Bubble shape — the hard way, because why not.

SpeechBubbleShape.kt

internal class SpeechBubbleShape(
    private val cornerRadius: Dp,
    @Px private val stemPosition: Float,
    private val stemSize: Dp
) : Shape {

    private val bubblePath = Path()

    override fun createOutline(
        size: Size,
        layoutDirection: LayoutDirection,
        density: Density
    ): Outline = with(density) {
        Outline.Generic(createSpeechBubblePath(size, cornerRadius.toPx(), stemPosition, stemSize.toPx()))
    }

    private fun createSpeechBubblePath(
        size: Size,
        @Px cornerRadius: Float,
        @Px stemPosition: Float,
        @Px stemSize: Float
    ): Path {
        //         /\
        //        /  \
        //  _____/    \__________________
        // /                             \
        // |                             |
        // |                             |
        // |                             |
        // \_____________________________/

        bubblePath.apply {
            reset()
            val cornerDiameter = cornerRadius * 2
            // Top left rounded corner
            arcTo(
                rect = Rect(left = 0f, top = stemSize, right = cornerDiameter, bottom = stemSize + cornerDiameter),
                startAngleDegrees = 180f,
                sweepAngleDegrees = 90f,
                forceMoveTo = false
            )
            // Left-hand part of the top edge of the rounded rect
            lineTo(x = stemPosition - (stemSize / 2), y = stemSize)
            // Stem
            lineTo(x = stemPosition, y = 0f)
            lineTo(x = stemPosition + (stemSize / 2), y = stemSize)
            // Right-hand part of the top edge of the rounded rect
            lineTo(x = size.width - cornerRadius, y = stemSize)
            // Top right rounded corner
            arcTo(
                rect = Rect(left = size.width - cornerDiameter, top = stemSize, right = size.width, bottom = stemSize + cornerDiameter),
                startAngleDegrees = 270f,
                sweepAngleDegrees = 90f,
                forceMoveTo = false
            )
            // Right edge
            lineTo(x = size.width, y = size.height - cornerRadius)
            // Bottom right rounded corner
            arcTo(
                rect = Rect(left = size.width - cornerDiameter, top = size.height - cornerDiameter, right = size.width, bottom = size.height),
                startAngleDegrees = 0f,
                sweepAngleDegrees = 90f,
                forceMoveTo = false
            )
            // Bottom edge
            lineTo(x = cornerRadius, y = size.height)
            // Bottom left rounded corner
            arcTo(
                rect = Rect(left = 0f, top = size.height - cornerDiameter, right = cornerDiameter, bottom = size.height),
                startAngleDegrees = 90f,
                sweepAngleDegrees = 90f,
                forceMoveTo = false
            )
            // Left edge (by cheating)
            close()
        }
        return bubblePath
    }
}