Modified this answer a little bit to use kotlin class and extend AppCompatTextView
, trimming vertical padding.
It allows setting android:fontFamily
. Method calculateTextParams()
moved from onDraw()
for performance. Not tested for multiple lines of text:
import android.content.Context
import android.graphics.Canvas
import android.graphics.Rect
import android.util.AttributeSet
import androidx.appcompat.widget.AppCompatTextView
class NoPaddingTextView : AppCompatTextView
{
private val boundsRect = Rect()
private val textParams = calculateTextParams()
constructor(context : Context?)
: super(context)
constructor(context : Context?, attrs : AttributeSet?)
: super(context, attrs)
constructor(context : Context?, attrs : AttributeSet?, defStyleAttr : Int)
: super(context, attrs, defStyleAttr)
override fun onDraw(canvas : Canvas)
{
with(boundsRect) {
paint.isAntiAlias = true
paint.color = currentTextColor
canvas.drawText(textParams,
-left.toFloat(),
(-top - bottom).toFloat(),
paint)
}
}
override fun onMeasure(widthMeasureSpec : Int, heightMeasureSpec : Int)
{
super.onMeasure(widthMeasureSpec, heightMeasureSpec)
calculateTextParams()
setMeasuredDimension(boundsRect.width() + 1, -boundsRect.top + 1)
}
private fun calculateTextParams() : String
{
return text.toString()
.also {text ->
text.length.let {textLength ->
paint.textSize = textSize
paint.getTextBounds(text, 0, textLength, boundsRect)
if(textLength == 0) boundsRect.right = boundsRect.left
}
}
}
}