Possible to specify TextView text to scale to fit within TextView?

Question

Is there any property of the TextView that can be specified so that its text (the font size) scales dynamically to fit within the TextView? (Similar to the iPhone auto shrink feature.)

If not, are there are any good, simple solutions which anyone has come across or come up with to solve this? (And such that it would work for non-English languages also.)

Answer 1

Following V4l3ri4's link and the links that spawned from there, I came up with the following bare bones solution which shrinks the text within the TextView continually until it fits width-wise in the TextView:

public class FontFitTextView extends TextView
{
  private float maxTextSizePx;

  public FontFitTextView(Context context)
  {
    super(context);
    initialise();
  }

  public FontFitTextView(Context context, AttributeSet attrs)
  {
    super(context, attrs);
    initialise();
  }

  public FontFitTextView(Context context, AttributeSet attrs, int defStyle)
  {
    super(context, attrs, defStyle);
    initialise();
  }

  /** Sets the maximum text size as the text size specified to use for this View.*/
  private void initialise()
  {
    maxTextSizePx = getTextSize(); 
  }

  /** Reduces the font size continually until the specified 'text' fits within the View (i.e. the specified 'viewWidth').*/
  private void refitText(String text, int viewWidth)
  { 
    if (viewWidth > 0)
    {
      TextPaint textPaintClone = new TextPaint();
      textPaintClone.set(getPaint());

      int availableWidth = viewWidth - getPaddingLeft() - getPaddingRight();
      float trySize = maxTextSizePx;

      // note that Paint text size works in px not sp
      textPaintClone.setTextSize(trySize); 

      while (textPaintClone.measureText(text) > availableWidth)
      {
        trySize--;
        textPaintClone.setTextSize(trySize);
      }

      setTextSize(TypedValue.COMPLEX_UNIT_PX, trySize);
    }
  }

  @Override
  protected void onTextChanged(final CharSequence text, final int start, final int lengthBefore, final int lengthAfter)
  {
    super.onTextChanged(text, start, lengthBefore, lengthAfter);

    refitText(text.toString(), getWidth());
  }

  @Override
  protected void onSizeChanged(int w, int h, int oldw, int oldh)
  {
    super.onSizeChanged(w, h, oldw, oldh);

    if (w != oldw)
      refitText(getText().toString(), w);
  }
}

An example usage is as follows:

<view
  class="com.mycompany.myapp.views.FontFitTextView"
  android:layout_width="0dp"
  android:layout_height="wrap_content"
  android:layout_weight="1"
  android:singleLine="true" />

I realise this implementation can be optimised and extended but just trying to show a bare bones solution for you to extend or modify as required.

Oh and if you need a Button which shrinks text to fit instead of a TextView, simply use the code exact as above but extend Button instead of TextView.