Auto Scrollable Text View in Kotlin-CodePudding

I have been searching on this for awhile. I have textView and it is Scrollable. The issue is it doesn't scroll while text is added. I have listed all my code and photos for an example. What I am needing is the textView to auto scroll when text is typed. This will be horizontal since it is a calculator.

I have tried using cursor position, using spannable, and several things I would normally do. However this has me stumped. Maybe i have something added that is conflicting the movement. This is also done in the androidx.constraintlayout.widget.ConstraintLayout

Design

<HorizontalScrollView
        android:id="@ id/scrView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:fillViewport="true"
        android:overScrollMode="always"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="1.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <TextView
            android:id="@ id/tv_equation"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="end"
            android:layout_marginTop="8dp"
            android:maxLines="1"
            android:padding="5dp"
            android:paddingStart="20dp"
            android:paddingEnd="20dp"
            android:text="@string/tv_equation"
            android:textAlignment="textEnd"
            android:textColor="@color/white"
            android:textSize="45sp"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
    </HorizontalScrollView>

MainActivity

 binding.tvEquation.movementMethod = ScrollingMovementMethod()

It seems to that the when the overScrollMode is called, it should auto scroll over. Maybe I am missing something?

android:overScrollMode="always"

So any advice would help.

CodePudding user response：

Change this:

<HorizontalScrollView......
   <TextView.......
   </TextView......
</HorizontalScrollView>

to this:

<EditText
        android:id="@ id/tv_equation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="end"
        android:layout_marginTop="8dp"
        android:inputType="text"
        android:maxLines="1"
        android:minLines="1"
        android:isScrollContainer="true"
        android:padding="5dp"
        android:paddingStart="20dp"
        android:paddingEnd="20dp"
        android:text="@string/tv_equation"
        android:textAlignment="textEnd"
        android:textColor="@color/white"
        android:textSize="45sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

And add this line in your code.

Kotlin:

binding.tv_equation.movementMethod = ScrollingMovementMethod()

Java:

EditText tv_equation = (EditText)findViewById(R.id.tv_equation); 
tv_equation.setMovementMethod(new ScrollingMovementMethod());

CodePudding user response：

What you need is a marquee behaviour in your EditText. However Marquee is a TextView Property and not an edit text one.

Create an edit text and textview and superimpose on on top of the other , On the textview click hide the textview and show the edittext.

have a scrollable textview by

 <TextView
      android:id = "@ id/text"
      android:textSize = "20dp"
      android:textAlignment = "center"
      android:layout_width = "match_parent"
      android:ellipsize = "marquee"
      android:fadingEdge = "horizontal"
      android:marqueeRepeatLimit = "marquee_forever"
      android:scrollHorizontally = "true"
      android:textColor = "#ff4500"
      android:text = "Simple application that shows how to use marquee, with a long text"
      android:layout_height = "wrap_content"
      android:singleLine = "true" />

now create a toggle functionality like

text.setVisibility(View.GONE); 
editText.setVisibility(View.VISIBLE);
editText.setText(edititemname);

That way it will give an illusion that the same text is being scrolled when unselected and scrolls when it loses focus.

PS: add editText.setSelection(editText.length()) for putting cursor at end

Ps: If you just need a Scrollable text view the code block of the textview is enough