Arrow¶

The arrow is part of the balloon's silhouette, not a separate image. It is carved into the same path as the body, so a border traces around it and a corner radius never clips it.

Size¶

setIsVisibleArrow(true)
setArrowSize(10.dp)  // square
setArrowSize(width = 16.dp, height = 8.dp)  // base along the edge, protrusion outward
setArrowWidth(16.dp)
setArrowHeight(8.dp)

width is always the base along the balloon's edge and height is always how far the tip sticks out, on every orientation. The visible protrusion is arrowHeight - 1px, which is the one pixel the arrow overlaps the body by so no seam shows between them.

Hiding the arrow frees its space

setIsVisibleArrow(false) also releases the space the arrow occupied, so the body sits flush against the anchor. Balloon 1.x kept reserving it, which left a gap the size of an arrow nobody could see.

Orientation¶

By default the arrow edge is derived from the alignment you show with, so it always points back at the anchor:

Shown with	Arrow edge
`showAlignTop()`	`BOTTOM`
`showAlignBottom()`	`TOP`
`showAlignStart()`	`END`
`showAlignEnd()`	`START`
`showAsDropDown()`	`TOP`

To pin it instead:

setArrowOrientation(ArrowOrientation.TOP)
setArrowOrientationRules(ArrowOrientationRules.ALIGN_FIXED)

ArrowOrientationRules decides what happens when a lack of room flips the balloon to the opposite side:

ALIGN_ANCHOR (default): the arrow follows the balloon so it keeps pointing at the anchor
ALIGN_FIXED: the arrow stays on the edge you named, wherever the balloon ends up

A flip never moves the arrow to a different axis. A horizontally pinned arrow stays horizontal even when the balloon flips vertically, because the arrow axis decides how the balloon reserves space and changing it mid placement would feed back into the decision that caused it.

Position along the edge¶

setArrowPosition(0.62f)  // 0f..1f
setArrowPositionRules(ArrowPositionRules.ALIGN_BALLOON)  // default

ALIGN_BALLOON reads the value as a fraction of the balloon, so 0.5f centers the arrow.

ALIGN_ANCHOR reads it as a fraction of the anchor instead, so the arrow keeps pointing at the same spot on the anchor no matter where the balloon lands or how the window clamps it. This is what you want for a wide balloon over a narrow anchor.

setArrowPositionRules(ArrowPositionRules.ALIGN_ANCHOR)
setArrowPosition(0.5f)  // always points at the middle of the anchor

Under ALIGN_ANCHOR the arrow is kept clear of the balloon's ends by

arrowSize * arrowAlignAnchorPaddingRatio + arrowAlignAnchorPadding

which you can tune:

setArrowAlignAnchorPaddingRatio(2.5f)  // default
setArrowAlignAnchorPadding(8.dp)  // default 0.dp

The arrow base is also clamped to the straight part of the edge, cornerRadius + arrowWidth / 2 in from each end, so it never rides up onto a rounded corner.

Color¶

setArrowColor(Color.White)

Leave it at Color.Unspecified, the default, and the arrow inherits backgroundColor. When you set a different color the arrow is painted in its own pass on top of the body fill but behind the balloon's content, so it can never cover what you put inside.