Rotate

Key rotation features#

• Touch-based rotation with intuitive drag handles
• Precise angle control through Kotlin APIs
• Rotation locking for template protection
• Multi-element rotation as grouped objects

Touch-based image rotation#

Users can rotate images naturally using the built-in rotation handles. When you select an image:

1. Rotation controls automatically appear.
2. You can now freely rotate the image through drag gestures.

Implementing rotation in Kotlin#

Your Android app can control image rotation programmatically using the setRotation method. Pass the block ID and rotation angle in radians:

import kotlin.math.PI

engine.block.setRotation(imageBlock, (PI / 4).toFloat())

Since Android developers often work with degrees, here are handy conversion utilities:

val angleInRadians: Float = (angleInDegrees * PI / 180).toFloat()

val angleInDegrees: Float = (angleInRadians * 180 / PI).toFloat()

To read the current rotation state in your app:

val currentRotation = engine.block.getRotation(imageBlock)

Locking Rotation#

You can remove the rotation handle from the UI by changing the setting for the engine. This will affect all blocks.

engine.editor.setSettingBoolean("controlGizmo/showRotateHandles", false)

Although the code makes the rotation handle invisible, the user can still use the two-finger rotation gesture on a touch device. You can turn off that gesture with the following setting:

engine.editor.setSettingBoolean("touch/rotateAction", false)

When you want to lock only certain blocks, you can toggle the transform lock property. This will apply to all transformations for the block.

engine.block.setTransformLocked(imageBlock, true)

Rotating As a Group#

To rotate multiple elements together, first add them to a group and then rotate the group.

import kotlin.math.PI

val groupId = engine.block.group(listOf(imageBlock, textBlock))
engine.block.setRotation(groupId, (PI / 2).toFloat())

Troubleshooting#

Troubleshooting