Android programming implements a method of automatically resizing TextView fonts to fit text length

This article illustrates an Android programming method to automatically adjust TextView font size to fit text length. To share for your reference, the details are as follows:

package com.test.android.textview;
import android.content.Context;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.widget.TextView;
public class CustomTextView extends TextView {
  private static float DEFAULT_MIN_TEXT_SIZE = 10;
  private static float DEFAULT_MAX_TEXT_SIZE = 20;
  // Attributes
  private Paint testPaint;
  private float minTextSize;
  private float maxTextSize;
  public CustomTextView(Context context, AttributeSet attrs) {
    super(context, attrs);
    initialise();
  }
  private void initialise() {
    testPaint = new Paint();
    testPaint.set(this.getPaint());
    // max size defaults to the intially specified text size unless it is
    // too small
    maxTextSize = this.getTextSize();
    if (maxTextSize <= DEFAULT_MIN_TEXT_SIZE) {
      maxTextSize = DEFAULT_MAX_TEXT_SIZE;
    }
    minTextSize = DEFAULT_MIN_TEXT_SIZE;
  }
  /**
  * Re size the font so the specified text fits in the text box * assuming
  * the text box is the specified width.
  */
  private void refitText(String text, int textWidth) {
    if (textWidth > 0) {
      int availableWidth = textWidth - this.getPaddingLeft() -
        this.getPaddingRight();
      float trySize = maxTextSize;
      testPaint.setTextSize(trySize);
      while ((trySize > minTextSize) &&
          (testPaint.measureText(text) > availableWidth)) {
        trySize -= 1;
        if (trySize <= minTextSize) {
          trySize = minTextSize;
          break;
        }
        testPaint.setTextSize(trySize);
      }
      this.setTextSize(trySize);
    }
  }
  @Override
  protected void onTextChanged(CharSequence text, int start, int before,
    int after) {
    super.onTextChanged(text, start, before, after);
    refitText(text.toString(), this.getWidth());
  }
  @Override
  protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    if (w != oldw) {
      refitText(this.getText().toString(), w);
    }
  }
}

I hope this article has been helpful in Android programming.