right_arrow"
        app:layout_constraintHorizontal_chainStyle="spread_inside"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/edit_track_divider_1"
        app:srcCompat="@drawable/ic_action_left" />

    <TextView
        android:id="@+id/position_header"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:gravity="center"
        app:layout_constraintBottom_toBottomOf="@id/left_arrow"
        app:layout_constraintEnd_toStartOf="@id/right_arrow"
        app:layout_constraintStart_toEndOf="@id/left_arrow"
        app:layout_constraintTop_toTopOf="@id/left_arrow" />

    <ImageButton
        android:id="@+id/right_arrow"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="@dimen/quadruple_margin"
        android:layout_marginRight="@dimen/quadruple_margin"
        android:background="@android:color/transparent"
        android:contentDescription="@string/right_arrow_image"
        android:scaleX="1.5"
        android:scaleY="1.5"
        app:layout_constraintBottom_toBottomOf="@+id/left_arrow"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toEndOf="@id/left_arrow"
        app:layout_constraintTop_toTopOf="@+id/left_arrow"
        app:srcCompat="@drawable/ic_action_right" />


    <androidx.viewpager2.widget.ViewPager2
        android:id="@+id/edit_tracks_pager"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toTopOf="@id/edit_track_divider_2"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/left_arrow" />

    <View
        android:id="@+id/edit_track_divider_2"
        style="@style/divider"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/edit_tracks_pager" />


</androidx.constraintlayout.widget.ConstraintLayout>

Answer 1

I eventually found some "hackish" unsatisfying way to fix this issue... I have added a dummy EditText in the layout right above the ViewPager2 and set its visibility to gone . Now the EditText s work as expected - ie the keyboard opens up. I have no idea why this works and therefore still don't know what caused the problem. I found this after playing around hopelessly for solutions. If anyone knows what caused the problem, why my solution practically solves it and what is the correct way to solve this - please let me know.