Letter avatar like Gmail Android best practice

Question

What is the best way of generating (in code) a letter avatar like in Gmail? Here you have an example https://drive.google.com/folderview?id=0B0Fhz5fDg1njSmpUakhhZllEWHM&

Answer 1

Below is a class that generates an Image avatar both a circle and Square. Source is here

    class AvatarGenerator {
    companion object {
    lateinit var uiContext: Context
    var texSize = 0F

    fun avatarImage(context: Context, size: Int, shape: Int, name: String): BitmapDrawable {
      uiContext = context
      val width = size
      val hieght = size

      texSize = calTextSize(size)
      val label = firstCharacter(name)
      val textPaint = textPainter()
      val painter = painter()
      val areaRect = Rect(0, 0, width, width)

      if (shape == 0) {
        painter.color = RandomColors().getColor()
      } else {
        painter.color = Color.TRANSPARENT
      }

      val bitmap = Bitmap.createBitmap(width, width, ARGB_8888)
      val canvas = Canvas(bitmap)
      canvas.drawRect(areaRect, painter)

      //reset painter
      if (shape == 0) {
        painter.color = Color.TRANSPARENT
      } else {
        painter.color = RandomColors().getColor()
      }

      val bounds = RectF(areaRect)
      bounds.right = textPaint.measureText(label, 0, 1)
      bounds.bottom = textPaint.descent() - textPaint.ascent()

      bounds.left += (areaRect.width() - bounds.right) / 2.0f
      bounds.top += (areaRect.height() - bounds.bottom) / 2.0f

      canvas.drawCircle(width.toFloat() / 2, hieght.toFloat() / 2, width.toFloat() / 2, painter)
      canvas.drawText(label, bounds.left, bounds.top - textPaint.ascent(), textPaint)
      return BitmapDrawable(uiContext.resources, bitmap)

    }

    private fun firstCharacter(name: String): String {
      return name.first().toString().toUpperCase()
    }

    private fun textPainter(): TextPaint {
      val textPaint = TextPaint()
      textPaint.textSize = texSize * uiContext.resources.displayMetrics.scaledDensity
      textPaint.color = Color.WHITE
      return textPaint
    }

    private fun painter(): Paint {
      return Paint()
    }

    private fun calTextSize(size: Int): Float {
      return (size / 3.125).toFloat()
    }
  }
}

You can then pass context, a string, size, and the shape to generate 1/0

    imageView.setImageDrawable(
      AvatarGenerator.avatarImage(
        this,
        200,
        1,
        "Skyways"
      )