Is it possible to get the text Rects of a TextView?

Question

Suppose I have a single TextView like this

As you can see, the text is broken into three lines.

Is there any way that I can get the text areas in Rects? As this text is broken into three lines, I would need three Rects.

It is important to highlight that the left of a Rect is the left of the first character of the line, and the right is the right of the last character of the line.

Answer 1

Onik has the right idea, but the results will all be relative to zero. You will have to do a little more computation if you want to know where in the canvas the text of your TextView lies.

Here is a custom TextView that will outline the text on the screen.

class CustomTextView @JvmOverloads constructor(
    context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = android.R.attr.textViewStyle
) : AppCompatTextView(context, attrs, defStyleAttr) {
    private val mPaint = Paint().apply {
        strokeWidth = 2f
        style = Paint.Style.STROKE
        color = Color.RED
    }
    private val mLineOutline = Rect()

    override fun onDraw(canvas: Canvas) {
        super.onDraw(canvas)

        canvas.save()
        // This is the view's padding which we want to ignore.
        canvas.translate(totalPaddingLeft.toFloat(), totalPaddingTop.toFloat())
        for (line in 0 until lineCount) {
            // This gets the outline of the text on a line but it is all relative to zero.
            paint.getTextBounds(
                text.toString(), layout.getLineStart(line), layout.getLineEnd(line), mLineOutline
            )
            canvas.save()
            // We have the outline relative to zero, shift it so it outlines the text.
            canvas.translate(layout.getLineLeft(line), layout.getLineBaseline(line).toFloat())
            canvas.drawRect(mLineOutline, mPaint)
            canvas.restore()
        }
        canvas.restore()
    }
}

This is what is displayed:

You might not need this TextView, but you can grab its computations.

I find this posting very helpful when thinking about Android typography.