how to change order of statically created layouts in a linear layout dynamically? (Android Studio)

Question

I have a layout created with XML code. which has a scrollview and in that scroll view there are two relative layouts

here's 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"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:background="#151515">


    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        >

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="@dimen/_10sdp"
            android:orientation="vertical">
            <RelativeLayout

                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_gravity="center"

                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent">


                <ImageView
                    android:onClick="monday"
                    android:id="@+id/monday"
                    android:layout_width="match_parent"
                    android:layout_height="@dimen/_145sdp"
                    app:srcCompat="@drawable/mondaysmolgray" />

                <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_alignParentBottom="true"
                    android:layout_centerHorizontal="true"
                    android:layout_marginStart="@dimen/_70sdp"

                    android:layout_marginBottom="0dp"
                    android:orientation="horizontal"
                    android:weightSum="3">

                    <TextView
                        android:id="@+id/mondaydate"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginBottom="@dimen/_18sdp"
                        android:layout_weight="1"
                        android:gravity="center"
                        android:text=" No tasks"
                        android:textColor="#151515"
                        android:textSize="@dimen/_15sdp"></TextView>

                    <TextView
                        android:id="@+id/mondaytasks"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginBottom="@dimen/_18sdp"
                        android:layout_weight="1"
                        android:gravity="center"

                        android:text=" No tasks"
                        android:textColor="#151515"
                        android:textSize="@dimen/_15sdp"></TextView>

                    <TextView
                        android:id="@+id/mondaytodos"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginBottom="@dimen/_18sdp"
                        android:layout_weight="1"
                        android:gravity="center"

                        android:text=" No tasks"
                        android:textColor="#151515"
                        android:textSize="@dimen/_15sdp"></TextView>


                </LinearLayout>
            </RelativeLayout>
            <RelativeLayout

                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_gravity="center"

                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent">


                <ImageView
                    android:onClick="tuesday"
                    android:id="@+id/tuesday"
                    android:layout_width="match_parent"
                    android:layout_height="@dimen/_145sdp"
                    app:srcCompat="@drawable/tuesdaysmolgray" />

                <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_alignParentBottom="true"
                    android:layout_centerHorizontal="true"
                    android:layout_marginStart="@dimen/_70sdp"

                    android:layout_marginBottom="0dp"
                    android:orientation="horizontal"
                    android:weightSum="3">

                    <TextView
                        android:id="@+id/tuesdaydate"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginBottom="@dimen/_18sdp"
                        android:layout_weight="1"
                        android:gravity="center"
                        android:text=" No tasks"
                        android:textColor="#151515"
                        android:textSize="@dimen/_15sdp"></TextView>

                    <TextView
                        android:id="@+id/tuesdaytasks"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginBottom="@dimen/_18sdp"
                        android:layout_weight="1"
                        android:gravity="center"

                        android:text=" No tasks"
                        android:textColor="#151515"
                        android:textSize="@dimen/_15sdp"></TextView>

                    <TextView
                        android:id="@+id/tuesdaytodos"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginBottom="@dimen/_18sdp"
                        android:layout_weight="1"
                        android:gravity="center"

                        android:text=" No tasks"
                        android:textColor="#151515"
                        android:textSize="@dimen/_15sdp"></TextView>


                </LinearLayout>
            </RelativeLayout>
         </LinearLayout>
     </ScrollView>
</androidx.constraintlayout.widget.ConstraintLayout>

as you can see there two relative layouts inside a scroll view. I want to change the order of two linear layouts dynamically from without creating the whole thing again in runtime code. how can I do that?

Answer 1

There is no reorder methods in android layout.

So you can try to remove all views with removeView(view).

And then you need to add them with addView(childView, index) in that order you like.

in your case need to define id to parent LinearLayout and two RelativeLayouts.

<ScrollView>
    <LinearLayout android:id="@+id/container">
        <RelativeLayout android:id="@+id/first">
        <RelativeLayout android:id="@+id/second">
    </LinearLayout>
</ScrollView>

In JAVA Code:

ViewGroup container = findViewById(R.id.container);
View first = findViewById(R.id.first);
View second = findViewById(R.id.second);
container.removeView(first);
container.addView(first); // append first view to last.