Después de una búsqueda larga y prolongada, no puedo encontrar un componente que pueda seleccionar texto en vista de texto para el nivel de API de Android <= 11. He escrito este componente que puede ser de ayuda para usted:

public class SelectableTextView extends TextView {

public static int _SelectedBackgroundColor = 0xffA6D4E1;
public static int _SelectedTextColor = 0xff000000;
private OnTouchListener lastOnTouch;
protected int textOffsetStart;
protected int textOffsetEnd;
private OnLongClickListener lastOnLongClick;
protected boolean longCliked;
protected boolean isDowned;
protected int textSelectedEnd;
protected int textSelectedStart;
private static SelectableTextView lastInstance;

public SelectableTextView(Context context) {
    super(context);
}

public void setTextIsSelectable(boolean selectable) {
    // TODO:ANDROID3
    // if:androidversion>=3
    // super.setTextIsSelectable(selectable);
    // else
    super.setLongClickable(true);
    super.setOnLongClickListener(getSelectableLongClick());
    super.setOnTouchListener(getSelectableOnTouch());
}

private OnLongClickListener getSelectableLongClick() {
    return new OnLongClickListener() {

        @Override
        public boolean onLongClick(View v) {
            longCliked = true;
            if (lastOnLongClick != null) {
                lastOnLongClick.onLongClick(v);
            }
            return true;
        }
    };
}

@Override
public void setOnTouchListener(OnTouchListener l) {
    super.setOnTouchListener(l);
    this.lastOnTouch = l;
}

@Override
public void setOnLongClickListener(OnLongClickListener l) {
    super.setOnLongClickListener(l);
    this.lastOnLongClick = l;
}

private OnTouchListener getSelectableOnTouch() {
    return new OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            int action = event.getAction();

            if (action == MotionEvent.ACTION_DOWN) {
                if (lastInstance == null)
                    lastInstance = SelectableTextView.this;
                if (lastInstance != null && lastInstance != SelectableTextView.this) {
                    lastInstance.clean();
                    lastInstance = SelectableTextView.this;
                }

                int offset = getOffset(event);
                if ((offset < textOffsetEnd && offset > textOffsetStart)
                        || (offset > textOffsetEnd && offset < textOffsetStart)) {
                    if (textOffsetEnd - offset > offset - textOffsetStart)
                        textOffsetStart = textOffsetEnd;
                } else {
                    clean();
                    textOffsetStart = offset;
                }
                isDowned = true;
            } else if (isDowned && longCliked && action == MotionEvent.ACTION_MOVE) {
                selectTextOnMove(event);
            } else if (action == MotionEvent.ACTION_UP) {
                isDowned = false;
                longCliked = false;
            }
            if (lastOnTouch != null)
                lastOnTouch.onTouch(v, event);
            return false;
        }

    };
}

private void selectTextOnMove(MotionEvent event) {
    int offset = getOffset(event);
    if (offset != Integer.MIN_VALUE) {
        String text = getText().toString();
        SpannableStringBuilder sb = new SpannableStringBuilder(text);
        BackgroundColorSpan bgc = new BackgroundColorSpan(_SelectedBackgroundColor);
        ForegroundColorSpan textColor = new ForegroundColorSpan(_SelectedTextColor);

        int start = textOffsetStart;
        textOffsetEnd = offset;
        int end = offset;
        if (start > end) {
            int temp = start;
            start = end;
            end = temp;
        }
        int[] curectStartEnd = curectStartEnd(text, start, end);
        start = curectStartEnd[0];
        end = curectStartEnd[1];
        SelectableTextView.this.textSelectedStart = start;
        SelectableTextView.this.textSelectedEnd = end;
        sb.setSpan(bgc, start, end, Spannable.SPAN_INCLUSIVE_INCLUSIVE);
        sb.setSpan(textColor, start, end, Spannable.SPAN_INCLUSIVE_INCLUSIVE);

        setText(sb);
    }
}

private int[] curectStartEnd(String text, int start, int end) {
    int length = text.length();

    while (start < length && start > 0 && text.charAt(start) != ' ') {
        start--;
    }
    while (end < length && text.charAt(end) != ' ') {
        end++;
    }
    return new int[] { start, end };
}

private int getOffset(MotionEvent event) {
    Layout layout = getLayout();
    if (layout == null)
        return Integer.MIN_VALUE;
    float x = event.getX() + getScrollX();
    float y = event.getY() + getScrollY();
    int line = layout.getLineForVertical((int) y);
    int offset = layout.getOffsetForHorizontal(line, x);
    return offset;
}

protected void clean() {
    if (this.getText() != null) {
        this.setText(this.getText().toString());
        textSelectedStart = 0;
        textSelectedEnd = 0;
    }
}

@Override
public int getSelectionStart() {
    return textSelectedStart;
}

@Override
public int getSelectionEnd() {
    return textSelectedEnd;
}

}

getOffset obtener el desplazamiento seleccionado del texto que el usuario Tocado para usar este componente establece estos atributos:

        SelectableTextView textView1 = new SelectableTextView(context);
    textView1.setClickable(false);
    textView1.setCursorVisible(false);
    textView1.setOnTouchListener(getOnTextTouch());//new after text select touch
    textView1.setEnabled(this.selectable);
    textView1.setTextIsSelectable(this.selectable);

¿Alguien puede actualizar este componente?

Este es el código en git hub.