AutofitHelper.java 文件源码

/**
    * Re-sizes the textSize of the TextView so that the text fits within the bounds of the View.
    */
   private static void autofit(AppCompatTextView view, TextPaint paint, float minTextSize, float maxTextSize,
                            int maxLines, float precision)
{
       if (maxLines <= 0 || maxLines == Integer.MAX_VALUE)
    {
           // Don't auto-size since there's no limit on lines.
           return;
       }

       int targetWidth = view.getWidth() - view.getPaddingLeft() - view.getPaddingRight();
       if (targetWidth <= 0)
    {
           return;
       }

       CharSequence text = view.getText();
       TransformationMethod method = view.getTransformationMethod();
       if (method != null)
    {
           text = method.getTransformation(text, view);
       }

       Context context = view.getContext();
       Resources r = Resources.getSystem();
       DisplayMetrics displayMetrics;

       float size = maxTextSize;
       float high = size;
       float low = 0;

       if (context != null)
    {
           r = context.getResources();
       }
       displayMetrics = r.getDisplayMetrics();

       paint.set(view.getPaint());
       paint.setTextSize(size);

       if ((maxLines == 1 && paint.measureText(text, 0, text.length()) > targetWidth)
        || getLineCount(text, paint, size, targetWidth, displayMetrics) > maxLines)
    {
           size = getAutofitTextSize(text, paint, targetWidth, maxLines, low, high, precision,
                                  displayMetrics);
       }

       if (size < minTextSize)
    {
           size = minTextSize;
       }

       view.setTextSize(TypedValue.COMPLEX_UNIT_PX, size);
   }